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Message-ID: <6ec22799669a0bd50d50ec4092e17384269f71a0.camel@ndufresne.ca>
Date: Mon, 11 Feb 2019 12:16:23 -0500
From: Nicolas Dufresne <nicolas@...fresne.ca>
To: Hans Verkuil <hverkuil@...all.nl>,
Maxime Ripard <maxime.ripard@...tlin.com>,
hans.verkuil@...co.com, acourbot@...omium.org,
sakari.ailus@...ux.intel.com,
Laurent Pinchart <laurent.pinchart@...asonboard.com>
Cc: tfiga@...omium.org, posciak@...omium.org,
Paul Kocialkowski <paul.kocialkowski@...tlin.com>,
Chen-Yu Tsai <wens@...e.org>, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-media@...r.kernel.org,
jenskuske@...il.com, jernej.skrabec@...il.com, jonas@...boo.se,
ezequiel@...labora.com, linux-sunxi@...glegroups.com,
Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
Guenter Roeck <groeck@...omium.org>
Subject: Re: [PATCH v3 1/2] media: uapi: Add H264 low-level decoder API
compound controls.
Le lundi 11 février 2019 à 16:16 +0100, Hans Verkuil a écrit :
> Hi Maxime,
>
> A quick review below. Note that I am no expert on the codec details, so
> I leave that to others. I'm mainly concentrating on the structs, flags, etc.
>
> On 2/11/19 3:39 PM, Maxime Ripard wrote:
> > From: Pawel Osciak <posciak@...omium.org>
> >
> > Stateless video codecs will require both the H264 metadata and slices in
> > order to be able to decode frames.
> >
> > This introduces the definitions for a new pixel format for H264 slices that
> > have been parsed, as well as the structures used to pass the metadata from
> > the userspace to the kernel.
> >
> > Co-Developed-by: Maxime Ripard <maxime.ripard@...tlin.com>
> > Signed-off-by: Pawel Osciak <posciak@...omium.org>
> > Signed-off-by: Guenter Roeck <groeck@...omium.org>
> > Signed-off-by: Maxime Ripard <maxime.ripard@...tlin.com>
> > ---
> > Documentation/media/uapi/v4l/biblio.rst | 9 +-
> > Documentation/media/uapi/v4l/extended-controls.rst | 530 ++++++++++++++-
> > Documentation/media/uapi/v4l/pixfmt-compressed.rst | 20 +-
> > Documentation/media/uapi/v4l/vidioc-queryctrl.rst | 30 +-
> > Documentation/media/videodev2.h.rst.exceptions | 5 +-
> > drivers/media/v4l2-core/v4l2-ctrls.c | 42 +-
> > drivers/media/v4l2-core/v4l2-ioctl.c | 1 +-
> > include/media/h264-ctrls.h | 179 +++++-
> > include/media/v4l2-ctrls.h | 13 +-
> > include/uapi/linux/videodev2.h | 1 +-
> > 10 files changed, 829 insertions(+), 1 deletion(-)
> > create mode 100644 include/media/h264-ctrls.h
> >
> > diff --git a/Documentation/media/uapi/v4l/biblio.rst b/Documentation/media/uapi/v4l/biblio.rst
> > index ec33768c055e..3fc3f7ff338a 100644
> > --- a/Documentation/media/uapi/v4l/biblio.rst
> > +++ b/Documentation/media/uapi/v4l/biblio.rst
> > @@ -122,6 +122,15 @@ ITU BT.1119
> >
> > :author: International Telecommunication Union (http://www.itu.ch)
> >
> > +.. _h264:
> > +
> > +ITU H.264
> > +=========
> > +
> > +:title: ITU-T Recommendation H.264 "Advanced Video Coding for Generic Audiovisual Services"
> > +
> > +:author: International Telecommunication Union (http://www.itu.ch)
> > +
> > .. _jfif:
> >
> > JFIF
> > diff --git a/Documentation/media/uapi/v4l/extended-controls.rst b/Documentation/media/uapi/v4l/extended-controls.rst
> > index af4273aa5e85..7e306aa0d0a6 100644
> > --- a/Documentation/media/uapi/v4l/extended-controls.rst
> > +++ b/Documentation/media/uapi/v4l/extended-controls.rst
> > @@ -1703,6 +1703,536 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
> > non-intra-coded frames, in zigzag scanning order. Only relevant for
> > non-4:2:0 YUV formats.
> >
> > +.. _v4l2-mpeg-h264:
> > +
> > +``V4L2_CID_MPEG_VIDEO_H264_SPS (struct)``
> > + Specifies the sequence parameter set (as extracted from the
> > + bitstream) for the associated H264 slice data. This includes the
> > + necessary parameters for configuring a stateless hardware decoding
> > + pipeline for H264. The bitstream parameters are defined according
> > + to :ref:`h264`. Unless there's a specific comment, refer to the
> > + specification for the documentation of these fields, section 7.4.2.1.1
> > + "Sequence Parameter Set Data Semantics".
> > +
> > + .. note::
> > +
> > + This compound control is not yet part of the public kernel API and
> > + it is expected to change.
