diff options
Diffstat (limited to 'Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst index 3fc04daa9ffb..72f5e85b4f34 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst @@ -1244,3 +1244,217 @@ FWHT Flags * - __u8 - ``padding[3]`` - Applications and drivers must set this to zero. + +.. _v4l2-codec-stateless-mpeg2: + +``V4L2_CID_STATELESS_MPEG2_SEQUENCE (struct)`` + Specifies the sequence parameters (as extracted from the bitstream) for the + associated MPEG-2 slice data. This includes fields matching the syntax + elements from the sequence header and sequence extension parts of the + bitstream as specified by :ref:`mpeg2part2`. + +.. c:type:: v4l2_ctrl_mpeg2_sequence + +.. raw:: latex + + \small + +.. cssclass:: longtable + +.. tabularcolumns:: |p{1.4cm}|p{6.5cm}|p{9.4cm}| + +.. flat-table:: struct v4l2_ctrl_mpeg2_sequence + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u16 + - ``horizontal_size`` + - The width of the displayable part of the frame's luminance component. + * - __u16 + - ``vertical_size`` + - The height of the displayable part of the frame's luminance component. + * - __u32 + - ``vbv_buffer_size`` + - Used to calculate the required size of the video buffering verifier, + defined (in bits) as: 16 * 1024 * vbv_buffer_size. + * - __u16 + - ``profile_and_level_indication`` + - The current profile and level indication as extracted from the + bitstream. + * - __u8 + - ``chroma_format`` + - The chrominance sub-sampling format (1: 4:2:0, 2: 4:2:2, 3: 4:4:4). + * - __u8 + - ``flags`` + - See :ref:`MPEG-2 Sequence Flags <mpeg2_sequence_flags>`. + +.. _mpeg2_sequence_flags: + +``MPEG-2 Sequence Flags`` + +.. cssclass:: longtable + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - ``V4L2_MPEG2_SEQ_FLAG_PROGRESSIVE`` + - 0x01 + - Indication that all the frames for the sequence are progressive instead + of interlaced. + +.. raw:: latex + + \normalsize + +``V4L2_CID_STATELESS_MPEG2_PICTURE (struct)`` + Specifies the picture parameters (as extracted from the bitstream) for the + associated MPEG-2 slice data. This includes fields matching the syntax + elements from the picture header and picture coding extension parts of the + bitstream as specified by :ref:`mpeg2part2`. + +.. c:type:: v4l2_ctrl_mpeg2_picture + +.. raw:: latex + + \small + +.. cssclass:: longtable + +.. tabularcolumns:: |p{1.0cm}|p{5.6cm}|p{10.7cm}| + +.. flat-table:: struct v4l2_ctrl_mpeg2_picture + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u64 + - ``backward_ref_ts`` + - Timestamp of the V4L2 capture buffer to use as backward reference, used + with B-coded and P-coded frames. The timestamp refers to the + ``timestamp`` field in struct :c:type:`v4l2_buffer`. Use the + :c:func:`v4l2_timeval_to_ns()` function to convert the struct + :c:type:`timeval` in struct :c:type:`v4l2_buffer` to a __u64. + * - __u64 + - ``forward_ref_ts`` + - Timestamp for the V4L2 capture buffer to use as forward reference, used + with B-coded frames. The timestamp refers to the ``timestamp`` field in + struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()` + function to convert the struct :c:type:`timeval` in struct + :c:type:`v4l2_buffer` to a __u64. + * - __u32 + - ``flags`` + - See :ref:`MPEG-2 Picture Flags <mpeg2_picture_flags>`. + * - __u8 + - ``f_code[2][2]`` + - Motion vector codes. + * - __u8 + - ``picture_coding_type`` + - Picture coding type for the frame covered by the current slice + (V4L2_MPEG2_PIC_CODING_TYPE_I, V4L2_MPEG2_PIC_CODING_TYPE_P