Documentation/DocBook/media/v4l/vidioc-g-tuner.xml

   1 <refentry id="vidioc-g-tuner">
   2   <refmeta>
   3     <refentrytitle>ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</refentrytitle>
   4     &manvol;
   5   </refmeta>
   6
   7   <refnamediv>
   8     <refname>VIDIOC_G_TUNER</refname>
   9     <refname>VIDIOC_S_TUNER</refname>
  10     <refpurpose>Get or set tuner attributes</refpurpose>
  11   </refnamediv>
  12
  13   <refsynopsisdiv>
  14     <funcsynopsis>
  15       <funcprototype>
  16         <funcdef>int <function>ioctl</function></funcdef>
  17         <paramdef>int <parameter>fd</parameter></paramdef>
  18         <paramdef>int <parameter>request</parameter></paramdef>
  19         <paramdef>struct v4l2_tuner
  20 *<parameter>argp</parameter></paramdef>
  21       </funcprototype>
  22     </funcsynopsis>
  23     <funcsynopsis>
  24       <funcprototype>
  25         <funcdef>int <function>ioctl</function></funcdef>
  26         <paramdef>int <parameter>fd</parameter></paramdef>
  27         <paramdef>int <parameter>request</parameter></paramdef>
  28         <paramdef>const struct v4l2_tuner
  29 *<parameter>argp</parameter></paramdef>
  30       </funcprototype>
  31     </funcsynopsis>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Arguments</title>
  36
  37     <variablelist>
  38       <varlistentry>
  39         <term><parameter>fd</parameter></term>
  40         <listitem>
  41           <para>&fd;</para>
  42         </listitem>
  43       </varlistentry>
  44       <varlistentry>
  45         <term><parameter>request</parameter></term>
  46         <listitem>
  47           <para>VIDIOC_G_TUNER, VIDIOC_S_TUNER</para>
  48         </listitem>
  49       </varlistentry>
  50       <varlistentry>
  51         <term><parameter>argp</parameter></term>
  52         <listitem>
  53           <para></para>
  54         </listitem>
  55       </varlistentry>
  56     </variablelist>
  57   </refsect1>
  58
  59   <refsect1>
  60     <title>Description</title>
  61
  62     <para>To query the attributes of a tuner applications initialize the
  63 <structfield>index</structfield> field and zero out the
  64 <structfield>reserved</structfield> array of a &v4l2-tuner; and call the
  65 <constant>VIDIOC_G_TUNER</constant> ioctl with a pointer to this
  66 structure. Drivers fill the rest of the structure or return an
  67 &EINVAL; when the index is out of bounds. To enumerate all tuners
  68 applications shall begin at index zero, incrementing by one until the
  69 driver returns <errorcode>EINVAL</errorcode>.</para>
  70
  71     <para>Tuners have two writable properties, the audio mode and
  72 the radio frequency. To change the audio mode, applications initialize
  73 the <structfield>index</structfield>,
  74 <structfield>audmode</structfield> and
  75 <structfield>reserved</structfield> fields and call the
  76 <constant>VIDIOC_S_TUNER</constant> ioctl. This will
  77 <emphasis>not</emphasis> change the current tuner, which is determined
  78 by the current video input. Drivers may choose a different audio mode
  79 if the requested mode is invalid or unsupported. Since this is a
  80 <!-- FIXME -->write-only ioctl, it does not return the actually
  81 selected audio mode.</para>
  82
  83     <para>To change the radio frequency the &VIDIOC-S-FREQUENCY; ioctl
  84 is available.</para>
  85
  86     <table pgwide="1" frame="none" id="v4l2-tuner">
  87       <title>struct <structname>v4l2_tuner</structname></title>
  88       <tgroup cols="3">
  89         <colspec colname="c1" colwidth="1*" />
  90         <colspec colname="c2" colwidth="1*" />
  91         <colspec colname="c3" colwidth="1*" />
  92         <colspec colname="c4" colwidth="1*" />
  93         <spanspec spanname="hspan" namest="c3" nameend="c4" />
  94         <tbody valign="top">
  95           <row>
  96             <entry>__u32</entry>
  97             <entry><structfield>index</structfield></entry>
  98             <entry spanname="hspan">Identifies the tuner, set by the
  99 application.</entry>
 100           </row>
 101           <row>
 102             <entry>__u8</entry>
 103             <entry><structfield>name</structfield>[32]</entry>
 104             <entry spanname="hspan"><para>Name of the tuner, a
 105 NUL-terminated ASCII string. This information is intended for the
 106 user.<!-- FIXME Video inputs already have a name, the purpose of this
 107 field is not quite clear.--></para></entry>
 108           </row>