> > +
> > +.. c:type:: v4l2_ctrl_h264_sps
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_ctrl_h264_sps
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u8
> > + - ``profile_idc``
> > + -
> > + * - __u8
> > + - ``constraint_set_flags``
> > + - See :ref:`Sequence Parameter Set Constraints Set Flags <h264_sps_constraints_set_flags>`
> > + * - __u8
> > + - ``level_idc``
> > + -
> > + * - __u8
> > + - ``seq_parameter_set_id``
> > + -
> > + * - __u8
> > + - ``chroma_format_idc``
> > + -
> > + * - __u8
> > + - ``bit_depth_luma_minus8``
> > + -
> > + * - __u8
> > + - ``bit_depth_chroma_minus8``
> > + -
> > + * - __u8
> > + - ``log2_max_frame_num_minus4``
> > + -
> > + * - __u8
> > + - ``pic_order_cnt_type``
> > + -
> > + * - __u8
> > + - ``log2_max_pic_order_cnt_lsb_minus4``
> > + -
> > + * - __u8
> > + - ``max_num_ref_frames``
> > + -
> > + * - __u8
> > + - ``num_ref_frames_in_pic_order_cnt_cycle``
> > + -
> > + * - __s32
> > + - ``offset_for_ref_frame[255]``
> > + -
> > + * - __s32
> > + - ``offset_for_non_ref_pic``
> > + -
> > + * - __s32
> > + - ``offset_for_top_to_bottom_field``
> > + -
> > + * - __u16
> > + - ``pic_width_in_mbs_minus1``
> > + -
> > + * - __u16
> > + - ``pic_height_in_map_units_minus1``
> > + -
> > + * - __u32
> > + - ``flags``
> > + - See :ref:`Sequence Parameter Set Flags <h264_sps_flags>`
> > +
> > +.. _h264_sps_constraints_set_flags:
> > +
> > +``Sequence Parameter Set Constraints Set Flags``
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET0_FLAG``
> > + - 0x00000001
> > + -
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET1_FLAG``
> > + - 0x00000002
> > + -
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET2_FLAG``
> > + - 0x00000004
> > + -
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET3_FLAG``
> > + - 0x00000008
> > + -
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET4_FLAG``
> > + - 0x00000010
> > + -
> > + * - ``V4L2_H264_SPS_CONSTRAINT_SET5_FLAG``
> > + - 0x00000020
> > + -
> > +
> > +.. _h264_sps_flags:
> > +
> > +``Sequence Parameter Set Flags``
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - ``V4L2_H264_SPS_FLAG_SEPARATE_COLOUR_PLANE``
> > + - 0x00000001
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_QPPRIME_Y_ZERO_TRANSFORM_BYPASS``
> > + - 0x00000002
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_DELTA_PIC_ORDER_ALWAYS_ZERO``
> > + - 0x00000004
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_GAPS_IN_FRAME_NUM_VALUE_ALLOWED``
> > + - 0x00000008
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY``
> > + - 0x00000010
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD``
> > + - 0x00000020
> > + -
> > + * - ``V4L2_H264_SPS_FLAG_DIRECT_8X8_INFERENCE``
> > + - 0x00000040
> > + -
> > +
> > +``V4L2_CID_MPEG_VIDEO_H264_PPS (struct)``
> > + Specifies the picture parameter set (as extracted from the
> > + bitstream) for the associated H264 slice data. This includes the
> > + necessary parameters for configuring a stateless hardware decoding
> > + pipeline for H264. The bitstream parameters are defined according
> > + to :ref:`h264`. Unless there's a specific comment, refer to the
> > + specification for the documentation of these fields, section 7.4.2.2
> > + "Picture Parameter Set RBSP Semantics".
> > +
> > + .. note::
> > +
> > + This compound control is not yet part of the public kernel API and
> > + it is expected to change.
> > +
> > +.. c:type:: v4l2_ctrl_h264_pps
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_ctrl_h264_pps
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u8
> > + - ``pic_parameter_set_id``
> > + -
> > + * - __u8
> > + - ``seq_parameter_set_id``
> > + -
> > + * - __u8
> > + - ``num_slice_groups_minus1``
> > + -
> > + * - __u8
> > + - ``num_ref_idx_l0_default_active_minus1``
> > + -
> > + * - __u8
> > + - ``num_ref_idx_l1_default_active_minus1``
> > + -
> > + * - __u8
> > + - ``weighted_bipred_idc``
> > + -
> > + * - __s8
> > + - ``pic_init_qp_minus26``
> > + -
> > + * - __s8
> > + - ``pic_init_qs_minus26``
> > + -
> > + * - __s8
> > + - ``chroma_qp_index_offset``
> > + -
> > + * - __s8
> > + - ``second_chroma_qp_index_offset``
> > + -
> > + * - __u16
> > + - ``flags``
> > + - See :ref:`Picture Parameter Set Flags <h264_pps_flags>`
> > +
> > +.. _h264_pps_flags:
> > +
> > +``Picture Parameter Set Flags``
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - ``V4L2_H264_PPS_FLAG_ENTROPY_CODING_MODE``
> > + - 0x00000001
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_BOTTOM_FIELD_PIC_ORDER_IN_FRAME_PRESENT``
> > + - 0x00000002
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_WEIGHTED_PRED``
> > + - 0x00000004
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_DEBLOCKING_FILTER_CONTROL_PRESENT``
> > + - 0x00000008
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_CONSTRAINED_INTRA_PRED``
> > + - 0x00000010
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_REDUNDANT_PIC_CNT_PRESENT``
> > + - 0x00000020
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_TRANSFORM_8X8_MODE``
> > + - 0x00000040
> > + -
> > + * - ``V4L2_H264_PPS_FLAG_PIC_SCALING_MATRIX_PRESENT``
> > + - 0x00000080
> > + -
> > +
> > +``V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX (struct)``
> > + Specifies the scaling matrix (as extracted from the bitstream) for
> > + the associated H264 slice data. The bitstream parameters are
> > + defined according to :ref:`h264`. Unless there's a specific
> > + comment, refer to the specification for the documentation of these
> > + fields, section 7.4.2.1.1.1 "Scaling List Semantics".
