Documentation/DocBook/media/v4l/controls.xml

   1   <section id="control">
   2     <title>User Controls</title>
   3
   4     <para>Devices typically have a number of user-settable controls
   5 such as brightness, saturation and so on, which would be presented to
   6 the user on a graphical user interface. But, different devices
   7 will have different controls available, and furthermore, the range of
   8 possible values, and the default value will vary from device to
   9 device. The control ioctls provide the information and a mechanism to
  10 create a nice user interface for these controls that will work
  11 correctly with any device.</para>
  12
  13     <para>All controls are accessed using an ID value. V4L2 defines
  14 several IDs for specific purposes. Drivers can also implement their
  15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
  16 and higher values. The pre-defined control IDs have the prefix
  17 <constant>V4L2_CID_</constant>, and are listed in <xref
  18 linkend="control-id" />. The ID is used when querying the attributes of
  19 a control, and when getting or setting the current value.</para>
  20
  21     <para>Generally applications should present controls to the user
  22 without assumptions about their purpose. Each control comes with a
  23 name string the user is supposed to understand. When the purpose is
  24 non-intuitive the driver writer should provide a user manual, a user
  25 interface plug-in or a driver specific panel application. Predefined
  26 IDs were introduced to change a few controls programmatically, for
  27 example to mute a device during a channel switch.</para>
  28
  29     <para>Drivers may enumerate different controls after switching
  30 the current video input or output, tuner or modulator, or audio input
  31 or output. Different in the sense of other bounds, another default and
  32 current value, step size or other menu items. A control with a certain
  33 <emphasis>custom</emphasis> ID can also change name and
  34 type.<footnote>
  35         <para>It will be more convenient for applications if drivers
  36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
  37 that was never required.</para>
  38       </footnote> Control values are stored globally, they do not
  39 change when switching except to stay within the reported bounds. They
  40 also do not change &eg; when the device is opened or closed, when the
  41 tuner radio frequency is changed or generally never without
  42 application request. Since V4L2 specifies no event mechanism, panel
  43 applications intended to cooperate with other panel applications (be
  44 they built into a larger application, as a TV viewer) may need to
  45 regularly poll control values to update their user
  46 interface.<footnote>
  47         <para>Applications could call an ioctl to request events.
  48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
  49 shared properties the &func-select; function would indicate
  50 readability until any ioctl (querying the properties) is
  51 called.</para>
  52       </footnote></para>
  53
  54     <para>
  55       All controls use machine endianness.
  56     </para>
  57
  58     <table pgwide="1" frame="none" id="control-id">
  59       <title>Control IDs</title>
  60       <tgroup cols="3">
  61         &cs-def;
  62         <thead>
  63           <row>
  64             <entry>ID</entry>
  65             <entry>Type</entry>
  66             <entry>Description</entry>
  67           </row>
  68         </thead>
  69         <tbody valign="top">
  70           <row>
  71             <entry><constant>V4L2_CID_BASE</constant></entry>
  72             <entry></entry>
  73             <entry>First predefined ID, equal to
  74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
  75           </row>
  76           <row>
  77             <entry><constant>V4L2_CID_USER_BASE</constant></entry>
  78             <entry></entry>
  79             <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
  80           </row>
  81           <row>
  82             <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
  83             <entry>integer</entry>
  84             <entry>Picture brightness, or more precisely, the black
  85 level.</entry>
  86           </row>
  87           <row>
  88             <entry><constant>V4L2_CID_CONTRAST</constant></entry>
  89             <entry>integer</entry>
  90             <entry>Picture contrast or luma gain.</entry>
  91           </row>
  92           <row>
  93             <entry><constant>V4L2_CID_SATURATION</constant></entry>
  94             <entry>integer</entry>
  95             <entry>Picture color saturation or chroma gain.</entry>
  96           </row>
  97           <row>
  98             <entry><constant>V4L2_CID_HUE</constant></entry>
  99             <entry>integer</entry>
 100             <entry>Hue or color balance.</entry>
 101           </row>
 102           <row>
 103             <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
 104             <entry>integer</entry>
 105             <entry>Overall audio volume. Note some drivers also
 106 provide an OSS or ALSA mixer interface.</entry>
 107           </row>
 108           <row>
 109             <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
 110             <entry>integer</entry>
 111             <entry>Audio stereo balance. Minimum corresponds to all
 112 the way left, maximum to right.</entry>
 113           </row>
 114           <row>
 115             <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
 116             <entry>integer</entry>
 117             <entry>Audio bass adjustment.</entry>
 118           </row>
 119           <row>
 120             <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
 121             <entry>integer</entry>
 122             <entry>Audio treble adjustment.</entry>
 123           </row>
 124           <row>
 125             <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
 126             <entry>boolean</entry>
 127             <entry>Mute audio, &ie; set the volume to zero, however
 128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
 129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
 130 noise. Actually the entire device should be reset to a low power
 131 consumption state.</entry>
 132           </row>
 133           <row>
 134             <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
 135             <entry>boolean</entry>
 136             <entry>Loudness mode (bass boost).</entry>
 137           </row>
 138           <row>
 139             <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
 140             <entry>integer</entry>
 141             <entry>Another name for brightness (not a synonym of
 142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
 143 and should not be used in new drivers and applications.</entry>
 144           </row>
 145           <row>
 146             <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
 147             <entry>boolean</entry>
 148             <entry>Automatic white balance (cameras).</entry>
 149           </row>
 150           <row>
 151             <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
 152             <entry>button</entry>
 153             <entry>This is an action control. When set (the value is
 154 ignored), the device will do a white balance and then hold the current
 155 setting. Contrast this with the boolean
 156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
 157 activated, keeps adjusting the white balance.</entry>
 158           </row>
 159           <row>
 160             <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
 161             <entry>integer</entry>
 162             <entry>Red chroma balance.</entry>
 163           </row>
 164           <row>
 165             <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
 166             <entry>integer</entry>
 167             <entry>Blue chroma balance.</entry>
 168           </row>
 169           <row>
 170             <entry><constant>V4L2_CID_GAMMA</constant></entry>
 171             <entry>integer</entry>
 172             <entry>Gamma adjust.</entry>
 173           </row>
 174           <row>
 175             <entry><constant>V4L2_CID_WHITENESS</constant></entry>
 176             <entry>integer</entry>
 177             <entry>Whiteness for grey-scale devices. This is a synonym
 178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
 179 and should not be used in new drivers and applications.</entry>
 180           </row>
 181           <row>
 182             <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
 183             <entry>integer</entry>
 184             <entry>Exposure (cameras). [Unit?]</entry>
 185           </row>
 186           <row>
 187             <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
 188             <entry>boolean</entry>
 189             <entry>Automatic gain/exposure control.</entry>
 190           </row>
 191           <row>
 192             <entry><constant>V4L2_CID_GAIN</constant></entry>
 193             <entry>integer</entry>
 194             <entry>Gain control.</entry>
 195           </row>
 196           <row>
 197             <entry><constant>V4L2_CID_HFLIP</constant></entry>
 198             <entry>boolean</entry>
 199             <entry>Mirror the picture horizontally.</entry>
 200           </row>
 201           <row>
 202             <entry><constant>V4L2_CID_VFLIP</constant></entry>
 203             <entry>boolean</entry>
 204             <entry>Mirror the picture vertically.</entry>
 205           </row>
 206           <row id="v4l2-power-line-frequency">
 207             <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
 208             <entry>enum</entry>
 209             <entry>Enables a power line frequency filter to avoid
 210 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
 211 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
 212 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
 213 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
 214 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
 215           </row>
 216           <row>
 217             <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
 218             <entry>boolean</entry>
 219             <entry>Enables automatic hue control by the device. The
 220 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
 221 hue control is enabled is undefined, drivers should ignore such
 222 request.</entry>
 223           </row>
 224           <row>
 225             <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
 226             <entry>integer</entry>
 227             <entry>This control specifies the white balance settings
 228 as a color temperature in Kelvin. A driver should have a minimum of
 229 2800 (incandescent) to 6500 (daylight). For more information about
 230 color temperature see <ulink
 231 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
 232           </row>
 233           <row>
 234             <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
 235             <entry>integer</entry>
 236             <entry>Adjusts the sharpness filters in a camera. The
 237 minimum value disables the filters, higher values give a sharper
 238 picture.</entry>
 239           </row>
 240           <row>
 241             <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
 242             <entry>integer</entry>
 243             <entry>Adjusts the backlight compensation in a camera. The
 244 minimum value disables backlight compensation.</entry>
 245           </row>
 246           <row>
 247             <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
 248             <entry>boolean</entry>
 249             <entry>Chroma automatic gain control.</entry>
 250           </row>
 251           <row>
 252             <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
 253             <entry>integer</entry>
 254             <entry>Adjusts the Chroma gain control (for use when chroma AGC
 255             is disabled).</entry>
 256           </row>
 257           <row>
 258             <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
 259             <entry>boolean</entry>
 260             <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>
 261           </row>
 262           <row id="v4l2-colorfx">
 263             <entry><constant>V4L2_CID_COLORFX</constant></entry>
 264             <entry>enum</entry>
 265             <entry>Selects a color effect. The following values are defined:
 266             </entry>
 267           </row><row>
 268           <entry></entry>
 269           <entry></entry>
 270             <entrytbl spanname="descr" cols="2">
 271               <tbody valign="top">
 272                 <row>
 273                   <entry><constant>V4L2_COLORFX_NONE</constant>&nbsp;</entry>
 274                   <entry>Color effect is disabled.</entry>
 275                 </row>
 276                 <row>
 277                   <entry><constant>V4L2_COLORFX_ANTIQUE</constant>&nbsp;</entry>
 278                   <entry>An aging (old photo) effect.</entry>
 279                 </row>
 280                 <row>
 281                   <entry><constant>V4L2_COLORFX_ART_FREEZE</constant>&nbsp;</entry>
 282                   <entry>Frost color effect.</entry>
 283                 </row>
 284                 <row>
 285                   <entry><constant>V4L2_COLORFX_AQUA</constant>&nbsp;</entry>
 286                   <entry>Water color, cool tone.</entry>
 287                 </row>
 288                 <row>
 289                   <entry><constant>V4L2_COLORFX_BW</constant>&nbsp;</entry>
 290                   <entry>Black and white.</entry>
 291                 </row>
 292                 <row>
 293                   <entry><constant>V4L2_COLORFX_EMBOSS</constant>&nbsp;</entry>
 294                   <entry>Emboss, the highlights and shadows replace light/dark boundaries
 295                   and low contrast areas are set to a gray background.</entry>
 296                 </row>
 297                 <row>
 298                   <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant>&nbsp;</entry>
 299                   <entry>Grass green.</entry>
 300                 </row>
 301                 <row>
 302                   <entry><constant>V4L2_COLORFX_NEGATIVE</constant>&nbsp;</entry>
 303                   <entry>Negative.</entry>
 304                 </row>
 305                 <row>
 306                   <entry><constant>V4L2_COLORFX_SEPIA</constant>&nbsp;</entry>
 307                   <entry>Sepia tone.</entry>
 308                 </row>
 309                 <row>
 310                   <entry><constant>V4L2_COLORFX_SKETCH</constant>&nbsp;</entry>
 311                   <entry>Sketch.</entry>
 312                 </row>
 313                 <row>
 314                   <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant>&nbsp;</entry>
 315                   <entry>Skin whiten.</entry>
 316                 </row>
 317                 <row>
 318                   <entry><constant>V4L2_COLORFX_SKY_BLUE</constant>&nbsp;</entry>
 319                   <entry>Sky blue.</entry>
 320                 </row>
 321                 <row>
 322                   <entry><constant>V4L2_COLORFX_SOLARIZATION</constant>&nbsp;</entry>
 323                   <entry>Solarization, the image is partially reversed in tone,
 324                   only color values above or below a certain threshold are inverted.
 325                   </entry>
 326                 </row>
 327                 <row>
 328                   <entry><constant>V4L2_COLORFX_SILHOUETTE</constant>&nbsp;</entry>
 329                   <entry>Silhouette (outline).</entry>
 330                 </row>
 331                 <row>
 332                   <entry><constant>V4L2_COLORFX_VIVID</constant>&nbsp;</entry>
 333                   <entry>Vivid colors.</entry>
 334                 </row>
 335                 <row>
 336                   <entry><constant>V4L2_COLORFX_SET_CBCR</constant>&nbsp;</entry>
 337                   <entry>The Cb and Cr chroma components are replaced by fixed
 338                   coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
 339                   control.</entry>
 340                 </row>
 341               </tbody>
 342             </entrytbl>
 343           </row>
 344           <row>
 345             <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
 346             <entry>integer</entry>
 347             <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
 348             color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
 349             Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
 350           </entry>
 351           </row>
 352           <row>
 353             <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
 354             <entry>boolean</entry>
 355             <entry>Enable Automatic Brightness.</entry>
 356           </row>
 357           <row>
 358             <entry><constant>V4L2_CID_ROTATE</constant></entry>
 359             <entry>integer</entry>
 360             <entry>Rotates the image by specified angle. Common angles are 90,
 361             270 and 180. Rotating the image to 90 and 270 will reverse the height
 362             and width of the display window. It is necessary to set the new height and
 363             width of the picture using the &VIDIOC-S-FMT; ioctl according to
 364             the rotation angle selected.</entry>
 365           </row>
 366           <row>
 367             <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
 368             <entry>integer</entry>
 369             <entry>Sets the background color on the current output device.
 370             Background color needs to be specified in the RGB24 format. The
 371             supplied 32 bit value is interpreted as bits 0-7 Red color information,
 372             bits 8-15 Green color information, bits 16-23 Blue color
 373             information and bits 24-31 must be zero.</entry>
 374           </row>
 375           <row>
 376             <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
 377                 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
 378             <entry>boolean</entry>
 379             <entry>Switch on or off the illuminator 1 or 2 of the device
 380                 (usually a microscope).</entry>
 381           </row>
 382           <row>
 383             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
 384             <entry>integer</entry>
 385             <entry>This is a read-only control that can be read by the application
 386 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
 387 The value is the minimum number of CAPTURE buffers that is necessary for hardware
 388 to work.</entry>
 389           </row>
 390           <row>
 391             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
 392             <entry>integer</entry>
 393             <entry>This is a read-only control that can be read by the application
 394 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
 395 The value is the minimum number of OUTPUT buffers that is necessary for hardware
 396 to work.</entry>
 397           </row>
 398           <row id="v4l2-alpha-component">
 399             <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
 400             <entry>integer</entry>
 401             <entry> Sets the alpha color component on the capture device or on
 402             the capture buffer queue of a mem-to-mem device. When a mem-to-mem
 403             device produces frame format that includes an alpha component
 404             (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
 405             and the alpha value is not defined by the mem-to-mem input data
 406             this control lets you select the alpha component value of all
 407             pixels. It is applicable to any pixel format that contains an alpha
 408             component.
 409             </entry>
 410           </row>
 411           <row>
 412             <entry><constant>V4L2_CID_LASTP1</constant></entry>
 413             <entry></entry>
 414             <entry>End of the predefined control IDs (currently
 415               <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
 416           </row>
 417           <row>
 418             <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
 419             <entry></entry>
 420             <entry>ID of the first custom (driver specific) control.
 421 Applications depending on particular custom controls should check the
 422 driver name and version, see <xref linkend="querycap" />.</entry>
 423           </row>
 424         </tbody>
 425       </tgroup>
 426     </table>
 427
 428     <para>Applications can enumerate the available controls with the
 429 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
 430 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
 431 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
 432 <constant>VIDIOC_G_CTRL</constant> and
 433 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
 434 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
 435 more menu type controls.</para>
 436
 437     <example>
 438       <title>Enumerating all controls</title>
 439
 440       <programlisting>
 441 &v4l2-queryctrl; queryctrl;
 442 &v4l2-querymenu; querymenu;
 443
 444 static void
 445 enumerate_menu (void)
 446 {
 447         printf ("  Menu items:\n");
 448
 449         memset (&amp;querymenu, 0, sizeof (querymenu));
 450         querymenu.id = queryctrl.id;
 451
 452         for (querymenu.index = queryctrl.minimum;
 453              querymenu.index &lt;= queryctrl.maximum;
 454               querymenu.index++) {
 455                 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
 456                         printf ("  %s\n", querymenu.name);
 457                 }
 458         }
 459 }
 460
 461 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 462
 463 for (queryctrl.id = V4L2_CID_BASE;
 464      queryctrl.id &lt; V4L2_CID_LASTP1;
 465      queryctrl.id++) {
 466         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 467                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 468                         continue;
 469
 470                 printf ("Control %s\n", queryctrl.name);
 471
 472                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 473                         enumerate_menu ();
 474         } else {
 475                 if (errno == EINVAL)
 476                         continue;
 477
 478                 perror ("VIDIOC_QUERYCTRL");
 479                 exit (EXIT_FAILURE);
 480         }
 481 }
 482
 483 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
 484      queryctrl.id++) {
 485         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 486                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 487                         continue;
 488
 489                 printf ("Control %s\n", queryctrl.name);
 490
 491                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 492                         enumerate_menu ();
 493         } else {
 494                 if (errno == EINVAL)
 495                         break;
 496
 497                 perror ("VIDIOC_QUERYCTRL");
 498                 exit (EXIT_FAILURE);
 499         }
 500 }
 501 </programlisting>
 502     </example>
 503
 504     <example>
 505       <title>Changing controls</title>
 506
 507       <programlisting>
 508 &v4l2-queryctrl; queryctrl;
 509 &v4l2-control; control;
 510
 511 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 512 queryctrl.id = V4L2_CID_BRIGHTNESS;
 513
 514 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 515         if (errno != EINVAL) {
 516                 perror ("VIDIOC_QUERYCTRL");
 517                 exit (EXIT_FAILURE);
 518         } else {
 519                 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 520         }
 521 } else if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED) {
 522         printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 523 } else {
 524         memset (&amp;control, 0, sizeof (control));
 525         control.id = V4L2_CID_BRIGHTNESS;
 526         control.value = queryctrl.default_value;
 527
 528         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)) {
 529                 perror ("VIDIOC_S_CTRL");
 530                 exit (EXIT_FAILURE);
 531         }
 532 }
 533
 534 memset (&amp;control, 0, sizeof (control));
 535 control.id = V4L2_CID_CONTRAST;
 536
 537 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &amp;control)) {
 538         control.value += 1;
 539
 540         /* The driver may clamp the value or return ERANGE, ignored here */
 541
 542         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)
 543             &amp;&amp; errno != ERANGE) {
 544                 perror ("VIDIOC_S_CTRL");
 545                 exit (EXIT_FAILURE);
 546         }
 547 /* Ignore if V4L2_CID_CONTRAST is unsupported */
 548 } else if (errno != EINVAL) {
 549         perror ("VIDIOC_G_CTRL");
 550         exit (EXIT_FAILURE);
 551 }
 552
 553 control.id = V4L2_CID_AUDIO_MUTE;
 554 control.value = TRUE; /* silence */
 555
 556 /* Errors ignored */
 557 ioctl (fd, VIDIOC_S_CTRL, &amp;control);
 558 </programlisting>
 559     </example>
 560   </section>
 561
 562   <section id="extended-controls">
 563     <title>Extended Controls</title>
 564
 565     <section>
 566       <title>Introduction</title>
 567
 568       <para>The control mechanism as originally designed was meant
 569 to be used for user settings (brightness, saturation, etc). However,
 570 it turned out to be a very useful model for implementing more
 571 complicated driver APIs where each driver implements only a subset of
 572 a larger API.</para>
 573
 574       <para>The MPEG encoding API was the driving force behind
 575 designing and implementing this extended control mechanism: the MPEG
 576 standard is quite large and the currently supported hardware MPEG
 577 encoders each only implement a subset of this standard. Further more,
 578 many parameters relating to how the video is encoded into an MPEG
 579 stream are specific to the MPEG encoding chip since the MPEG standard
 580 only defines the format of the resulting MPEG stream, not how the
 581 video is actually encoded into that format.</para>
 582
 583       <para>Unfortunately, the original control API lacked some
 584 features needed for these new uses and so it was extended into the
 585 (not terribly originally named) extended control API.</para>
 586
 587       <para>Even though the MPEG encoding API was the first effort
 588 to use the Extended Control API, nowadays there are also other classes
 589 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
 590 The Extended Controls API as well as all Extended Controls classes are
 591 described in the following text.</para>
 592     </section>
 593
 594     <section>
 595       <title>The Extended Control API</title>
 596
 597       <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
 598 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
 599 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
 600 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
 601 since it is often required to atomically change several controls at
 602 once.</para>
 603
 604       <para>Each of the new ioctls expects a pointer to a
 605 &v4l2-ext-controls;. This structure contains a pointer to the control
 606 array, a count of the number of controls in that array and a control
 607 class. Control classes are used to group similar controls into a
 608 single class. For example, control class
 609 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
 610 (&ie; all controls that can also be set using the old
 611 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
 612 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
 613 relating to MPEG encoding, etc.</para>
 614
 615       <para>All controls in the control array must belong to the
 616 specified control class. An error is returned if this is not the
 617 case.</para>
 618
 619       <para>It is also possible to use an empty control array (count
 620 == 0) to check whether the specified control class is
 621 supported.</para>
 622
 623       <para>The control array is a &v4l2-ext-control; array. The
 624 <structname>v4l2_ext_control</structname> structure is very similar to
 625 &v4l2-control;, except for the fact that it also allows for 64-bit
 626 values and pointers to be passed.</para>
 627
 628       <para>It is important to realize that due to the flexibility of
 629 controls it is necessary to check whether the control you want to set
 630 actually is supported in the driver and what the valid range of values
 631 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
 632 check this. Also note that it is possible that some of the menu
 633 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
 634 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
 635 return an error). A good example is the list of supported MPEG audio
 636 bitrates. Some drivers only support one or two bitrates, others
 637 support a wider range.</para>
 638
 639       <para>
 640         All controls use machine endianness.
 641       </para>
 642     </section>
 643
 644     <section>
 645       <title>Enumerating Extended Controls</title>
 646
 647       <para>The recommended way to enumerate over the extended
 648 controls is by using &VIDIOC-QUERYCTRL; in combination with the
 649 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
 650
 651       <informalexample>
 652         <programlisting>
 653 &v4l2-queryctrl; qctrl;
 654
 655 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
 656 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 657         /* ... */
 658         qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 659 }
 660 </programlisting>
 661       </informalexample>
 662
 663       <para>The initial control ID is set to 0 ORed with the
 664 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
 665 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
 666 control with a higher ID than the specified one. When no such controls
 667 are found an error is returned.</para>
 668
 669       <para>If you want to get all controls within a specific control
 670 class, then you can set the initial
 671 <structfield>qctrl.id</structfield> value to the control class and add
 672 an extra check to break out of the loop when a control of another
 673 control class is found:</para>
 674
 675       <informalexample>
 676         <programlisting>
 677 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
 678 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 679         if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
 680                 break;
 681                 /* ... */
 682                 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 683         }
 684 </programlisting>
 685       </informalexample>
 686
 687       <para>The 32-bit <structfield>qctrl.id</structfield> value is
 688 subdivided into three bit ranges: the top 4 bits are reserved for
 689 flags (&eg; <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
 690 actually part of the ID. The remaining 28 bits form the control ID, of
 691 which the most significant 12 bits define the control class and the
 692 least significant 16 bits identify the control within the control
 693 class. It is guaranteed that these last 16 bits are always non-zero
 694 for controls. The range of 0x1000 and up are reserved for
 695 driver-specific controls. The macro
 696 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
 697 ID based on a control ID.</para>
 698
 699       <para>If the driver does not support extended controls, then
 700 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
 701 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
 702 that case the old method of enumerating control should be used (see
 703 1.8). But if it is supported, then it is guaranteed to enumerate over
 704 all controls, including driver-private controls.</para>
 705     </section>
 706
 707     <section>
 708       <title>Creating Control Panels</title>
 709
 710       <para>It is possible to create control panels for a graphical
 711 user interface where the user can select the various controls.
