On 09/07/2018 12:24 AM, Paul Kocialkowski wrote: > From: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> > > 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@xxxxxxxxxxx> > --- > .../media/uapi/v4l/extended-controls.rst | 176 ++++++++++++++++++ > .../media/uapi/v4l/pixfmt-compressed.rst | 16 ++ > .../media/uapi/v4l/vidioc-queryctrl.rst | 14 +- > .../media/videodev2.h.rst.exceptions | 2 + > drivers/media/v4l2-core/v4l2-ctrls.c | 63 +++++++ > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > include/media/v4l2-ctrls.h | 18 +- > include/uapi/linux/v4l2-controls.h | 65 +++++++ > include/uapi/linux/videodev2.h | 5 + > 9 files changed, 351 insertions(+), 9 deletions(-) > > diff --git a/Documentation/media/uapi/v4l/extended-controls.rst b/Documentation/media/uapi/v4l/extended-controls.rst > index 9f7312bf3365..f1951236266a 100644 > --- a/Documentation/media/uapi/v4l/extended-controls.rst > +++ b/Documentation/media/uapi/v4l/extended-controls.rst > @@ -1497,6 +1497,182 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > > > > +.. _v4l2-mpeg-mpeg2: > + > +``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS (struct)`` > + Specifies the slice parameters (as extracted from the bitstream) for the > + associated MPEG-2 slice data. This includes the necessary parameters for > + configuring a stateless hardware decoding pipeline for MPEG-2. > + The bitstream parameters are defined according to :ref:`mpeg2part2`. > + > +.. c:type:: v4l2_ctrl_mpeg2_slice_params > + > +.. cssclass:: longtable > + > +.. flat-table:: struct v4l2_ctrl_mpeg2_slice_params > + :header-rows: 0 > + :stub-columns: 0 > + :widths: 1 1 2 > + > + * - __u32 > + - ``bit_size`` > + - Size (in bits) of the current slice data. > + * - __u32 > + - ``data_bit_offset`` > + - Offset (in bits) to the video data in the current slice data. > + * - struct :c:type:`v4l2_mpeg2_sequence` > + - ``sequence`` > + - Structure with MPEG-2 sequence metadata, merging relevant fields from > + the sequence header and sequence extension parts of the bitstream. > + * - struct :c:type:`v4l2_mpeg2_picture` > + - ``picture`` > + - Structure with MPEG-2 picture metadata, merging relevant fields from > + the picture header and picture coding extension parts of the bitstream. > + * - __u8 > + - ``quantiser_scale_code`` > + - Code used to determine the quantization scale to use for the IDCT. > + * - __u8 > + - ``backward_ref_index`` > + - Index for the V4L2 buffer to use as backward reference, used with > + B-coded and P-coded frames. > + * - __u8 > + - ``forward_ref_index`` > + - Index for the V4L2 buffer to use as forward reference, used with > + P-coded frames. Do these indices refer to the output or capture buffers? I think these should refer to the output buffers, since this control is used in a request for the output side. Regards, Hans