> > +
> > + .. note::
> > +
> > + This compound control is not yet part of the public kernel API and
> > + it is expected to change.
> > +
> > +.. c:type:: v4l2_ctrl_h264_scaling_matrix
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_ctrl_h264_scaling_matrix
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u8
> > + - ``scaling_list_4x4[6][16]``
> > + -
> > + * - __u8
> > + - ``scaling_list_8x8[6][64]``
> > + -
> > +
> > +``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS (struct)``
> > + Specifies the slice parameters (as extracted from the bitstream)
> > + for the associated H264 slice data. This includes the necessary
> > + parameters for configuring a stateless hardware decoding pipeline
> > + for H264. The bitstream parameters are defined according to
> > + :ref:`h264`. Unless there's a specific comment, refer to the
> > + specification for the documentation of these fields, section 7.4.3
> > + "Slice Header Semantics".
> > +
> > + .. note::
> > +
> > + This compound control is not yet part of the public kernel API and
> > + it is expected to change.
> > +
> > +.. c:type:: v4l2_ctrl_h264_slice_param
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_ctrl_h264_slice_param
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u32
> > + - ``size``
> > + -
> > + * - __u32
> > + - ``header_bit_size``
> > + -
> > + * - __u16
> > + - ``first_mb_in_slice``
> > + -
> > + * - __u8
> > + - ``slice_type``
> > + -
> > + * - __u8
> > + - ``pic_parameter_set_id``
> > + -
> > + * - __u8
> > + - ``colour_plane_id``
> > + -
> > + * - __u16
> > + - ``frame_num``
> > + -
> > + * - __u16
> > + - ``idr_pic_id``
> > + -
> > + * - __u16
> > + - ``pic_order_cnt_lsb``
> > + -
> > + * - __s32
> > + - ``delta_pic_order_cnt_bottom``
> > + -
> > + * - __s32
> > + - ``delta_pic_order_cnt0``
> > + -
> > + * - __s32
> > + - ``delta_pic_order_cnt1``
> > + -
> > + * - __u8
> > + - ``redundant_pic_cnt``
>
> This should be moved to just before 'frame_num' as per the actual struct.
>
> > + -
> > + * - struct :c:type:`v4l2_h264_pred_weight_table`
> > + - ``pred_weight_table``
> > + -
> > + * - __u32
> > + - ``dec_ref_pic_marking_bit_size``
> > + -
> > + * - __u32
> > + - ``pic_order_cnt_bit_size``
> > + -
> > + * - __u8
> > + - ``cabac_init_idc``
> > + -
> > + * - __s8
> > + - ``slice_qp_delta``
> > + -
> > + * - __s8
> > + - ``slice_qs_delta``
> > + -
> > + * - __u8
> > + - ``disable_deblocking_filter_idc``
> > + -
> > + * - __s8
> > + - ``slice_alpha_c0_offset_div2``
> > + -
> > + * - __s8
> > + - ``slice_beta_offset_div2``
> > + -
> > + * - __u32
> > + - ``slice_group_change_cycle``
> > + -
> > + * - __u8
> > + - ``num_ref_idx_l0_active_minus1``
> > + -
> > + * - __u8
> > + - ``num_ref_idx_l1_active_minus1``
>
> These two fields should be moved to just before the slice_group_change_cycle
> field as per the actual struct.
>
> > + -
> > + * - __u8
> > + - ``ref_pic_list0[32]``
> > + -
> > + * - __u8
> > + - ``ref_pic_list1[32]``
> > + -
> > + * - __u32
> > + - ``flags``
> > + - See :ref:`Slice Parameter Flags <h264_slice_flags>`
> > +
> > +.. _h264_slice_flags:
> > +
> > +``Slice Parameter Set Flags``
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - ``V4L2_H264_SLICE_FLAG_FIELD_PIC``
> > + - 0x00000001
> > + -
> > + * - ``V4L2_H264_SLICE_FLAG_BOTTOM_FIELD``
> > + - 0x00000002
> > + -
> > + * - ``V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED``
> > + - 0x00000004
> > + -
> > + * - ``V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH``
> > + - 0x00000008
> > + -
> > +
> > +``Prediction Weight Table``
> > +
> > + Unless there's a specific comment, refer to the specification for
> > + the documentation of these fields, section 7.4.3.2 "Prediction
> > + Weight Table Semantics".