 109           <row>
 110             <entry>__u32</entry>
 111             <entry><structfield>type</structfield></entry>
 112             <entry spanname="hspan">Type of the tuner, see <xref
 113                 linkend="v4l2-tuner-type" />.</entry>
 114           </row>
 115           <row>
 116             <entry>__u32</entry>
 117             <entry><structfield>capability</structfield></entry>
 118             <entry spanname="hspan"><para>Tuner capability flags, see
 119 <xref linkend="tuner-capability" />. Audio flags indicate the ability
 120 to decode audio subprograms. They will <emphasis>not</emphasis>
 121 change, for example with the current video standard.</para><para>When
 122 the structure refers to a radio tuner the
 123 <constant>V4L2_TUNER_CAP_LANG1</constant>,
 124 <constant>V4L2_TUNER_CAP_LANG2</constant> and
 125 <constant>V4L2_TUNER_CAP_NORM</constant> flags can't be used.</para>
 126 <para>If multiple frequency bands are supported, then
 127 <structfield>capability</structfield> is the union of all
 128 <structfield>capability</structfield> fields of each &v4l2-frequency-band;.
 129 </para></entry>
 130           </row>
 131           <row>
 132             <entry>__u32</entry>
 133             <entry><structfield>rangelow</structfield></entry>
 134             <entry spanname="hspan">The lowest tunable frequency in
 135 units of 62.5 kHz, or if the <structfield>capability</structfield>
 136 flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
 137 Hz, or if the <structfield>capability</structfield> flag
 138 <constant>V4L2_TUNER_CAP_1HZ</constant> is set, in units of 1 Hz.
 139 If multiple frequency bands are supported, then
 140 <structfield>rangelow</structfield> is the lowest frequency
 141 of all the frequency bands.</entry>
 142           </row>
 143           <row>
 144             <entry>__u32</entry>
 145             <entry><structfield>rangehigh</structfield></entry>
 146             <entry spanname="hspan">The highest tunable frequency in
 147 units of 62.5 kHz, or if the <structfield>capability</structfield>
 148 flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5
 149 Hz, or if the <structfield>capability</structfield> flag
 150 <constant>V4L2_TUNER_CAP_1HZ</constant> is set, in units of 1 Hz.
 151 If multiple frequency bands are supported, then
 152 <structfield>rangehigh</structfield> is the highest frequency
 153 of all the frequency bands.</entry>
 154           </row>
 155           <row>
 156             <entry>__u32</entry>
 157             <entry><structfield>rxsubchans</structfield></entry>
 158             <entry spanname="hspan"><para>Some tuners or audio
 159 decoders can determine the received audio subprograms by analyzing
 160 audio carriers, pilot tones or other indicators. To pass this
 161 information drivers set flags defined in <xref
 162                   linkend="tuner-rxsubchans" /> in this field. For
 163 example:</para></entry>
 164           </row>
 165           <row>
 166             <entry></entry>
 167             <entry></entry>
 168             <entry><constant>V4L2_TUNER_SUB_MONO</constant></entry>
 169             <entry>receiving mono audio</entry>
 170           </row>
 171           <row>
 172             <entry></entry>
 173             <entry></entry>
 174             <entry><constant>STEREO | SAP</constant></entry>
 175             <entry>receiving stereo audio and a secondary audio
 176 program</entry>
 177           </row>
 178           <row>
 179             <entry></entry>
 180             <entry></entry>
 181             <entry><constant>MONO | STEREO</constant></entry>
 182             <entry>receiving mono or stereo audio, the hardware cannot
 183 distinguish</entry>
 184           </row>
 185           <row>
 186             <entry></entry>
 187             <entry></entry>
 188             <entry><constant>LANG1 | LANG2</constant></entry>
 189             <entry>receiving bilingual audio</entry>
 190           </row>
 191           <row>
 192             <entry></entry>
 193             <entry></entry>
 194             <entry><constant>MONO | STEREO | LANG1 | LANG2</constant></entry>
 195             <entry>receiving mono, stereo or bilingual
 196 audio</entry>
 197           </row>
 198           <row>
 199             <entry></entry>
 200             <entry></entry>
 201             <entry spanname="hspan"><para>When the
 202 <constant>V4L2_TUNER_CAP_STEREO</constant>,
 203 <constant>_LANG1</constant>, <constant>_LANG2</constant> or
