diff options
Diffstat (limited to 'Documentation/userspace-api')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 39 |
1 files changed, 10 insertions, 29 deletions
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst index e74a2531ab67..304b6012b358 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst @@ -1748,9 +1748,6 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - This compound control is not yet part of the public kernel API and it is expected to change. - This structure is expected to be passed as an array, with one - entry for each slice included in the bitstream buffer. - .. c:type:: v4l2_ctrl_h264_slice_params .. cssclass:: longtable @@ -1761,16 +1758,8 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - :widths: 1 1 2 * - __u32 - - ``start_byte_offset`` - Offset (in bytes) from the beginning of the OUTPUT buffer to the start - of the slice. If the slice starts with a start code, then this is the - offset to such start code. When operating in slice-based decoding mode - (see :c:type:`v4l2_mpeg_video_h264_decode_mode`), this field should - be set to 0. When operating in frame-based decoding mode, this field - should be 0 for the first slice. - * - __u32 - ``header_bit_size`` - - + - Offset in bits to slice_data() from the beginning of this slice. * - __u32 - ``first_mb_in_slice`` - @@ -1999,12 +1988,6 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - - ``dpb[16]`` - * - __u16 - - ``num_slices`` - - Number of slices needed to decode the current frame/field. When - operating in slice-based decoding mode (see - :c:type:`v4l2_mpeg_video_h264_decode_mode`), this field - should always be set to one. - * - __u16 - ``nal_ref_idc`` - NAL reference ID value coming from the NAL Unit header * - __s32 @@ -2121,22 +2104,20 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - * - ``V4L2_MPEG_VIDEO_H264_DECODE_MODE_SLICE_BASED`` - 0 - Decoding is done at the slice granularity. - In this mode, ``num_slices`` field in struct - :c:type:`v4l2_ctrl_h264_decode_params` should be set to 1, - and ``start_byte_offset`` in struct - :c:type:`v4l2_ctrl_h264_slice_params` should be set to 0. The OUTPUT buffer must contain a single slice. + When this mode is selected, the ``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS`` + control shall be set. When multiple slices compose a frame, + use of ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` flag + is required. * - ``V4L2_MPEG_VIDEO_H264_DECODE_MODE_FRAME_BASED`` - 1 - - Decoding is done at the frame granularity. - In this mode, ``num_slices`` field in struct - :c:type:`v4l2_ctrl_h264_decode_params` should be set to the number - of slices in the frame, and ``start_byte_offset`` in struct - :c:type:`v4l2_ctrl_h264_slice_params` should be set accordingly - for each slice. For the first slice, ``start_byte_offset`` should - be zero. + - Decoding is done at the frame granularity, The OUTPUT buffer must contain all slices needed to decode the frame. The OUTPUT buffer must also contain both fields. + This mode will be supported by devices that + parse the slice(s) header(s) in hardware. When this mode is + selected, the ``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS`` + control shall not be set. ``V4L2_CID_MPEG_VIDEO_H264_START_CODE (enum)`` Specifies the H264 slice start code expected for each slice. |