> > +
> > +.. c:type:: v4l2_h264_pred_weight_table
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_h264_pred_weight_table
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u16
> > + - ``luma_log2_weight_denom``
> > + -
> > + * - __u16
> > + - ``chroma_log2_weight_denom``
> > + -
> > + * - struct :c:type:`v4l2_h264_weight_factors`
> > + - ``weight_factors[2]``
> > + -
> > +
> > +.. c:type:: v4l2_h264_weight_factors
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_h264_weight_factors
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __s8
> > + - ``luma_weight[32]``
> > + -
> > + * - __s8
> > + - ``luma_offset[32]``
> > + -
> > + * - __s8
> > + - ``chroma_weight[32][2]``
> > + -
> > + * - __s8
> > + - ``chroma_offset[32][2]``
> > + -
> > +
> > +``V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS (struct)``
> > + Specifies the decode parameters (as extracted from the bitstream)
> > + for the associated H264 slice data. This includes the necessary
> > + parameters for configuring a stateless hardware decoding pipeline
> > + for H264. The bitstream parameters are defined according to
> > + :ref:`h264`. Unless there's a specific comment, refer to the
> > + specification for the documentation of these fields.
> > +
> > + .. note::
> > +
> > + This compound control is not yet part of the public kernel API and
> > + it is expected to change.
> > +
> > +.. c:type:: v4l2_ctrl_h264_decode_param
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_ctrl_h264_decode_param
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u32
> > + - ``num_slices``
> > + - Number of slices needed to decode the current frame
> > + * - __u16
> > + - ``idr_pic_flag``
> > + - Is the picture an IDR picture?
> > + * - __u16
> > + - ``nal_ref_idc``
> > + - NAL reference ID value coming from the NAL Unit header
> > + * - __s32
> > + - ``top_field_order_cnt``
> > + - Picture Order Count for the coded top field
> > + * - __s32
> > + - ``bottom_field_order_cnt``
> > + - Picture Order Count for the coded bottom field
> > + * - struct :c:type:`v4l2_h264_dpb_entry`
> > + - ``dpb[16]``
> > + -
> > +
> > +.. c:type:: v4l2_h264_dpb_entry
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table:: struct v4l2_h264_dpb_entry
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - __u32
> > + - ``tag``
> > + - tag to identify the buffer containing the reference frame
>
> This is outdated: it's a __u64 timestamp.
>
> You can copy the struct backward_ref_ts documentation from struct
> v4l2_ctrl_mpeg2_slice_params and edit it a bit for H.264.
>
> > + * - __u16
> > + - ``frame_num``
> > + -
> > + * - __u16
> > + - ``pic_num``
> > + -
> > + * - __s32
> > + - ``top_field_order_cnt``
> > + -
> > + * - __s32
> > + - ``bottom_field_order_cnt``
> > + -
> > + * - __u32
> > + - ``flags``
> > + - See :ref:`DPB Entry Flags <h264_dpb_flags>`
> > +
> > +.. _h264_dpb_flags:
> > +
> > +``DPB Entries Flags``
> > +
> > +.. cssclass:: longtable
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 1 1 2
> > +
> > + * - ``V4L2_H264_DPB_ENTRY_FLAG_VALID``
> > + - 0x00000001
> > + -
> > + * - ``V4L2_H264_DPB_ENTRY_FLAG_ACTIVE``
> > + - 0x00000002
> > + -
> > +
> > MFC 5.1 MPEG Controls
> > ---------------------
> >
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-compressed.rst b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
> > index e4c5e456df59..95905b967693 100644
> > --- a/Documentation/media/uapi/v4l/pixfmt-compressed.rst
> > +++ b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
> > @@ -52,6 +52,26 @@ Compressed Formats
> > - ``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, as extracted from the H264 bitstream.
> > + This format is adapted for stateless video decoders that
> > + implement an H264 pipeline (using the :ref:`codec` and
> > + :ref:`media-request-api`). 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_SLICE_PARAMS`` and
> > + ``V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS`` controls and
> > + scaling matrices can optionally be specified through the
> > + ``V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX`` control. 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.
> > * .. _V4L2-PIX-FMT-H263:
> >
> > - ``V4L2_PIX_FMT_H263``
> > diff --git a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
> > index f824162d0ea9..bf29dc5b9758 100644
> > --- a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
> > +++ b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst
> > @@ -443,6 +443,36 @@ See also the examples in :ref:`control`.
> > - n/a
> > - A struct :c:type:`v4l2_ctrl_mpeg2_quantization`, containing MPEG-2
> > quantization matrices for stateless video decoders.
> > + * - ``V4L2_CTRL_TYPE_H264_SPS``
> > + - n/a
> > + - n/a
> > + - n/a
> > + - A struct :c:type:`v4l2_ctrl_h264_sps`, containing H264
> > + sequence parameters for stateless video decoders.
> > + * - ``V4L2_CTRL_TYPE_H264_PPS``
> > + - n/a
> > + - n/a
> > + - n/a
> > + - A struct :c:type:`v4l2_ctrl_h264_pps`, containing H264
> > + picture parameters for stateless video decoders.
> > + * - ``V4L2_CTRL_TYPE_H264_SCALING_MATRIX``
> > + - n/a
> > + - n/a
> > + - n/a
> > + - A struct :c:type:`v4l2_ctrl_h264_scaling_matrix`, containing H264
> > + scaling matrices for stateless video decoders.
