media: v4l: Add definitions for MPEG-2 slice format and metadata
Stateless video decoding engines require both the MPEG-2 slices and associated metadata from the video stream in order to decode frames. This introduces definitions for a new pixel format, describing buffers with MPEG-2 slice data, as well as control structure sfor passing the frame metadata to drivers. This is based on work from both Florent Revest and Hugues Fruchet. Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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Paul Kocialkowski
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Mauro Carvalho Chehab
Mauro Carvalho Chehab
parent
515c5a7333
commit
c27bb30e7b
@@ -1497,6 +1497,182 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
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.. _v4l2-mpeg-mpeg2:
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``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS (struct)``
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Specifies the slice parameters (as extracted from the bitstream) for the
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associated MPEG-2 slice data. This includes the necessary parameters for
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configuring a stateless hardware decoding pipeline for MPEG-2.
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The bitstream parameters are defined according to :ref:`mpeg2part2`.
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.. c:type:: v4l2_ctrl_mpeg2_slice_params
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.. cssclass:: longtable
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.. flat-table:: struct v4l2_ctrl_mpeg2_slice_params
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 1 2
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* - __u32
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- ``bit_size``
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- Size (in bits) of the current slice data.
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* - __u32
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- ``data_bit_offset``
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- Offset (in bits) to the video data in the current slice data.
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* - struct :c:type:`v4l2_mpeg2_sequence`
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- ``sequence``
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- Structure with MPEG-2 sequence metadata, merging relevant fields from
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the sequence header and sequence extension parts of the bitstream.
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* - struct :c:type:`v4l2_mpeg2_picture`
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- ``picture``
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- Structure with MPEG-2 picture metadata, merging relevant fields from
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the picture header and picture coding extension parts of the bitstream.
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* - __u8
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- ``quantiser_scale_code``
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- Code used to determine the quantization scale to use for the IDCT.
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* - __u8
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- ``backward_ref_index``
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- Index for the V4L2 buffer to use as backward reference, used with
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B-coded and P-coded frames.
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* - __u8
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- ``forward_ref_index``
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- Index for the V4L2 buffer to use as forward reference, used with
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B-coded frames.
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.. c:type:: v4l2_mpeg2_sequence
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.. cssclass:: longtable
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.. flat-table:: struct v4l2_mpeg2_sequence
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 1 2
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* - __u16
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- ``horizontal_size``
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- The width of the displayable part of the frame's luminance component.
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* - __u16
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- ``vertical_size``
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- The height of the displayable part of the frame's luminance component.
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* - __u32
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- ``vbv_buffer_size``
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- Used to calculate the required size of the video buffering verifier,
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defined (in bits) as: 16 * 1024 * vbv_buffer_size.
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* - __u8
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- ``profile_and_level_indication``
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- The current profile and level indication as extracted from the
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bitstream.
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* - __u8
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- ``progressive_sequence``
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- Indication that all the frames for the sequence are progressive instead
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of interlaced.
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* - __u8
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- ``chroma_format``
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- The chrominance sub-sampling format (1: 4:2:0, 2: 4:2:2, 3: 4:4:4).
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.. c:type:: v4l2_mpeg2_picture
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.. cssclass:: longtable
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.. flat-table:: struct v4l2_mpeg2_picture
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 1 2
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* - __u8
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- ``picture_coding_type``
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- Picture coding type for the frame covered by the current slice
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(V4L2_MPEG2_PICTURE_CODING_TYPE_I, V4L2_MPEG2_PICTURE_CODING_TYPE_P or
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V4L2_MPEG2_PICTURE_CODING_TYPE_B).
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* - __u8
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- ``f_code[2][2]``
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- Motion vector codes.
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* - __u8
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- ``intra_dc_precision``
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- Precision of Discrete Cosine transform (0: 8 bits precision,
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1: 9 bits precision, 2: 10 bits precision, 3: 11 bits precision).
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* - __u8
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- ``picture_structure``
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- Picture structure (1: interlaced top field, 2: interlaced bottom field,
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3: progressive frame).
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* - __u8
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- ``top_field_first``
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- If set to 1 and interlaced stream, top field is output first.
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* - __u8
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- ``frame_pred_frame_dct``
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- If set to 1, only frame-DCT and frame prediction are used.
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* - __u8
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- ``concealment_motion_vectors``
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- If set to 1, motion vectors are coded for intra macroblocks.
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* - __u8
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- ``q_scale_type``
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- This flag affects the inverse quantization process.