 204 <constant>_SAP</constant> flag is cleared in the
 205 <structfield>capability</structfield> field, the corresponding
 206 <constant>V4L2_TUNER_SUB_</constant> flag must not be set
 207 here.</para><para>This field is valid only if this is the tuner of the
 208 current video input, or when the structure refers to a radio
 209 tuner.</para></entry>
 210           </row>
 211           <row>
 212             <entry>__u32</entry>
 213             <entry><structfield>audmode</structfield></entry>
 214             <entry spanname="hspan"><para>The selected audio mode, see
 215 <xref linkend="tuner-audmode" /> for valid values. The audio mode does
 216 not affect audio subprogram detection, and like a <link
 217 linkend="control">control</link> it does not automatically change
 218 unless the requested mode is invalid or unsupported. See <xref
 219                   linkend="tuner-matrix" /> for possible results when
 220 the selected and received audio programs do not
 221 match.</para><para>Currently this is the only field of struct
 222 <structname>v4l2_tuner</structname> applications can
 223 change.</para></entry>
 224           </row>
 225           <row>
 226             <entry>__u32</entry>
 227             <entry><structfield>signal</structfield></entry>
 228             <entry spanname="hspan">The signal strength if known, ranging
 229 from 0 to 65535. Higher values indicate a better signal.</entry>
 230           </row>
 231           <row>
 232             <entry>__s32</entry>
 233             <entry><structfield>afc</structfield></entry>
 234             <entry spanname="hspan">Automatic frequency control: When the
 235 <structfield>afc</structfield> value is negative, the frequency is too
 236 low, when positive too high.<!-- FIXME need example what to do when it never
 237 settles at zero, &ie; range is what? --></entry>
 238           </row>
 239           <row>
 240             <entry>__u32</entry>
 241             <entry><structfield>reserved</structfield>[4]</entry>
 242             <entry spanname="hspan">Reserved for future extensions. Drivers and
 243 applications must set the array to zero.</entry>
 244           </row>
 245         </tbody>
 246       </tgroup>
 247     </table>
 248
 249     <table pgwide="1" frame="none" id="v4l2-tuner-type">
 250       <title>enum v4l2_tuner_type</title>
 251       <tgroup cols="3">
 252         &cs-def;
 253         <tbody valign="top">
 254           <row>
 255             <entry><constant>V4L2_TUNER_RADIO</constant></entry>
 256             <entry>1</entry>
 257             <entry></entry>
 258           </row>
 259           <row>
 260             <entry><constant>V4L2_TUNER_ANALOG_TV</constant></entry>
 261             <entry>2</entry>
 262             <entry></entry>
 263           </row>
 264         </tbody>
 265       </tgroup>
 266     </table>
 267
 268     <table pgwide="1" frame="none" id="tuner-capability">
 269       <title>Tuner and Modulator Capability Flags</title>
 270       <tgroup cols="3">
 271         &cs-def;
 272         <tbody valign="top">
 273           <row>
 274             <entry><constant>V4L2_TUNER_CAP_LOW</constant></entry>
 275             <entry>0x0001</entry>
 276             <entry>When set, tuning frequencies are expressed in units of
 277 62.5 Hz instead of 62.5 kHz.</entry>
 278           </row>
 279           <row>
 280             <entry><constant>V4L2_TUNER_CAP_NORM</constant></entry>
 281             <entry>0x0002</entry>
 282             <entry>This is a multi-standard tuner; the video standard
 283 can or must be switched. (B/G PAL tuners for example are typically not
 284       considered multi-standard because the video standard is automatically
 285       determined from the frequency band.) The set of supported video
 286       standards is available from the &v4l2-input; pointing to this tuner,
 287       see the description of ioctl &VIDIOC-ENUMINPUT; for details. Only
 288       <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry>
 289           </row>
 290           <row>
 291             <entry><constant>V4L2_TUNER_CAP_HWSEEK_BOUNDED</constant></entry>
 292             <entry>0x0004</entry>
 293             <entry>If set, then this tuner supports the hardware seek functionality
 294             where the seek stops when it reaches the end of the frequency range.</entry>
 295           </row>
 296           <row>
 297             <entry><constant>V4L2_TUNER_CAP_HWSEEK_WRAP</constant></entry>