or + V4L2_MPEG2_PIC_CODING_TYPE_B). + * - __u8 + - ``picture_structure`` + - Picture structure (1: interlaced top field, 2: interlaced bottom field, + 3: progressive frame). + * - __u8 + - ``intra_dc_precision`` + - Precision of Discrete Cosine transform (0: 8 bits precision, + 1: 9 bits precision, 2: 10 bits precision, 3: 11 bits precision). + * - __u8 + - ``reserved[5]`` + - Applications and drivers must set this to zero. + +.. _mpeg2_picture_flags: + +``MPEG-2 Picture Flags`` + +.. cssclass:: longtable + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - ``V4L2_MPEG2_PIC_FLAG_TOP_FIELD_FIRST`` + - 0x00000001 + - If set and it's an interlaced stream, top field is output first. + * - ``V4L2_MPEG2_PIC_FLAG_FRAME_PRED_DCT`` + - 0x00000002 + - If set only frame-DCT and frame prediction are used. + * - ``V4L2_MPEG2_PIC_FLAG_CONCEALMENT_MV`` + - 0x00000004 + - If set motion vectors are coded for intra macroblocks. + * - ``V4L2_MPEG2_PIC_FLAG_Q_SCALE_TYPE`` + - 0x00000008 + - This flag affects the inverse quantization process. + * - ``V4L2_MPEG2_PIC_FLAG_INTRA_VLC`` + - 0x00000010 + - This flag affects the decoding of transform coefficient data. + * - ``V4L2_MPEG2_PIC_FLAG_ALT_SCAN`` + - 0x00000020 + - This flag affects the decoding of transform coefficient data. + * - ``V4L2_MPEG2_PIC_FLAG_REPEAT_FIRST`` + - 0x00000040 + - This flag affects the decoding process of progressive frames. + * - ``V4L2_MPEG2_PIC_FLAG_PROGRESSIVE`` + - 0x00000080 + - Indicates whether the current frame is progressive. + +.. raw:: latex + + \normalsize + +``V4L2_CID_STATELESS_MPEG2_QUANTISATION (struct)`` + Specifies quantisation matrices, in zigzag scanning order, for the + associated MPEG-2 slice data. This control is initialized by the kernel + to the matrices default values. If a bitstream transmits a user-defined + quantisation matrices load, applications are expected to use this control. + Applications are also expected to set the control loading the default + values, if the quantisation matrices need to be reset, for instance on a + sequence header. This process is specified by section 6.3.7. + "Quant matrix extension" of the specification. + +.. c:type:: v4l2_ctrl_mpeg2_quantisation + +.. tabularcolumns:: |p{0.8cm}|p{8.0cm}|p{8.5cm}| + +.. cssclass:: longtable + +.. raw:: latex + + \small + +.. flat-table:: struct v4l2_ctrl_mpeg2_quantisation + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u8 + - ``intra_quantiser_matrix[64]`` + - The quantisation matrix coefficients for intra-coded frames, in zigzag + scanning order. It is relevant for both luma and chroma components, + although it can be superseded by the chroma-specific matrix for + non-4:2:0 YUV formats. + * - __u8 + - ``non_intra_quantiser_matrix[64]`` + - The quantisation matrix coefficients for non-intra-coded frames, in + zigzag scanning order. It is relevant for both luma and chroma + components, although it can be superseded by the chroma-specific matrix + for non-4:2:0 YUV formats. + * - __u8 + - ``chroma_intra_quantiser_matrix[64]`` + - The quantisation matrix coefficients for the chominance component of + intra-coded frames, in zigzag scanning order. Only relevant for + non-4:2:0 YUV formats. + * - __u8 + - ``chroma_non_intra_quantiser_matrix[64]`` + - The quantisation matrix coefficients for the chrominance component of + non-intra-coded frames, in zigzag scanning order. Only relevant for + non-4:2:0 YUV formats. + +.. raw:: latex + + \normalsize |