 712 Basically you will have to iterate over all controls using the method
 713 described above. Each control class starts with a control of type
 714 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
 715 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
 716 control class which can be used as the title of a tab page within a
 717 control panel.</para>
 718
 719       <para>The flags field of &v4l2-queryctrl; also contains hints on
 720 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
 721 for more details.</para>
 722     </section>
 723
 724     <section id="mpeg-controls">
 725       <title>Codec Control Reference</title>
 726
 727       <para>Below all controls within the Codec control class are
 728 described. First the generic controls, then controls specific for
 729 certain hardware.</para>
 730
 731       <para>Note: These controls are applicable to all codecs and
 732 not just MPEG. The defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG
 733 as the controls were originally made for MPEG codecs and later
 734 extended to cover all encoding formats.</para>
 735
 736       <section>
 737         <title>Generic Codec Controls</title>
 738
 739         <table pgwide="1" frame="none" id="mpeg-control-id">
 740           <title>Codec Control IDs</title>
 741           <tgroup cols="4">
 742             <colspec colname="c1" colwidth="1*" />
 743             <colspec colname="c2" colwidth="6*" />
 744             <colspec colname="c3" colwidth="2*" />
 745             <colspec colname="c4" colwidth="6*" />
 746             <spanspec namest="c1" nameend="c2" spanname="id" />
 747             <spanspec namest="c2" nameend="c4" spanname="descr" />
 748             <thead>
 749               <row>
 750                 <entry spanname="id" align="left">ID</entry>
 751                 <entry align="left">Type</entry>
 752               </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
 753               </row>
 754             </thead>
 755             <tbody valign="top">
 756               <row><entry></entry></row>
 757               <row>
 758                 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant>&nbsp;</entry>
 759                 <entry>class</entry>
 760               </row><row><entry spanname="descr">The Codec class
 761 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
 762 description of this control class. This description can be used as the
 763 caption of a Tab page in a GUI, for example.</entry>
 764               </row>
 765               <row><entry></entry></row>
 766               <row id="v4l2-mpeg-stream-type">
 767                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant>&nbsp;</entry>
 768                 <entry>enum&nbsp;v4l2_mpeg_stream_type</entry>
 769               </row><row><entry spanname="descr">The MPEG-1, -2 or -4
 770 output stream type. One cannot assume anything here. Each hardware
 771 MPEG encoder tends to support different subsets of the available MPEG
 772 stream types. This control is specific to multiplexed MPEG streams.
 773 The currently defined stream types are:</entry>
 774               </row>
 775               <row>
 776                 <entrytbl spanname="descr" cols="2">
 777                   <tbody valign="top">
 778                     <row>
 779                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant>&nbsp;</entry>
 780                       <entry>MPEG-2 program stream</entry>
 781                     </row>
 782                     <row>
 783                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant>&nbsp;</entry>
 784                       <entry>MPEG-2 transport stream</entry>
 785                     </row>
 786                     <row>
 787                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant>&nbsp;</entry>
 788                       <entry>MPEG-1 system stream</entry>
 789                     </row>
 790                     <row>
 791                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant>&nbsp;</entry>
 792                       <entry>MPEG-2 DVD-compatible stream</entry>
 793                     </row>
 794                     <row>
 795                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant>&nbsp;</entry>
 796                       <entry>MPEG-1 VCD-compatible stream</entry>
 797                     </row>
 798                     <row>
 799                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant>&nbsp;</entry>
 800                       <entry>MPEG-2 SVCD-compatible stream</entry>
 801                     </row>
 802                   </tbody>
 803                 </entrytbl>
 804               </row>
 805               <row><entry></entry></row>
 806               <row>
 807                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant>&nbsp;</entry>
 808                 <entry>integer</entry>
 809               </row><row><entry spanname="descr">Program Map Table
 810 Packet ID for the MPEG transport stream (default 16)</entry>
 811               </row>
 812               <row><entry></entry></row>
 813               <row>
 814                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant>&nbsp;</entry>
 815                 <entry>integer</entry>
 816               </row><row><entry spanname="descr">Audio Packet ID for
 817 the MPEG transport stream (default 256)</entry>
 818               </row>
 819               <row><entry></entry></row>
 820               <row>
 821                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant>&nbsp;</entry>
 822                 <entry>integer</entry>
 823               </row><row><entry spanname="descr">Video Packet ID for
 824 the MPEG transport stream (default 260)</entry>
 825               </row>
 826               <row><entry></entry></row>
 827               <row>
 828                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant>&nbsp;</entry>
 829                 <entry>integer</entry>
 830               </row><row><entry spanname="descr">Packet ID for the
 831 MPEG transport stream carrying PCR fields (default 259)</entry>
 832               </row>
 833               <row><entry></entry></row>
 834               <row>
 835                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant>&nbsp;</entry>
 836                 <entry>integer</entry>
 837               </row><row><entry spanname="descr">Audio ID for MPEG
 838 PES</entry>
 839               </row>
 840               <row><entry></entry></row>
 841               <row>
 842                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant>&nbsp;</entry>
 843                 <entry>integer</entry>
 844               </row><row><entry spanname="descr">Video ID for MPEG
 845 PES</entry>
 846               </row>
 847               <row><entry></entry></row>
 848               <row id="v4l2-mpeg-stream-vbi-fmt">
 849                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant>&nbsp;</entry>
 850                 <entry>enum&nbsp;v4l2_mpeg_stream_vbi_fmt</entry>
 851               </row><row><entry spanname="descr">Some cards can embed
 852 VBI data (&eg; Closed Caption, Teletext) into the MPEG stream. This
 853 control selects whether VBI data should be embedded, and if so, what
 854 embedding method should be used. The list of possible VBI formats
 855 depends on the driver. The currently defined VBI format types
 856 are:</entry>
 857               </row>
 858               <row>
 859                 <entrytbl spanname="descr" cols="2">
 860                   <tbody valign="top">
 861                     <row>
 862                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant>&nbsp;</entry>
 863                       <entry>No VBI in the MPEG stream</entry>
 864                     </row>
 865                     <row>
 866                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant>&nbsp;</entry>
 867                       <entry>VBI in private packets, IVTV format (documented
 868 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
 869                     </row>
 870                   </tbody>
 871                 </entrytbl>
 872               </row>
 873               <row><entry></entry></row>
 874               <row id="v4l2-mpeg-audio-sampling-freq">
 875                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant>&nbsp;</entry>
 876                 <entry>enum&nbsp;v4l2_mpeg_audio_sampling_freq</entry>
 877               </row><row><entry spanname="descr">MPEG Audio sampling
 878 frequency. Possible values are:</entry>
 879               </row>
 880               <row>
 881                 <entrytbl spanname="descr" cols="2">
 882                   <tbody valign="top">
 883                     <row>
 884                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant>&nbsp;</entry>
 885                       <entry>44.1 kHz</entry>
 886                     </row>
 887                     <row>
 888                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant>&nbsp;</entry>
 889                       <entry>48 kHz</entry>
 890                     </row>
 891                     <row>
 892                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant>&nbsp;</entry>
 893                       <entry>32 kHz</entry>
 894                     </row>
 895                   </tbody>
 896                 </entrytbl>
 897               </row>
 898               <row><entry></entry></row>
 899               <row id="v4l2-mpeg-audio-encoding">
 900                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant>&nbsp;</entry>
 901                 <entry>enum&nbsp;v4l2_mpeg_audio_encoding</entry>
 902               </row><row><entry spanname="descr">MPEG Audio encoding.
 903 This control is specific to multiplexed MPEG streams.
 904 Possible values are:</entry>
 905               </row>
 906               <row>
 907                 <entrytbl spanname="descr" cols="2">
 908                   <tbody valign="top">
 909                     <row>
 910                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant>&nbsp;</entry>
 911                       <entry>MPEG-1/2 Layer I encoding</entry>
 912                     </row>
 913                     <row>
 914                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant>&nbsp;</entry>
 915                       <entry>MPEG-1/2 Layer II encoding</entry>
 916                     </row>
 917                     <row>
 918                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant>&nbsp;</entry>
 919                       <entry>MPEG-1/2 Layer III encoding</entry>
 920                     </row>
 921                     <row>
 922                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant>&nbsp;</entry>
 923                       <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
 924                     </row>
 925                     <row>
 926                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant>&nbsp;</entry>
 927                       <entry>AC-3 aka ATSC A/52 encoding</entry>
 928                     </row>
 929                   </tbody>
 930                 </entrytbl>
 931               </row>
 932               <row><entry></entry></row>
 933               <row id="v4l2-mpeg-audio-l1-bitrate">
 934                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant>&nbsp;</entry>
 935                 <entry>enum&nbsp;v4l2_mpeg_audio_l1_bitrate</entry>
 936               </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
 937 Possible values are:</entry>
 938               </row>
 939               <row>
 940                 <entrytbl spanname="descr" cols="2">
 941                   <tbody valign="top">
 942                     <row>
 943                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant>&nbsp;</entry>
 944                       <entry>32 kbit/s</entry></row>
 945                     <row>
 946                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant>&nbsp;</entry>
 947                       <entry>64 kbit/s</entry>
 948                     </row>
 949                     <row>
 950                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant>&nbsp;</entry>
 951                       <entry>96 kbit/s</entry>
 952                     </row>
 953                     <row>
 954                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant>&nbsp;</entry>
 955                       <entry>128 kbit/s</entry>
 956                     </row>
 957                     <row>
 958                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant>&nbsp;</entry>
 959                       <entry>160 kbit/s</entry>
 960                     </row>
 961                     <row>
 962                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant>&nbsp;</entry>
 963                       <entry>192 kbit/s</entry>
 964                     </row>
 965                     <row>
 966                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant>&nbsp;</entry>
 967                       <entry>224 kbit/s</entry>
 968                     </row>
 969                     <row>
 970                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant>&nbsp;</entry>
 971                       <entry>256 kbit/s</entry>
 972                     </row>
 973                     <row>
 974                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant>&nbsp;</entry>
 975                       <entry>288 kbit/s</entry>
 976                     </row>
 977                     <row>
 978                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant>&nbsp;</entry>
 979                       <entry>320 kbit/s</entry>
 980                     </row>
 981                     <row>
 982                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant>&nbsp;</entry>
 983                       <entry>352 kbit/s</entry>
 984                     </row>
 985                     <row>
 986                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant>&nbsp;</entry>
 987                       <entry>384 kbit/s</entry>
 988                     </row>
 989                     <row>
 990                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant>&nbsp;</entry>
 991                       <entry>416 kbit/s</entry>
 992                     </row>
 993                     <row>
 994                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant>&nbsp;</entry>
 995                       <entry>448 kbit/s</entry>
 996                     </row>
 997                   </tbody>
 998                 </entrytbl>
 999               </row>
1000               <row><entry></entry></row>
1001               <row id="v4l2-mpeg-audio-l2-bitrate">
1002                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant>&nbsp;</entry>
1003                 <entry>enum&nbsp;v4l2_mpeg_audio_l2_bitrate</entry>
1004               </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1005 Possible values are:</entry>
1006               </row>
1007               <row>
1008                 <entrytbl spanname="descr" cols="2">
1009                   <tbody valign="top">
1010                     <row>
1011                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant>&nbsp;</entry>
1012                       <entry>32 kbit/s</entry>
1013                     </row>
1014                     <row>
1015                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant>&nbsp;</entry>
1016                       <entry>48 kbit/s</entry>
1017                     </row>
1018                     <row>
1019                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant>&nbsp;</entry>
1020                       <entry>56 kbit/s</entry>
1021                     </row>
1022                     <row>
1023                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant>&nbsp;</entry>
1024                       <entry>64 kbit/s</entry>
1025                     </row>
1026                     <row>
1027                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant>&nbsp;</entry>
1028                       <entry>80 kbit/s</entry>
1029                     </row>
1030                     <row>
1031                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant>&nbsp;</entry>
1032                       <entry>96 kbit/s</entry>
1033                     </row>
1034                     <row>
1035                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant>&nbsp;</entry>
1036                       <entry>112 kbit/s</entry>
1037                     </row>
1038                     <row>
1039                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant>&nbsp;</entry>
1040                       <entry>128 kbit/s</entry>
1041                     </row>
1042                     <row>
1043                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant>&nbsp;</entry>
1044                       <entry>160 kbit/s</entry>
1045                     </row>
1046                     <row>
1047                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant>&nbsp;</entry>
1048                       <entry>192 kbit/s</entry>
1049                     </row>
1050                     <row>
1051                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant>&nbsp;</entry>
1052                       <entry>224 kbit/s</entry>
1053                     </row>
1054                     <row>
1055                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant>&nbsp;</entry>
1056                       <entry>256 kbit/s</entry>
1057                     </row>
1058                     <row>
1059                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant>&nbsp;</entry>
1060                       <entry>320 kbit/s</entry>
1061                     </row>
1062                     <row>
1063                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant>&nbsp;</entry>
1064                       <entry>384 kbit/s</entry>
1065                     </row>
1066                   </tbody>
1067                 </entrytbl>
1068               </row>
1069               <row><entry></entry></row>
1070               <row id="v4l2-mpeg-audio-l3-bitrate">
1071                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant>&nbsp;</entry>
1072                 <entry>enum&nbsp;v4l2_mpeg_audio_l3_bitrate</entry>
1073               </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1074 Possible values are:</entry>
1075               </row>
1076               <row>
1077                 <entrytbl spanname="descr" cols="2">
1078                   <tbody valign="top">
1079                     <row>
1080                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant>&nbsp;</entry>
1081                       <entry>32 kbit/s</entry>
1082                     </row>
1083                     <row>
1084                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant>&nbsp;</entry>
1085                       <entry>40 kbit/s</entry>
1086                     </row>
1087                     <row>
1088                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant>&nbsp;</entry>
1089                       <entry>48 kbit/s</entry>
1090                     </row>
1091                     <row>
1092                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant>&nbsp;</entry>
1093                       <entry>56 kbit/s</entry>
1094                     </row>
1095                     <row>
1096                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant>&nbsp;</entry>
1097                       <entry>64 kbit/s</entry>
1098                     </row>
1099                     <row>
1100                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant>&nbsp;</entry>
1101                       <entry>80 kbit/s</entry>
1102                     </row>
1103                     <row>
1104                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant>&nbsp;</entry>
1105                       <entry>96 kbit/s</entry>
1106                     </row>
1107                     <row>
1108                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant>&nbsp;</entry>
1109                       <entry>112 kbit/s</entry>
1110                     </row>
1111                     <row>
1112                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant>&nbsp;</entry>
1113                       <entry>128 kbit/s</entry>
1114                     </row>
1115                     <row>
1116                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant>&nbsp;</entry>
1117                       <entry>160 kbit/s</entry>
1118                     </row>
1119                     <row>
1120                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant>&nbsp;</entry>
1121                       <entry>192 kbit/s</entry>
1122                     </row>
1123                     <row>
1124                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant>&nbsp;</entry>
1125                       <entry>224 kbit/s</entry>
1126                     </row>
1127                     <row>
1128                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant>&nbsp;</entry>
1129                       <entry>256 kbit/s</entry>
1130                     </row>
1131                     <row>
1132                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant>&nbsp;</entry>
1133                       <entry>320 kbit/s</entry>
1134                     </row>
1135                   </tbody>
1136                 </entrytbl>
1137               </row>
1138               <row><entry></entry></row>
1139               <row>
1140                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant>&nbsp;</entry>
1141                 <entry>integer</entry>
1142               </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1143               </row>
1144               <row><entry></entry></row>
1145               <row id="v4l2-mpeg-audio-ac3-bitrate">
1146                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant>&nbsp;</entry>
1147                 <entry>enum&nbsp;v4l2_mpeg_audio_ac3_bitrate</entry>
1148               </row><row><entry spanname="descr">AC-3 bitrate.
1149 Possible values are:</entry>
1150               </row>
1151               <row>
1152                 <entrytbl spanname="descr" cols="2">
1153                   <tbody valign="top">
1154                     <row>
1155                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant>&nbsp;</entry>
1156                       <entry>32 kbit/s</entry>
1157                     </row>
1158                     <row>
1159                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant>&nbsp;</entry>
1160                       <entry>40 kbit/s</entry>
1161                     </row>
1162                     <row>
1163                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant>&nbsp;</entry>
1164                       <entry>48 kbit/s</entry>
1165                     </row>
1166                     <row>
1167                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant>&nbsp;</entry>
1168                       <entry>56 kbit/s</entry>
1169                     </row>
1170                     <row>
1171                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant>&nbsp;</entry>
1172                       <entry>64 kbit/s</entry>
1173                     </row>
1174                     <row>
1175                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant>&nbsp;</entry>
1176                       <entry>80 kbit/s</entry>
1177                     </row>
1178                     <row>
1179                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant>&nbsp;</entry>
1180                       <entry>96 kbit/s</entry>
1181                     </row>
1182                     <row>
1183                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant>&nbsp;</entry>
1184                       <entry>112 kbit/s</entry>
1185                     </row>
1186                     <row>
1187                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant>&nbsp;</entry>
1188                       <entry>128 kbit/s</entry>
1189                     </row>
1190                     <row>
1191                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant>&nbsp;</entry>
1192                       <entry>160 kbit/s</entry>
1193                     </row>
1194                     <row>
1195                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant>&nbsp;</entry>
1196                       <entry>192 kbit/s</entry>
1197                     </row>
1198                     <row>
1199                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant>&nbsp;</entry>
1200                       <entry>224 kbit/s</entry>
1201                     </row>
1202                     <row>
1203                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant>&nbsp;</entry>
1204                       <entry>256 kbit/s</entry>
1205                     </row>
1206                     <row>
1207                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant>&nbsp;</entry>
1208                       <entry>320 kbit/s</entry>
1209                     </row>
1210                     <row>
1211                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant>&nbsp;</entry>
1212                       <entry>384 kbit/s</entry>
1213                     </row>
1214                     <row>
1215                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant>&nbsp;</entry>
1216                       <entry>448 kbit/s</entry>
1217                     </row>
1218                     <row>
1219                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant>&nbsp;</entry>
1220                       <entry>512 kbit/s</entry>
1221                     </row>
1222                     <row>
1223                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant>&nbsp;</entry>
1224                       <entry>576 kbit/s</entry>
1225                     </row>
1226                     <row>
1227                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant>&nbsp;</entry>
1228                       <entry>640 kbit/s</entry>
1229                     </row>
1230                   </tbody>
1231                 </entrytbl>
1232               </row>
1233               <row><entry></entry></row>
1234               <row id="v4l2-mpeg-audio-mode">
1235                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant>&nbsp;</entry>
1236                 <entry>enum&nbsp;v4l2_mpeg_audio_mode</entry>
1237               </row><row><entry spanname="descr">MPEG Audio mode.