 298             <entry>0x0008</entry>
 299             <entry>If set, then this tuner supports the hardware seek functionality
 300             where the seek wraps around when it reaches the end of the frequency range.</entry>
 301           </row>
 302           <row>
 303         <entry><constant>V4L2_TUNER_CAP_STEREO</constant></entry>
 304         <entry>0x0010</entry>
 305         <entry>Stereo audio reception is supported.</entry>
 306           </row>
 307           <row>
 308             <entry><constant>V4L2_TUNER_CAP_LANG1</constant></entry>
 309             <entry>0x0040</entry>
 310             <entry>Reception of the primary language of a bilingual
 311 audio program is supported. Bilingual audio is a feature of
 312 two-channel systems, transmitting the primary language monaural on the
 313 main audio carrier and a secondary language monaural on a second
 314 carrier. Only
 315       <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry>
 316           </row>
 317           <row>
 318             <entry><constant>V4L2_TUNER_CAP_LANG2</constant></entry>
 319             <entry>0x0020</entry>
 320             <entry>Reception of the secondary language of a bilingual
 321 audio program is supported. Only
 322       <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry>
 323           </row>
 324           <row>
 325             <entry><constant>V4L2_TUNER_CAP_SAP</constant></entry>
 326             <entry>0x0020</entry>
 327             <entry><para>Reception of a secondary audio program is
 328 supported. This is a feature of the BTSC system which accompanies the
 329 NTSC video standard. Two audio carriers are available for mono or
 330 stereo transmissions of a primary language, and an independent third
 331 carrier for a monaural secondary language. Only
 332       <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</para><para>Note the
 333 <constant>V4L2_TUNER_CAP_LANG2</constant> and
 334 <constant>V4L2_TUNER_CAP_SAP</constant> flags are synonyms.
 335 <constant>V4L2_TUNER_CAP_SAP</constant> applies when the tuner
 336 supports the <constant>V4L2_STD_NTSC_M</constant> video
 337 standard.</para><!-- FIXME what if PAL+NTSC and Bi but not SAP? --></entry>
 338           </row>
 339           <row>
 340         <entry><constant>V4L2_TUNER_CAP_RDS</constant></entry>
 341         <entry>0x0080</entry>
 342         <entry>RDS capture is supported. This capability is only valid for
 343 radio tuners.</entry>
 344           </row>
 345           <row>
 346         <entry><constant>V4L2_TUNER_CAP_RDS_BLOCK_IO</constant></entry>
 347         <entry>0x0100</entry>
 348         <entry>The RDS data is passed as unparsed RDS blocks.</entry>
 349           </row>
 350           <row>
 351         <entry><constant>V4L2_TUNER_CAP_RDS_CONTROLS</constant></entry>
 352         <entry>0x0200</entry>
 353         <entry>The RDS data is parsed by the hardware and set via controls.</entry>
 354           </row>
 355           <row>
 356         <entry><constant>V4L2_TUNER_CAP_FREQ_BANDS</constant></entry>
 357         <entry>0x0400</entry>
 358         <entry>The &VIDIOC-ENUM-FREQ-BANDS; ioctl can be used to enumerate
 359         the available frequency bands.</entry>
 360           </row>
 361           <row>
 362         <entry><constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant></entry>
 363         <entry>0x0800</entry>
 364         <entry>The range to search when using the hardware seek functionality
 365         is programmable, see &VIDIOC-S-HW-FREQ-SEEK; for details.</entry>
 366           </row>
 367           <row>
 368         <entry><constant>V4L2_TUNER_CAP_1HZ</constant></entry>
 369         <entry>0x1000</entry>
 370         <entry>When set, tuning frequencies are expressed in units of 1 Hz instead of 62.5 kHz.</entry>
 371           </row>
 372         </tbody>
 373       </tgroup>
 374     </table>
 375
 376     <table pgwide="1" frame="none" id="tuner-rxsubchans">
 377       <title>Tuner Audio Reception Flags</title>
 378       <tgroup cols="3">
 379         &cs-def;
 380         <tbody valign="top">
 381           <row>
 382             <entry><constant>V4L2_TUNER_SUB_MONO</constant></entry>
 383             <entry>0x0001</entry>
 384             <entry>The tuner receives a mono audio signal.</entry>
 385           </row>
 386           <row>
 387             <entry><constant>V4L2_TUNER_SUB_STEREO</constant></entry>
 388             <entry>0x0002</entry>
