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| author |   Ezequiel Garcia <ezequiel@collabora.com> | 2021-04-29 16:48:12 +0200 |
|---|---|---|
| committer |   Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2021-05-23 19:21:31 +0200 |
| commit | f329e21e9dadc5c8ee37c781b30fe63bf7217201 (patch) | |
| tree | 34db63bf2ecfa482b87a92cdecd3fb7bc084536c /Documentation/userspace-api/media/v4l/pixfmt-compressed.rst | |
| parent | media: uapi: mpeg2: Cleanup flags (diff) | |
| download | linux-dev-f329e21e9dadc5c8ee37c781b30fe63bf7217201.tar.xz linux-dev-f329e21e9dadc5c8ee37c781b30fe63bf7217201.zip | |
media: uapi: mpeg2: Split sequence and picture parameters
Typically, bitstreams are composed of a sequence header,
followed by a number of picture header and picture coding extension
headers. Each picture can be composed of a number of slices.
Let's split the MPEG-2 uAPI to follow these semantics more closely,
allowing more usage flexibility. Having these controls split up
allows applications to set a sequence control at the beginning
of a sequence, and then set a picture control for each frame.
While here add padding fields where needed, and document
the uAPI header thoroughly.
Note that the V4L2_CTRL_TYPE_{} defines had to be moved because
it clashes with existing ones. This is not really an issue
since they will be re-defined when the controls are moved
out of staging.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/pixfmt-compressed.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/pixfmt-compressed.rst | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/Documentation/userspace-api/media/v4l/pixfmt-compressed.rst b/Documentation/userspace-api/media/v4l/pixfmt-compressed.rst index cba607f789f0..bbbacbd65d6f 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-compressed.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-compressed.rst @@ -114,8 +114,9 @@ Compressed Formats This format is adapted for stateless video decoders that implement a MPEG-2 pipeline (using the :ref:`mem2mem` and :ref:`media-request-api`). Metadata associated with the frame to decode is required to be passed - through the ``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS`` control and - quantisation matrices can optionally be specified through the + through the ``V4L2_CID_MPEG_VIDEO_MPEG2_SEQUENCE``, + ``V4L2_CID_MPEG_VIDEO_MPEG2_PICTURE``, and ``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS`` + controls. Quantisation matrices can optionally be specified through the ``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTISATION`` control. See the :ref:`associated Codec Control IDs <v4l2-mpeg-mpeg2>`. Exactly one output and one capture buffer must be provided for use with |