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authorLinus Torvalds <torvalds@linux-foundation.org>2016-07-28 00:58:31 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-28 00:58:31 +0300
commitff9a082fda424257976f08fce942609f358015e0 (patch)
tree478e6b449b19baaf842369a13923499ce83ef895 /Documentation/media/uapi/v4l/dv-timings.rst
parent6a492b0f23d28e1f946cdf08e54617484400dafb (diff)
parent85538b1ad145c67198cb55d02de14ba269cc323d (diff)
downloadlinux-ff9a082fda424257976f08fce942609f358015e0.tar.xz
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab: "This patch series does the conversion of all media documentation stuff to Restrutured Text markup format and add them to the Documentation/index.rst file. The media documentation was grouped into 4 books: - media uAPI - media kAPI - V4L driver-specific documentation - DVB driver-specific documentation It also contains several documentation improvements and one fixup patch for a core issue with cropcap. PS. After this patch series, the media DocBook is deprecated and should be removed. I'll add such patch on a future pull request" * tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits) [media] cx23885-cardlist.rst: add a new card [media] doc-rst: add some needed escape codes [media] doc-rst: kapi: use :c:func: instead of :cpp:func doc-rst: kernel-doc: fix a change introduced by mistake [media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops [media] dvb_ringbuffer.h: some documentation improvements [media] v4l2-ctrls.h: fully document the header file [media] doc-rst: Fix some typedef ugly warnings [media] doc-rst: reorganize the kAPI v4l2 chapters [media] rename v4l2-framework.rst to v4l2-intro.rst [media] move V4L2 clocks to a separate .rst file [media] v4l2-fh.rst: add cross references and markups [media] v4l2-fh.rst: add fh contents from v4l2-framework.rst [media] v4l2-fh.h: add documentation for it [media] v4l2-event.rst: add cross-references and markups [media] v4l2-event.h: document all functions [media] v4l2-event.rst: add text from v4l2-framework.rst [media] v4l2-framework.rst: remove videobuf quick chapter [media] v4l2-dev: add cross-references and improve markup [media] doc-rst: move v4l2-dev doc to a separate file ...
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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _dv-timings:
+
+**************************
+Digital Video (DV) Timings
+**************************
+
+The video standards discussed so far have been dealing with Analog TV
+and the corresponding video timings. Today there are many more different
+hardware interfaces such as High Definition TV interfaces (HDMI), VGA,
+DVI connectors etc., that carry video signals and there is a need to
+extend the API to select the video timings for these interfaces. Since
+it is not possible to extend the :ref:`v4l2_std_id <v4l2-std-id>`
+due to the limited bits available, a new set of ioctls was added to
+set/get video timings at the input and output.
+
+These ioctls deal with the detailed digital video timings that define
+each video format. This includes parameters such as the active video
+width and height, signal polarities, frontporches, backporches, sync
+widths etc. The ``linux/v4l2-dv-timings.h`` header can be used to get
+the timings of the formats in the :ref:`cea861` and :ref:`vesadmt`
+standards.
+
+To enumerate and query the attributes of the DV timings supported by a
+device applications use the
+:ref:`VIDIOC_ENUM_DV_TIMINGS` and
+:ref:`VIDIOC_DV_TIMINGS_CAP` ioctls. To set
+DV timings for the device applications use the
+:ref:`VIDIOC_S_DV_TIMINGS <VIDIOC_G_DV_TIMINGS>` ioctl and to get
+current DV timings they use the
+:ref:`VIDIOC_G_DV_TIMINGS <VIDIOC_G_DV_TIMINGS>` ioctl. To detect
+the DV timings as seen by the video receiver applications use the
+:ref:`VIDIOC_QUERY_DV_TIMINGS` ioctl.
+
+Applications can make use of the :ref:`input-capabilities` and
+:ref:`output-capabilities` flags to determine whether the digital
+video ioctls can be used with the given input or output.