Commit d4e0f82a authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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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: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 051f8d2d

Documentation/media/uapi/v4l/pixfmt-compressed.rst

+30 −6
Original line number Diff line number Diff line
@@ -41,7 +41,12 @@ Compressed Formats 


      - ``V4L2_PIX_FMT_H264``

      - 'H264'

      - H264 video elementary stream with start codes.

      - H264 Access Unit.

	The decoder expects one Access Unit per buffer.

	The encoder generates one Access Unit per buffer.

	If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``

	then the decoder has no requirements since it can parse all the

	information from the raw bytestream.

    * .. _V4L2-PIX-FMT-H264-NO-SC:



      - ``V4L2_PIX_FMT_H264_NO_SC``
@@ -89,12 +94,20 @@ Compressed Formats 


      - ``V4L2_PIX_FMT_MPEG1``

      - 'MPG1'

      - MPEG1 video elementary stream.

      - MPEG1 Picture. Each buffer starts with a Picture header, followed

	by other headers as needed and ending with the Picture data.

	If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``

	then the decoder has no requirements since it can parse all the

	information from the raw bytestream.

    * .. _V4L2-PIX-FMT-MPEG2:



      - ``V4L2_PIX_FMT_MPEG2``

      - 'MPG2'

      - MPEG2 video elementary stream.

      - MPEG2 Picture. Each buffer starts with a Picture header, followed

	by other headers as needed and ending with the Picture data.

	If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``

	then the decoder has no requirements since it can parse all the

	information from the raw bytestream.

    * .. _V4L2-PIX-FMT-MPEG2-SLICE:



      - ``V4L2_PIX_FMT_MPEG2_SLICE``
@@ -135,7 +148,9 @@ Compressed Formats 


      - ``V4L2_PIX_FMT_VP8``

      - 'VP80'

      - VP8 video elementary stream.

      - VP8 compressed video frame. The encoder generates one

	compressed frame per buffer, and the decoder requires one

	compressed frame per buffer.

    * .. _V4L2-PIX-FMT-VP8-FRAME:



      - ``V4L2_PIX_FMT_VP8_FRAME``
@@ -160,12 +175,19 @@ Compressed Formats 


      - ``V4L2_PIX_FMT_VP9``

      - 'VP90'

      - VP9 video elementary stream.

      - VP9 compressed video frame. The encoder generates one

	compressed frame per buffer, and the decoder requires one

	compressed frame per buffer.

    * .. _V4L2-PIX-FMT-HEVC:



      - ``V4L2_PIX_FMT_HEVC``

      - 'HEVC'

      - HEVC/H.265 video elementary stream.

      - HEVC/H.265 Access Unit.

	The decoder expects one Access Unit per buffer.

	The encoder generates one Access Unit per buffer.

	If :ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``

	then the decoder has no	requirements since it can parse all the

	information from the raw bytestream.

    * .. _V4L2-PIX-FMT-FWHT:



      - ``V4L2_PIX_FMT_FWHT``
@@ -173,6 +195,8 @@ Compressed Formats 
      - Video elementary stream using a codec based on the Fast Walsh Hadamard

        Transform. This codec is implemented by the vicodec ('Virtual Codec')

	driver. See the codec-fwht.h header for more details.

	:ref:`VIDIOC_ENUM_FMT` reports ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``

	since the decoder can parse all the information from the raw bytestream.

    * .. _V4L2-PIX-FMT-FWHT-STATELESS:



      - ``V4L2_PIX_FMT_FWHT_STATELESS``

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