Le jeudi 07 avril 2022 à 17:29 +0200, Benjamin Gaignard a écrit :
> 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@xxxxxxxxxxxxx>
> ---
> Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 ++
> include/media/hevc-ctrls.h | 3 +++
> 2 files changed, 5 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index 7fcc6c2bac4c..1aaf3b84b584 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -2964,6 +2964,8 @@ 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/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> index 96a9b71d1def..28049e1a8a07 100644
> --- a/include/media/hevc-ctrls.h
> +++ b/include/media/hevc-ctrls.h
> @@ -314,6 +314,9 @@ struct v4l2_hevc_pred_weight_table {
> /**
> * 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.
> + *
I'm not sure about this comment, but I'm sure you forgot:
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1505,6 +1505,7 @@ 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;
Also, in AV1 we have V4L2_AV1_MAX_TILE_COUNT, which can be used in cfg.dims,
something the driver will actually set. We could have
#define V4L2_HEVC_MAX_TILE_COUNT 600
And drives can set:
.dims = { V4L2_HEVC_MAX_TILE_COUNT },
In the control config.
> * @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)