1238 Possible values are:</entry>
1239               </row>
1240               <row>
1241                 <entrytbl spanname="descr" cols="2">
1242                   <tbody valign="top">
1243                     <row>
1244                       <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant>&nbsp;</entry>
1245                       <entry>Stereo</entry>
1246                     </row>
1247                     <row>
1248                       <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant>&nbsp;</entry>
1249                       <entry>Joint Stereo</entry>
1250                     </row>
1251                     <row>
1252                       <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant>&nbsp;</entry>
1253                       <entry>Bilingual</entry>
1254                     </row>
1255                     <row>
1256                       <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant>&nbsp;</entry>
1257                       <entry>Mono</entry>
1258                     </row>
1259                   </tbody>
1260                 </entrytbl>
1261               </row>
1262               <row><entry></entry></row>
1263               <row id="v4l2-mpeg-audio-mode-extension">
1264                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant>&nbsp;</entry>
1265                 <entry>enum&nbsp;v4l2_mpeg_audio_mode_extension</entry>
1266               </row><row><entry spanname="descr">Joint Stereo
1267 audio mode extension. In Layer I and II they indicate which subbands
1268 are in intensity stereo. All other subbands are coded in stereo. Layer
1269 III is not (yet) supported. Possible values
1270 are:</entry>
1271               </row>
1272               <row>
1273                 <entrytbl spanname="descr" cols="2">
1274                   <tbody valign="top">
1275                     <row>
1276                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant>&nbsp;</entry>
1277                       <entry>Subbands 4-31 in intensity stereo</entry>
1278                     </row>
1279                     <row>
1280                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant>&nbsp;</entry>
1281                       <entry>Subbands 8-31 in intensity stereo</entry>
1282                     </row>
1283                     <row>
1284                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant>&nbsp;</entry>
1285                       <entry>Subbands 12-31 in intensity stereo</entry>
1286                     </row>
1287                     <row>
1288                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant>&nbsp;</entry>
1289                       <entry>Subbands 16-31 in intensity stereo</entry>
1290                     </row>
1291                   </tbody>
1292                 </entrytbl>
1293               </row>
1294               <row><entry></entry></row>
1295               <row id="v4l2-mpeg-audio-emphasis">
1296                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant>&nbsp;</entry>
1297                 <entry>enum&nbsp;v4l2_mpeg_audio_emphasis</entry>
1298               </row><row><entry spanname="descr">Audio Emphasis.
1299 Possible values are:</entry>
1300               </row>
1301               <row>
1302                 <entrytbl spanname="descr" cols="2">
1303                   <tbody valign="top">
1304                     <row>
1305                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant>&nbsp;</entry>
1306                       <entry>None</entry>
1307                     </row>
1308                     <row>
1309                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant>&nbsp;</entry>
1310                       <entry>50/15 microsecond emphasis</entry>
1311                     </row>
1312                     <row>
1313                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant>&nbsp;</entry>
1314                       <entry>CCITT J.17</entry>
1315                     </row>
1316                   </tbody>
1317                 </entrytbl>
1318               </row>
1319               <row><entry></entry></row>
1320               <row id="v4l2-mpeg-audio-crc">
1321                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant>&nbsp;</entry>
1322                 <entry>enum&nbsp;v4l2_mpeg_audio_crc</entry>
1323               </row><row><entry spanname="descr">CRC method. Possible
1324 values are:</entry>
1325               </row>
1326               <row>
1327                 <entrytbl spanname="descr" cols="2">
1328                   <tbody valign="top">
1329                     <row>
1330                       <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant>&nbsp;</entry>
1331                       <entry>None</entry>
1332                     </row>
1333                     <row>
1334                       <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant>&nbsp;</entry>
1335                       <entry>16 bit parity check</entry>
1336                     </row>
1337                   </tbody>
1338                 </entrytbl>
1339               </row>
1340               <row><entry></entry></row>
1341               <row>
1342                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant>&nbsp;</entry>
1343                 <entry>boolean</entry>
1344               </row><row><entry spanname="descr">Mutes the audio when
1345 capturing. This is not done by muting audio hardware, which can still
1346 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1347 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1348               </row>
1349               <row><entry></entry></row>
1350               <row id="v4l2-mpeg-audio-dec-playback">
1351                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant>&nbsp;</entry>
1352                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1353               </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1354 Possible values are:</entry>
1355               </row>
1356               <row>
1357                 <entrytbl spanname="descr" cols="2">
1358                   <tbody valign="top">
1359                     <row>
1360                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant>&nbsp;</entry>
1361                       <entry>Automatically determines the best playback mode.</entry>
1362                     </row>
1363                     <row>
1364                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant>&nbsp;</entry>
1365                       <entry>Stereo playback.</entry>
1366                     </row>
1367                     <row>
1368                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant>&nbsp;</entry>
1369                       <entry>Left channel playback.</entry>
1370                     </row>
1371                     <row>
1372                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant>&nbsp;</entry>
1373                       <entry>Right channel playback.</entry>
1374                     </row>
1375                     <row>
1376                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant>&nbsp;</entry>
1377                       <entry>Mono playback.</entry>
1378                     </row>
1379                     <row>
1380                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant>&nbsp;</entry>
1381                       <entry>Stereo playback with swapped left and right channels.</entry>
1382                     </row>
1383                   </tbody>
1384                 </entrytbl>
1385               </row>
1386               <row><entry></entry></row>
1387               <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1388                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant>&nbsp;</entry>
1389                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1390               </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1391               </row>
1392               <row><entry></entry></row>
1393               <row id="v4l2-mpeg-video-encoding">
1394                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant>&nbsp;</entry>
1395                 <entry>enum&nbsp;v4l2_mpeg_video_encoding</entry>
1396               </row><row><entry spanname="descr">MPEG Video encoding
1397 method. This control is specific to multiplexed MPEG streams.
1398 Possible values are:</entry>
1399               </row>
1400               <row>
1401                 <entrytbl spanname="descr" cols="2">
1402                   <tbody valign="top">
1403                     <row>
1404                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant>&nbsp;</entry>
1405                       <entry>MPEG-1 Video encoding</entry>
1406                     </row>
1407                     <row>
1408                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant>&nbsp;</entry>
1409                       <entry>MPEG-2 Video encoding</entry>
1410                     </row>
1411                     <row>
1412                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant>&nbsp;</entry>
1413                       <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1414                     </row>
1415                   </tbody>
1416                 </entrytbl>
1417               </row>
1418               <row><entry></entry></row>
1419               <row id="v4l2-mpeg-video-aspect">
1420                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant>&nbsp;</entry>
1421                 <entry>enum&nbsp;v4l2_mpeg_video_aspect</entry>
1422               </row><row><entry spanname="descr">Video aspect.
1423 Possible values are:</entry>
1424               </row>
1425               <row>
1426                 <entrytbl spanname="descr" cols="2">
1427                   <tbody valign="top">
1428                     <row>
1429                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant>&nbsp;</entry>
1430                     </row>
1431                     <row>
1432                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant>&nbsp;</entry>
1433                     </row>
1434                     <row>
1435                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant>&nbsp;</entry>
1436                     </row>
1437                     <row>
1438                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant>&nbsp;</entry>
1439                     </row>
1440                   </tbody>
1441                 </entrytbl>
1442               </row>
1443               <row><entry></entry></row>
1444               <row>
1445                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant>&nbsp;</entry>
1446                 <entry>integer</entry>
1447               </row><row><entry spanname="descr">Number of B-Frames
1448 (default 2)</entry>
1449               </row>
1450               <row><entry></entry></row>
1451               <row>
1452                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant>&nbsp;</entry>
1453                 <entry>integer</entry>
1454               </row><row><entry spanname="descr">GOP size (default
1455 12)</entry>
1456               </row>
1457               <row><entry></entry></row>
1458               <row>
1459                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant>&nbsp;</entry>
1460                 <entry>boolean</entry>
1461               </row><row><entry spanname="descr">GOP closure (default
1462 1)</entry>
1463               </row>
1464               <row><entry></entry></row>
1465               <row>
1466                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant>&nbsp;</entry>
1467                 <entry>boolean</entry>
1468               </row><row><entry spanname="descr">Enable 3:2 pulldown
1469 (default 0)</entry>
1470               </row>
1471               <row><entry></entry></row>
1472               <row id="v4l2-mpeg-video-bitrate-mode">
1473                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant>&nbsp;</entry>
1474                 <entry>enum&nbsp;v4l2_mpeg_video_bitrate_mode</entry>
1475               </row><row><entry spanname="descr">Video bitrate mode.
1476 Possible values are:</entry>
1477               </row>
1478               <row>
1479                 <entrytbl spanname="descr" cols="2">
1480                   <tbody valign="top">
1481                     <row>
1482                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant>&nbsp;</entry>
1483                       <entry>Variable bitrate</entry>
1484                     </row>
1485                     <row>
1486                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant>&nbsp;</entry>
1487                       <entry>Constant bitrate</entry>
1488                     </row>
1489                   </tbody>
1490                 </entrytbl>
1491               </row>
1492               <row><entry></entry></row>
1493               <row>
1494                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant>&nbsp;</entry>
1495                 <entry>integer</entry>
1496               </row><row><entry spanname="descr">Video bitrate in bits
1497 per second.</entry>
1498               </row>
1499               <row><entry></entry></row>
1500               <row>
1501                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant>&nbsp;</entry>
1502                 <entry>integer</entry>
1503               </row><row><entry spanname="descr">Peak video bitrate in
1504 bits per second. Must be larger or equal to the average video bitrate.
1505 It is ignored if the video bitrate mode is set to constant
1506 bitrate.</entry>
1507               </row>
1508               <row><entry></entry></row>
1509               <row>
1510                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant>&nbsp;</entry>
1511                 <entry>integer</entry>
1512               </row><row><entry spanname="descr">For every captured
1513 frame, skip this many subsequent frames (default 0).</entry>
1514               </row>
1515               <row><entry></entry></row>
1516               <row>
1517                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant>&nbsp;</entry>
1518                 <entry>boolean</entry>
1519               </row>
1520               <row><entry spanname="descr">"Mutes" the video to a
1521 fixed color when capturing. This is useful for testing, to produce a
1522 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1523               </row>
1524               <row><entry></entry></row>
1525               <row>
1526                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant>&nbsp;</entry>
1527                 <entry>integer</entry>
1528               </row><row><entry spanname="descr">Sets the "mute" color
1529 of the video. The supplied 32-bit integer is interpreted as follows (bit
1530 0 = least significant bit):</entry>
1531               </row>
1532               <row>
1533                 <entrytbl spanname="descr" cols="2">
1534                   <tbody valign="top">
1535                     <row>
1536                       <entry>Bit 0:7</entry>
1537                       <entry>V chrominance information</entry>
1538                     </row>
1539                     <row>
1540                       <entry>Bit 8:15</entry>
1541                       <entry>U chrominance information</entry>
1542                     </row>
1543                     <row>
1544                       <entry>Bit 16:23</entry>
1545                       <entry>Y luminance information</entry>
1546                     </row>
1547                     <row>
1548                       <entry>Bit 24:31</entry>
1549                       <entry>Must be zero.</entry>
1550                     </row>
1551                   </tbody>
1552                 </entrytbl>
1553               </row>
1554               <row><entry></entry></row>
1555               <row id="v4l2-mpeg-video-dec-pts">
1556                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant>&nbsp;</entry>
1557                 <entry>integer64</entry>
1558               </row><row><entry spanname="descr">This read-only control returns the
1559 33-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1560 the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1561               </row>
1562               <row><entry></entry></row>
1563               <row id="v4l2-mpeg-video-dec-frame">
1564                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant>&nbsp;</entry>
1565                 <entry>integer64</entry>
1566               </row><row><entry spanname="descr">This read-only control returns the
1567 frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1568 the decoder is started.</entry>
1569               </row>
1570
1571               <row><entry></entry></row>
1572               <row>
1573                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant>&nbsp;</entry>
1574                 <entry>boolean</entry>
1575               </row>
1576               <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1577 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1578 </entry>
1579               </row>
1580
1581               <row><entry></entry></row>
1582               <row>
1583                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant>&nbsp;</entry>
1584                 <entry>boolean</entry>
1585               </row>
1586               <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1587 Applicable to the H264 encoder.</entry>
1588               </row>
1589
1590               <row><entry></entry></row>
1591               <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1592                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant>&nbsp;</entry>
1593                 <entry>enum&nbsp;v4l2_mpeg_video_h264_vui_sar_idc</entry>
1594               </row>
1595               <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1596 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1597               </row>
1598               <row>
1599                 <entrytbl spanname="descr" cols="2">
1600                   <tbody valign="top">
1601
1602                         <row>
1603                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant>&nbsp;</entry>
1604                           <entry>Unspecified</entry>
1605                         </row>
1606                         <row>
1607                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant>&nbsp;</entry>
1608                           <entry>1x1</entry>
1609                         </row>
1610                         <row>
1611                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant>&nbsp;</entry>
1612                           <entry>12x11</entry>
1613                         </row>
1614                         <row>
1615                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant>&nbsp;</entry>
1616                           <entry>10x11</entry>
1617                         </row>
1618                         <row>
1619                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant>&nbsp;</entry>
1620                           <entry>16x11</entry>
1621                         </row>
1622                         <row>
1623                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant>&nbsp;</entry>
1624                           <entry>40x33</entry>
1625                         </row>
1626                         <row>
1627                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant>&nbsp;</entry>
1628                           <entry>24x11</entry>
1629                         </row>
1630                         <row>
1631                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant>&nbsp;</entry>
1632                           <entry>20x11</entry>
1633                         </row>
1634                         <row>
1635                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant>&nbsp;</entry>
1636                           <entry>32x11</entry>
1637                         </row>
1638                         <row>
1639                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant>&nbsp;</entry>
1640                           <entry>80x33</entry>
1641                         </row>
1642                         <row>
1643                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant>&nbsp;</entry>
1644                           <entry>18x11</entry>
1645                         </row>
1646                         <row>
1647                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant>&nbsp;</entry>
1648                           <entry>15x11</entry>
1649                         </row>
1650                         <row>
1651                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant>&nbsp;</entry>
1652                           <entry>64x33</entry>
1653                         </row>
1654                         <row>
1655                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant>&nbsp;</entry>
1656                           <entry>160x99</entry>
1657                         </row>
1658                         <row>
1659                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant>&nbsp;</entry>
1660                           <entry>4x3</entry>
1661                         </row>
1662                         <row>
1663                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant>&nbsp;</entry>
1664                           <entry>3x2</entry>
1665                         </row>
1666                         <row>
1667                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant>&nbsp;</entry>
1668                           <entry>2x1</entry>
1669                         </row>
1670                         <row>
1671                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant>&nbsp;</entry>
1672                           <entry>Extended SAR</entry>
1673                         </row>
1674                   </tbody>
1675                 </entrytbl>
1676               </row>
1677
1678               <row><entry></entry></row>
1679               <row>
1680                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant>&nbsp;</entry>
1681                 <entry>integer</entry>
1682               </row>
1683               <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1684 Applicable to the H264 encoder.</entry>
1685               </row>
1686
1687               <row><entry></entry></row>
1688               <row>
1689                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant>&nbsp;</entry>
1690                 <entry>integer</entry>
1691               </row>
1692               <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1693 Applicable to the H264 encoder.</entry>
1694               </row>
1695
1696               <row><entry></entry></row>
1697               <row id="v4l2-mpeg-video-h264-level">
1698                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant>&nbsp;</entry>
1699                 <entry>enum&nbsp;v4l2_mpeg_video_h264_level</entry>
1700               </row>
1701               <row><entry spanname="descr">The level information for the H264 video elementary stream.
1702 Applicable to the H264 encoder.
1703 Possible values are:</entry>
1704               </row>
1705               <row>
1706                 <entrytbl spanname="descr" cols="2">
1707                   <tbody valign="top">
1708                     <row>
1709                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant>&nbsp;</entry>
1710                       <entry>Level 1.0</entry>
1711                     </row>
1712                     <row>
1713                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant>&nbsp;</entry>
1714                       <entry>Level 1B</entry>
1715                     </row>
1716                     <row>
1717                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant>&nbsp;</entry>
1718                       <entry>Level 1.1</entry>
1719                     </row>
1720                     <row>
1721                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant>&nbsp;</entry>
1722                       <entry>Level 1.2</entry>
1723                     </row>
1724                     <row>
1725                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant>&nbsp;</entry>
1726                       <entry>Level 1.3</entry>
1727                     </row>
1728                     <row>
1729                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant>&nbsp;</entry>
1730                       <entry>Level 2.0</entry>
1731                     </row>
1732                     <row>
1733                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant>&nbsp;</entry>
1734                       <entry>Level 2.1</entry>
1735                     </row>
1736                     <row>
1737                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant>&nbsp;</entry>
1738                       <entry>Level 2.2</entry>
1739                     </row>
1740                     <row>
1741                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant>&nbsp;</entry>
1742                       <entry>Level 3.0</entry>
1743                     </row>
1744                     <row>
1745                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant>&nbsp;</entry>
1746                       <entry>Level 3.1</entry>
1747                     </row>
1748                     <row>
1749                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant>&nbsp;</entry>
1750                       <entry>Level 3.2</entry>
1751                     </row>
1752                     <row>
1753                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant>&nbsp;</entry>
1754                       <entry>Level 4.0</entry>
1755                     </row>
1756                     <row>
1757                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant>&nbsp;</entry>
1758                       <entry>Level 4.1</entry>
1759                     </row>
1760                     <row>
1761                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant>&nbsp;</entry>
1762                       <entry>Level 4.2</entry>
1763                     </row>
1764                     <row>
1765                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant>&nbsp;</entry>
1766                       <entry>Level 5.0</entry>
1767                     </row>
1768                     <row>
1769                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant>&nbsp;</entry>
1770                       <entry>Level 5.1</entry>
1771                     </row>
1772                   </tbody>
1773                 </entrytbl>
1774               </row>
1775
1776               <row><entry></entry></row>
1777               <row id="v4l2-mpeg-video-mpeg4-level">
1778                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant>&nbsp;</entry>
1779                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_level</entry>
1780               </row>
1781               <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1782 Applicable to the MPEG4 encoder.
1783 Possible values are:</entry>
1784               </row>
1785               <row>
1786                 <entrytbl spanname="descr" cols="2">
1787                   <tbody valign="top">
1788                     <row>
1789                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant>&nbsp;</entry>
1790                       <entry>Level 0</entry>
1791                     </row>
1792                     <row>
1793                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant>&nbsp;</entry>
1794                       <entry>Level 0b</entry>
1795                     </row>
1796                     <row>
1797                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant>&nbsp;</entry>
1798                       <entry>Level 1</entry>
1799                     </row>
1800                     <row>
1801                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant>&nbsp;</entry>
1802                       <entry>Level 2</entry>
1803                     </row>
1804                     <row>
1805                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant>&nbsp;</entry>
1806                       <entry>Level 3</entry>
1807                     </row>
1808                     <row>
1809                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant>&nbsp;</entry>
1810                       <entry>Level 3b</entry>
1811                     </row>
1812                     <row>
1813                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant>&nbsp;</entry>
1814                       <entry>Level 4</entry>
1815                     </row>
1816                     <row>
1817                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant>&nbsp;</entry>
1818                       <entry>Level 5</entry>
1819                     </row>
1820                   </tbody>
1821                 </entrytbl>
1822               </row>
1823
1824               <row><entry></entry></row>
1825               <row id="v4l2-mpeg-video-h264-profile">
1826                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant>&nbsp;</entry>
1827                 <entry>enum&nbsp;v4l2_mpeg_video_h264_profile</entry>
1828               </row>
1829               <row><entry spanname="descr">The profile information for H264.
1830 Applicable to the H264 encoder.
1831 Possible values are:</entry>
1832               </row>
1833               <row>
1834                 <entrytbl spanname="descr" cols="2">
1835                   <tbody valign="top">
1836                     <row>
1837                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant>&nbsp;</entry>
1838                       <entry>Baseline profile</entry>
1839                     </row>
1840                     <row>
1841                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant>&nbsp;</entry>
1842                       <entry>Constrained Baseline profile</entry>
1843                     </row>
1844                     <row>
1845                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant>&nbsp;</entry>
1846                       <entry>Main profile</entry>
1847                     </row>
1848                     <row>
1849                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant>&nbsp;</entry>
1850                       <entry>Extended profile</entry>
1851                     </row>
1852                     <row>
1853                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant>&nbsp;</entry>
1854                       <entry>High profile</entry>
1855                     </row>
1856                     <row>
1857                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant>&nbsp;</entry>
1858                       <entry>High 10 profile</entry>
1859                     </row>
1860                     <row>
1861                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant>&nbsp;</entry>
1862                       <entry>High 422 profile</entry>
1863                     </row>
1864                     <row>
1865                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant>&nbsp;</entry>
1866                       <entry>High 444 Predictive profile</entry>
1867                     </row>
1868                     <row>
1869                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant>&nbsp;</entry>
1870                       <entry>High 10 Intra profile</entry>
1871                     </row>
1872                     <row>
1873                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant>&nbsp;</entry>
1874                       <entry>High 422 Intra profile</entry>
1875                     </row>
1876                     <row>
1877                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant>&nbsp;</entry>
1878                       <entry>High 444 Intra profile</entry>
1879                     </row>
1880                     <row>
1881                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant>&nbsp;</entry>
1882                       <entry>CAVLC 444 Intra profile</entry>
1883                     </row>
1884                     <row>
1885                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant>&nbsp;</entry>
1886                       <entry>Scalable Baseline profile</entry>
1887                     </row>
1888                     <row>
1889                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant>&nbsp;</entry>
1890                       <entry>Scalable High profile</entry>
1891                     </row>
1892                     <row>
1893                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant>&nbsp;</entry>
1894                       <entry>Scalable High Intra profile</entry>
1895                     </row>
1896                     <row>
1897                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant>&nbsp;</entry>
1898                       <entry>Stereo High profile</entry>
1899                     </row>
1900                     <row>
1901                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant>&nbsp;</entry>
1902                       <entry>Multiview High profile</entry>
1903                     </row>
1904
1905                   </tbody>
1906                 </entrytbl>
1907               </row>
1908
1909               <row><entry></entry></row>
1910               <row id="v4l2-mpeg-video-mpeg4-profile">
1911                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant>&nbsp;</entry>
1912                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_profile</entry>
1913               </row>
1914               <row><entry spanname="descr">The profile information for MPEG4.
