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

From: Hans Verkuil
Date: Fri Feb 18 2022 - 06:32:13 EST


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.

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;