 389             <entry>The tuner receives a stereo audio signal.</entry>
 390           </row>
 391           <row>
 392             <entry><constant>V4L2_TUNER_SUB_LANG1</constant></entry>
 393             <entry>0x0008</entry>
 394             <entry>The tuner receives the primary language of a
 395 bilingual audio signal. Drivers must clear this flag when the current
 396 video standard is <constant>V4L2_STD_NTSC_M</constant>.</entry>
 397           </row>
 398           <row>
 399             <entry><constant>V4L2_TUNER_SUB_LANG2</constant></entry>
 400             <entry>0x0004</entry>
 401             <entry>The tuner receives the secondary language of a
 402 bilingual audio signal (or a second audio program).</entry>
 403           </row>
 404           <row>
 405             <entry><constant>V4L2_TUNER_SUB_SAP</constant></entry>
 406             <entry>0x0004</entry>
 407             <entry>The tuner receives a Second Audio Program. Note the
 408 <constant>V4L2_TUNER_SUB_LANG2</constant> and
 409 <constant>V4L2_TUNER_SUB_SAP</constant> flags are synonyms. The
 410 <constant>V4L2_TUNER_SUB_SAP</constant> flag applies when the
 411 current video standard is <constant>V4L2_STD_NTSC_M</constant>.</entry>
 412           </row>
 413           <row>
 414             <entry><constant>V4L2_TUNER_SUB_RDS</constant></entry>
 415             <entry>0x0010</entry>
 416             <entry>The tuner receives an RDS channel.</entry>
 417           </row>
 418         </tbody>
 419       </tgroup>
 420     </table>
 421
 422     <table pgwide="1" frame="none" id="tuner-audmode">
 423       <title>Tuner Audio Modes</title>
 424       <tgroup cols="3">
 425         &cs-def;
 426         <tbody valign="top">
 427           <row>
 428             <entry><constant>V4L2_TUNER_MODE_MONO</constant></entry>
 429             <entry>0</entry>
 430             <entry>Play mono audio. When the tuner receives a stereo
 431 signal this a down-mix of the left and right channel. When the tuner
 432 receives a bilingual or SAP signal this mode selects the primary
 433 language.</entry>
 434           </row>
 435           <row>
 436             <entry><constant>V4L2_TUNER_MODE_STEREO</constant></entry>
 437             <entry>1</entry>
 438             <entry><para>Play stereo audio. When the tuner receives
 439 bilingual audio it may play different languages on the left and right
 440 channel or the primary language is played on both channels.</para><para>Playing
 441 different languages in this mode is
 442 deprecated. New drivers should do this only in
 443 <constant>MODE_LANG1_LANG2</constant>.</para><para>When the tuner
 444 receives no stereo signal or does not support stereo reception the
 445 driver shall fall back to <constant>MODE_MONO</constant>.</para></entry>
 446           </row>
 447           <row>
 448             <entry><constant>V4L2_TUNER_MODE_LANG1</constant></entry>
 449             <entry>3</entry>
 450             <entry>Play the primary language, mono or stereo. Only
 451 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this
 452 mode.</entry>
 453           </row>
 454           <row>
 455             <entry><constant>V4L2_TUNER_MODE_LANG2</constant></entry>
 456             <entry>2</entry>
 457             <entry>Play the secondary language, mono. When the tuner
 458 receives no bilingual audio or SAP, or their reception is not
 459 supported the driver shall fall back to mono or stereo mode. Only
 460 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this
 461 mode.</entry>
 462           </row>
 463           <row>
 464             <entry><constant>V4L2_TUNER_MODE_SAP</constant></entry>
 465             <entry>2</entry>
 466             <entry>Play the Second Audio Program. When the tuner
 467 receives no bilingual audio or SAP, or their reception is not
 468 supported the driver shall fall back to mono or stereo mode. Only
 469 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this mode.
 470 Note the <constant>V4L2_TUNER_MODE_LANG2</constant> and
 471 <constant>V4L2_TUNER_MODE_SAP</constant> are synonyms.</entry>
 472           </row>
 473           <row>
 474             <entry><constant>V4L2_TUNER_MODE_LANG1_LANG2</constant></entry>
 475             <entry>4</entry>
 476             <entry>Play the primary language on the left channel, the
 477 secondary language on the right channel. When the tuner receives no
 478 bilingual audio or SAP, it shall fall back to
 479 <constant>MODE_LANG1</constant> or <constant>MODE_MONO</constant>.