1915 Applicable to the MPEG4 encoder.
1916 Possible values are:</entry>
1917               </row>
1918               <row>
1919                 <entrytbl spanname="descr" cols="2">
1920                   <tbody valign="top">
1921                     <row>
1922                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant>&nbsp;</entry>
1923                       <entry>Simple profile</entry>
1924                     </row>
1925                     <row>
1926                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant>&nbsp;</entry>
1927                       <entry>Advanced Simple profile</entry>
1928                     </row>
1929                     <row>
1930                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant>&nbsp;</entry>
1931                       <entry>Core profile</entry>
1932                     </row>
1933                     <row>
1934                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant>&nbsp;</entry>
1935                       <entry>Simple Scalable profile</entry>
1936                     </row>
1937                     <row>
1938                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant>&nbsp;</entry>
1939                       <entry></entry>
1940                     </row>
1941                   </tbody>
1942                 </entrytbl>
1943               </row>
1944
1945               <row><entry></entry></row>
1946               <row>
1947                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant>&nbsp;</entry>
1948                 <entry>integer</entry>
1949               </row>
1950               <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1951 Applicable to the encoder.
1952 </entry>
1953               </row>
1954
1955               <row><entry></entry></row>
1956               <row id="v4l2-mpeg-video-multi-slice-mode">
1957                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant>&nbsp;</entry>
1958                 <entry>enum&nbsp;v4l2_mpeg_video_multi_slice_mode</entry>
1959               </row>
1960               <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1961 Applicable to the encoder.
1962 Possible values are:</entry>
1963               </row>
1964               <row>
1965                 <entrytbl spanname="descr" cols="2">
1966                   <tbody valign="top">
1967                     <row>
1968                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant>&nbsp;</entry>
1969                       <entry>Single slice per frame.</entry>
1970                     </row>
1971                     <row>
1972                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>&nbsp;</entry>
1973                       <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1974                     </row>
1975                     <row>
1976                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>&nbsp;</entry>
1977                       <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1978                     </row>
1979                   </tbody>
1980                 </entrytbl>
1981               </row>
1982
1983               <row><entry></entry></row>
1984               <row>
1985                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant>&nbsp;</entry>
1986                 <entry>integer</entry>
1987               </row>
1988               <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
1989 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
1990 Applicable to the encoder.</entry>
1991               </row>
1992
1993               <row><entry></entry></row>
1994               <row>
1995                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant>&nbsp;</entry>
1996                 <entry>integer</entry>
1997               </row>
1998               <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
1999 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
2000 Applicable to the encoder.</entry>
2001               </row>
2002
2003               <row><entry></entry></row>
2004               <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2005                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant>&nbsp;</entry>
2006                 <entry>enum&nbsp;v4l2_mpeg_video_h264_loop_filter_mode</entry>
2007               </row>
2008               <row><entry spanname="descr">Loop filter mode for H264 encoder.
2009 Possible values are:</entry>
2010               </row>
2011               <row>
2012                 <entrytbl spanname="descr" cols="2">
2013                   <tbody valign="top">
2014                     <row>
2015                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant>&nbsp;</entry>
2016                       <entry>Loop filter is enabled.</entry>
2017                     </row>
2018                     <row>
2019                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant>&nbsp;</entry>
2020                       <entry>Loop filter is disabled.</entry>
2021                     </row>
2022                     <row>
2023                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant>&nbsp;</entry>
2024                       <entry>Loop filter is disabled at the slice boundary.</entry>
2025                     </row>
2026                   </tbody>
2027                 </entrytbl>
2028               </row>
2029
2030               <row><entry></entry></row>
2031               <row>
2032                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant>&nbsp;</entry>
2033                 <entry>integer</entry>
2034               </row>
2035               <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2036 Applicable to the H264 encoder.</entry>
2037               </row>
2038
2039               <row><entry></entry></row>
2040               <row>
2041                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant>&nbsp;</entry>
2042                 <entry>integer</entry>
2043               </row>
2044               <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2045 Applicable to the H264 encoder.</entry>
2046               </row>
2047
2048               <row><entry></entry></row>
2049               <row id="v4l2-mpeg-video-h264-entropy-mode">
2050                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant>&nbsp;</entry>
2051                 <entry>enum&nbsp;v4l2_mpeg_video_h264_entropy_mode</entry>
2052               </row>
2053               <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2054 Applicable to the H264 encoder.
2055 Possible values are:</entry>
2056               </row>
2057               <row>
2058                 <entrytbl spanname="descr" cols="2">
2059                   <tbody valign="top">
2060                     <row>
2061                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant>&nbsp;</entry>
2062                       <entry>Use CAVLC entropy coding.</entry>
2063                     </row>
2064                     <row>
2065                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant>&nbsp;</entry>
2066                       <entry>Use CABAC entropy coding.</entry>
2067                     </row>
2068                   </tbody>
2069                 </entrytbl>
2070               </row>
2071
2072               <row><entry></entry></row>
2073               <row>
2074                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant>&nbsp;</entry>
2075                 <entry>boolean</entry>
2076               </row>
2077               <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2078               </row>
2079
2080               <row><entry></entry></row>
2081               <row>
2082                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant>&nbsp;</entry>
2083                 <entry>integer</entry>
2084               </row>
2085               <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2086 refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2087 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2088               </row>
2089
2090               <row><entry></entry></row>
2091               <row>
2092                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant>&nbsp;</entry>
2093                 <entry>boolean</entry>
2094               </row>
2095               <row><entry spanname="descr">Frame level rate control enable.
2096 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2097 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2098 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2099 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2100 Applicable to encoders.</entry>
2101               </row>
2102
2103               <row><entry></entry></row>
2104               <row>
2105                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>&nbsp;</entry>
2106                 <entry>boolean</entry>
2107               </row>
2108               <row><entry spanname="descr">Macroblock level rate control enable.
2109 Applicable to the MPEG4 and H264 encoders.</entry>
2110               </row>
2111
2112               <row><entry></entry></row>
2113               <row>
2114                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant>&nbsp;</entry>
2115                 <entry>boolean</entry>
2116               </row>
2117               <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2118               </row>
2119
2120               <row><entry></entry></row>
2121               <row>
2122                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>&nbsp;</entry>
2123                 <entry>integer</entry>
2124               </row>
2125               <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2126               </row>
2127
2128               <row><entry></entry></row>
2129               <row>
2130                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>&nbsp;</entry>
2131                 <entry>integer</entry>
2132               </row>
2133               <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2134               </row>
2135
2136               <row><entry></entry></row>
2137               <row>
2138                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant>&nbsp;</entry>
2139                 <entry>integer</entry>
2140               </row>
2141               <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2142               </row>
2143
2144               <row><entry></entry></row>
2145               <row>
2146                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant>&nbsp;</entry>
2147                 <entry>integer</entry>
2148               </row>
2149               <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2150               </row>
2151
2152               <row><entry></entry></row>
2153               <row>
2154                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant>&nbsp;</entry>
2155                 <entry>integer</entry>
2156               </row>
2157               <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2158               </row>
2159
2160               <row><entry></entry></row>
2161               <row>
2162                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant>&nbsp;</entry>
2163                 <entry>integer</entry>
2164               </row>
2165               <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2166               </row>
2167
2168               <row><entry></entry></row>
2169               <row>
2170                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant>&nbsp;</entry>
2171                 <entry>integer</entry>
2172               </row>
2173               <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2174               </row>
2175
2176               <row><entry></entry></row>
2177               <row>
2178                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant>&nbsp;</entry>
2179                 <entry>integer</entry>
2180               </row>
2181               <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2182               </row>
2183
2184               <row><entry></entry></row>
2185               <row>
2186                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant>&nbsp;</entry>
2187                 <entry>integer</entry>
2188               </row>
2189               <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2190               </row>
2191
2192               <row><entry></entry></row>
2193               <row>
2194                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant>&nbsp;</entry>
2195                 <entry>integer</entry>
2196               </row>
2197               <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2198               </row>
2199
2200               <row><entry></entry></row>
2201               <row>
2202                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant>&nbsp;</entry>
2203                 <entry>integer</entry>
2204               </row>
2205               <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2206               </row>
2207
2208               <row><entry></entry></row>
2209               <row>
2210                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant>&nbsp;</entry>
2211                 <entry>integer</entry>
2212               </row>
2213               <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2214               </row>
2215
2216               <row><entry></entry></row>
2217               <row>
2218                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant>&nbsp;</entry>
2219                 <entry>integer</entry>
2220               </row>
2221               <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2222               </row>
2223
2224               <row><entry></entry></row>
2225               <row>
2226                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant>&nbsp;</entry>
2227                 <entry>integer</entry>
2228               </row>
2229               <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2230               </row>
2231
2232               <row><entry></entry></row>
2233               <row>
2234                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant>&nbsp;</entry>
2235                 <entry>integer</entry>
2236               </row>
2237               <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2238               </row>
2239
2240               <row><entry></entry></row>
2241               <row>
2242                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant>&nbsp;</entry>
2243                 <entry>integer</entry>
2244               </row>
2245               <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2246 The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2247 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2248 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2249 encoder or editing process may produce.".
2250 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2251               </row>
2252
2253               <row><entry></entry></row>
2254               <row id="v4l2-mpeg-video-vbv-delay">
2255                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant>&nbsp;</entry>
2256                 <entry>integer</entry>
2257               </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2258 VBV buffer control.</entry>
2259               </row>
2260
2261                   <row><entry></entry></row>
2262               <row id="v4l2-mpeg-video-hor-search-range">
2263                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MV_H_SEARCH_RANGE</constant>&nbsp;</entry>
2264                 <entry>integer</entry>
2265               </row>
2266                 <row><entry spanname="descr">Horizontal search range defines maximum horizontal search area in pixels
2267 to search and match for the present Macroblock (MB) in the reference picture. This V4L2 control macro is used to set
2268 horizontal search range for motion estimation module in video encoder.</entry>
2269               </row>
2270
2271                  <row><entry></entry></row>
2272               <row id="v4l2-mpeg-video-vert-search-range">
2273                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE</constant>&nbsp;</entry>
2274                 <entry>integer</entry>
2275               </row>
2276                 <row><entry spanname="descr">Vertical search range defines maximum vertical search area in pixels
2277 to search and match for the present Macroblock (MB) in the reference picture. This V4L2 control macro is used to set
2278 vertical search range for motion estimation module in video encoder.</entry>
2279               </row>
2280
2281               <row><entry></entry></row>
2282               <row>
2283                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant>&nbsp;</entry>
2284                 <entry>integer</entry>
2285               </row>
2286               <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2287 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2288 Applicable to the H264 encoder.</entry>
2289               </row>
2290
2291               <row><entry></entry></row>
2292               <row>
2293                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant>&nbsp;</entry>
2294                 <entry>integer</entry>
2295               </row>
2296               <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2297 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2298 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2299 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2300 previous frames. Applicable to the H264 encoder.</entry>
2301               </row>
2302
2303               <row><entry></entry></row>
2304               <row id="v4l2-mpeg-video-header-mode">
2305                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant>&nbsp;</entry>
2306                 <entry>enum&nbsp;v4l2_mpeg_video_header_mode</entry>
2307               </row>
2308               <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2309 it returned together with the first frame. Applicable to encoders.
2310 Possible values are:</entry>
2311               </row>
2312               <row>
2313                 <entrytbl spanname="descr" cols="2">
2314                   <tbody valign="top">
2315                     <row>
2316                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant>&nbsp;</entry>
2317                       <entry>The stream header is returned separately in the first buffer.</entry>
2318                     </row>
2319                     <row>
2320                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant>&nbsp;</entry>
2321                       <entry>The stream header is returned together with the first encoded frame.</entry>
2322                     </row>
2323                   </tbody>
2324                 </entrytbl>
2325               </row>
2326               <row><entry></entry></row>
2327               <row>
2328                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER</constant>&nbsp;</entry>
2329                 <entry>boolean</entry>
2330               </row><row><entry spanname="descr">Repeat the video sequence headers. Repeating these
2331 headers makes random access to the video stream easier. Applicable to the MPEG1, 2 and 4 encoder.</entry>
2332               </row>
2333               <row>
2334                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant>&nbsp;</entry>
2335                 <entry>boolean</entry>
2336               </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2337 Applicable to the MPEG4 decoder.</entry>
2338               </row>
2339               <row><entry></entry></row>
2340               <row>
2341                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant>&nbsp;</entry>
2342                 <entry>integer</entry>
2343               </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2344               </row>
2345               <row><entry></entry></row>
2346               <row>
2347                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant>&nbsp;</entry>
2348                 <entry>integer</entry>
2349               </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2350               </row>
2351
2352               <row><entry></entry></row>
2353               <row>
2354                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant>&nbsp;</entry>
2355                 <entry>boolean</entry>
2356               </row>
2357               <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2358 The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2359               </row>
2360
2361               <row><entry></entry></row>
2362               <row>
2363                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant>&nbsp;</entry>
2364                 <entry>boolean</entry>
2365               </row>
2366               <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2367 Applicable to the H264 encoder.</entry>
2368               </row>
2369
2370               <row><entry></entry></row>
2371               <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2372                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant>&nbsp;</entry>
2373                 <entry>enum&nbsp;v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2374               </row>
2375               <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2376 Applicable to the H264 encoder.
2377 Possible values are:</entry>
2378               </row>
2379               <row>
2380                 <entrytbl spanname="descr" cols="2">
2381                   <tbody valign="top">
2382                     <row>
2383                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant>&nbsp;</entry>
2384                       <entry>Pixels are alternatively from L and R.</entry>
2385                     </row>
2386                     <row>
2387                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant>&nbsp;</entry>
2388                       <entry>L and R are interlaced by column.</entry>
2389                     </row>
2390                     <row>
2391                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant>&nbsp;</entry>
2392                       <entry>L and R are interlaced by row.</entry>
2393                     </row>
2394                     <row>
2395                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant>&nbsp;</entry>
2396                       <entry>L is on the left, R on the right.</entry>
2397                     </row>
2398                     <row>
2399                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant>&nbsp;</entry>
2400                       <entry>L is on top, R on bottom.</entry>
2401                     </row>
2402                     <row>
2403                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant>&nbsp;</entry>
2404                       <entry>One view per frame.</entry>
2405                     </row>
2406                   </tbody>
2407                 </entrytbl>
2408               </row>
2409
2410               <row><entry></entry></row>
2411               <row>
2412                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant>&nbsp;</entry>
2413                 <entry>boolean</entry>
2414               </row>
2415               <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2416 used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2417               </row>
2418
2419               <row><entry></entry></row>
2420               <row id="v4l2-mpeg-video-h264-fmo-map-type">
2421                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant>&nbsp;</entry>
2422                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_map_type</entry>
2423               </row>
2424               <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2425 Applicable to the H264 encoder.
2426 Possible values are:</entry>
2427               </row>
2428               <row>
2429                 <entrytbl spanname="descr" cols="2">
2430                   <tbody valign="top">
2431                     <row>
2432                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant>&nbsp;</entry>
2433                       <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2434                     </row>
2435                     <row>
2436                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant>&nbsp;</entry>
2437                       <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2438                     </row>
2439                     <row>
2440                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant>&nbsp;</entry>
2441                       <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2442                     </row>
2443                     <row>
2444                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant>&nbsp;</entry>
2445                       <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2446                     </row>
2447                     <row>
2448                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant>&nbsp;</entry>
2449                       <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2450                     </row>
2451                     <row>
2452                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant>&nbsp;</entry>
2453                       <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2454                     </row>
2455                     <row>
2456                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant>&nbsp;</entry>
2457                       <entry>User defined map type.</entry>
2458                     </row>
2459                   </tbody>
2460                 </entrytbl>
2461               </row>
2462
2463               <row><entry></entry></row>
2464               <row>
2465                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant>&nbsp;</entry>
2466                 <entry>integer</entry>
2467               </row>
2468               <row><entry spanname="descr">Number of slice groups in FMO.
2469 Applicable to the H264 encoder.</entry>
2470               </row>
2471
2472               <row><entry></entry></row>
2473               <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2474                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant>&nbsp;</entry>
2475                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_change_dir</entry>
2476               </row>
2477               <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2478 Applicable to the H264 encoder.
2479 Possible values are:</entry>
2480               </row>
2481               <row>
2482                 <entrytbl spanname="descr" cols="2">
2483                   <tbody valign="top">
2484                     <row>
2485                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant>&nbsp;</entry>
2486                       <entry>Raster scan or wipe right.</entry>
2487                     </row>
2488                     <row>
2489                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant>&nbsp;</entry>
2490                       <entry>Reverse raster scan or wipe left.</entry>
2491                     </row>
2492                   </tbody>
2493                 </entrytbl>
2494               </row>
2495
2496               <row><entry></entry></row>
2497               <row>
2498                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant>&nbsp;</entry>
2499                 <entry>integer</entry>
2500               </row>
2501               <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2502 Applicable to the H264 encoder.</entry>
2503               </row>
2504
2505               <row><entry></entry></row>
2506               <row>
2507                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant>&nbsp;</entry>
2508                 <entry>integer</entry>
2509               </row>
2510               <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2511 Applicable to the H264 encoder.</entry>
2512               </row>
2513
2514               <row><entry></entry></row>
2515               <row>
2516                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant>&nbsp;</entry>
2517                 <entry>boolean</entry>
2518               </row>
2519               <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2520 Applicable to the H264 encoder.</entry>
2521               </row>
2522
2523               <row><entry></entry></row>
2524               <row>
2525                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant>&nbsp;</entry>
2526                 <entry>integer</entry>
2527               </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2528 The supplied 32-bit integer is interpreted as follows (bit
2529 0 = least significant bit):</entry>
2530               </row>
2531               <row>
2532                 <entrytbl spanname="descr" cols="2">
2533                   <tbody valign="top">
2534                     <row>
2535                       <entry>Bit 0:15</entry>
2536                       <entry>Slice ID</entry>
2537                     </row>
2538                     <row>
2539                       <entry>Bit 16:32</entry>
2540                       <entry>Slice position or order</entry>
2541                     </row>
2542                   </tbody>
2543                 </entrytbl>
2544               </row>
2545
2546               <row><entry></entry></row>
2547               <row>
2548                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant>&nbsp;</entry>
2549                 <entry>boolean</entry>
2550               </row>
2551               <row><entry spanname="descr">Enables H264 hierarchical coding.
2552 Applicable to the H264 encoder.</entry>
2553               </row>
2554
2555               <row><entry></entry></row>
2556               <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2557                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant>&nbsp;</entry>
2558                 <entry>enum&nbsp;v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2559               </row>
2560               <row><entry spanname="descr">Specifies the hierarchical coding type.
2561 Applicable to the H264 encoder.
2562 Possible values are:</entry>
2563               </row>
2564               <row>
2565                 <entrytbl spanname="descr" cols="2">
2566                   <tbody valign="top">
2567                     <row>
2568                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant>&nbsp;</entry>
2569                       <entry>Hierarchical B coding.</entry>
2570                     </row>
2571                     <row>
2572                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant>&nbsp;</entry>
2573                       <entry>Hierarchical P coding.</entry>
2574                     </row>
2575                   </tbody>
2576                 </entrytbl>
2577               </row>
2578
2579               <row><entry></entry></row>
2580               <row>
2581                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant>&nbsp;</entry>
2582                 <entry>integer</entry>
2583               </row>
2584               <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2585 Applicable to the H264 encoder.</entry>
2586               </row>
2587
2588               <row><entry></entry></row>
2589               <row>
2590                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant>&nbsp;</entry>
2591                 <entry>integer</entry>
2592               </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2593 The supplied 32-bit integer is interpreted as follows (bit
2594 0 = least significant bit):</entry>
2595               </row>
2596               <row>
2597                 <entrytbl spanname="descr" cols="2">
2598                   <tbody valign="top">
2599                     <row>
2600                       <entry>Bit 0:15</entry>
2601                       <entry>QP value</entry>
2602                     </row>
2603                     <row>
2604                       <entry>Bit 16:32</entry>
2605                       <entry>Layer number</entry>
2606                     </row>
2607                   </tbody>
2608                 </entrytbl>
2609               </row>
2610
2611             </tbody>
2612           </tgroup>
2613         </table>
2614       </section>
2615
2616       <section>
2617         <title>MFC 5.1 MPEG Controls</title>
2618
2619         <para>The following MPEG class controls deal with MPEG
2620 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2621 in the S5P family of SoCs by Samsung.
2622 </para>
2623
2624         <table pgwide="1" frame="none" id="mfc51-control-id">
2625           <title>MFC 5.1 Control IDs</title>
2626           <tgroup cols="4">
2627             <colspec colname="c1" colwidth="1*" />
2628             <colspec colname="c2" colwidth="6*" />
2629             <colspec colname="c3" colwidth="2*" />
2630             <colspec colname="c4" colwidth="6*" />
2631             <spanspec namest="c1" nameend="c2" spanname="id" />
2632             <spanspec namest="c2" nameend="c4" spanname="descr" />
2633             <thead>
2634               <row>
2635                 <entry spanname="id" align="left">ID</entry>
2636                 <entry align="left">Type</entry>
2637               </row><row><entry spanname="descr" align="left">Description</entry>
2638               </row>
2639             </thead>
2640             <tbody valign="top">
2641               <row><entry></entry></row>
2642               <row>
2643                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant>&nbsp;</entry>
2644                 <entry>integer</entry>
2645               </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2646 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2647 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2648 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2649 Applicable to the H264 decoder.
