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media: pixfmt-compressed.rst: improve H264/HEVC/MPEG1+2/VP8+9 documentation
The existing documentation was incorrect and did not correspond
to how actual codec drivers implemented this.
Update the documentation to explicitly specify what is actually
expected.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
authored by
Hans Verkuil
and committed by
Mauro Carvalho Chehab
d4e0f82a
051f8d2d
+30
-6
+30
-6
Documentation/media/uapi/v4l/pixfmt-compressed.rst
+30
-6
Documentation/media/uapi/v4l/pixfmt-compressed.rst
···
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- ``V4L2_PIX_FMT_H264``
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- 'H264'
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-
- H264 video elementary stream with start codes.
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- H264 Access Unit.
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The decoder expects one Access Unit per buffer.
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The encoder generates one Access Unit per buffer.
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If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
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then the decoder has no requirements since it can parse all the
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information from the raw bytestream.
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* .. _V4L2-PIX-FMT-H264-NO-SC:
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- ``V4L2_PIX_FMT_H264_NO_SC``
···
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- ``V4L2_PIX_FMT_MPEG1``
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- 'MPG1'
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- MPEG1 video elementary stream.
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- MPEG1 Picture. Each buffer starts with a Picture header, followed
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by other headers as needed and ending with the Picture data.
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If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
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then the decoder has no requirements since it can parse all the
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information from the raw bytestream.
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* .. _V4L2-PIX-FMT-MPEG2:
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- ``V4L2_PIX_FMT_MPEG2``
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- 'MPG2'
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-
- MPEG2 video elementary stream.
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- MPEG2 Picture. Each buffer starts with a Picture header, followed
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by other headers as needed and ending with the Picture data.
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If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
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then the decoder has no requirements since it can parse all the
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information from the raw bytestream.
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* .. _V4L2-PIX-FMT-MPEG2-SLICE:
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- ``V4L2_PIX_FMT_MPEG2_SLICE``
···
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- ``V4L2_PIX_FMT_VP8``
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- 'VP80'
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-
- VP8 video elementary stream.
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- VP8 compressed video frame. The encoder generates one
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compressed frame per buffer, and the decoder requires one
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compressed frame per buffer.
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* .. _V4L2-PIX-FMT-VP8-FRAME:
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- ``V4L2_PIX_FMT_VP8_FRAME``
···
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- ``V4L2_PIX_FMT_VP9``
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- 'VP90'
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- VP9 video elementary stream.
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- VP9 compressed video frame. The encoder generates one
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compressed frame per buffer, and the decoder requires one
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compressed frame per buffer.
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* .. _V4L2-PIX-FMT-HEVC:
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- ``V4L2_PIX_FMT_HEVC``
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- 'HEVC'
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- HEVC/H.265 video elementary stream.
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- HEVC/H.265 Access Unit.
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The decoder expects one Access Unit per buffer.
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The encoder generates one Access Unit per buffer.
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If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
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then the decoder has no requirements since it can parse all the
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information from the raw bytestream.
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* .. _V4L2-PIX-FMT-FWHT:
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- ``V4L2_PIX_FMT_FWHT``
···
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- Video elementary stream using a codec based on the Fast Walsh Hadamard
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Transform. This codec is implemented by the vicodec ('Virtual Codec')
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driver. See the codec-fwht.h header for more details.
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:ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
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since the decoder can parse all the information from the raw bytestream.
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* .. _V4L2-PIX-FMT-FWHT-STATELESS:
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- ``V4L2_PIX_FMT_FWHT_STATELESS``