1 .. SPDX-License-Identifier: GFDL-1.1-no-invari
2 .. c:namespace:: V4L
3
4 .. _VIDIOC_G_DV_TIMINGS:
5
6 **********************************************
7 ioctl VIDIOC_G_DV_TIMINGS, VIDIOC_S_DV_TIMINGS
8 **********************************************
9
10 Name
11 ====
12
13 VIDIOC_G_DV_TIMINGS - VIDIOC_S_DV_TIMINGS - VI
14
15 Synopsis
16 ========
17
18 .. c:macro:: VIDIOC_G_DV_TIMINGS
19
20 ``int ioctl(int fd, VIDIOC_G_DV_TIMINGS, struc
21
22 .. c:macro:: VIDIOC_S_DV_TIMINGS
23
24 ``int ioctl(int fd, VIDIOC_S_DV_TIMINGS, struc
25
26 .. c:macro:: VIDIOC_SUBDEV_G_DV_TIMINGS
27
28 ``int ioctl(int fd, VIDIOC_SUBDEV_G_DV_TIMINGS
29
30 .. c:macro:: VIDIOC_SUBDEV_S_DV_TIMINGS
31
32 ``int ioctl(int fd, VIDIOC_SUBDEV_S_DV_TIMINGS
33
34 Arguments
35 =========
36
37 ``fd``
38 File descriptor returned by :c:func:`open(
39
40 ``argp``
41 Pointer to struct :c:type:`v4l2_dv_timings
42
43 Description
44 ===========
45
46 To set DV timings for the input or output, app
47 :ref:`VIDIOC_S_DV_TIMINGS <VIDIOC_G_DV_TIMINGS
48 applications use the :ref:`VIDIOC_G_DV_TIMINGS
49 information is filled in using the structure s
50 :c:type:`v4l2_dv_timings`. These ioctls take a
51 pointer to the struct :c:type:`v4l2_dv_timings
52 structure as argument. If the ioctl is not sup
53 values are not correct, the driver returns ``E
54
55 Calling ``VIDIOC_SUBDEV_S_DV_TIMINGS`` on a su
56 registered in read-only mode is not allowed. A
57 variable is set to ``-EPERM``.
58
59 The ``linux/v4l2-dv-timings.h`` header can be
60 the formats in the :ref:`cea861` and :ref:`ves
61 the current input or output does not support D
62 :ref:`VIDIOC_ENUMINPUT` does not set the
63 ``V4L2_IN_CAP_DV_TIMINGS`` flag), then ``ENODA
64
65 Return Value
66 ============
67
68 On success 0 is returned, on error -1 and the
69 appropriately. The generic error codes are des
70 :ref:`Generic Error Codes <gen-errors>` chapte
71
72 EINVAL
73 This ioctl is not supported, or the :ref:`
74 parameter was unsuitable.
75
76 ENODATA
77 Digital video timings are not supported fo
78
79 EBUSY
80 The device is busy and therefore can not c
81
82 EPERM
83 ``VIDIOC_SUBDEV_S_DV_TIMINGS`` has been ca
84
85 .. c:type:: v4l2_bt_timings
86
87 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm
88
89 .. cssclass:: longtable
90
91 .. flat-table:: struct v4l2_bt_timings
92 :header-rows: 0
93 :stub-columns: 0
94 :widths: 1 1 2
95
96 * - __u32
97 - ``width``
98 - Width of the active video in pixels.
99 * - __u32
100 - ``height``
101 - Height of the active video frame in li
102 formats the height of the active video
103 ``height``/2.
104 * - __u32
105 - ``interlaced``
106 - Progressive (``V4L2_DV_PROGRESSIVE``)
107 * - __u32
108 - ``polarities``
109 - This is a bit mask that defines polari
110 (``V4L2_DV_VSYNC_POS_POL``) is for ver
111 1 (``V4L2_DV_HSYNC_POS_POL``) is for h
112 the bit is set (1) it is positive pola
113 it is negative polarity.
114 * - __u64
115 - ``pixelclock``
116 - Pixel clock in Hz. Ex. 74.25MHz->74250
117 * - __u32
118 - ``hfrontporch``
119 - Horizontal front porch in pixels
120 * - __u32
121 - ``hsync``
122 - Horizontal sync length in pixels
123 * - __u32
124 - ``hbackporch``
125 - Horizontal back porch in pixels
126 * - __u32
127 - ``vfrontporch``
128 - Vertical front porch in lines. For int
129 to the odd field (aka field 1).
130 * - __u32
131 - ``vsync``
132 - Vertical sync length in lines. For int
133 to the odd field (aka field 1).
134 * - __u32
135 - ``vbackporch``
136 - Vertical back porch in lines. For inte
137 to the odd field (aka field 1).
138 * - __u32
139 - ``il_vfrontporch``
140 - Vertical front porch in lines for the
141 interlaced field formats. Must be 0 fo
142 * - __u32
143 - ``il_vsync``
144 - Vertical sync length in lines for the
145 interlaced field formats. Must be 0 fo
146 * - __u32
147 - ``il_vbackporch``
148 - Vertical back porch in lines for the e
149 interlaced field formats. Must be 0 fo
150 * - __u32
151 - ``standards``
152 - The video standard(s) this format belo
153 in by the driver. Applications must se
154 :ref:`dv-bt-standards` for a list of s
155 * - __u32
156 - ``flags``
157 - Several flags giving more information
158 :ref:`dv-bt-flags` for a description o
159 * - struct :c:type:`v4l2_fract`
160 - ``picture_aspect``
161 - The picture aspect if the pixels are n
162 ``V4L2_DV_FL_HAS_PICTURE_ASPECT`` flag
163 * - __u8
164 - ``cea861_vic``
165 - The Video Identification Code accordin
166 Only valid if the ``V4L2_DV_FL_HAS_CEA
167 * - __u8
168 - ``hdmi_vic``
169 - The Video Identification Code accordin
170 Only valid if the ``V4L2_DV_FL_HAS_HDM
171 * - __u8
172 - ``reserved[46]``
173 - Reserved for future extensions. Driver
174 the array to zero.