2650               </entry>
2651               </row>
2652               <row><entry></entry></row>
2653               <row>
2654                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>&nbsp;</entry>
2655                 <entry>integer</entry>
2656               </row><row><entry spanname="descr">Display delay value for H264 decoder.
2657 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2658 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2659 as a reference picture for subsequent frames.
2660 </entry>
2661               </row>
2662               <row><entry></entry></row>
2663               <row>
2664                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant>&nbsp;</entry>
2665                 <entry>integer</entry>
2666               </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2667 Applicable to the H264 encoder.</entry>
2668               </row>
2669               <row><entry></entry></row>
2670               <row>
2671                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant>&nbsp;</entry>
2672                 <entry>boolean</entry>
2673               </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2674 Applicable to encoders.</entry>
2675               </row>
2676               <row><entry></entry></row>
2677               <row>
2678                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant>&nbsp;</entry>
2679                 <entry>integer</entry>
2680               </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2681 0 = least significant bit):</entry>
2682               </row>
2683               <row>
2684                 <entrytbl spanname="descr" cols="2">
2685                   <tbody valign="top">
2686                     <row>
2687                       <entry>Bit 0:7</entry>
2688                       <entry>V chrominance information</entry>
2689                     </row>
2690                     <row>
2691                       <entry>Bit 8:15</entry>
2692                       <entry>U chrominance information</entry>
2693                     </row>
2694                     <row>
2695                       <entry>Bit 16:23</entry>
2696                       <entry>Y luminance information</entry>
2697                     </row>
2698                     <row>
2699                       <entry>Bit 24:31</entry>
2700                       <entry>Must be zero.</entry>
2701                     </row>
2702                   </tbody>
2703                 </entrytbl>
2704               </row>
2705               <row><entry></entry></row>
2706               <row>
2707                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant>&nbsp;</entry>
2708                 <entry>integer</entry>
2709               </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2710 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2711 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2712 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2713 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2714 </entry>
2715               </row>
2716               <row><entry></entry></row>
2717               <row>
2718                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant>&nbsp;</entry>
2719                 <entry>boolean</entry>
2720               </row><row><entry spanname="descr">Adaptive rate control for dark region.
2721 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2722 Applicable to the H264 encoder.</entry>
2723               </row>
2724               <row><entry></entry></row>
2725               <row>
2726                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant>&nbsp;</entry>
2727                 <entry>boolean</entry>
2728               </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2729 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2730 Applicable to the H264 encoder.</entry>
2731               </row>
2732               <row><entry></entry></row>
2733               <row>
2734                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant>&nbsp;</entry>
2735                 <entry>boolean</entry>
2736               </row><row><entry spanname="descr">Adaptive rate control for static region.
2737 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2738 Applicable to the H264 encoder.</entry>
2739               </row>
2740               <row><entry></entry></row>
2741               <row>
2742                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant>&nbsp;</entry>
2743                 <entry>boolean</entry>
2744               </row><row><entry spanname="descr">Adaptive rate control for activity region.
2745 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2746 Applicable to the H264 encoder.</entry>
2747               </row>
2748               <row><entry></entry></row>
2749               <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2750                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant>&nbsp;</entry>
2751                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2752               </row>
2753               <row><entry spanname="descr">
2754 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2755 a chosen data limit then the frame will be skipped.
2756 Possible values are:</entry>
2757               </row>
2758               <row>
2759                 <entrytbl spanname="descr" cols="2">
2760                   <tbody valign="top">
2761                     <row>
2762                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant>&nbsp;</entry>
2763                       <entry>Frame skip mode is disabled.</entry>
2764                     </row>
2765                     <row>
2766                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant>&nbsp;</entry>
2767                       <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2768                     </row>
2769                     <row>
2770                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant>&nbsp;</entry>
2771                       <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2772                     </row>
2773                   </tbody>
2774                 </entrytbl>
2775               </row>
2776               <row><entry></entry></row>
2777               <row>
2778                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant>&nbsp;</entry>
2779                 <entry>integer</entry>
2780               </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2781 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2782 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2783 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2784 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2785 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2786 the stream will meet tight bandwidth contraints. Applicable to encoders.
2787 </entry>
2788               </row>
2789               <row><entry></entry></row>
2790               <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2791                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant>&nbsp;</entry>
2792                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_force_frame_type</entry>
2793               </row>
2794               <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2795 Possible values are:</entry>
2796               </row>
2797               <row>
2798                 <entrytbl spanname="descr" cols="2">
2799                   <tbody valign="top">
2800                     <row>
2801                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant>&nbsp;</entry>
2802                       <entry>Forcing a specific frame type disabled.</entry>
2803                     </row>
2804                     <row>
2805                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant>&nbsp;</entry>
2806                       <entry>Force an I-frame.</entry>
2807                     </row>
2808                     <row>
2809                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant>&nbsp;</entry>
2810                       <entry>Force a non-coded frame.</entry>
2811                     </row>
2812                   </tbody>
2813                 </entrytbl>
2814               </row>
2815             </tbody>
2816           </tgroup>
2817         </table>
2818       </section>
2819
2820       <section>
2821         <title>CX2341x MPEG Controls</title>
2822
2823         <para>The following MPEG class controls deal with MPEG
2824 encoding settings that are specific to the Conexant CX23415 and
2825 CX23416 MPEG encoding chips.</para>
2826
2827         <table pgwide="1" frame="none" id="cx2341x-control-id">
2828           <title>CX2341x Control IDs</title>
2829           <tgroup cols="4">
2830             <colspec colname="c1" colwidth="1*" />
2831             <colspec colname="c2" colwidth="6*" />
2832             <colspec colname="c3" colwidth="2*" />
2833             <colspec colname="c4" colwidth="6*" />
2834             <spanspec namest="c1" nameend="c2" spanname="id" />
2835             <spanspec namest="c2" nameend="c4" spanname="descr" />
2836             <thead>
2837               <row>
2838                 <entry spanname="id" align="left">ID</entry>
2839                 <entry align="left">Type</entry>
2840               </row><row><entry spanname="descr" align="left">Description</entry>
2841               </row>
2842             </thead>
2843             <tbody valign="top">
2844               <row><entry></entry></row>
2845               <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2846                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant>&nbsp;</entry>
2847                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2848               </row><row><entry spanname="descr">Sets the Spatial
2849 Filter mode (default <constant>MANUAL</constant>). Possible values
2850 are:</entry>
2851               </row>
2852               <row>
2853                 <entrytbl spanname="descr" cols="2">
2854                   <tbody valign="top">
2855                     <row>
2856                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2857                       <entry>Choose the filter manually</entry>
2858                     </row>
2859                     <row>
2860                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2861                       <entry>Choose the filter automatically</entry>
2862                     </row>
2863                   </tbody>
2864                 </entrytbl>
2865               </row>
2866               <row><entry></entry></row>
2867               <row>
2868                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant>&nbsp;</entry>
2869                 <entry>integer&nbsp;(0-15)</entry>
2870               </row><row><entry spanname="descr">The setting for the
2871 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2872               </row>
2873               <row><entry></entry></row>
2874               <row id="luma-spatial-filter-type">
2875                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2876                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2877               </row><row><entry spanname="descr">Select the algorithm
2878 to use for the Luma Spatial Filter (default
2879 <constant>1D_HOR</constant>). Possible values:</entry>
2880               </row>
2881               <row>
2882                 <entrytbl spanname="descr" cols="2">
2883                   <tbody valign="top">
2884                     <row>
2885                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2886                       <entry>No filter</entry>
2887                     </row>
2888                     <row>
2889                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2890                       <entry>One-dimensional horizontal</entry>
2891                     </row>
2892                     <row>
2893                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant>&nbsp;</entry>
2894                       <entry>One-dimensional vertical</entry>
2895                     </row>
2896                     <row>
2897                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant>&nbsp;</entry>
2898                       <entry>Two-dimensional separable</entry>
2899                     </row>
2900                     <row>
2901                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant>&nbsp;</entry>
2902                       <entry>Two-dimensional symmetrical
2903 non-separable</entry>
2904                     </row>
2905                   </tbody>
2906                 </entrytbl>
2907               </row>
2908               <row><entry></entry></row>
2909               <row id="chroma-spatial-filter-type">
2910                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2911                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2912               </row><row><entry spanname="descr">Select the algorithm
2913 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2914 Possible values are:</entry>
2915               </row>
2916               <row>
2917                 <entrytbl spanname="descr" cols="2">
2918                   <tbody valign="top">
2919                     <row>
2920                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2921                       <entry>No filter</entry>
2922                     </row>
2923                     <row>
2924                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2925                       <entry>One-dimensional horizontal</entry>
2926                     </row>
2927                   </tbody>
2928                 </entrytbl>
2929               </row>
2930               <row><entry></entry></row>
2931               <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2932                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant>&nbsp;</entry>
2933                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2934               </row><row><entry spanname="descr">Sets the Temporal
2935 Filter mode (default <constant>MANUAL</constant>). Possible values
2936 are:</entry>
2937               </row>
2938               <row>
2939                 <entrytbl spanname="descr" cols="2">
2940                   <tbody valign="top">
2941                     <row>
2942                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2943                       <entry>Choose the filter manually</entry>
2944                     </row>
2945                     <row>
2946                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2947                       <entry>Choose the filter automatically</entry>
2948                     </row>
2949                   </tbody>
2950                 </entrytbl>
2951               </row>
2952               <row><entry></entry></row>
2953               <row>
2954                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant>&nbsp;</entry>
2955                 <entry>integer&nbsp;(0-31)</entry>
2956               </row><row><entry spanname="descr">The setting for the
2957 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2958 capturing and 0 for scaled capturing.)</entry>
2959               </row>
2960               <row><entry></entry></row>
2961               <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2962                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant>&nbsp;</entry>
2963                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2964               </row><row><entry spanname="descr">Median Filter Type
2965 (default <constant>OFF</constant>). Possible values are:</entry>
2966               </row>
2967               <row>
2968                 <entrytbl spanname="descr" cols="2">
2969                   <tbody valign="top">
2970                     <row>
2971                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2972                       <entry>No filter</entry>
2973                     </row>
2974                     <row>
2975                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant>&nbsp;</entry>
2976                       <entry>Horizontal filter</entry>
2977                     </row>
2978                     <row>
2979                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant>&nbsp;</entry>
2980                       <entry>Vertical filter</entry>
2981                     </row>
2982                     <row>
2983                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant>&nbsp;</entry>
2984                       <entry>Horizontal and vertical filter</entry>
2985                     </row>
2986                     <row>
2987                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant>&nbsp;</entry>
2988                       <entry>Diagonal filter</entry>
2989                     </row>
2990                   </tbody>
2991                 </entrytbl>
2992               </row>
2993               <row><entry></entry></row>
2994               <row>
2995                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2996                 <entry>integer&nbsp;(0-255)</entry>
2997               </row><row><entry spanname="descr">Threshold above which
2998 the luminance median filter is enabled (default 0)</entry>
2999               </row>
3000               <row><entry></entry></row>
3001               <row>
3002                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3003                 <entry>integer&nbsp;(0-255)</entry>
3004               </row><row><entry spanname="descr">Threshold below which
3005 the luminance median filter is enabled (default 255)</entry>
3006               </row>
3007               <row><entry></entry></row>
3008               <row>
3009                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
3010                 <entry>integer&nbsp;(0-255)</entry>
3011               </row><row><entry spanname="descr">Threshold above which
3012 the chroma median filter is enabled (default 0)</entry>
3013               </row>
3014               <row><entry></entry></row>
3015               <row>
3016                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3017                 <entry>integer&nbsp;(0-255)</entry>
3018               </row><row><entry spanname="descr">Threshold below which
3019 the chroma median filter is enabled (default 255)</entry>
3020               </row>
3021               <row><entry></entry></row>
3022               <row>
3023                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant>&nbsp;</entry>
3024                 <entry>boolean</entry>
3025               </row>
3026               <row><entry spanname="descr">The CX2341X MPEG encoder
3027 can insert one empty MPEG-2 PES packet into the stream between every
3028 four video frames. The packet size is 2048 bytes, including the
3029 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
3030 (private stream 2). The payload consists of 0x00 bytes, to be filled
3031 in by the application. 0 = do not insert, 1 = insert packets.</entry>
3032               </row>
3033             </tbody>
3034           </tgroup>
3035         </table>
3036       </section>
3037
3038     <section>
3039       <title>VPX Control Reference</title>
3040
3041       <para>The VPX controls include controls for encoding parameters
3042       of VPx video codec.</para>
3043
3044       <table pgwide="1" frame="none" id="vpx-control-id">
3045       <title>VPX Control IDs</title>
3046
3047       <tgroup cols="4">
3048         <colspec colname="c1" colwidth="1*" />
3049         <colspec colname="c2" colwidth="6*" />
3050         <colspec colname="c3" colwidth="2*" />
3051         <colspec colname="c4" colwidth="6*" />
3052         <spanspec namest="c1" nameend="c2" spanname="id" />
3053         <spanspec namest="c2" nameend="c4" spanname="descr" />
3054         <thead>
3055           <row>
3056             <entry spanname="id" align="left">ID</entry>
3057             <entry align="left">Type</entry>
3058           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3059           </row>
3060         </thead>
3061         <tbody valign="top">
3062           <row><entry></entry></row>
3063
3064               <row><entry></entry></row>
3065               <row id="v4l2-vpx-num-partitions">
3066                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS</constant></entry>
3067                 <entry>enum v4l2_vp8_num_partitions</entry>
3068               </row>
3069               <row><entry spanname="descr">The number of token partitions to use in VP8 encoder.
3070 Possible values are:</entry>
3071               </row>
3072               <row>
3073                 <entrytbl spanname="descr" cols="2">
3074                   <tbody valign="top">
3075                     <row>
3076                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_PARTITION</constant></entry>
3077                       <entry>1 coefficient partition</entry>
3078                     </row>
3079                     <row>
3080                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_PARTITIONS</constant></entry>
3081                       <entry>2 coefficient partitions</entry>
3082                     </row>
3083                     <row>
3084                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_4_PARTITIONS</constant></entry>
3085                       <entry>4 coefficient partitions</entry>
3086                     </row>
3087                     <row>
3088                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_8_PARTITIONS</constant></entry>
3089                       <entry>8 coefficient partitions</entry>
3090                     </row>
3091                   </tbody>
3092                 </entrytbl>
3093               </row>
3094
3095               <row><entry></entry></row>
3096               <row>
3097                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_IMD_DISABLE_4X4</constant></entry>
3098                 <entry>boolean</entry>
3099               </row>
3100               <row><entry spanname="descr">Setting this prevents intra 4x4 mode in the intra mode decision.</entry>
3101               </row>
3102
3103               <row><entry></entry></row>
3104               <row id="v4l2-vpx-num-ref-frames">
3105                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_REF_FRAMES</constant></entry>
3106                 <entry>enum v4l2_vp8_num_ref_frames</entry>
3107               </row>
3108               <row><entry spanname="descr">The number of reference pictures for encoding P frames.
3109 Possible values are:</entry>
3110               </row>
3111               <row>
3112                 <entrytbl spanname="descr" cols="2">
3113                   <tbody valign="top">
3114                     <row>
3115                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_REF_FRAME</constant></entry>
3116                       <entry>Last encoded frame will be searched</entry>
3117                     </row>
3118                     <row>
3119                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_REF_FRAME</constant></entry>
3120                       <entry>Two frames will be searched among the last encoded frame, the golden frame
3121 and the alternate reference (altref) frame. The encoder implementation will decide which two are chosen.</entry>
3122                     </row>
3123                     <row>
3124                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_3_REF_FRAME</constant></entry>
3125                       <entry>The last encoded frame, the golden frame and the altref frame will be searched.</entry>
3126                     </row>
3127                   </tbody>
3128                 </entrytbl>
3129               </row>
3130
3131               <row><entry></entry></row>
3132               <row>
3133                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_LEVEL</constant></entry>
3134                 <entry>integer</entry>
3135               </row>
3136               <row><entry spanname="descr">Indicates the loop filter level. The adjustment of the loop
3137 filter level is done via a delta value against a baseline loop filter value.</entry>
3138               </row>
3139
3140               <row><entry></entry></row>
3141               <row>
3142                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_SHARPNESS</constant></entry>
3143                 <entry>integer</entry>
3144               </row>
3145               <row><entry spanname="descr">This parameter affects the loop filter. Anything above
3146 zero weakens the deblocking effect on the loop filter.</entry>
3147               </row>
3148
3149               <row><entry></entry></row>
3150               <row>
3151                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD</constant></entry>
3152                 <entry>integer</entry>
3153               </row>
3154               <row><entry spanname="descr">Sets the refresh period for the golden frame. The period is defined
3155 in number of frames. For a value of 'n', every nth frame starting from the first key frame will be taken as a golden frame.
3156 For eg. for encoding sequence of 0, 1, 2, 3, 4, 5, 6, 7 where the golden frame refresh period is set as 4, the frames
3157 0, 4, 8 etc will be taken as the golden frames as frame 0 is always a key frame.</entry>
3158               </row>
3159
3160               <row><entry></entry></row>
3161               <row id="v4l2-vpx-golden-frame-sel">
3162                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_SEL</constant></entry>
3163                 <entry>enum v4l2_vp8_golden_frame_sel</entry>
3164               </row>
3165               <row><entry spanname="descr">Selects the golden frame for encoding.
3166 Possible values are:</entry>
3167               </row>
3168               <row>
3169                 <entrytbl spanname="descr" cols="2">
3170                   <tbody valign="top">
3171                     <row>
3172                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_PREV</constant></entry>
3173                       <entry>Use the (n-2)th frame as a golden frame, current frame index being 'n'.</entry>
3174                     </row>
3175                     <row>
3176                       <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_REF_PERIOD</constant></entry>
3177                       <entry>Use the previous specific frame indicated by
3178 V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD as a golden frame.</entry>
3179                     </row>
3180                   </tbody>
3181                 </entrytbl>
3182               </row>
3183
3184               <row><entry></entry></row>
3185               <row>
3186                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MIN_QP</constant></entry>
3187                 <entry>integer</entry>
3188               </row>
3189               <row><entry spanname="descr">Minimum quantization parameter for VP8.</entry>
3190               </row>
3191
3192               <row><entry></entry></row>
3193               <row>
3194                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MAX_QP</constant></entry>
3195                 <entry>integer</entry>
3196               </row>
3197               <row><entry spanname="descr">Maximum quantization parameter for VP8.</entry>
3198               </row>
3199
3200               <row><entry></entry></row>
3201               <row>
3202                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_I_FRAME_QP</constant>&nbsp;</entry>
3203                 <entry>integer</entry>
3204               </row>
3205               <row><entry spanname="descr">Quantization parameter for an I frame for VP8.</entry>
3206               </row>
3207
3208               <row><entry></entry></row>
3209               <row>
3210                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP</constant>&nbsp;</entry>
3211                 <entry>integer</entry>
3212               </row>
3213               <row><entry spanname="descr">Quantization parameter for a P frame for VP8.</entry>
3214               </row>
3215
3216               <row><entry></entry></row>
3217               <row>
3218                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_PROFILE</constant>&nbsp;</entry>
3219                 <entry>integer</entry>
3220               </row>
3221               <row><entry spanname="descr">Select the desired profile for VPx encoder.
3222 Acceptable values are 0, 1, 2 and 3 corresponding to encoder profiles 0, 1, 2 and 3.</entry>
3223               </row>
3224
3225           <row><entry></entry></row>
3226         </tbody>
3227       </tgroup>
3228       </table>
3229
3230       </section>
3231     </section>
3232
3233     <section id="camera-controls">
3234       <title>Camera Control Reference</title>
3235
3236       <para>The Camera class includes controls for mechanical (or
3237 equivalent digital) features of a device such as controllable lenses
3238 or sensors.</para>
3239
3240     <table pgwide="1" frame="none" id="camera-control-id">
3241       <title>Camera Control IDs</title>
3242       <tgroup cols="4">
3243         <colspec colname="c1" colwidth="1*" />
3244         <colspec colname="c2" colwidth="6*" />
3245         <colspec colname="c3" colwidth="2*" />
3246         <colspec colname="c4" colwidth="6*" />
3247         <spanspec namest="c1" nameend="c2" spanname="id" />
3248         <spanspec namest="c2" nameend="c4" spanname="descr" />
3249         <thead>
3250           <row>
3251             <entry spanname="id" align="left">ID</entry>
3252             <entry align="left">Type</entry>
3253           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3254           </row>
3255         </thead>
3256         <tbody valign="top">
3257           <row><entry></entry></row>
3258           <row>
3259             <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant>&nbsp;</entry>
3260             <entry>class</entry>
3261           </row><row><entry spanname="descr">The Camera class
3262 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3263 description of this control class.</entry>
3264           </row>
3265           <row><entry></entry></row>
3266
3267           <row id="v4l2-exposure-auto-type">
3268             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant>&nbsp;</entry>
3269             <entry>enum&nbsp;v4l2_exposure_auto_type</entry>
3270           </row><row><entry spanname="descr">Enables automatic
3271 adjustments of the exposure time and/or iris aperture. The effect of
3272 manual changes of the exposure time or iris aperture while these
3273 features are enabled is undefined, drivers should ignore such
3274 requests. Possible values are:</entry>
3275           </row>
3276           <row>
3277             <entrytbl spanname="descr" cols="2">
3278               <tbody valign="top">
3279                 <row>
3280                   <entry><constant>V4L2_EXPOSURE_AUTO</constant>&nbsp;</entry>
3281                       <entry>Automatic exposure time, automatic iris
3282 aperture.</entry>
3283                 </row>
3284                 <row>
3285                   <entry><constant>V4L2_EXPOSURE_MANUAL</constant>&nbsp;</entry>
3286                   <entry>Manual exposure time, manual iris.</entry>
3287                 </row>
3288                 <row>
3289                   <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant>&nbsp;</entry>
3290                   <entry>Manual exposure time, auto iris.</entry>
3291                 </row>
3292                 <row>
3293                   <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant>&nbsp;</entry>
3294                   <entry>Auto exposure time, manual iris.</entry>
3295                 </row>
3296               </tbody>
3297             </entrytbl>
3298           </row>
3299           <row><entry></entry></row>
3300
3301           <row>
3302             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant>&nbsp;</entry>
3303             <entry>integer</entry>
3304           </row><row><entry spanname="descr">Determines the exposure
3305 time of the camera sensor. The exposure time is limited by the frame
3306 interval. Drivers should interpret the values as 100 &micro;s units,
3307 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3308 and 100000 for 10 seconds.</entry>
3309           </row>
3310           <row><entry></entry></row>
3311
3312           <row>
3313             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant>&nbsp;</entry>
3314             <entry>boolean</entry>
3315           </row><row><entry spanname="descr">When
3316 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3317 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3318 this control determines if the device may dynamically vary the frame
3319 rate. By default this feature is disabled (0) and the frame rate must
3320 remain constant.</entry>
3321           </row>
3322           <row><entry></entry></row>
3323
3324           <row>
3325             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant>&nbsp;</entry>
3326             <entry>integer menu</entry>
3327           </row><row><entry spanname="descr"> Determines the automatic
3328 exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3329 control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3330 or <constant>APERTURE_PRIORITY</constant>.
