Re: [RFC v2 5/8] media: uapi: Add fields needed for RKVDEC driver

[Benjamin Gaignard]

Le 18/02/2022 à 13:22, Hans Verkuil a écrit :
> On 18/02/2022 13:19, Benjamin Gaignard wrote:
> > Le 18/02/2022 à 12:32, Hans Verkuil a écrit :
> > > On 15/02/2022 12:01, Benjamin Gaignard wrote:
> > > > RKVDEC driver requires additional fields to perform HEVC decoding.
> > > > Even if the driver isn't mainlined yet WIP patches could be find here:
> > > > https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/patches/linux/default/linux-2000-v4l2-wip-rkvdec-hevc.patch
> > > >
> > > > This patch only include the change in HEVC uAPI.
> > > >
> > > > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> > > > ---
> > > >    .../userspace-api/media/v4l/ext-ctrls-codec.rst  | 16 ++++++++++++++++
> > > >    include/uapi/linux/v4l2-controls.h               |  5 +++++
> > > >    2 files changed, 21 insertions(+)
> > > >
> > > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > > > index 4f3b3ba8319f..3296ac3b9fca 100644
> > > > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > > > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > > > @@ -2661,6 +2661,13 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> > > >        :stub-columns: 0
> > > >        :widths:       1 1 2
> > > >    +    * - __u8
> > > > +      - ``video_parameter_set_id``
> > > > +      - Identifies the VPS for reference by other syntax elements.
> > > > +    * - __u8
> > > > +      - ``seq_parameter_set_id``
> > > > +      - Provides an identifier for the SPS for reference by other syntax
> > > > +        elements.
> > > >        * - __u16
> > > >          - ``pic_width_in_luma_samples``
> > > >          -
> > > > @@ -2800,6 +2807,9 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> > > >        :stub-columns: 0
> > > >        :widths:       1 1 2
> > > >    +    * - __u8
> > > > +      - ``pic_parameter_set_id``
> > > > +      - Identifies the PPS for reference by other syntax elements.
> > > >        * - __u8
> > > >          - ``num_extra_slice_header_bits``
> > > >          -
> > > > @@ -3026,6 +3036,12 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> > > >        * - __u8
> > > >          - ``ref_idx_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
> > > >          - The list of L1 reference elements as indices in the DPB.
> > > > +    * - __u16
> > > > +      - ``short_term_ref_pic_set_size``
> > > > +      -
> > > > +    * - __u16
> > > > +      - ``long_term_ref_pic_set_size``
> > > > +      -
> > > >        * - __u8
> > > >          - ``padding``
> > > >          - Applications and drivers must set this to zero.
> > > Just to confirm: these additional fields are all from the H.265 spec, right?
> > > They are not rkvdec specific.
> > They are in H.265 spec section "7.4.3.2.2 Sequence parameter set range extension semantics":
> > - num_short_term_ref_pic_sets specifies the number of st_ref_pic_set( ) syntax structures included in the SPS. The value
> > of num_short_term_ref_pic_sets shall be in the range of 0 to 64, inclusive.
> >
> > - num_long_term_ref_pics_sps specifies the number of candidate long-term reference pictures that are specified in the
> > SPS. The value of num_long_term_ref_pics_sps shall be in the range of 0 to 32, inclusive.
> And what about video/seq/pic_parameter_set_id?

It is the same they come from section "7.4.3.2.1 General sequence parameter set RBSP semantics":
- sps_video_parameter_set_id specifies the value of the vps_video_parameter_set_id of the active VPS.
- sps_seq_parameter_set_id provides an identifier for the SPS for reference by other syntax elements.
  The value of
 sps_seq_parameter_set_id shall be in the range of 0 to 15, inclusive.

Regards,
Benjamin

> Regards,
>
> 	Hans
>
> > I mention rkvdec because that it is the only driver to use they (as far I knows)
> >
> > Regards,
> > Benjamin
> >
> > > Regards,
> > >
> > >      Hans
> > >
> > > > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > > > index 0e0ec2c61b80..b1a3dc05f02f 100644
> > > > --- a/include/uapi/linux/v4l2-controls.h
> > > > +++ b/include/uapi/linux/v4l2-controls.h
> > > > @@ -2341,6 +2341,8 @@ enum v4l2_stateless_hevc_start_code {
> > > >      struct v4l2_ctrl_hevc_sps {
> > > >        /* ISO/IEC 23008-2, ITU-T Rec. H.265: Sequence parameter set */
> > > > +    __u8    video_parameter_set_id;
> > > > +    __u8    seq_parameter_set_id;
> > > >        __u16    pic_width_in_luma_samples;
> > > >        __u16    pic_height_in_luma_samples;
> > > >        __u8    bit_depth_luma_minus8;
> > > > @@ -2393,6 +2395,7 @@ struct v4l2_ctrl_hevc_sps {
> > > >      struct v4l2_ctrl_hevc_pps {
> > > >        /* ISO/IEC 23008-2, ITU-T Rec. H.265: Picture parameter set */
> > > > +    __u8    pic_parameter_set_id;
> > > >        __u8    num_extra_slice_header_bits;
> > > >        __u8    num_ref_idx_l0_default_active_minus1;
> > > >        __u8    num_ref_idx_l1_default_active_minus1;
> > > > @@ -2487,6 +2490,8 @@ struct v4l2_ctrl_hevc_slice_params {
> > > >        __u32    slice_segment_addr;
> > > >        __u8    ref_idx_l0[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> > > >        __u8    ref_idx_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
> > > > +    __u16    short_term_ref_pic_set_size;
> > > > +    __u16    long_term_ref_pic_set_size;
> > > >          /* ISO/IEC 23008-2, ITU-T Rec. H.265: Weighted prediction parameter */
> > > >        struct v4l2_hevc_pred_weight_table pred_weight_table;