 480 Only <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this
 481 mode.</entry>
 482           </row>
 483         </tbody>
 484       </tgroup>
 485     </table>
 486
 487     <table pgwide="1" frame="all" id="tuner-matrix">
 488       <title>Tuner Audio Matrix</title>
 489       <tgroup cols="6" align="center">
 490         <colspec align="left" />
 491         <colspec colname="c2" colwidth="1*" />
 492         <colspec colwidth="1*" />
 493         <colspec colwidth="1*" />
 494         <colspec colnum="6" colname="c6" colwidth="1*" />
 495         <spanspec namest="c2" nameend="c6" spanname="hspan" align="center" />
 496         <thead>
 497           <row>
 498             <entry></entry>
 499             <entry spanname="hspan">Selected
 500 <constant>V4L2_TUNER_MODE_</constant></entry>
 501           </row>
 502           <row>
 503             <entry>Received <constant>V4L2_TUNER_SUB_</constant></entry>
 504             <entry><constant>MONO</constant></entry>
 505             <entry><constant>STEREO</constant></entry>
 506             <entry><constant>LANG1</constant></entry>
 507             <entry><constant>LANG2 = SAP</constant></entry>
 508             <entry><constant>LANG1_LANG2</constant><footnote><para>This
 509 mode has been added in Linux 2.6.17 and may not be supported by older
 510 drivers.</para></footnote></entry>
 511           </row>
 512         </thead>
 513         <tbody valign="top">
 514           <row>
 515             <entry><constant>MONO</constant></entry>
 516             <entry>Mono</entry>
 517             <entry>Mono/Mono</entry>
 518             <entry>Mono</entry>
 519             <entry>Mono</entry>
 520             <entry>Mono/Mono</entry>
 521           </row>
 522           <row>
 523             <entry><constant>MONO | SAP</constant></entry>
 524             <entry>Mono</entry>
 525             <entry>Mono/Mono</entry>
 526             <entry>Mono</entry>
 527             <entry>SAP</entry>
 528             <entry>Mono/SAP (preferred) or Mono/Mono</entry>
 529           </row>
 530           <row>
 531             <entry><constant>STEREO</constant></entry>
 532             <entry>L+R</entry>
 533             <entry>L/R</entry>
 534             <entry>Stereo L/R (preferred) or Mono L+R</entry>
 535             <entry>Stereo L/R (preferred) or Mono L+R</entry>
 536             <entry>L/R (preferred) or L+R/L+R</entry>
 537           </row>
 538           <row>
 539             <entry><constant>STEREO | SAP</constant></entry>
 540             <entry>L+R</entry>
 541             <entry>L/R</entry>
 542             <entry>Stereo L/R (preferred) or Mono L+R</entry>
 543             <entry>SAP</entry>
 544             <entry>L+R/SAP (preferred) or L/R or L+R/L+R</entry>
 545           </row>
 546           <row>
 547             <entry><constant>LANG1 | LANG2</constant></entry>
 548             <entry>Language&nbsp;1</entry>
 549             <entry>Lang1/Lang2 (deprecated<footnote><para>Playback of
 550 both languages in <constant>MODE_STEREO</constant> is deprecated. In
 551 the future drivers should produce only the primary language in this
 552 mode. Applications should request
 553 <constant>MODE_LANG1_LANG2</constant> to record both languages or a
 554 stereo signal.</para></footnote>) or
 555 Lang1/Lang1</entry>
 556             <entry>Language&nbsp;1</entry>
 557             <entry>Language&nbsp;2</entry>
 558             <entry>Lang1/Lang2 (preferred) or Lang1/Lang1</entry>
 559           </row>
 560         </tbody>
 561       </tgroup>
 562     </table>
 563   </refsect1>
 564
 565   <refsect1>
 566     &return-value;
 567
 568     <variablelist>
 569       <varlistentry>
 570         <term><errorcode>EINVAL</errorcode></term>
 571         <listitem>
 572           <para>The &v4l2-tuner; <structfield>index</structfield> is
 573 out of bounds.</para>
 574         </listitem>
 575       </varlistentry>
 576     </variablelist>
 577   </refsect1>
 578 </refentry>