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

[Hans Verkuil]

On 18/02/2022 13:30, Benjamin Gaignard wrote:
> 
> 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.

Then I'm satisfied :-)

Thanks!

	Hans

> 
> 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;