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* - __u8
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- ``intra_vlc_format``
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- This flag affects the decoding of transform coefficient data.
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* - __u8
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- ``alternate_scan``
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- This flag affects the decoding of transform coefficient data.
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* - __u8
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- ``repeat_first_field``
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- This flag affects the decoding process of progressive frames.
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* - __u8
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- ``progressive_frame``
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- Indicates whether the current frame is progressive.
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``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION (struct)``
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Specifies quantization matrices (as extracted from the bitstream) for the
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associated MPEG-2 slice data.
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.. c:type:: v4l2_ctrl_mpeg2_quantization
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.. cssclass:: longtable
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.. flat-table:: struct v4l2_ctrl_mpeg2_quantization
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:header-rows: 0
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:stub-columns: 0
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:widths: 1 1 2
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* - __u8
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- ``load_intra_quantiser_matrix``
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- One bit to indicate whether to load the ``intra_quantiser_matrix`` data.
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* - __u8
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- ``load_non_intra_quantiser_matrix``
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- One bit to indicate whether to load the ``non_intra_quantiser_matrix``
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data.
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* - __u8
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- ``load_chroma_intra_quantiser_matrix``
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- One bit to indicate whether to load the
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``chroma_intra_quantiser_matrix`` data, only relevant for non-4:2:0 YUV
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formats.
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* - __u8
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- ``load_chroma_non_intra_quantiser_matrix``
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- One bit to indicate whether to load the
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``chroma_non_intra_quantiser_matrix`` data, only relevant for non-4:2:0
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YUV formats.
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* - __u8
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- ``intra_quantiser_matrix[64]``
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- The quantization matrix coefficients for intra-coded frames, in zigzag
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scanning order. It is relevant for both luma and chroma components,
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although it can be superseded by the chroma-specific matrix for
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non-4:2:0 YUV formats.
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* - __u8
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- ``non_intra_quantiser_matrix[64]``
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- The quantization matrix coefficients for non-intra-coded frames, in
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zigzag scanning order. It is relevant for both luma and chroma
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components, although it can be superseded by the chroma-specific matrix
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for non-4:2:0 YUV formats.
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* - __u8
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- ``chroma_intra_quantiser_matrix[64]``
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- The quantization matrix coefficients for the chominance component of
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intra-coded frames, in zigzag scanning order. Only relevant for
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non-4:2:0 YUV formats.
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* - __u8
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- ``chroma_non_intra_quantiser_matrix[64]``
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- The quantization matrix coefficients for the chrominance component of
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non-intra-coded frames, in zigzag scanning order. Only relevant for
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non-4:2:0 YUV formats.
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MFC 5.1 MPEG Controls
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---------------------
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@@ -60,6 +60,22 @@ Compressed Formats
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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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* .. _V4L2-PIX-FMT-MPEG2-SLICE:
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- ``V4L2_PIX_FMT_MPEG2_SLICE``
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- 'MG2S'
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- MPEG-2 parsed slice data, as extracted from the MPEG-2 bitstream.
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This format is adapted for stateless video decoders that implement a
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MPEG-2 pipeline (using the :ref:`codec` and :ref:`media-request-api`).
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Metadata associated with the frame to decode is required to be passed
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through the ``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS`` control and
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quantization matrices can optionally be specified through the
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``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION`` control.
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See the :ref:`associated Codec Control IDs <v4l2-mpeg-mpeg2>`.
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Exactly one output and one capture buffer must be provided for use with
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this pixel format. The output buffer must contain the appropriate number
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of macroblocks to decode a full corresponding frame to the matching
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capture buffer.
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* .. _V4L2-PIX-FMT-MPEG4:
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- ``V4L2_PIX_FMT_MPEG4``
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@@ -424,8 +424,18 @@ See also the examples in :ref:`control`.
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- any
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- An unsigned 32-bit valued control ranging from minimum to maximum
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inclusive. The step value indicates the increment between values.
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* - ``V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS``
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- n/a
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- n/a
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- n/a
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- A struct :c:type:`v4l2_ctrl_mpeg2_slice_params`, containing MPEG-2
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slice parameters for stateless video decoders.
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* - ``V4L2_CTRL_TYPE_MPEG2_QUANTIZATION``
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- n/a
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- n/a
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- n/a
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- A struct :c:type:`v4l2_ctrl_mpeg2_quantization`, containing MPEG-2
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quantization matrices for stateless video decoders.
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.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
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