> > + * - ``V4L2_CTRL_TYPE_H264_SLICE_PARAMS``
> > + - n/a
> > + - n/a
> > + - n/a
> > + - A struct :c:type:`v4l2_ctrl_h264_slice_param`, containing H264
> > + slice parameters for stateless video decoders.
> > + * - ``V4L2_CTRL_TYPE_H264_DECODE_PARAMS``
> > + - n/a
> > + - n/a
> > + - n/a
> > + - A struct :c:type:`v4l2_ctrl_h264_decode_param`, containing H264
> > + decode parameters for stateless video decoders.
> >
> > .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
> >
> > diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
> > index 64d348e67df9..55cbe324b9fc 100644
> > --- a/Documentation/media/videodev2.h.rst.exceptions
> > +++ b/Documentation/media/videodev2.h.rst.exceptions
> > @@ -136,6 +136,11 @@ replace symbol V4L2_CTRL_TYPE_U32 :c:type:`v4l2_ctrl_type`
> > replace symbol V4L2_CTRL_TYPE_U8 :c:type:`v4l2_ctrl_type`
> > replace symbol V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS :c:type:`v4l2_ctrl_type`
> > replace symbol V4L2_CTRL_TYPE_MPEG2_QUANTIZATION :c:type:`v4l2_ctrl_type`
> > +replace symbol V4L2_CTRL_TYPE_H264_SPS :c:type:`v4l2_ctrl_type`
> > +replace symbol V4L2_CTRL_TYPE_H264_PPS :c:type:`v4l2_ctrl_type`
> > +replace symbol V4L2_CTRL_TYPE_H264_SCALING_MATRIX :c:type:`v4l2_ctrl_type`
> > +replace symbol V4L2_CTRL_TYPE_H264_SLICE_PARAMS :c:type:`v4l2_ctrl_type`
> > +replace symbol V4L2_CTRL_TYPE_H264_DECODE_PARAMS :c:type:`v4l2_ctrl_type`
> >
> > # V4L2 capability defines
> > replace define V4L2_CAP_VIDEO_CAPTURE device-capabilities
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> > index e3bd441fa29a..fe9f9447caba 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> > @@ -825,6 +825,11 @@ const char *v4l2_ctrl_get_name(u32 id)
> > case V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER:return "H264 Number of HC Layers";
> > case V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP:
> > return "H264 Set QP Value for HC Layers";
> > + case V4L2_CID_MPEG_VIDEO_H264_SPS: return "H264 Sequence Parameter Set";
> > + case V4L2_CID_MPEG_VIDEO_H264_PPS: return "H264 Picture Parameter Set";
> > + case V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX: return "H264 Scaling Matrix";
> > + case V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS: return "H264 Slice Parameters";
> > + case V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS: return "H264 Decode Parameters";
> > case V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP: return "MPEG4 I-Frame QP Value";
> > case V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP: return "MPEG4 P-Frame QP Value";
> > case V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP: return "MPEG4 B-Frame QP Value";
> > @@ -1300,6 +1305,21 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> > case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION:
> > *type = V4L2_CTRL_TYPE_MPEG2_QUANTIZATION;
> > break;
> > + case V4L2_CID_MPEG_VIDEO_H264_SPS:
> > + *type = V4L2_CTRL_TYPE_H264_SPS;
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_PPS:
> > + *type = V4L2_CTRL_TYPE_H264_PPS;
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX:
> > + *type = V4L2_CTRL_TYPE_H264_SCALING_MATRIX;
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS:
> > + *type = V4L2_CTRL_TYPE_H264_SLICE_PARAMS;
> > + break;
> > + case V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS:
> > + *type = V4L2_CTRL_TYPE_H264_DECODE_PARAMS;
> > + break;
> > default:
> > *type = V4L2_CTRL_TYPE_INTEGER;
> > break;
> > @@ -1666,6 +1686,13 @@ static int std_validate(const struct v4l2_ctrl *ctrl, u32 idx,
> > case V4L2_CTRL_TYPE_MPEG2_QUANTIZATION:
> > return 0;
> >
> > + case V4L2_CTRL_TYPE_H264_SPS:
> > + case V4L2_CTRL_TYPE_H264_PPS:
> > + case V4L2_CTRL_TYPE_H264_SCALING_MATRIX:
> > + case V4L2_CTRL_TYPE_H264_SLICE_PARAMS:
> > + case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
> > + return 0;
> > +
> > default:
> > return -EINVAL;
> > }
> > @@ -2246,6 +2273,21 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> > case V4L2_CTRL_TYPE_MPEG2_QUANTIZATION:
> > elem_size = sizeof(struct v4l2_ctrl_mpeg2_quantization);
> > break;
> > + case V4L2_CTRL_TYPE_H264_SPS:
> > + elem_size = sizeof(struct v4l2_ctrl_h264_sps);
> > + break;
> > + case V4L2_CTRL_TYPE_H264_PPS:
> > + elem_size = sizeof(struct v4l2_ctrl_h264_pps);
> > + break;
> > + case V4L2_CTRL_TYPE_H264_SCALING_MATRIX:
> > + elem_size = sizeof(struct v4l2_ctrl_h264_scaling_matrix);
> > + break;
> > + case V4L2_CTRL_TYPE_H264_SLICE_PARAMS:
> > + elem_size = sizeof(struct v4l2_ctrl_h264_slice_param);
> > + break;
> > + case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
> > + elem_size = sizeof(struct v4l2_ctrl_h264_decode_param);
> > + break;
> > default:
> > if (type < V4L2_CTRL_COMPOUND_TYPES)
> > elem_size = sizeof(s32);
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index 1441a73ce64c..f42d6e7049eb 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1313,6 +1313,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > case V4L2_PIX_FMT_H264: descr = "H.264"; break;
> > case V4L2_PIX_FMT_H264_NO_SC: descr = "H.264 (No Start Codes)"; break;
> > case V4L2_PIX_FMT_H264_MVC: descr = "H.264 MVC"; break;
> > + case V4L2_PIX_FMT_H264_SLICE: descr = "H.264 Parsed Slice Data"; break;
> > case V4L2_PIX_FMT_H263: descr = "H.263"; break;
> > case V4L2_PIX_FMT_MPEG1: descr = "MPEG-1 ES"; break;
> > case V4L2_PIX_FMT_MPEG2: descr = "MPEG-2 ES"; break;
> > diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h
> > new file mode 100644
> > index 000000000000..7b0563dfa05f
> > --- /dev/null
> > +++ b/include/media/h264-ctrls.h
> > @@ -0,0 +1,179 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * These are the H.264 state controls for use with stateless H.264
> > + * codec drivers.
> > + *
> > + * It turns out that these structs are not stable yet and will undergo
> > + * more changes. So keep them private until they are stable and ready to
> > + * become part of the official public API.
> > + */
> > +
> > +#ifndef _H264_CTRLS_H_
> > +#define _H264_CTRLS_H_
> > +
> > +#define V4L2_CID_MPEG_VIDEO_H264_SPS (V4L2_CID_MPEG_BASE+383)
> > +#define V4L2_CID_MPEG_VIDEO_H264_PPS (V4L2_CID_MPEG_BASE+384)
> > +#define V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX (V4L2_CID_MPEG_BASE+385)
> > +#define V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS (V4L2_CID_MPEG_BASE+386)
> > +#define V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS (V4L2_CID_MPEG_BASE+387)
> > +
> > +/* enum v4l2_ctrl_type type values */
> > +#define V4L2_CTRL_TYPE_H264_SPS 0x0105
> > +#define V4L2_CTRL_TYPE_H264_PPS 0x0106
> > +#define V4L2_CTRL_TYPE_H264_SCALING_MATRIX 0x0107
> > +#define V4L2_CTRL_TYPE_H264_SLICE_PARAMS 0x0108
> > +#define V4L2_CTRL_TYPE_H264_DECODE_PARAMS 0x0109
> > +
> > +#define V4L2_H264_SPS_CONSTRAINT_SET0_FLAG 0x01
> > +#define V4L2_H264_SPS_CONSTRAINT_SET1_FLAG 0x02
> > +#define V4L2_H264_SPS_CONSTRAINT_SET2_FLAG 0x04
> > +#define V4L2_H264_SPS_CONSTRAINT_SET3_FLAG 0x08
> > +#define V4L2_H264_SPS_CONSTRAINT_SET4_FLAG 0x10
> > +#define V4L2_H264_SPS_CONSTRAINT_SET5_FLAG 0x20
> > +
> > +#define V4L2_H264_SPS_FLAG_SEPARATE_COLOUR_PLANE 0x01
> > +#define V4L2_H264_SPS_FLAG_QPPRIME_Y_ZERO_TRANSFORM_BYPASS 0x02
> > +#define V4L2_H264_SPS_FLAG_DELTA_PIC_ORDER_ALWAYS_ZERO 0x04
> > +#define V4L2_H264_SPS_FLAG_GAPS_IN_FRAME_NUM_VALUE_ALLOWED 0x08
> > +#define V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY 0x10
> > +#define V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD 0x20
> > +#define V4L2_H264_SPS_FLAG_DIRECT_8X8_INFERENCE 0x40
> > +
> > +struct v4l2_ctrl_h264_sps {
> > + __u8 profile_idc;
> > + __u8 constraint_set_flags;
> > + __u8 level_idc;
> > + __u8 seq_parameter_set_id;
> > + __u8 chroma_format_idc;
> > + __u8 bit_depth_luma_minus8;
> > + __u8 bit_depth_chroma_minus8;
> > + __u8 log2_max_frame_num_minus4;
> > + __u8 pic_order_cnt_type;
> > + __u8 log2_max_pic_order_cnt_lsb_minus4;
> > + __u8 max_num_ref_frames;
> > + __u8 num_ref_frames_in_pic_order_cnt_cycle;
> > + __s32 offset_for_ref_frame[255];
>
> Where does 255 come from? Should this be a define?
this is indexed relative to num_ref_frames_in_pic_order_cnt_cycle
(right before), which is defined in 7.4.2.1.1 as being between 0 and
255.
>
> If this is not based on the standard but instead a driver limitation, then
> I think that should be documented. In that case I assume that if more is needed
> in the future, then that will be done through additional controls.