3331 It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3332 units, where the value 1000 stands for +1 EV.
3333 <para>Increasing the exposure compensation value is equivalent to decreasing
3334 the exposure value (EV) and will increase the amount of light at the image
3335 sensor. The camera performs the exposure compensation by adjusting absolute
3336 exposure time and/or aperture.</para></entry>
3337           </row>
3338           <row><entry></entry></row>
3339
3340           <row id="v4l2-exposure-metering">
3341             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant>&nbsp;</entry>
3342             <entry>enum&nbsp;v4l2_exposure_metering</entry>
3343           </row><row><entry spanname="descr">Determines how the camera measures
3344 the amount of light available for the frame exposure. Possible values are:</entry>
3345           </row>
3346           <row>
3347             <entrytbl spanname="descr" cols="2">
3348               <tbody valign="top">
3349                 <row>
3350                   <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant>&nbsp;</entry>
3351                   <entry>Use the light information coming from the entire frame
3352 and average giving no weighting to any particular portion of the metered area.
3353                   </entry>
3354                 </row>
3355                 <row>
3356                   <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant>&nbsp;</entry>
3357                   <entry>Average the light information coming from the entire frame
3358 giving priority to the center of the metered area.</entry>
3359                 </row>
3360                 <row>
3361                   <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant>&nbsp;</entry>
3362                   <entry>Measure only very small area at the center of the frame.</entry>
3363                 </row>
3364                 <row>
3365                   <entry><constant>V4L2_EXPOSURE_METERING_MATRIX</constant>&nbsp;</entry>
3366                   <entry>A multi-zone metering. The light intensity is measured
3367 in several points of the frame and the the results are combined. The
3368 algorithm of the zones selection and their significance in calculating the
3369 final value is device dependent.</entry>
3370                 </row>
3371               </tbody>
3372             </entrytbl>
3373           </row>
3374           <row><entry></entry></row>
3375
3376           <row>
3377             <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant>&nbsp;</entry>
3378             <entry>integer</entry>
3379           </row><row><entry spanname="descr">This control turns the
3380 camera horizontally by the specified amount. The unit is undefined. A
3381 positive value moves the camera to the right (clockwise when viewed
3382 from above), a negative value to the left. A value of zero does not
3383 cause motion. This is a write-only control.</entry>
3384           </row>
3385           <row><entry></entry></row>
3386
3387           <row>
3388             <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant>&nbsp;</entry>
3389             <entry>integer</entry>
3390           </row><row><entry spanname="descr">This control turns the
3391 camera vertically by the specified amount. The unit is undefined. A
3392 positive value moves the camera up, a negative value down. A value of
3393 zero does not cause motion. This is a write-only control.</entry>
3394           </row>
3395           <row><entry></entry></row>
3396
3397           <row>
3398             <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant>&nbsp;</entry>
3399             <entry>button</entry>
3400           </row><row><entry spanname="descr">When this control is set,
3401 the camera moves horizontally to the default position.</entry>
3402           </row>
3403           <row><entry></entry></row>
3404
3405           <row>
3406             <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant>&nbsp;</entry>
3407             <entry>button</entry>
3408           </row><row><entry spanname="descr">When this control is set,
3409 the camera moves vertically to the default position.</entry>
3410           </row>
3411           <row><entry></entry></row>
3412
3413           <row>
3414             <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant>&nbsp;</entry>
3415             <entry>integer</entry>
3416           </row><row><entry spanname="descr">This control
3417 turns the camera horizontally to the specified position. Positive
3418 values move the camera to the right (clockwise when viewed from above),
3419 negative values to the left. Drivers should interpret the values as arc
3420 seconds, with valid values between -180 * 3600 and +180 * 3600
3421 inclusive.</entry>
3422           </row>
3423           <row><entry></entry></row>
3424
3425           <row>
3426             <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant>&nbsp;</entry>
3427             <entry>integer</entry>
3428           </row><row><entry spanname="descr">This control
3429 turns the camera vertically to the specified position. Positive values
3430 move the camera up, negative values down. Drivers should interpret the
3431 values as arc seconds, with valid values between -180 * 3600 and +180
3432 * 3600 inclusive.</entry>
3433           </row>
3434           <row><entry></entry></row>
3435
3436           <row>
3437             <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant>&nbsp;</entry>
3438             <entry>integer</entry>
3439           </row><row><entry spanname="descr">This control sets the
3440 focal point of the camera to the specified position. The unit is
3441 undefined. Positive values set the focus closer to the camera,
3442 negative values towards infinity.</entry>
3443           </row>
3444           <row><entry></entry></row>
3445
3446           <row>
3447             <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant>&nbsp;</entry>
3448             <entry>integer</entry>
3449           </row><row><entry spanname="descr">This control moves the
3450 focal point of the camera by the specified amount. The unit is
3451 undefined. Positive values move the focus closer to the camera,
3452 negative values towards infinity. This is a write-only control.</entry>
3453           </row>
3454           <row><entry></entry></row>
3455
3456           <row>
3457             <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant>&nbsp;</entry>
3458             <entry>boolean</entry>
3459           </row><row><entry spanname="descr">Enables continuous automatic
3460 focus adjustments. The effect of manual focus adjustments while this feature
3461 is enabled is undefined, drivers should ignore such requests.</entry>
3462           </row>
3463           <row><entry></entry></row>
3464
3465           <row>
3466             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant>&nbsp;</entry>
3467             <entry>button</entry>
3468           </row><row><entry spanname="descr">Starts single auto focus process.
3469 The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3470 is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3471 such requests.</entry>
3472           </row>
3473           <row><entry></entry></row>
3474
3475           <row>
3476             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant>&nbsp;</entry>
3477             <entry>button</entry>
3478           </row><row><entry spanname="descr">Aborts automatic focusing
3479 started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3480 effective only when the continuous autofocus is disabled, that is when
3481 <constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3482 </constant> (0).</entry>
3483           </row>
3484           <row><entry></entry></row>
3485
3486           <row id="v4l2-auto-focus-status">
3487             <entry spanname="id">
3488               <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>&nbsp;</entry>
3489             <entry>bitmask</entry>
3490           </row>
3491           <row><entry spanname="descr">The automatic focus status. This is a read-only
3492           control.</entry>
3493           </row>
3494           <row>
3495             <entrytbl spanname="descr" cols="2">
3496               <tbody valign="top">
3497                 <row>
3498                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant>&nbsp;</entry>
3499                   <entry>Automatic focus is not active.</entry>
3500                 </row>
3501                 <row>
3502                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant>&nbsp;</entry>
3503                   <entry>Automatic focusing is in progress.</entry>
3504                 </row>
3505                 <row>
3506                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant>&nbsp;</entry>
3507                   <entry>Focus has been reached.</entry>
3508                 </row>
3509                 <row>
3510                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant>&nbsp;</entry>
3511                   <entry>Automatic focus has failed, the driver will not
3512                   transition from this state until another action is
3513                   performed by an application.</entry>
3514                 </row>
3515               </tbody>
3516             </entrytbl>
3517           </row>
3518           <row><entry spanname="descr">
3519 Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3520 </constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3521 control value.</entry>
3522           </row>
3523           <row><entry></entry></row>
3524
3525           <row id="v4l2-auto-focus-range">
3526             <entry spanname="id">
3527               <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant>&nbsp;</entry>
3528             <entry>enum&nbsp;v4l2_auto_focus_range</entry>
3529           </row>
3530           <row><entry spanname="descr">Determines auto focus distance range
3531 for which lens may be adjusted. </entry>
3532           </row>
3533           <row>
3534             <entrytbl spanname="descr" cols="2">
3535               <tbody valign="top">
3536                 <row>
3537                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant>&nbsp;</entry>
3538                   <entry>The camera automatically selects the focus range.</entry>
3539                 </row>
3540                 <row>
3541                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant>&nbsp;</entry>
3542                   <entry>Normal distance range, limited for best automatic focus
3543 performance.</entry>
3544                 </row>
3545                 <row>
3546                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant>&nbsp;</entry>
3547                   <entry>Macro (close-up) auto focus. The camera will
3548 use its minimum possible distance for auto focus.</entry>
3549                 </row>
3550                 <row>
3551                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant>&nbsp;</entry>
3552                   <entry>The lens is set to focus on an object at infinite distance.</entry>
3553                 </row>
3554               </tbody>
3555             </entrytbl>
3556           </row>
3557           <row><entry></entry></row>
3558
3559           <row>
3560             <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant>&nbsp;</entry>
3561             <entry>integer</entry>
3562           </row><row><entry spanname="descr">Specify the objective lens
3563 focal length as an absolute value. The zoom unit is driver-specific and its
3564 value should be a positive integer.</entry>
3565           </row>
3566           <row><entry></entry></row>
3567
3568           <row>
3569             <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant>&nbsp;</entry>
3570             <entry>integer</entry>
3571           </row><row><entry spanname="descr">Specify the objective lens
3572 focal length relatively to the current value. Positive values move the zoom
3573 lens group towards the telephoto direction, negative values towards the
3574 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3575           </row>
3576           <row><entry></entry></row>
3577
3578           <row>
3579             <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant>&nbsp;</entry>
3580             <entry>integer</entry>
3581           </row><row><entry spanname="descr">Move the objective lens group
3582 at the specified speed until it reaches physical device limits or until an
3583 explicit request to stop the movement. A positive value moves the zoom lens
3584 group towards the telephoto direction. A value of zero stops the zoom lens
3585 group movement. A negative value moves the zoom lens group towards the
3586 wide-angle direction. The zoom speed unit is driver-specific.</entry>
3587           </row>
3588           <row><entry></entry></row>
3589
3590           <row>
3591             <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
3592             <entry>integer</entry>
3593           </row><row><entry spanname="descr">This control sets the
3594 camera's aperture to the specified value. The unit is undefined.
3595 Larger values open the iris wider, smaller values close it.</entry>
3596           </row>
3597           <row><entry></entry></row>
3598
3599           <row>
3600             <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
3601             <entry>integer</entry>
3602           </row><row><entry spanname="descr">This control modifies the
3603 camera's aperture by the specified amount. The unit is undefined.
3604 Positive values open the iris one step further, negative values close
3605 it one step further. This is a write-only control.</entry>
3606           </row>
3607           <row><entry></entry></row>
3608
3609           <row>
3610             <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
3611             <entry>boolean</entry>
3612           </row><row><entry spanname="descr">Prevent video from being acquired
3613 by the camera. When this control is set to <constant>TRUE</constant> (1), no
3614 image can be captured by the camera. Common means to enforce privacy are
3615 mechanical obturation of the sensor and firmware image processing, but the
3616 device is not restricted to these methods. Devices that implement the privacy
3617 control must support read access and may support write access.</entry>
3618           </row>
3619
3620           <row>
3621             <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant>&nbsp;</entry>
3622             <entry>integer</entry>
3623           </row><row><entry spanname="descr">Switch the band-stop filter of a
3624 camera sensor on or off, or specify its strength. Such band-stop filters can
3625 be used, for example, to filter out the fluorescent light component.</entry>
3626           </row>
3627           <row><entry></entry></row>
3628
3629           <row id="v4l2-auto-n-preset-white-balance">
3630             <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
3631             <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
3632           </row><row><entry spanname="descr">Sets white balance to automatic,
3633 manual or a preset. The presets determine color temperature of the light as
3634 a hint to the camera for white balance adjustments resulting in most accurate
3635 color representation. The following white balance presets are listed in order
3636 of increasing color temperature.</entry>
3637           </row>
3638           <row>
3639             <entrytbl spanname="descr" cols="2">
3640               <tbody valign="top">
3641                 <row>
3642                   <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
3643                   <entry>Manual white balance.</entry>
3644                 </row>
3645                 <row>
3646                   <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
3647                   <entry>Automatic white balance adjustments.</entry>
3648                 </row>
3649                 <row>
3650                   <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
3651                   <entry>White balance setting for incandescent (tungsten) lighting.
3652 It generally cools down the colors and corresponds approximately to 2500...3500 K
3653 color temperature range.</entry>
3654                 </row>
3655                 <row>
3656                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
3657                   <entry>White balance preset for fluorescent lighting.
3658 It corresponds approximately to 4000...5000 K color temperature.</entry>
3659                 </row>
3660                 <row>
3661                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
3662                   <entry>With this setting the camera will compensate for
3663 fluorescent H lighting.</entry>
3664                 </row>
3665                 <row>
3666                   <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
3667                   <entry>White balance setting for horizon daylight.
3668 It corresponds approximately to 5000 K color temperature.</entry>
3669                 </row>
3670                 <row>
3671                   <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
3672                   <entry>White balance preset for daylight (with clear sky).
3673 It corresponds approximately to 5000...6500 K color temperature.</entry>
3674                 </row>
3675                 <row>
3676                   <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
3677                   <entry>With this setting the camera will compensate for the flash
3678 light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3679 color temperature.</entry>
3680                 </row>
3681                 <row>
3682                   <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
3683                   <entry>White balance preset for moderately overcast sky.
3684 This option corresponds approximately to 6500...8000 K color temperature
3685 range.</entry>
3686                 </row>
3687                 <row>
3688                   <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
3689                   <entry>White balance preset for shade or heavily overcast
3690 sky. It corresponds approximately to 9000...10000 K color temperature.
3691 </entry>
3692                 </row>
3693               </tbody>
3694             </entrytbl>
3695           </row>
3696           <row><entry></entry></row>
3697
3698           <row id="v4l2-wide-dynamic-range">
3699             <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3700             <entry>boolean</entry>
3701           </row>
3702           <row>
3703             <entry spanname="descr">Enables or disables the camera's wide dynamic
3704 range feature. This feature allows to obtain clear images in situations where
3705 intensity of the illumination varies significantly throughout the scene, i.e.
3706 there are simultaneously very dark and very bright areas. It is most commonly
3707 realized in cameras by combining two subsequent frames with different exposure
3708 times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3709 control in the future, if more options are required.</para></footnote></entry>
3710           </row>
3711           <row><entry></entry></row>
3712
3713           <row id="v4l2-image-stabilization">
3714             <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3715             <entry>boolean</entry>
3716           </row>
3717           <row>
3718             <entry spanname="descr">Enables or disables image stabilization.
3719               <footnoteref linkend="ctypeconv"/></entry>
3720           </row>
3721           <row><entry></entry></row>
3722
3723           <row>
3724             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
3725             <entry>integer menu</entry>
3726           </row><row><entry spanname="descr">Determines ISO equivalent of an
3727 image sensor indicating the sensor's sensitivity to light. The numbers are
3728 expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3729 where doubling the sensor sensitivity is represented by doubling the numerical
3730 ISO value. Applications should interpret the values as standard ISO values
3731 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3732 usually support only a subset of standard ISO values. The effect of setting
3733 this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3734 control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3735 </constant> is undefined, drivers should ignore such requests.</entry>
3736           </row>
3737           <row><entry></entry></row>
3738
3739           <row id="v4l2-iso-sensitivity-auto-type">
3740             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3741             <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
3742           </row><row><entry spanname="descr">Enables or disables automatic ISO
3743 sensitivity adjustments.</entry>
3744           </row>
3745           <row>
3746             <entrytbl spanname="descr" cols="2">
3747               <tbody valign="top">
3748                 <row>
3749                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
3750                   <entry>Manual ISO sensitivity.</entry>
3751                 </row>
3752                 <row>
3753                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3754                   <entry>Automatic ISO sensitivity adjustments.</entry>
3755                 </row>
3756               </tbody>
3757             </entrytbl>
3758           </row>
3759           <row><entry></entry></row>
3760
3761           <row id="v4l2-scene-mode">
3762             <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant>&nbsp;</entry>
3763             <entry>enum&nbsp;v4l2_scene_mode</entry>
3764           </row><row><entry spanname="descr">This control allows to select
3765 scene programs as the camera automatic modes optimized for common shooting
3766 scenes. Within these modes the camera determines best exposure, aperture,
3767 focusing, light metering, white balance and equivalent sensitivity. The
3768 controls of those parameters are influenced by the scene mode control.
