Re: [PATCH v13 09/17] media: uapi: HEVC: Define V4L2_CID_STATELESS_HEVC_SLICE_PARAMS as a dynamic array

Ezequiel Garcia
2022-07-08T17:27:00Z

On Fri, Jul 08, 2022 at 06:21:48PM +0200, Benjamin Gaignard wrote:
> Make explicit that V4L2_CID_STATELESS_HEVC_SLICE_PARAMS control is
> a dynamic array control type.
> Some drivers may be able to receive multiple slices in one control
> to improve decoding performance.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>

Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

> ---
> Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 ++
> drivers/media/v4l2-core/v4l2-ctrls-defs.c | 1 +
> drivers/staging/media/sunxi/cedrus/cedrus.c | 2 ++
> include/media/hevc-ctrls.h | 3 +++
> 4 files changed, 8 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index e88b5e6944a6..c2e0adece613 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -2986,6 +2986,8 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> These bitstream parameters are defined according to :ref:`hevc`.
> They are described in section 7.4.7 "General slice segment header
> semantics" of the specification.
> + This control is a dynamically sized 1-dimensional array,
> + V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
>
> .. c:type:: v4l2_ctrl_hevc_slice_params
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index 9f55503cd3d6..d594efbcbb93 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -1510,6 +1510,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> break;
> case V4L2_CID_STATELESS_HEVC_SLICE_PARAMS:
> *type = V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS;
> + *flags |= V4L2_CTRL_FLAG_DYNAMIC_ARRAY;
> break;
> case V4L2_CID_STATELESS_HEVC_SCALING_MATRIX:
> *type = V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX;
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
> index 87be975a72b6..b12219123a6b 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
> @@ -178,6 +178,8 @@ static const struct cedrus_control cedrus_controls[] = {
> {
> .cfg = {
> .id = V4L2_CID_STATELESS_HEVC_SLICE_PARAMS,
> + /* The driver can only handle 1 entry per slice for now */
> + .dims = { 1 },
> },
> .codec = CEDRUS_CODEC_H265,
> },
> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> index 57053cfa099b..341fc795d550 100644
> --- a/include/media/hevc-ctrls.h
> +++ b/include/media/hevc-ctrls.h
> @@ -314,6 +314,9 @@ struct v4l2_hevc_pred_weight_table {
> /**
> * struct v4l2_ctrl_hevc_slice_params - HEVC slice parameters
> *
> + * This control is a dynamically sized 1-dimensional array,
> + * V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
> + *
> * @bit_size: size (in bits) of the current slice data
> * @data_bit_offset: offset (in bits) to the video data in the current slice data
> * @nal_unit_type: specifies the coding type of the slice (B, P or I)
> --
> 2.32.0
>