media/v4l/dv-timings.rst

1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
3 .. _dv-timings:
6 Digital Video (DV) Timings
9 The video standards discussed so far have been dealing with Analog TV
10 and the corresponding video timings. Today there are many more different
11 hardware interfaces such as High Definition TV interfaces (HDMI), VGA,
12 DVI connectors etc., that carry video signals and there is a need to
13 extend the API to select the video timings for these interfaces. Since
14 it is not possible to extend the :ref:`v4l2_std_id <v4l2-std-id>`
16 set/get video timings at the input and output.
18 These ioctls deal with the detailed digital video timings that define
19 each video format. This includes parameters such as the active video
21 widths etc. The ``linux/v4l2-dv-timings.h`` header can be used to get
33 the DV timings as seen by the video receiver applications use the
36 When the hardware detects a video source change (e.g. the video
37 signal appears or disappears, or the video resolution changes), then
42 If the video signal changed, then the application has to stop
44 to obtain the new video timings, and if they are valid, it can set
54 video. The correct approach is to rely on the `V4L2_EVENT_SOURCE_CHANGE`
57 Applications can make use of the :ref:`input-capabilities` and
58 :ref:`output-capabilities` flags to determine whether the digital
59 video ioctls can be used with the given input or output.