3769 An exact behavior in each mode is subject to the camera specification.
3770
3771 <para>When the scene mode feature is not used, this control should be set to
3772 <constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3773 related controls are accessible. The following scene programs are defined:
3774 </para>
3775 </entry>
3776           </row>
3777           <row>
3778             <entrytbl spanname="descr" cols="2">
3779               <tbody valign="top">
3780                 <row>
3781                   <entry><constant>V4L2_SCENE_MODE_NONE</constant>&nbsp;</entry>
3782                   <entry>The scene mode feature is disabled.</entry>
3783                 </row>
3784                 <row>
3785                   <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant>&nbsp;</entry>
3786                   <entry>Backlight. Compensates for dark shadows when light is
3787                   coming from behind a subject, also by automatically turning
3788                   on the flash.</entry>
3789                 </row>
3790                 <row>
3791                   <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant>&nbsp;</entry>
3792                   <entry>Beach and snow. This mode compensates for all-white or
3793 bright scenes, which tend to look gray and low contrast, when camera's automatic
3794 exposure is based on an average scene brightness. To compensate, this mode
3795 automatically slightly overexposes the frames. The white balance may also be
3796 adjusted to compensate for the fact that reflected snow looks bluish rather
3797 than white.</entry>
3798                 </row>
3799                 <row>
3800                   <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant>&nbsp;</entry>
3801                   <entry>Candle light. The camera generally raises the ISO
3802 sensitivity and lowers the shutter speed. This mode compensates for relatively
3803 close subject in the scene. The flash is disabled in order to preserve the
3804 ambiance of the light.</entry>
3805                 </row>
3806                 <row>
3807                   <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant>&nbsp;</entry>
3808                   <entry>Dawn and dusk. Preserves the colors seen in low
3809 natural light before dusk and after down. The camera may turn off the flash,
3810 and automatically focus at infinity. It will usually boost saturation and
3811 lower the shutter speed.</entry>
3812                 </row>
3813                 <row>
3814                   <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant>&nbsp;</entry>
3815                   <entry>Fall colors. Increases saturation and adjusts white
3816 balance for color enhancement. Pictures of autumn leaves get saturated reds
3817 and yellows.</entry>
3818                 </row>
3819                 <row>
3820                   <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant>&nbsp;</entry>
3821                   <entry>Fireworks. Long exposure times are used to capture
3822 the expanding burst of light from a firework. The camera may invoke image
3823 stabilization.</entry>
3824                 </row>
3825                 <row>
3826                   <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant>&nbsp;</entry>
3827                   <entry>Landscape. The camera may choose a small aperture to
3828 provide deep depth of field and long exposure duration to help capture detail
3829 in dim light conditions. The focus is fixed at infinity. Suitable for distant
3830 and wide scenery.</entry>
3831                 </row>
3832                 <row>
3833                   <entry><constant>V4L2_SCENE_MODE_NIGHT</constant>&nbsp;</entry>
3834                   <entry>Night, also known as Night Landscape. Designed for low
3835 light conditions, it preserves detail in the dark areas without blowing out bright
3836 objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3837 with a relatively long exposure time, and turns flash off. As such, there will be
3838 increased image noise and the possibility of blurred image.</entry>
3839                 </row>
3840                 <row>
3841                   <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant>&nbsp;</entry>
3842                   <entry>Party and indoor. Designed to capture indoor scenes
3843 that are lit by indoor background lighting as well as the flash. The camera
3844 usually increases ISO sensitivity, and adjusts exposure for the low light
3845 conditions.</entry>
3846                 </row>
3847                 <row>
3848                   <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant>&nbsp;</entry>
3849                   <entry>Portrait. The camera adjusts the aperture so that the
3850 depth of field is reduced, which helps to isolate the subject against a smooth
3851 background. Most cameras recognize the presence of faces in the scene and focus
3852 on them. The color hue is adjusted to enhance skin tones. The intensity of the
3853 flash is often reduced.</entry>
3854                 </row>
3855                 <row>
3856                   <entry><constant>V4L2_SCENE_MODE_SPORTS</constant>&nbsp;</entry>
3857                   <entry>Sports. Significantly increases ISO and uses a fast
3858 shutter speed to freeze motion of rapidly-moving subjects. Increased image
3859 noise may be seen in this mode.</entry>
3860                 </row>
3861                 <row>
3862                   <entry><constant>V4L2_SCENE_MODE_SUNSET</constant>&nbsp;</entry>
3863                   <entry>Sunset. Preserves deep hues seen in sunsets and
3864 sunrises. It bumps up the saturation.</entry>
3865                 </row>
3866                 <row>
3867                   <entry><constant>V4L2_SCENE_MODE_TEXT</constant>&nbsp;</entry>
3868                   <entry>Text. It applies extra contrast and sharpness, it is
3869 typically a black-and-white mode optimized for readability. Automatic focus
3870 may be switched to close-up mode and this setting may also involve some
3871 lens-distortion correction.</entry>
3872                 </row>
3873               </tbody>
3874             </entrytbl>
3875           </row>
3876           <row><entry></entry></row>
3877
3878           <row>
3879             <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3880             <entry>bitmask</entry>
3881           </row>
3882           <row>
3883             <entry spanname="descr">This control locks or unlocks the automatic
3884 focus, exposure and white balance. The automatic adjustments can be paused
3885 independently by setting the corresponding lock bit to 1. The camera then retains
3886 the settings until the lock bit is cleared. The following lock bits are defined:
3887 </entry>
3888           </row>
3889           <row>
3890             <entrytbl spanname="descr" cols="2">
3891               <tbody valign="top">
3892                 <row>
3893                   <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3894                   <entry>Automatic exposure adjustments lock.</entry>
3895                 </row>
3896                 <row>
3897                   <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3898                   <entry>Automatic white balance adjustments lock.</entry>
3899                 </row>
3900                 <row>
3901                   <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3902                   <entry>Automatic focus lock.</entry>
3903                 </row>
3904               </tbody>
3905             </entrytbl>
3906           </row>
3907           <row><entry spanname="descr">
3908 When a given algorithm is not enabled, drivers should ignore requests
3909 to lock it and should return no error. An example might be an application
3910 setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3911 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3912 <constant>FALSE</constant>. The value of this control may be changed
3913 by exposure, white balance or focus controls.</entry>
3914           </row>
3915           <row><entry></entry></row>
3916
3917         </tbody>
3918       </tgroup>
3919     </table>
3920   </section>
3921
3922     <section id="fm-tx-controls">
3923       <title>FM Transmitter Control Reference</title>
3924
3925       <para>The FM Transmitter (FM_TX) class includes controls for common features of
3926 FM transmissions capable devices. Currently this class includes parameters for audio
3927 compression, pilot tone generation, audio deviation limiter, RDS transmission and
3928 tuning power features.</para>
3929
3930       <table pgwide="1" frame="none" id="fm-tx-control-id">
3931       <title>FM_TX Control IDs</title>
3932
3933       <tgroup cols="4">
3934         <colspec colname="c1" colwidth="1*" />
3935         <colspec colname="c2" colwidth="6*" />
3936         <colspec colname="c3" colwidth="2*" />
3937         <colspec colname="c4" colwidth="6*" />
3938         <spanspec namest="c1" nameend="c2" spanname="id" />
3939         <spanspec namest="c2" nameend="c4" spanname="descr" />
3940         <thead>
3941           <row>
3942             <entry spanname="id" align="left">ID</entry>
3943             <entry align="left">Type</entry>
3944           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3945           </row>
3946         </thead>
3947         <tbody valign="top">
3948           <row><entry></entry></row>
3949           <row>
3950             <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant>&nbsp;</entry>
3951             <entry>class</entry>
3952           </row><row><entry spanname="descr">The FM_TX class
3953 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3954 description of this control class.</entry>
3955           </row>
3956           <row>
3957             <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant>&nbsp;</entry>
3958             <entry>integer</entry>
3959           </row>
3960           <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3961 The range and step are driver-specific.</entry>
3962           </row>
3963           <row>
3964             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant>&nbsp;</entry>
3965             <entry>integer</entry>
3966           </row>
3967           <row><entry spanname="descr">Sets the RDS Programme Identification field
3968 for transmission.</entry>
3969           </row>
3970           <row>
3971             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant>&nbsp;</entry>
3972             <entry>integer</entry>
3973           </row>
3974           <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3975 This encodes up to 31 pre-defined programme types.</entry>
3976           </row>
3977           <row>
3978             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant>&nbsp;</entry>
3979             <entry>string</entry>
3980           </row>
3981           <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
3982 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
3983 identification and selection.  In Annex E of <xref linkend="iec62106" />, the RDS specification,
3984 there is a full description of the correct character encoding for Programme Service name strings.
3985 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
3986 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
3987 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
3988           </row>
3989           <row>
3990             <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant>&nbsp;</entry>
3991             <entry>string</entry>
3992           </row>
3993           <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
3994 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
3995 programme-related information or any other text. In these cases, RadioText should be used in addition to
3996 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
3997 in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
3998 used to transmit it, either 32 (2A block) or 64 (2B block).  However, it is also possible
3999 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
4000 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
4001           </row>
4002           <row>
4003             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant>&nbsp;</entry>
4004             <entry>boolean</entry>
4005           </row>
4006           <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
4007 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
4008 distortion and prevent overmodulation.
4009 </entry>
4010           </row>
4011           <row>
4012             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant>&nbsp;</entry>
4013             <entry>integer</entry>
4014           </row>
4015           <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
4016 Unit is in useconds. Step and range are driver-specific.</entry>
4017           </row>
4018           <row>
4019             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant>&nbsp;</entry>
4020             <entry>integer</entry>
4021           </row>
4022           <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
4023 The range and step are driver-specific.</entry>
4024           </row>
4025           <row>
4026             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant>&nbsp;</entry>
4027             <entry>boolean</entry>
4028           </row>
4029           <row><entry spanname="descr">Enables or disables the audio compression feature.
4030 This feature amplifies signals below the threshold by a fixed gain and compresses audio
4031 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
4032           </row>
4033           <row>
4034             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant>&nbsp;</entry>
4035             <entry>integer</entry>
4036           </row>
4037           <row><entry spanname="descr">Sets the gain for audio compression feature. It is
4038 a dB value. The range and step are driver-specific.</entry>
4039           </row>
4040           <row>
4041             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant>&nbsp;</entry>
4042             <entry>integer</entry>
4043           </row>
4044           <row><entry spanname="descr">Sets the threshold level for audio compression freature.
4045 It is a dB value. The range and step are driver-specific.</entry>
4046           </row>
4047           <row>
4048             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant>&nbsp;</entry>
4049             <entry>integer</entry>
4050           </row>
4051           <row><entry spanname="descr">Sets the attack time for audio compression feature.
4052 It is a useconds value. The range and step are driver-specific.</entry>
4053           </row>
4054           <row>
4055             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant>&nbsp;</entry>
4056             <entry>integer</entry>
4057           </row>
4058           <row><entry spanname="descr">Sets the release time for audio compression feature.
4059 It is a useconds value. The range and step are driver-specific.</entry>
4060           </row>
4061           <row>
4062             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant>&nbsp;</entry>
4063             <entry>boolean</entry>
4064           </row>
4065           <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
4066           </row>
4067           <row>
4068             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant>&nbsp;</entry>
4069             <entry>integer</entry>
4070           </row>
4071           <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
4072 in Hz. The range and step are driver-specific.</entry>
4073           </row>
4074           <row>
4075             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant>&nbsp;</entry>
4076             <entry>integer</entry>
4077           </row>
4078           <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
4079 in Hz. The range and step are driver-specific.</entry>
4080           </row>
4081           <row>
4082             <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant>&nbsp;</entry>
4083             <entry>enum v4l2_preemphasis</entry>
4084           </row>
4085           <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
4086 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4087 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_preemphasis
4088 defines possible values for pre-emphasis. Here they are:</entry>
4089         </row><row>
4090         <entrytbl spanname="descr" cols="2">
4091                   <tbody valign="top">
4092                     <row>
4093                       <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant>&nbsp;</entry>
4094                       <entry>No pre-emphasis is applied.</entry>
4095                     </row>
4096                     <row>
4097                       <entry><constant>V4L2_PREEMPHASIS_50_uS</constant>&nbsp;</entry>
4098                       <entry>A pre-emphasis of 50 uS is used.</entry>
4099                     </row>
4100                     <row>
4101                       <entry><constant>V4L2_PREEMPHASIS_75_uS</constant>&nbsp;</entry>
4102                       <entry>A pre-emphasis of 75 uS is used.</entry>
4103                     </row>
4104                   </tbody>
4105                 </entrytbl>
4106
4107           </row>
4108           <row>
4109             <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant>&nbsp;</entry>
4110             <entry>integer</entry>
4111           </row>
4112           <row><entry spanname="descr">Sets the output power level for signal transmission.
4113 Unit is in dBuV. Range and step are driver-specific.</entry>
4114           </row>
4115           <row>
4116             <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant>&nbsp;</entry>
4117             <entry>integer</entry>
4118           </row>
4119           <row><entry spanname="descr">This selects the value of antenna tuning capacitor
4120 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
4121           </row>
4122           <row><entry></entry></row>
4123         </tbody>
4124       </tgroup>
4125       </table>
4126
4127 <para>For more details about RDS specification, refer to
4128 <xref linkend="iec62106" /> document, from CENELEC.</para>
4129     </section>
4130
4131     <section id="flash-controls">
4132       <title>Flash Control Reference</title>
4133
4134       <note>
4135         <title>Experimental</title>
4136
4137         <para>This is an <link linkend="experimental">experimental</link>
4138 interface and may change in the future.</para>
4139       </note>
4140
4141       <para>
4142         The V4L2 flash controls are intended to provide generic access
4143         to flash controller devices. Flash controller devices are
4144         typically used in digital cameras.
4145       </para>
4146
4147       <para>
4148         The interface can support both LED and xenon flash devices. As
4149         of writing this, there is no xenon flash driver using this
4150         interface.
4151       </para>
4152
4153       <section id="flash-controls-use-cases">
4154         <title>Supported use cases</title>
4155
4156         <section>
4157           <title>Unsynchronised LED flash (software strobe)</title>
4158
4159           <para>
4160             Unsynchronised LED flash is controlled directly by the
4161             host as the sensor. The flash must be enabled by the host
4162             before the exposure of the image starts and disabled once
4163             it ends. The host is fully responsible for the timing of
4164             the flash.
4165           </para>
4166
4167           <para>Example of such device: Nokia N900.</para>
4168         </section>
4169
4170         <section>
4171           <title>Synchronised LED flash (hardware strobe)</title>
4172
4173           <para>
4174             The synchronised LED flash is pre-programmed by the host
4175             (power and timeout) but controlled by the sensor through a
4176             strobe signal from the sensor to the flash.
4177           </para>
4178
4179           <para>
4180             The sensor controls the flash duration and timing. This
4181             information typically must be made available to the
4182             sensor.
4183           </para>
4184
4185         </section>
4186
4187         <section>
4188           <title>LED flash as torch</title>
4189
4190           <para>
4191             LED flash may be used as torch in conjunction with another
4192             use case involving camera or individually.
4193           </para>
4194
4195
4196           <table pgwide="1" frame="none" id="flash-control-id">
4197           <title>Flash Control IDs</title>
4198
4199           <tgroup cols="4">
4200         <colspec colname="c1" colwidth="1*" />
4201         <colspec colname="c2" colwidth="6*" />
4202         <colspec colname="c3" colwidth="2*" />
4203         <colspec colname="c4" colwidth="6*" />
4204         <spanspec namest="c1" nameend="c2" spanname="id" />
4205         <spanspec namest="c2" nameend="c4" spanname="descr" />
4206         <thead>
4207           <row>
4208             <entry spanname="id" align="left">ID</entry>
4209             <entry align="left">Type</entry>
4210           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4211           </row>
4212         </thead>
4213         <tbody valign="top">
4214           <row><entry></entry></row>
4215           <row>
4216             <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4217             <entry>class</entry>
4218           </row>
4219           <row>
4220             <entry spanname="descr">The FLASH class descriptor.</entry>
4221           </row>
4222           <row>
4223             <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
4224             <entry>menu</entry>
4225           </row>
4226           <row id="v4l2-flash-led-mode">
4227             <entry spanname="descr">Defines the mode of the flash LED,
4228             the high-power white LED attached to the flash controller.
4229             Setting this control may not be possible in presence of
4230             some faults. See V4L2_CID_FLASH_FAULT.</entry>
4231           </row>
4232           <row>
4233             <entrytbl spanname="descr" cols="2">
4234               <tbody valign="top">
4235                 <row>
4236                   <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4237                   <entry>Off.</entry>
4238                 </row>
4239                 <row>
4240                   <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4241                   <entry>Flash mode.</entry>
4242                 </row>
4243                 <row>
4244                   <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4245                   <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4246                 </row>
4247               </tbody>
4248             </entrytbl>
4249           </row>
4250           <row>
4251             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4252             <entry>menu</entry>
4253           </row>
4254           <row id="v4l2-flash-strobe-source"><entry
4255           spanname="descr">Defines the source of the flash LED
4256           strobe.</entry>
4257           </row>
4258           <row>
4259             <entrytbl spanname="descr" cols="2">
4260               <tbody valign="top">
4261                 <row>
4262                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4263                   <entry>The flash strobe is triggered by using
4264                   the V4L2_CID_FLASH_STROBE control.</entry>
4265                 </row>
4266                 <row>
4267                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4268                   <entry>The flash strobe is triggered by an
4269                   external source. Typically this is a sensor,
4270                   which makes it possible to synchronises the
4271                   flash strobe start to exposure start.</entry>
4272                 </row>
4273               </tbody>
4274             </entrytbl>
4275           </row>
4276           <row>
4277             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4278             <entry>button</entry>
4279           </row>
4280           <row>
4281             <entry spanname="descr">Strobe flash. Valid when
4282             V4L2_CID_FLASH_LED_MODE is set to
4283             V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4284             is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4285             control may not be possible in presence of some faults.
4286             See V4L2_CID_FLASH_FAULT.</entry>
4287           </row>
4288           <row>
4289             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4290             <entry>button</entry>
4291           </row>
4292           <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4293           </row>
4294           <row>
4295             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4296             <entry>boolean</entry>
4297           </row>
4298           <row>
4299             <entry spanname="descr">Strobe status: whether the flash
4300             is strobing at the moment or not. This is a read-only
4301             control.</entry>
4302           </row>
4303           <row>
4304             <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4305             <entry>integer</entry>
4306           </row>
4307           <row>
4308             <entry spanname="descr">Hardware timeout for flash. The
4309             flash strobe is stopped after this period of time has
4310             passed from the start of the strobe.</entry>
4311           </row>
4312           <row>
4313             <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4314             <entry>integer</entry>
4315           </row>
4316           <row>
4317             <entry spanname="descr">Intensity of the flash strobe when
4318             the flash LED is in flash mode
4319             (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4320             (mA) if possible.</entry>
4321           </row>
4322           <row>
4323             <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4324             <entry>integer</entry>
4325           </row>
4326           <row>
4327             <entry spanname="descr">Intensity of the flash LED in
4328             torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4329             milliamps (mA) if possible. Setting this control may not
4330             be possible in presence of some faults. See
4331             V4L2_CID_FLASH_FAULT.</entry>
4332           </row>
4333           <row>
4334             <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4335             <entry>integer</entry>
4336           </row>
4337           <row>
4338             <entry spanname="descr">Intensity of the indicator LED.
4339             The indicator LED may be fully independent of the flash
4340             LED. The unit should be microamps (uA) if possible.</entry>
4341           </row>
4342           <row>
4343             <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4344             <entry>bitmask</entry>
4345           </row>
4346           <row>
4347             <entry spanname="descr">Faults related to the flash. The
4348             faults tell about specific problems in the flash chip
4349             itself or the LEDs attached to it. Faults may prevent
4350             further use of some of the flash controls. In particular,
4351             V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4352             if the fault affects the flash LED. Exactly which faults
4353             have such an effect is chip dependent. Reading the faults
4354             resets the control and returns the chip to a usable state
4355             if possible.</entry>
4356           </row>
4357           <row>
4358             <entrytbl spanname="descr" cols="2">
4359               <tbody valign="top">
4360                 <row>
4361                   <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4362                   <entry>Flash controller voltage to the flash LED
4363                   has exceeded the limit specific to the flash
4364                   controller.</entry>
4365                 </row>
4366                 <row>
4367                   <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4368                   <entry>The flash strobe was still on when
4369                   the timeout set by the user ---
4370                   V4L2_CID_FLASH_TIMEOUT control --- has expired.
4371                   Not all flash controllers may set this in all
4372                   such conditions.</entry>
4373                 </row>
4374                 <row>
4375                   <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4376                   <entry>The flash controller has overheated.</entry>
4377                 </row>
4378                 <row>
4379                   <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4380                   <entry>The short circuit protection of the flash
4381                   controller has been triggered.</entry>
4382                 </row>
4383                 <row>
4384                   <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4385                   <entry>Current in the LED power supply has exceeded the limit
4386                   specific to the flash controller.</entry>
4387                 </row>
4388                 <row>
4389                   <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4390                   <entry>The flash controller has detected a short or open
4391                   circuit condition on the indicator LED.</entry>
4392                 </row>
4393                 <row>
4394                   <entry><constant>V4L2_FLASH_FAULT_UNDER_VOLTAGE</constant></entry>
4395                   <entry>Flash controller voltage to the flash LED
4396                   has been below the minimum limit specific to the flash
4397                   controller.</entry>
4398                 </row>
4399                 <row>
4400                   <entry><constant>V4L2_FLASH_FAULT_INPUT_VOLTAGE</constant></entry>
4401                   <entry>The input voltage of the flash controller is below
4402                   the limit under which strobing the flash at full current
4403                   will not be possible.The condition persists until this flag
4404                   is no longer set.</entry>
4405                 </row>
4406                 <row>
4407                   <entry><constant>V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE</constant></entry>
4408                   <entry>The temperature of the LED has exceeded its
4409                   allowed upper limit.</entry>
4410                 </row>
4411               </tbody>
4412             </entrytbl>
4413           </row>
4414           <row>
4415             <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4416             <entry>boolean</entry>
4417           </row>
4418           <row><entry spanname="descr">Enable or disable charging of the xenon
4419           flash capacitor.</entry>
4420           </row>
4421           <row>
4422             <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4423             <entry>boolean</entry>
4424           </row>
4425           <row>
4426             <entry spanname="descr">Is the flash ready to strobe?
4427             Xenon flashes require their capacitors charged before
4428             strobing. LED flashes often require a cooldown period
4429             after strobe during which another strobe will not be
4430             possible. This is a read-only control.</entry>
4431           </row>
4432           <row><entry></entry></row>
4433         </tbody>
4434           </tgroup>
4435           </table>
4436         </section>
4437       </section>
4438     </section>
4439
4440     <section id="jpeg-controls">
4441       <title>JPEG Control Reference</title>
4442       <para>The JPEG class includes controls for common features of JPEG
4443       encoders and decoders. Currently it includes features for codecs
4444       implementing progressive baseline DCT compression process with
4445       Huffman entrophy coding.</para>
4446       <table pgwide="1" frame="none" id="jpeg-control-id">
4447       <title>JPEG Control IDs</title>
4448
4449       <tgroup cols="4">
4450         <colspec colname="c1" colwidth="1*" />
4451         <colspec colname="c2" colwidth="6*" />
4452         <colspec colname="c3" colwidth="2*" />
4453         <colspec colname="c4" colwidth="6*" />
4454         <spanspec namest="c1" nameend="c2" spanname="id" />
4455         <spanspec namest="c2" nameend="c4" spanname="descr" />
4456         <thead>
4457           <row>
4458             <entry spanname="id" align="left">ID</entry>
4459             <entry align="left">Type</entry>
4460           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4461           </row>
4462         </thead>
4463         <tbody valign="top">
4464           <row><entry></entry></row>
4465           <row>
4466             <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant>&nbsp;</entry>
4467             <entry>class</entry>
4468           </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4469           &VIDIOC-QUERYCTRL; for this control will return a description of this
4470           control class.
4471
4472         </entry>
4473           </row>
4474           <row>
4475             <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4476             <entry>menu</entry>
4477           </row>
4478           <row id="v4l2-jpeg-chroma-subsampling">
4479             <entry spanname="descr">The chroma subsampling factors describe how
4480             each component of an input image is sampled, in respect to maximum
4481             sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4482             clause A.1.1. for more details. The <constant>
4483             V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4484             Cb and Cr components are downsampled after coverting an input image
4485             from RGB to Y'CbCr color space.
4486             </entry>
4487           </row>
4488           <row>
4489             <entrytbl spanname="descr" cols="2">
4490               <tbody valign="top">
4491                 <row>
4492                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4493                   </entry><entry>No chroma subsampling, each pixel has
4494                   Y, Cr and Cb values.</entry>
4495                 </row>
4496                 <row>
4497                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4498                   </entry><entry>Horizontally subsample Cr, Cb components
4499                   by a factor of 2.</entry>
4500                 </row>
4501                 <row>
4502                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4503                   </entry><entry>Subsample Cr, Cb components horizontally
4504                   and vertically by 2.</entry>
4505                 </row>
4506                 <row>
4507                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4508                   </entry><entry>Horizontally subsample Cr, Cb components
4509                   by a factor of 4.</entry>
4510                 </row>
4511                 <row>
4512                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4513                   </entry><entry>Subsample Cr, Cb components horizontally
4514                   by 4 and vertically by 2.</entry>
4515                 </row>
4516                 <row>
4517                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4518                   </entry><entry>Use only luminance component.</entry>
4519                 </row>
4520               </tbody>
4521             </entrytbl>
4522           </row>
4523           <row>
4524             <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4525             </entry><entry>integer</entry>
4526           </row>
4527           <row><entry spanname="descr">
4528               The restart interval determines an interval of inserting RSTm
4529               markers (m = 0..7). The purpose of these markers is to additionally
4530               reinitialize the encoder process, in order to process blocks of
4531               an image independently.
