xref: /kernel/linux/linux-5.10/Documentation/userspace-api/media/v4l/pixfmt-compressed.rst

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later

******************
Compressed Formats
******************


.. _compressed-formats:

.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|

.. flat-table:: Compressed Image Formats
    :header-rows:  1
    :stub-columns: 0
    :widths:       3 1 4

    * - Identifier
      - Code
      - Details
    * .. _V4L2-PIX-FMT-JPEG:

      - ``V4L2_PIX_FMT_JPEG``
      - 'JPEG'
      - TBD. See also :ref:`VIDIOC_G_JPEGCOMP <VIDIOC_G_JPEGCOMP>`,
	:ref:`VIDIOC_S_JPEGCOMP <VIDIOC_G_JPEGCOMP>`.
    * .. _V4L2-PIX-FMT-MPEG:

      - ``V4L2_PIX_FMT_MPEG``
      - 'MPEG'
      - MPEG multiplexed stream. The actual format is determined by
	extended control ``V4L2_CID_MPEG_STREAM_TYPE``, see
	:ref:`mpeg-control-id`.
    * .. _V4L2-PIX-FMT-H264:

      - ``V4L2_PIX_FMT_H264``
      - 'H264'
      - 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``
      - 'AVC1'
      - H264 video elementary stream without start codes.
    * .. _V4L2-PIX-FMT-H264-MVC:

      - ``V4L2_PIX_FMT_H264_MVC``
      - 'M264'
      - H264 MVC video elementary stream.
    * .. _V4L2-PIX-FMT-H264-SLICE:

      - ``V4L2_PIX_FMT_H264_SLICE``
      - 'S264'
      - H264 parsed slice data, including slice headers, either with or
	without the start code, as extracted from the H264 bitstream.
	This format is adapted for stateless video decoders that implement an
	H264 pipeline (using the :ref:`mem2mem` and :ref:`media-request-api`).
	This pixelformat has two modifiers that must be set at least once
	through the ``V4L2_CID_MPEG_VIDEO_H264_DECODE_MODE``
        and ``V4L2_CID_MPEG_VIDEO_H264_START_CODE`` controls.
	In addition, metadata associated with the frame to decode are
	required to be passed through the ``V4L2_CID_MPEG_VIDEO_H264_SPS``,
	``V4L2_CID_MPEG_VIDEO_H264_PPS``,
	``V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX``,
	``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS`` and
	``V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS`` controls.  See the
	:ref:`associated Codec Control IDs <v4l2-mpeg-h264>`.  Exactly
	one output and one capture buffer must be provided for use
	with this pixel format. The output buffer must contain the
	appropriate number of macroblocks to decode a full
	corresponding frame to the matching capture buffer.

	The syntax for this format is documented in :ref:`h264`, section
	7.3.2.8 "Slice layer without partitioning RBSP syntax" and the following
	sections.

	.. note::

	   This format is not yet part of the public kernel API and it
	   is expected to change.

    * .. _V4L2-PIX-FMT-H263:

      - ``V4L2_PIX_FMT_H263``
      - 'H263'
      - H263 video elementary stream.
    * .. _V4L2-PIX-FMT-MPEG1:

      - ``V4L2_PIX_FMT_MPEG1``
      - 'MPG1'
      - 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 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``
      - 'MG2S'
      - MPEG-2 parsed slice data, as extracted from the MPEG-2 bitstream.
	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
	quantization matrices can optionally be specified through the
	``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION`` control.
	See the :ref:`associated Codec Control IDs <v4l2-mpeg-mpeg2>`.
	Exactly one output and one capture buffer must be provided for use with
	this pixel format. The output buffer must contain the appropriate number
	of macroblocks to decode a full corresponding frame to the matching
	capture buffer.
    * .. _V4L2-PIX-FMT-MPEG4:

      - ``V4L2_PIX_FMT_MPEG4``
      - 'MPG4'
      - MPEG4 video elementary stream.
    * .. _V4L2-PIX-FMT-XVID:

      - ``V4L2_PIX_FMT_XVID``
      - 'XVID'
      - Xvid video elementary stream.
    * .. _V4L2-PIX-FMT-VC1-ANNEX-G:

      - ``V4L2_PIX_FMT_VC1_ANNEX_G``
      - 'VC1G'
      - VC1, SMPTE 421M Annex G compliant stream.
    * .. _V4L2-PIX-FMT-VC1-ANNEX-L:

      - ``V4L2_PIX_FMT_VC1_ANNEX_L``
      - 'VC1L'
      - VC1, SMPTE 421M Annex L compliant stream.
    * .. _V4L2-PIX-FMT-VP8:

      - ``V4L2_PIX_FMT_VP8``
      - 'VP80'
      - 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``
      - 'VP8F'
      - VP8 parsed frame, as extracted from the container.
	This format is adapted for stateless video decoders that implement a
	VP8 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_VP8_FRAME_HEADER`` control.
	See the :ref:`associated Codec Control IDs <v4l2-mpeg-vp8>`.
	Exactly one output and one capture buffer must be provided for use with
	this pixel format. The output buffer must contain the appropriate number
	of macroblocks to decode a full corresponding frame to the matching
	capture buffer.

	.. note::

	   This format is not yet part of the public kernel API and it
	   is expected to change.

    * .. _V4L2-PIX-FMT-VP9:

      - ``V4L2_PIX_FMT_VP9``
      - 'VP90'
      - 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 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-HEVC-SLICE:

      - ``V4L2_PIX_FMT_HEVC_SLICE``
      - 'S265'
      - HEVC parsed slice data, as extracted from the HEVC bitstream.
	This format is adapted for stateless video decoders that implement a
	HEVC pipeline (using the :ref:`mem2mem` and :ref:`media-request-api`).
	This pixelformat has two modifiers that must be set at least once
	through the ``V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE``
        and ``V4L2_CID_MPEG_VIDEO_HEVC_START_CODE`` controls.
	Metadata associated with the frame to decode is required to be passed
	through the following controls :
        * ``V4L2_CID_MPEG_VIDEO_HEVC_SPS``
        * ``V4L2_CID_MPEG_VIDEO_HEVC_PPS``
        * ``V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS``
	See the :ref:`associated Codec Control IDs <v4l2-mpeg-hevc>`.
	Buffers associated with this pixel format must contain the appropriate
	number of macroblocks to decode a full corresponding frame.

	.. note::

	   This format is not yet part of the public kernel API and it
	   is expected to change.
    * .. _V4L2-PIX-FMT-FWHT:

      - ``V4L2_PIX_FMT_FWHT``
      - 'FWHT'
      - 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``
      - 'SFWH'
      - Same format as V4L2_PIX_FMT_FWHT but requires stateless codec implementation.
	See the :ref:`associated Codec Control IDs <v4l2-mpeg-fwht>`.