1 .. Permission is granted to copy, distribute and/or modify this
2 .. document under the terms of the GNU Free Documentation License,
3 .. Version 1.1 or any later version published by the Free Software
4 .. Foundation, with no Invariant Sections, no Front-Cover Texts
5 .. and no Back-Cover Texts. A copy of the license is included at
6 .. Documentation/media/uapi/fdl-appendix.rst.
8 .. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
12 *******************************************
13 ioctl VIDIOC_ENUMSTD, VIDIOC_SUBDEV_ENUMSTD
14 *******************************************
19 VIDIOC_ENUMSTD - VIDIOC_SUBDEV_ENUMSTD - Enumerate supported video standards
25 .. c:function:: int ioctl( int fd, VIDIOC_ENUMSTD, struct v4l2_standard *argp )
28 .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUMSTD, struct v4l2_standard *argp )
29 :name: VIDIOC_SUBDEV_ENUMSTD
36 File descriptor returned by :ref:`open() <func-open>`.
39 Pointer to struct :c:type:`v4l2_standard`.
45 To query the attributes of a video standard, especially a custom (driver
46 defined) one, applications initialize the ``index`` field of struct
47 :c:type:`v4l2_standard` and call the :ref:`VIDIOC_ENUMSTD`
48 ioctl with a pointer to this structure. Drivers fill the rest of the
49 structure or return an ``EINVAL`` error code when the index is out of
50 bounds. To enumerate all standards applications shall begin at index
51 zero, incrementing by one until the driver returns ``EINVAL``. Drivers may
52 enumerate a different set of standards after switching the video input
56 .. c:type:: v4l2_standard
58 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
60 .. flat-table:: struct v4l2_standard
67 - Number of the video standard, set by the application.
68 * - :ref:`v4l2_std_id <v4l2-std-id>`
70 - The bits in this field identify the standard as one of the common
71 standards listed in :ref:`v4l2-std-id`, or if bits 32 to 63 are
72 set as custom standards. Multiple bits can be set if the hardware
73 does not distinguish between these standards, however separate
74 indices do not indicate the opposite. The ``id`` must be unique.
75 No other enumerated struct :c:type:`v4l2_standard` structure,
76 for this input or output anyway, can contain the same set of bits.
79 - Name of the standard, a NUL-terminated ASCII string, for example:
80 "PAL-B/G", "NTSC Japan". This information is intended for the
82 * - struct :c:type:`v4l2_fract`
84 - The frame period (not field period) is numerator / denominator.
85 For example M/NTSC has a frame period of 1001 / 30000 seconds.
88 - Total lines per frame including blanking, e. g. 625 for B/PAL.
91 - Reserved for future extensions. Drivers must set the array to
96 .. c:type:: v4l2_fract
98 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
100 .. flat-table:: struct v4l2_fract
113 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
117 .. flat-table:: typedef v4l2_std_id
124 - This type is a set, each bit representing another video standard
125 as listed below and in :ref:`video-standards`. The 32 most
126 significant bits are reserved for custom (driver defined) video
133 #define V4L2_STD_PAL_B ((v4l2_std_id)0x00000001)
134 #define V4L2_STD_PAL_B1 ((v4l2_std_id)0x00000002)
135 #define V4L2_STD_PAL_G ((v4l2_std_id)0x00000004)
136 #define V4L2_STD_PAL_H ((v4l2_std_id)0x00000008)
137 #define V4L2_STD_PAL_I ((v4l2_std_id)0x00000010)
138 #define V4L2_STD_PAL_D ((v4l2_std_id)0x00000020)
139 #define V4L2_STD_PAL_D1 ((v4l2_std_id)0x00000040)
140 #define V4L2_STD_PAL_K ((v4l2_std_id)0x00000080)
142 #define V4L2_STD_PAL_M ((v4l2_std_id)0x00000100)
143 #define V4L2_STD_PAL_N ((v4l2_std_id)0x00000200)
144 #define V4L2_STD_PAL_Nc ((v4l2_std_id)0x00000400)
145 #define V4L2_STD_PAL_60 ((v4l2_std_id)0x00000800)
147 ``V4L2_STD_PAL_60`` is a hybrid standard with 525 lines, 60 Hz refresh
148 rate, and PAL color modulation with a 4.43 MHz color subcarrier. Some
149 PAL video recorders can play back NTSC tapes in this mode for display on
150 a 50/60 Hz agnostic PAL TV.
155 #define V4L2_STD_NTSC_M ((v4l2_std_id)0x00001000)
156 #define V4L2_STD_NTSC_M_JP ((v4l2_std_id)0x00002000)
157 #define V4L2_STD_NTSC_443 ((v4l2_std_id)0x00004000)
159 ``V4L2_STD_NTSC_443`` is a hybrid standard with 525 lines, 60 Hz refresh
160 rate, and NTSC color modulation with a 4.43 MHz color subcarrier.