4532               For the lossy compression processes the restart interval unit is
4533               MCU (Minimum Coded Unit) and its value is contained in DRI
4534               (Define Restart Interval) marker. If <constant>
4535               V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4536               DRI and RSTm markers will not be inserted.
4537             </entry>
4538           </row>
4539           <row id="jpeg-quality-control">
4540             <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4541             <entry>integer</entry>
4542           </row>
4543           <row>
4544             <entry spanname="descr">
4545               <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4546               determines trade-off between image quality and size.
4547               It provides simpler method for applications to control image quality,
4548               without a need for direct reconfiguration of luminance and chrominance
4549               quantization tables.
4550
4551               In cases where a driver uses quantization tables configured directly
4552               by an application, using interfaces defined elsewhere, <constant>
4553               V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4554               by driver to 0.
4555
4556               <para>The value range of this control is driver-specific. Only
4557               positive, non-zero values are meaningful. The recommended range
4558               is 1 - 100, where larger values correspond to better image quality.
4559               </para>
4560             </entry>
4561             </row>
4562           <row id="jpeg-active-marker-control">
4563             <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4564             <entry>bitmask</entry>
4565           </row>
4566           <row>
4567             <entry spanname="descr">Specify which JPEG markers are included
4568             in compressed stream. This control is valid only for encoders.
4569             </entry>
4570           </row>
4571           <row>
4572             <entrytbl spanname="descr" cols="2">
4573               <tbody valign="top">
4574                 <row>
4575                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4576                   <entry>Application data segment APP<subscript>0</subscript>.</entry>
4577                 </row><row>
4578                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4579                   <entry>Application data segment APP<subscript>1</subscript>.</entry>
4580                 </row><row>
4581                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4582                   <entry>Comment segment.</entry>
4583                 </row><row>
4584                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4585                   <entry>Quantization tables segment.</entry>
4586                 </row><row>
4587                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4588                   <entry>Huffman tables segment.</entry>
4589                 </row>
4590               </tbody>
4591             </entrytbl>
4592           </row>
4593           <row><entry></entry></row>
4594         </tbody>
4595       </tgroup>
4596       </table>
4597       <para>For more details about JPEG specification, refer
4598       to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4599       <xref linkend="w3c-jpeg-jfif"/>.</para>
4600     </section>
4601
4602     <section id="image-source-controls">
4603       <title>Image Source Control Reference</title>
4604
4605       <note>
4606         <title>Experimental</title>
4607
4608         <para>This is an <link
4609         linkend="experimental">experimental</link> interface and may
4610         change in the future.</para>
4611       </note>
4612
4613       <para>
4614         The Image Source control class is intended for low-level
4615         control of image source devices such as image sensors. The
4616         devices feature an analogue to digital converter and a bus
4617         transmitter to transmit the image data out of the device.
4618       </para>
4619
4620       <table pgwide="1" frame="none" id="image-source-control-id">
4621       <title>Image Source Control IDs</title>
4622
4623       <tgroup cols="4">
4624         <colspec colname="c1" colwidth="1*" />
4625         <colspec colname="c2" colwidth="6*" />
4626         <colspec colname="c3" colwidth="2*" />
4627         <colspec colname="c4" colwidth="6*" />
4628         <spanspec namest="c1" nameend="c2" spanname="id" />
4629         <spanspec namest="c2" nameend="c4" spanname="descr" />
4630         <thead>
4631           <row>
4632             <entry spanname="id" align="left">ID</entry>
4633             <entry align="left">Type</entry>
4634           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4635           </row>
4636         </thead>
4637         <tbody valign="top">
4638           <row><entry></entry></row>
4639           <row>
4640             <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4641             <entry>class</entry>
4642           </row>
4643           <row>
4644             <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4645           </row>
4646           <row>
4647             <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4648             <entry>integer</entry>
4649           </row>
4650           <row>
4651             <entry spanname="descr">Vertical blanking. The idle period
4652             after every frame during which no image data is produced.
4653             The unit of vertical blanking is a line. Every line has
4654             length of the image width plus horizontal blanking at the
4655             pixel rate defined by
4656             <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4657             same sub-device.</entry>
4658           </row>
4659           <row>
4660             <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4661             <entry>integer</entry>
4662           </row>
4663           <row>
4664             <entry spanname="descr">Horizontal blanking. The idle
4665             period after every line of image data during which no
4666             image data is produced. The unit of horizontal blanking is
4667             pixels.</entry>
4668           </row>
4669           <row>
4670             <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4671             <entry>integer</entry>
4672           </row>
4673           <row>
4674             <entry spanname="descr">Analogue gain is gain affecting
4675             all colour components in the pixel matrix. The gain
4676             operation is performed in the analogue domain before A/D
4677             conversion.
4678             </entry>
4679           </row>
4680           <row><entry></entry></row>
4681         </tbody>
4682       </tgroup>
4683       </table>
4684
4685     </section>
4686
4687     <section id="image-process-controls">
4688       <title>Image Process Control Reference</title>
4689
4690       <note>
4691         <title>Experimental</title>
4692
4693         <para>This is an <link
4694         linkend="experimental">experimental</link> interface and may
4695         change in the future.</para>
4696       </note>
4697
4698       <para>
4699         The Image Source control class is intended for low-level control of
4700         image processing functions. Unlike
4701         <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4702         this class affect processing the image, and do not control capturing
4703         of it.
4704       </para>
4705
4706       <table pgwide="1" frame="none" id="image-process-control-id">
4707       <title>Image Source Control IDs</title>
4708
4709       <tgroup cols="4">
4710         <colspec colname="c1" colwidth="1*" />
4711         <colspec colname="c2" colwidth="6*" />
4712         <colspec colname="c3" colwidth="2*" />
4713         <colspec colname="c4" colwidth="6*" />
4714         <spanspec namest="c1" nameend="c2" spanname="id" />
4715         <spanspec namest="c2" nameend="c4" spanname="descr" />
4716         <thead>
4717           <row>
4718             <entry spanname="id" align="left">ID</entry>
4719             <entry align="left">Type</entry>
4720           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4721           </row>
4722         </thead>
4723         <tbody valign="top">
4724           <row><entry></entry></row>
4725           <row>
4726             <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4727             <entry>class</entry>
4728           </row>
4729           <row>
4730             <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4731           </row>
4732           <row>
4733             <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4734             <entry>integer menu</entry>
4735           </row>
4736           <row>
4737             <entry spanname="descr">Data bus frequency. Together with the
4738             media bus pixel code, bus type (clock cycles per sample), the
4739             data bus frequency defines the pixel rate
4740             (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4741             pixel array (or possibly elsewhere, if the device is not an
4742             image sensor). The frame rate can be calculated from the pixel
4743             clock, image width and height and horizontal and vertical
4744             blanking. While the pixel rate control may be defined elsewhere
4745             than in the subdev containing the pixel array, the frame rate
4746             cannot be obtained from that information. This is because only
4747             on the pixel array it can be assumed that the vertical and
4748             horizontal blanking information is exact: no other blanking is
4749             allowed in the pixel array. The selection of frame rate is
4750             performed by selecting the desired horizontal and vertical
4751             blanking. The unit of this control is Hz. </entry>
4752           </row>
4753           <row>
4754             <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4755             <entry>64-bit integer</entry>
4756           </row>
4757           <row>
4758             <entry spanname="descr">Pixel rate in the source pads of
4759             the subdev. This control is read-only and its unit is
4760             pixels / second.
4761             </entry>
4762           </row>
4763           <row>
4764             <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4765             <entry>menu</entry>
4766           </row>
4767           <row id="v4l2-test-pattern">
4768             <entry spanname="descr"> Some capture/display/sensor devices have
4769             the capability to generate test pattern images. These hardware
4770             specific test patterns can be used to test if a device is working
4771             properly.</entry>
4772           </row>
4773           <row><entry></entry></row>
4774         </tbody>
4775       </tgroup>
4776       </table>
4777
4778     </section>
4779
4780     <section id="dv-controls">
4781       <title>Digital Video Control Reference</title>
4782
4783       <note>
4784         <title>Experimental</title>
4785
4786         <para>This is an <link
4787         linkend="experimental">experimental</link> interface and may
4788         change in the future.</para>
4789       </note>
4790
4791       <para>
4792         The Digital Video control class is intended to control receivers
4793         and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4794         <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4795         (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4796         These controls are generally expected to be private to the receiver or transmitter
4797         subdevice that implements them, so they are only exposed on the
4798         <filename>/dev/v4l-subdev*</filename> device node.
4799       </para>
4800
4801       <para>Note that these devices can have multiple input or output pads which are
4802       hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4803       transmit video from/to only one of those pads, the other pads can still be
4804       active when it comes to EDID (Extended Display Identification Data,
4805       <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4806       Protection System, <xref linkend="hdcp" />) processing, allowing the device
4807       to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4808       switching between connectors.</para>
4809
4810       <para>These pads appear in several of the controls in this section as
4811       bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4812       etc. The maximum value of the control is the set of valid pads.</para>
4813
4814       <table pgwide="1" frame="none" id="dv-control-id">
4815       <title>Digital Video Control IDs</title>
4816
4817       <tgroup cols="4">
4818         <colspec colname="c1" colwidth="1*" />
4819         <colspec colname="c2" colwidth="6*" />
4820         <colspec colname="c3" colwidth="2*" />
4821         <colspec colname="c4" colwidth="6*" />
4822         <spanspec namest="c1" nameend="c2" spanname="id" />
4823         <spanspec namest="c2" nameend="c4" spanname="descr" />
4824         <thead>
4825           <row>
4826             <entry spanname="id" align="left">ID</entry>
4827             <entry align="left">Type</entry>
4828           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4829           </row>
4830         </thead>
4831         <tbody valign="top">
4832           <row><entry></entry></row>
4833           <row>
4834             <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4835             <entry>class</entry>
4836           </row>
4837           <row>
4838             <entry spanname="descr">The Digital Video class descriptor.</entry>
4839           </row>
4840           <row>
4841             <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4842             <entry>bitmask</entry>
4843           </row>
4844           <row>
4845             <entry spanname="descr">Many connectors have a hotplug pin which is high
4846             if EDID information is available from the source. This control shows the
4847             state of the hotplug pin as seen by the transmitter.
4848             Each bit corresponds to an output pad on the transmitter. If an output pad
4849             does not have an associated hotplug pin, then the bit for that pad will be 0.
4850             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4851             </entry>
4852           </row>
4853           <row>
4854             <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4855             <entry>bitmask</entry>
4856           </row>
4857           <row>
4858             <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
4859             clock lines. This normally means that the sink has left/entered standby (i.e.
4860             the transmitter can sense that the receiver is ready to receive video).
4861             Each bit corresponds to an output pad on the transmitter. If an output pad
4862             does not have an associated Rx Sense, then the bit for that pad will be 0.
4863             This read-only control is applicable to DVI-D and HDMI devices.
4864             </entry>
4865           </row>
4866           <row>
4867             <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4868             <entry>bitmask</entry>
4869           </row>
4870           <row>
4871             <entry spanname="descr">When the transmitter sees the hotplug signal from the
4872             receiver it will attempt to read the EDID. If set, then the transmitter has read
4873             at least the first block (= 128 bytes).
4874             Each bit corresponds to an output pad on the transmitter. If an output pad
4875             does not support EDIDs, then the bit for that pad will be 0.
4876             This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4877             </entry>
4878           </row>
4879           <row>
4880             <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
4881             <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
4882           </row>
4883           <row>
4884             <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
4885             or in HDMI mode (video + audio + auxiliary data). This control selects which mode
4886             to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
4887             This control is applicable to HDMI connectors.
4888             </entry>
4889           </row>
4890           <row>
4891             <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
4892             <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
4893           </row>
4894           <row>
4895             <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
4896             follows the RGB quantization range specified in the standard for the video interface
4897             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4898             to be compatible with sinks that have not implemented the standard correctly
4899             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4900             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4901             where N is the number of bits per component.
4902             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4903             </entry>
4904           </row>
4905           <row>
4906             <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4907             <entry>bitmask</entry>
4908           </row>
4909           <row>
4910             <entry spanname="descr">Detects whether the receiver receives power from the source
4911             (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
4912             which contains EDID information, such that the source can read the EDID even if
4913             the sink is in standby/power off.
4914             Each bit corresponds to an input pad on the transmitter. If an input pad
4915             cannot detect whether power is present, then the bit for that pad will be 0.
4916             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4917             </entry>
4918           </row>
4919           <row>
4920             <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4921             <entry>enum v4l2_dv_rgb_range</entry>
4922           </row>
4923           <row>
4924             <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
4925             follows the RGB quantization range specified in the standard for the video interface
4926             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4927             to be compatible with sources that have not implemented the standard correctly
4928             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4929             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4930             where N is the number of bits per component.
4931             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4932             </entry>
4933           </row>
4934           <row><entry></entry></row>
4935         </tbody>
4936       </tgroup>
4937       </table>
4938
4939     </section>
4940
4941     <section id="fm-rx-controls">
4942       <title>FM Receiver Control Reference</title>
4943
4944       <para>The FM Receiver (FM_RX) class includes controls for common features of
4945       FM Reception capable devices.</para>
4946
4947       <table pgwide="1" frame="none" id="fm-rx-control-id">
4948       <title>FM_RX Control IDs</title>
4949
4950       <tgroup cols="4">
4951         <colspec colname="c1" colwidth="1*" />
4952         <colspec colname="c2" colwidth="6*" />
4953         <colspec colname="c3" colwidth="2*" />
4954         <colspec colname="c4" colwidth="6*" />
4955         <spanspec namest="c1" nameend="c2" spanname="id" />
4956         <spanspec namest="c2" nameend="c4" spanname="descr" />
4957         <thead>
4958           <row>
4959             <entry spanname="id" align="left">ID</entry>
4960             <entry align="left">Type</entry>
4961           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4962           </row>
4963         </thead>
4964         <tbody valign="top">
4965           <row><entry></entry></row>
4966           <row>
4967             <entry spanname="id"><constant>V4L2_CID_FM_RX_CLASS</constant>&nbsp;</entry>
4968             <entry>class</entry>
4969           </row><row><entry spanname="descr">The FM_RX class
4970 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
4971 description of this control class.</entry>
4972           </row>
4973           <row>
4974             <entry spanname="id"><constant>V4L2_CID_RDS_RECEPTION</constant>&nbsp;</entry>
4975             <entry>boolean</entry>
4976           </row><row><entry spanname="descr">Enables/disables RDS
4977           reception by the radio tuner</entry>
4978           </row>
4979           <row>
4980             <entry spanname="id"><constant>V4L2_CID_TUNE_DEEMPHASIS</constant>&nbsp;</entry>
4981             <entry>enum v4l2_deemphasis</entry>
4982           </row>
4983           <row id="v4l2-deemphasis"><entry spanname="descr">Configures the de-emphasis value for reception.
4984 A de-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4985 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_deemphasis
4986 defines possible values for de-emphasis. Here they are:</entry>
4987         </row><row>
4988         <entrytbl spanname="descr" cols="2">
4989                   <tbody valign="top">
4990                     <row>
4991                       <entry><constant>V4L2_DEEMPHASIS_DISABLED</constant>&nbsp;</entry>
4992                       <entry>No de-emphasis is applied.</entry>
4993                     </row>
4994                     <row>
4995                       <entry><constant>V4L2_DEEMPHASIS_50_uS</constant>&nbsp;</entry>
4996                       <entry>A de-emphasis of 50 uS is used.</entry>
4997                     </row>
4998                     <row>
4999                       <entry><constant>V4L2_DEEMPHASIS_75_uS</constant>&nbsp;</entry>
5000                       <entry>A de-emphasis of 75 uS is used.</entry>
5001                     </row>
5002                   </tbody>
5003                 </entrytbl>
5004
5005           </row>
5006           <row><entry></entry></row>
5007         </tbody>
5008       </tgroup>
5009       </table>
5010
5011       </section>
5012
5013     <section id="rf-tuner-controls">
5014       <title>RF Tuner Control Reference</title>
5015
5016       <para>
5017 The RF Tuner (RF_TUNER) class includes controls for common features of devices
5018 having RF tuner.
5019       </para>
5020       <para>
5021 In this context, RF tuner is radio receiver circuit between antenna and
5022 demodulator. It receives radio frequency (RF) from the antenna and converts that
5023 received signal to lower intermediate frequency (IF) or baseband frequency (BB).
5024 Tuners that could do baseband output are often called Zero-IF tuners. Older
5025 tuners were typically simple PLL tuners inside a metal box, whilst newer ones
5026 are highly integrated chips without a metal box "silicon tuners". These controls
5027 are mostly applicable for new feature rich silicon tuners, just because older
5028 tuners does not have much adjustable features.
5029       </para>
5030       <para>
5031 For more information about RF tuners see
5032 <ulink url="http://en.wikipedia.org/wiki/Tuner_%28radio%29">Tuner (radio)</ulink>
5033 and
5034 <ulink url="http://en.wikipedia.org/wiki/RF_front_end">RF front end</ulink>
5035 from Wikipedia.
5036       </para>
5037
5038       <table pgwide="1" frame="none" id="rf-tuner-control-id">
5039         <title>RF_TUNER Control IDs</title>
5040
5041         <tgroup cols="4">
5042           <colspec colname="c1" colwidth="1*" />
5043           <colspec colname="c2" colwidth="6*" />
5044           <colspec colname="c3" colwidth="2*" />
5045           <colspec colname="c4" colwidth="6*" />
5046           <spanspec namest="c1" nameend="c2" spanname="id" />
5047           <spanspec namest="c2" nameend="c4" spanname="descr" />
5048           <thead>
5049             <row>
5050               <entry spanname="id" align="left">ID</entry>
5051               <entry align="left">Type</entry>
5052             </row>
5053             <row rowsep="1">
5054               <entry spanname="descr" align="left">Description</entry>
5055             </row>
5056           </thead>
5057           <tbody valign="top">
5058             <row><entry></entry></row>
5059             <row>
5060               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_CLASS</constant>&nbsp;</entry>
5061               <entry>class</entry>
5062             </row><row><entry spanname="descr">The RF_TUNER class
5063 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
5064 description of this control class.</entry>
5065             </row>
5066             <row>
5067               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_BANDWIDTH_AUTO</constant>&nbsp;</entry>
5068               <entry>boolean</entry>
5069             </row>
5070             <row>
5071               <entry spanname="descr">Enables/disables tuner radio channel
5072 bandwidth configuration. In automatic mode bandwidth configuration is performed
5073 by the driver.</entry>
5074             </row>
5075             <row>
5076               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_BANDWIDTH</constant>&nbsp;</entry>
5077               <entry>integer</entry>
5078             </row>
5079             <row>
5080               <entry spanname="descr">Filter(s) on tuner signal path are used to
5081 filter signal according to receiving party needs. Driver configures filters to
5082 fulfill desired bandwidth requirement. Used when V4L2_CID_RF_TUNER_BANDWIDTH_AUTO is not
5083 set. Unit is in Hz. The range and step are driver-specific.</entry>
5084             </row>
5085             <row>
5086               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant>&nbsp;</entry>
5087               <entry>boolean</entry>
5088             </row>
5089             <row>
5090               <entry spanname="descr">Enables/disables LNA automatic gain control (AGC)</entry>
5091             </row>
5092             <row>
5093               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO</constant>&nbsp;</entry>
5094               <entry>boolean</entry>
5095             </row>
5096             <row>
5097               <entry spanname="descr">Enables/disables mixer automatic gain control (AGC)</entry>
5098             </row>
5099             <row>
5100               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_IF_GAIN_AUTO</constant>&nbsp;</entry>
5101               <entry>boolean</entry>
5102             </row>
5103             <row>
5104               <entry spanname="descr">Enables/disables IF automatic gain control (AGC)</entry>
5105             </row>
5106             <row>
5107               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN</constant>&nbsp;</entry>
5108               <entry>integer</entry>
5109             </row>
5110             <row>
5111               <entry spanname="descr">LNA (low noise amplifier) gain is first
5112 gain stage on the RF tuner signal path. It is located very close to tuner
5113 antenna input. Used when <constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant> is not set.
5114 The range and step are driver-specific.</entry>
5115             </row>
5116             <row>
5117               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_MIXER_GAIN</constant>&nbsp;</entry>
5118               <entry>integer</entry>
5119             </row>
5120             <row>
5121               <entry spanname="descr">Mixer gain is second gain stage on the RF
5122 tuner signal path. It is located inside mixer block, where RF signal is
5123 down-converted by the mixer. Used when <constant>V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO</constant>
5124 is not set. The range and step are driver-specific.</entry>
5125             </row>
5126             <row>
5127               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_IF_GAIN</constant>&nbsp;</entry>
5128               <entry>integer</entry>
5129             </row>
5130             <row>
5131               <entry spanname="descr">IF gain is last gain stage on the RF tuner
5132 signal path. It is located on output of RF tuner. It controls signal level of
5133 intermediate frequency output or baseband output. Used when
5134 <constant>V4L2_CID_RF_TUNER_IF_GAIN_AUTO</constant> is not set. The range and step are
5135 driver-specific.</entry>
5136             </row>
5137             <row>
5138               <entry spanname="id"><constant>V4L2_CID_RF_TUNER_PLL_LOCK</constant>&nbsp;</entry>
5139               <entry>boolean</entry>
5140             </row>
5141             <row>
5142               <entry spanname="descr">Is synthesizer PLL locked? RF tuner is
5143 receiving given frequency when that control is set. This is a read-only control.
5144 </entry>
5145             </row>
5146           </tbody>
5147         </tgroup>
5148       </table>
5149     </section>
5150 </section>