>
> > + __s32 offset_for_non_ref_pic;
> > + __s32 offset_for_top_to_bottom_field;
> > + __u16 pic_width_in_mbs_minus1;
> > + __u16 pic_height_in_map_units_minus1;
> > + __u32 flags;
> > +};
> > +
> > +#define V4L2_H264_PPS_FLAG_ENTROPY_CODING_MODE 0x0001
> > +#define V4L2_H264_PPS_FLAG_BOTTOM_FIELD_PIC_ORDER_IN_FRAME_PRESENT 0x0002
> > +#define V4L2_H264_PPS_FLAG_WEIGHTED_PRED 0x0004
> > +#define V4L2_H264_PPS_FLAG_DEBLOCKING_FILTER_CONTROL_PRESENT 0x0008
> > +#define V4L2_H264_PPS_FLAG_CONSTRAINED_INTRA_PRED 0x0010
> > +#define V4L2_H264_PPS_FLAG_REDUNDANT_PIC_CNT_PRESENT 0x0020
> > +#define V4L2_H264_PPS_FLAG_TRANSFORM_8X8_MODE 0x0040
> > +#define V4L2_H264_PPS_FLAG_PIC_SCALING_MATRIX_PRESENT 0x0080
> > +
> > +struct v4l2_ctrl_h264_pps {
> > + __u8 pic_parameter_set_id;
> > + __u8 seq_parameter_set_id;
> > + __u8 num_slice_groups_minus1;
> > + __u8 num_ref_idx_l0_default_active_minus1;
> > + __u8 num_ref_idx_l1_default_active_minus1;
> > + __u8 weighted_bipred_idc;
> > + __s8 pic_init_qp_minus26;
> > + __s8 pic_init_qs_minus26;
> > + __s8 chroma_qp_index_offset;
> > + __s8 second_chroma_qp_index_offset;
> > + __u16 flags;
> > +};
> > +
> > +struct v4l2_ctrl_h264_scaling_matrix {
> > + __u8 scaling_list_4x4[6][16];
> > + __u8 scaling_list_8x8[6][64];
> > +};
> > +
> > +struct v4l2_h264_weight_factors {
> > + __s8 luma_weight[32];
> > + __s8 luma_offset[32];
> > + __s8 chroma_weight[32][2];
> > + __s8 chroma_offset[32][2];
>
> Same question here.
As per 7.4.3.1 the second index refer to Cb (0) and 1 Cr(). And the 32
is the maximum number of RefPicList0, as limited by the range of
num_ref_idx_l0_active_minus1 (if I read properly). This will never
change, so if we add defines it would only be for documentation purpose
I think.
>
> > +};
> > +
> > +struct v4l2_h264_pred_weight_table {
> > + __u16 luma_log2_weight_denom;
> > + __u16 chroma_log2_weight_denom;
> > + struct v4l2_h264_weight_factors weight_factors[2];
>
> I assume [0] is for luma and [1] is for chroma? Should be documented.
Yes.
>
> > +};
> > +
> > +#define V4L2_H264_SLICE_TYPE_P 0
> > +#define V4L2_H264_SLICE_TYPE_B 1
> > +#define V4L2_H264_SLICE_TYPE_I 2
> > +#define V4L2_H264_SLICE_TYPE_SP 3
> > +#define V4L2_H264_SLICE_TYPE_SI 4
> > +
> > +#define V4L2_H264_SLICE_FLAG_FIELD_PIC 0x01
> > +#define V4L2_H264_SLICE_FLAG_BOTTOM_FIELD 0x02
> > +#define V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED 0x04
> > +#define V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH 0x08
> > +
> > +struct v4l2_ctrl_h264_slice_param {
> > + /* Size in bytes, including header */
> > + __u32 size;
> > + /* Offset in bits to slice_data() from the beginning of this slice. */
> > + __u32 header_bit_size;
> > +
> > + __u16 first_mb_in_slice;
> > + __u8 slice_type;
> > + __u8 pic_parameter_set_id;
> > + __u8 colour_plane_id;
> > + __u8 redundant_pic_cnt;
> > + __u16 frame_num;
> > + __u16 idr_pic_id;
> > + __u16 pic_order_cnt_lsb;
> > + __s32 delta_pic_order_cnt_bottom;
> > + __s32 delta_pic_order_cnt0;
> > + __s32 delta_pic_order_cnt1;
> > +
> > + struct v4l2_h264_pred_weight_table pred_weight_table;
> > + /* Size in bits of dec_ref_pic_marking() syntax element. */
> > + __u32 dec_ref_pic_marking_bit_size;
> > + /* Size in bits of pic order count syntax. */
> > + __u32 pic_order_cnt_bit_size;
> > +
> > + __u8 cabac_init_idc;
> > + __s8 slice_qp_delta;
> > + __s8 slice_qs_delta;
> > + __u8 disable_deblocking_filter_idc;
> > + __s8 slice_alpha_c0_offset_div2;
> > + __s8 slice_beta_offset_div2;
> > + __u8 num_ref_idx_l0_active_minus1;
> > + __u8 num_ref_idx_l1_active_minus1;
> > + __u32 slice_group_change_cycle;
> > +
> > + /* Entries on each list are indices
> > + * into v4l2_ctrl_h264_decode_param.dpb[]. */
> > + __u8 ref_pic_list0[32];
> > + __u8 ref_pic_list1[32];
>
> Where does 32 come from?
