[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <d1ba4e57-2f13-ab3b-f79a-dc812cd4c2bf@collabora.com>
Date: Mon, 25 Apr 2022 18:16:59 +0200
From: Benjamin Gaignard <benjamin.gaignard@...labora.com>
To: Sebastian Fricke <sebastian.fricke@...labora.com>
Cc: mchehab@...nel.org, hverkuil@...all.nl,
ezequiel@...guardiasur.com.ar, p.zabel@...gutronix.de,
gregkh@...uxfoundation.org, mripard@...nel.org,
paul.kocialkowski@...tlin.com, wens@...e.org,
jernej.skrabec@...il.com, samuel@...lland.org,
nicolas.dufresne@...labora.com, linux-media@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-rockchip@...ts.infradead.org,
linux-staging@...ts.linux.dev,
linux-arm-kernel@...ts.infradead.org, linux-sunxi@...ts.linux.dev
Subject: Re: [PATCH v5 04/17] media: uapi: HEVC: Add missing fields in HEVC
controls
Le 25/04/2022 à 15:54, Sebastian Fricke a écrit :
> On 07.04.2022 17:29, Benjamin Gaignard wrote:
>> Complete the HEVC controls with missing fields from H.265
>> specifications.
>> Even if these fields aren't used by the current mainlined drivers
>> they will be need for (at least) rkvdec driver.
>
> s/be need/be required/
> or
> s/be need/be needed/
>
> s/rkvdec/the rkvdec/
>
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@...labora.com>
>> ---
>> .../media/v4l/ext-ctrls-codec.rst | 19 +++++++++++++++++++
>> include/media/hevc-ctrls.h | 6 +++++-
>> 2 files changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git
>> a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>> b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>> index 4cd7c541fc30..dbb08603217b 100644
>> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>> @@ -2661,6 +2661,16 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
>> :stub-columns: 0
>> :widths: 1 1 2
>>
>> + * - __u8
>> + - ``video_parameter_set_id``
>> + - Specifies the value of the vps_video_parameter_set_id of the
>> active VPS
>> + as descibed in section "7.4.3.2.1 General sequence parameter
>> set RBSP semantics"
>> + of H.265 specifications.
>> + * - __u8
>> + - ``seq_parameter_set_id``
>> + - Provides an identifier for the SPS for reference by other
>> syntax elements
>> + as descibed in section "7.4.3.2.1 General sequence parameter
>> set RBSP semantics"
>> + of H.265 specifications.
>> * - __u16
>> - ``pic_width_in_luma_samples``
>> -
>> @@ -2800,6 +2810,9 @@ 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 +3039,12 @@ 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``
>> + - Specifies the size of short-term reference pictures set
>> included in the SPS.
>
> s/size of/size of the/
>
> Section 7.4.8 depicts that the st_ref_pic_set syntax
> structure can be part of the SPS or the slice header.
>
> I think we should mention that we talk about the size of the
> st_ref_pic_set
> syntax structure from section 7.4.8 of the specification.
>> + * - __u16
>> + - ``long_term_ref_pic_set_size``
>> + - Specifies the size of long-term reference pictures set
>> include in the SPS.
>
> s/size of/size of the/
>
> Can we make this a bit more helpful? The specification doesn't contain
> a similar structure to `st_ref_pic_set` for long term pictures. So, as a
> programmer this leaves me guessing:
> - Which syntax structure's size are we talking about?
> - Does this correlate to any of the existing sections of the
> specification?
> Because in the end, I feel like this documentation should be able to
> help a programmer to provide the correct data for the uABI.
I will reword it like that:
* - __u16
- ``short_term_ref_pic_set_size``
- Specifies the size, in bits, of the short-term reference pictures set, described as st_ref_pic_set()
in the specification, included in the slice header (section 7.3.6.1).
* - __u16
- ``long_term_ref_pic_set_size``
- Specifies the size, in bits, of the long-term reference pictures set include in the slice header.
It is the number of bits in the conditional block if( long_term_ref_pics_present_flag ) {...}
in section 7.3.6.1 of the specification.
Benjamin
>
> Greetings,
> Sebastian
>
>> * - __u8
>> - ``padding``
>> - Applications and drivers must set this to zero.
>> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
>> index 01ccda48d8c5..a329e086a89a 100644
>> --- a/include/media/hevc-ctrls.h
>> +++ b/include/media/hevc-ctrls.h
>> @@ -58,6 +58,8 @@ enum v4l2_mpeg_video_hevc_start_code {
>> /* The controls are not stable at the moment and will likely be
>> reworked. */
>> 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;
>> @@ -108,6 +110,7 @@ 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;
>> @@ -199,7 +202,8 @@ 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;
>> __u8 padding;
>>
>> /* ISO/IEC 23008-2, ITU-T Rec. H.265: Weighted prediction
>> parameter */
>> --
>> 2.32.0
>>
Powered by blists - more mailing lists