165 #define V4L2_STD_NTSC_M_KR ((v4l2_std_id)0x00008000)
167 #define V4L2_STD_SECAM_B ((v4l2_std_id)0x00010000)
168 #define V4L2_STD_SECAM_D ((v4l2_std_id)0x00020000)
169 #define V4L2_STD_SECAM_G ((v4l2_std_id)0x00040000)
170 #define V4L2_STD_SECAM_H ((v4l2_std_id)0x00080000)
171 #define V4L2_STD_SECAM_K ((v4l2_std_id)0x00100000)
172 #define V4L2_STD_SECAM_K1 ((v4l2_std_id)0x00200000)
173 #define V4L2_STD_SECAM_L ((v4l2_std_id)0x00400000)
174 #define V4L2_STD_SECAM_LC ((v4l2_std_id)0x00800000)
177 #define V4L2_STD_ATSC_8_VSB ((v4l2_std_id)0x01000000)
178 #define V4L2_STD_ATSC_16_VSB ((v4l2_std_id)0x02000000)
180 ``V4L2_STD_ATSC_8_VSB`` and ``V4L2_STD_ATSC_16_VSB`` are U.S.
181 terrestrial digital TV standards. Presently the V4L2 API does not
182 support digital TV. See also the Linux DVB API at
183 `https://linuxtv.org <https://linuxtv.org>`__.
188 #define V4L2_STD_PAL_BG (V4L2_STD_PAL_B |
191 #define V4L2_STD_B (V4L2_STD_PAL_B |
194 #define V4L2_STD_GH (V4L2_STD_PAL_G |
198 #define V4L2_STD_PAL_DK (V4L2_STD_PAL_D |
201 #define V4L2_STD_PAL (V4L2_STD_PAL_BG |
205 #define V4L2_STD_NTSC (V4L2_STD_NTSC_M |
208 #define V4L2_STD_MN (V4L2_STD_PAL_M |
212 #define V4L2_STD_SECAM_DK (V4L2_STD_SECAM_D |
215 #define V4L2_STD_DK (V4L2_STD_PAL_DK |
218 #define V4L2_STD_SECAM (V4L2_STD_SECAM_B |
225 #define V4L2_STD_525_60 (V4L2_STD_PAL_M |
229 #define V4L2_STD_625_50 (V4L2_STD_PAL |
234 #define V4L2_STD_UNKNOWN 0
235 #define V4L2_STD_ALL (V4L2_STD_525_60 |
243 \setlength{\tabcolsep}{2pt}
245 .. NTSC/M PAL/M /N /B /D /H /I SECAM/B /D /K1 /L
246 .. tabularcolumns:: |p{1.43cm}|p{1.38cm}|p{1.59cm}|p{1.7cm}|p{1.7cm}|p{1.17cm}|p{0.64cm}|p{1.71cm}|p{1.6cm}|p{1.07cm}|p{1.07cm}|p{1.07cm}|
250 .. flat-table:: Video Standards (based on :ref:`itu470`)
270 - :cspan:`1` 1001/30000
272 * - Chrominance sub-carrier frequency (Hz)
278 - :cspan:`3` 4433618.75 ± 5
280 - :cspan:`2` f\ :sub:`OR` = 4406250 ± 2000,
282 f\ :sub:`OB` = 4250000 ± 2000
283 * - Nominal radio-frequency channel bandwidth (MHz)
295 * - Sound carrier relative to vision carrier (MHz)
299 - 5.5 ± 0.001 [#f4]_ [#f5]_ [#f6]_ [#f7]_
317 On success 0 is returned, on error -1 and the ``errno`` variable is set
318 appropriately. The generic error codes are described at the
319 :ref:`Generic Error Codes <gen-errors>` chapter.
322 The struct :c:type:`v4l2_standard` ``index`` is out
326 Standard video timings are not supported for this input or output.
329 The supported standards may overlap and we need an unambiguous set to
330 find the current standard returned by :ref:`VIDIOC_G_STD <VIDIOC_G_STD>`.
333 Japan uses a standard similar to M/NTSC (V4L2_STD_NTSC_M_JP).
336 The values in brackets apply to the combination N/PAL a.k.a.
337 N\ :sub:`C` used in Argentina (V4L2_STD_PAL_Nc).
340 In the Federal Republic of Germany, Austria, Italy, the Netherlands,
341 Slovakia and Switzerland a system of two sound carriers is used, the
342 frequency of the second carrier being 242.1875 kHz above the
343 frequency of the first sound carrier. For stereophonic sound
344 transmissions a similar system is used in Australia.
347 New Zealand uses a sound carrier displaced 5.4996 ± 0.0005 MHz from
351 In Denmark, Finland, New Zealand, Sweden and Spain a system of two
352 sound carriers is used. In Iceland, Norway and Poland the same system
353 is being introduced. The second carrier is 5.85 MHz above the vision
354 carrier and is DQPSK modulated with 728 kbit/s sound and data
355 multiplex. (NICAM system)
358 In the United Kingdom, a system of two sound carriers is used. The
359 second sound carrier is 6.552 MHz above the vision carrier and is
360 DQPSK modulated with a 728 kbit/s sound and data multiplex able to
361 carry two sound channels. (NICAM system)
364 In France, a digital carrier 5.85 MHz away from the vision carrier
365 may be used in addition to the main sound carrier. It is modulated in
366 differentially encoded QPSK with a 728 kbit/s sound and data
367 multiplexer capable of carrying two sound channels. (NICAM system)