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

From: Hans Verkuil
Date: Fri Feb 18 2022 - 07:22:44 EST


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?

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;