175
176 .. tabularcolumns:: |p{3.5cm}|p{3.5cm}|p{7.0cm
177
178 .. c:type:: v4l2_dv_timings
179
180 .. flat-table:: struct v4l2_dv_timings
181 :header-rows: 0
182 :stub-columns: 0
183 :widths: 1 1 2
184
185 * - __u32
186 - ``type``
187 - Type of DV timings as listed in :ref:`
188 * - union {
189 - (anonymous)
190 * - struct :c:type:`v4l2_bt_timings`
191 - ``bt``
192 - Timings defined by BT.656/1120 specifi
193 * - __u32
194 - ``reserved``\ [32]
195 -
196 * - }
197 -
198
199 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm
200
201 .. _dv-timing-types:
202
203 .. flat-table:: DV Timing types
204 :header-rows: 0
205 :stub-columns: 0
206 :widths: 1 1 2
207
208 * - Timing type
209 - value
210 - Description
211 * -
212 -
213 -
214 * - ``V4L2_DV_BT_656_1120``
215 - 0
216 - BT.656/1120 timings
217
218 .. tabularcolumns:: |p{6.5cm}|p{11.0cm}|
219
220 .. cssclass:: longtable
221
222 .. _dv-bt-standards:
223
224 .. flat-table:: DV BT Timing standards
225 :header-rows: 0
226 :stub-columns: 0
227
228 * - Timing standard
229 - Description
230 * - ``V4L2_DV_BT_STD_CEA861``
231 - The timings follow the CEA-861 Digital
232 * - ``V4L2_DV_BT_STD_DMT``
233 - The timings follow the VESA Discrete M
234 * - ``V4L2_DV_BT_STD_CVT``
235 - The timings follow the VESA Coordinate
236 * - ``V4L2_DV_BT_STD_GTF``
237 - The timings follow the VESA Generalize
238 * - ``V4L2_DV_BT_STD_SDI``
239 - The timings follow the SDI Timings sta
240 There are no horizontal syncs/porches
241 Total blanking timings must be set in
242
243 .. tabularcolumns:: |p{7.7cm}|p{9.8cm}|
244
245 .. cssclass:: longtable
246
247 .. _dv-bt-flags:
248
249 .. flat-table:: DV BT Timing flags
250 :header-rows: 0
251 :stub-columns: 0
252
253 * - Flag
254 - Description
255 * - ``V4L2_DV_FL_REDUCED_BLANKING``
256 - CVT/GTF specific: the timings use redu
257 'Secondary GTF' curve (GTF). In both c
258 vertical blanking intervals are reduce
259 resolution over the same bandwidth. Th
260 applications must not set this.
261 * - ``V4L2_DV_FL_CAN_REDUCE_FPS``
262 - CEA-861 specific: set for CEA-861 form
263 a multiple of six. These formats can b
264 1.001 speed to be compatible with 60 H
265 NTSC and PAL-M that use a framerate of
266 the transmitter can't generate such fr
267 will also be cleared. This is a read-o
268 not set this.
269 * - ``V4L2_DV_FL_REDUCED_FPS``
270 - CEA-861 specific: only valid for video
271 receivers that have the ``V4L2_DV_FL_C
272 set. This flag is cleared otherwise. I
273 formats with the ``V4L2_DV_FL_CAN_REDU
274 formats the flag will be cleared by th
275
276 If the application sets this flag for
277 pixelclock used to set up the transmit
278 make it compatible with NTSC framerate
279 generate such frequencies, then the fl
280
281 If a video receiver detects that the f
282 then it will set this flag to signal t
283 * - ``V4L2_DV_FL_HALF_LINE``
284 - Specific to interlaced formats: if set
285 frontporch of field 1 (aka the odd fie
286 longer and the vertical backporch of f
287 is really one half-line shorter, so ea
288 same number of half-lines. Whether hal
289 used depends on the hardware.
290 * - ``V4L2_DV_FL_IS_CE_VIDEO``
291 - If set, then this is a Consumer Electr
292 Such formats differ from other formats
293 formats) in that if R'G'B' encoding is
294 R'G'B' values use limited range (i.e.
295 range (i.e. 0-255). All formats define
296 640x480p59.94 format are CE formats.
297 * - ``V4L2_DV_FL_FIRST_FIELD_EXTRA_LINE``
298 - Some formats like SMPTE-125M have an i
299 total height. For these formats, if th
300 field has the extra line. Else, it is
301 * - ``V4L2_DV_FL_HAS_PICTURE_ASPECT``
302 - If set, then the picture_aspect field
303 the pixels are square, so the picture
304 width to height ratio.
305 * - ``V4L2_DV_FL_HAS_CEA861_VIC``
306 - If set, then the cea861_vic field is v
307 Identification Code as per the CEA-861
308 * - ``V4L2_DV_FL_HAS_HDMI_VIC``
309 - If set, then the hdmi_vic field is val
310 Identification Code as per the HDMI st
311 InfoFrame).
312 * - ``V4L2_DV_FL_CAN_DETECT_REDUCED_FPS``
313 - CEA-861 specific: only valid for video
314 cleared by transmitters.
315 If set, then the hardware can detect t
316 regular framerates and framerates redu
317 60 vs 59.94 Hz, 30 vs 29.97 Hz or 24 v
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