It's the range of num_ref_idx_l0_active_minus1,
>
> > +
> > + __u32 flags;
> > +};
> > +
> > +#define V4L2_H264_DPB_ENTRY_FLAG_VALID 0x01
> > +#define V4L2_H264_DPB_ENTRY_FLAG_ACTIVE 0x02
> > +
> > +struct v4l2_h264_dpb_entry {
> > + __u64 timestamp;
> > + __u16 frame_num;
> > + __u16 pic_num;
> > + /* Note that field is indicated by v4l2_buffer.field */
> > + __s32 top_field_order_cnt;
> > + __s32 bottom_field_order_cnt;
> > + __u32 flags; /* V4L2_H264_DPB_ENTRY_FLAG_* */
> > +};
> > +
> > +struct v4l2_ctrl_h264_decode_param {
> > + __u32 num_slices;
> > + __u16 idr_pic_flag;
> > + __u16 nal_ref_idc;
> > + __s32 top_field_order_cnt;
> > + __s32 bottom_field_order_cnt;
> > + struct v4l2_h264_dpb_entry dpb[16];
>
> And 16?
H264 DPB size cannot exceed 16, that's well known normally.
>
> Nothing special needs to be done for those constants that are based on the
> standard. But if it isn't part of the standard but a driver constraint, then
> that should be documented, and there should be an idea on how it can be
> extended for future drivers without that constraint.
>
> I think the API should be designed with 4k video in mind. So if some of
> these constants would be too small when dealing with 4k (even if the
> current HW doesn't support this yet), then these constants would have to
> be increased.
>
> And yes, I know 8k video is starting to appear, but I think it is OK
> that additional control(s) would be needed to support 8k.
>
> > +};
> > +
> > +#endif
> > diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> > index d63cf227b0ab..22b6d09c4764 100644
> > --- a/include/media/v4l2-ctrls.h
> > +++ b/include/media/v4l2-ctrls.h
> > @@ -23,10 +23,11 @@
> > #include <media/media-request.h>
> >
> > /*
> > - * Include the mpeg2 stateless codec compound control definitions.
> > + * Include the stateless codec compound control definitions.
> > * This will move to the public headers once this API is fully stable.
> > */
> > #include <media/mpeg2-ctrls.h>
> > +#include <media/h264-ctrls.h>
> >
> > /* forward references */
> > struct file;
> > @@ -49,6 +50,11 @@ struct poll_table_struct;
> > * @p_char: Pointer to a string.
> > * @p_mpeg2_slice_params: Pointer to a MPEG2 slice parameters structure.
> > * @p_mpeg2_quantization: Pointer to a MPEG2 quantization data structure.
> > + * @p_h264_sps: Pointer to a struct v4l2_ctrl_h264_sps.
> > + * @p_h264_pps: Pointer to a struct v4l2_ctrl_h264_pps.
> > + * @p_h264_scaling_matrix: Pointer to a struct v4l2_ctrl_h264_scaling_matrix.
> > + * @p_h264_slice_param: Pointer to a struct v4l2_ctrl_h264_slice_param.
> > + * @p_h264_decode_param: Pointer to a struct v4l2_ctrl_h264_decode_param.
> > * @p: Pointer to a compound value.
> > */
> > union v4l2_ctrl_ptr {
> > @@ -60,6 +66,11 @@ union v4l2_ctrl_ptr {
> > char *p_char;
> > struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
> > struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
> > + struct v4l2_ctrl_h264_sps *p_h264_sps;
> > + struct v4l2_ctrl_h264_pps *p_h264_pps;
> > + struct v4l2_ctrl_h264_scaling_matrix *p_h264_scaling_matrix;
> > + struct v4l2_ctrl_h264_slice_param *p_h264_slice_param;
> > + struct v4l2_ctrl_h264_decode_param *p_h264_decode_param;
> > void *p;
> > };
> >
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index d6eed479c3a6..6fc955926bdb 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -645,6 +645,7 @@ struct v4l2_pix_format {
> > #define V4L2_PIX_FMT_H264 v4l2_fourcc('H', '2', '6', '4') /* H264 with start codes */
> > #define V4L2_PIX_FMT_H264_NO_SC v4l2_fourcc('A', 'V', 'C', '1') /* H264 without start codes */
> > #define V4L2_PIX_FMT_H264_MVC v4l2_fourcc('M', '2', '6', '4') /* H264 MVC */
> > +#define V4L2_PIX_FMT_H264_SLICE v4l2_fourcc('S', '2', '6', '4') /* H264 parsed slices */
> > #define V4L2_PIX_FMT_H263 v4l2_fourcc('H', '2', '6', '3') /* H263 */
> > #define V4L2_PIX_FMT_MPEG1 v4l2_fourcc('M', 'P', 'G', '1') /* MPEG-1 ES */
> > #define V4L2_PIX_FMT_MPEG2 v4l2_fourcc('M', 'P', 'G', '2') /* MPEG-2 ES */
> >
>
> Regards,
>
> Hans
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