Re: [PATCH v2 7/8] media: hevc: Add scaling matrix control

From: Hans Verkuil
Date: Mon Jun 14 2021 - 03:28:11 EST

On 10/06/2021 17:44, Benjamin Gaignard wrote:
> HEVC scaling lists are used for the scaling process for transform
> coefficients.
> V4L2_HEVC_SPS_FLAG_SCALING_LIST_ENABLED has to set when they are
> encoded in the bitstream.

Comparing H264 with HEVC I noticed that the corresponding flag for H264 is
called V4L2_H264_PPS_FLAG_SCALING_MATRIX_PRESENT.

Should those names be aligned? Also, it is part of PPS for H264 and SPS in HEVC,
is that difference correct?

Regards,

Hans

>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> ---
> version 2:
> - Fix structure name in ext-ctrls-codec.rst
>
> .../media/v4l/ext-ctrls-codec.rst | 45 +++++++++++++++++++
> .../media/v4l/vidioc-queryctrl.rst | 6 +++
> drivers/media/v4l2-core/v4l2-ctrls-core.c | 6 +++
> drivers/media/v4l2-core/v4l2-ctrls-defs.c | 4 ++
> include/media/hevc-ctrls.h | 11 +++++
> 5 files changed, 72 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index 8c6e2a11ed95..d4f40bb85263 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -3068,6 +3068,51 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
>
> \normalsize
>
> +``V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX (struct)``
> + Specifies the HEVC scaling matrix parameters used for the scaling process
> + for transform coefficients.
> + These matrix and parameters are defined according to :ref:`hevc`.
> + They are described in section 7.4.5 "Scaling list data semantics" of
> + the specification.
> +
> +.. c:type:: v4l2_ctrl_hevc_scaling_matrix
> +
> +.. raw:: latex
> +
> + \scriptsize
> +
> +.. tabularcolumns:: |p{5.4cm}|p{6.8cm}|p{5.1cm}|
> +
> +.. cssclass:: longtable
> +
> +.. flat-table:: struct v4l2_ctrl_hevc_scaling_matrix
> + :header-rows: 0
> + :stub-columns: 0
> + :widths: 1 1 2
> +
> + * - __u8
> + - ``scaling_list_4x4[6][16]``
> + -
> + * - __u8
> + - ``scaling_list_8x8[6][64]``
> + -
> + * - __u8
> + - ``scaling_list_16x16[6][64]``
> + -
> + * - __u8
> + - ``scaling_list_32x32[2][64]``
> + -
> + * - __u8
> + - ``scaling_list_dc_coef_16x16[6]``
> + -
> + * - __u8
> + - ``scaling_list_dc_coef_32x32[2]``
> + -
> +
> +.. raw:: latex
> +
> + \normalsize
> +
> .. c:type:: v4l2_hevc_dpb_entry
>
> .. raw:: latex
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> index f9ecf6276129..2f491c17dd5d 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> @@ -495,6 +495,12 @@ See also the examples in :ref:`control`.
> - n/a
> - A struct :c:type:`v4l2_ctrl_hevc_slice_params`, containing HEVC
> slice parameters for stateless video decoders.
> + * - ``V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX``
> + - n/a
> + - n/a
> + - n/a
> + - A struct :c:type:`v4l2_ctrl_hevc_scaling_matrix`, containing HEVC
> + scaling matrix for stateless video decoders.
> * - ``V4L2_CTRL_TYPE_VP8_FRAME``
> - n/a
> - n/a
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> index c4b5082849b6..70adfc1b9c81 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> @@ -687,6 +687,9 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>
> break;
>
> + case V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX:
> + break;
> +
> case V4L2_CTRL_TYPE_AREA:
> area = p;
> if (!area->width || !area->height)
> @@ -1240,6 +1243,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
> case V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS:
> elem_size = sizeof(struct v4l2_ctrl_hevc_slice_params);
> break;
> + case V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX:
> + elem_size = sizeof(struct v4l2_ctrl_hevc_scaling_matrix);
> + break;
> case V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS:
> elem_size = sizeof(struct v4l2_ctrl_hevc_decode_params);
> break;
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index b6344bbf1e00..cb29c2a7fabe 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -996,6 +996,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> case V4L2_CID_MPEG_VIDEO_HEVC_SPS: return "HEVC Sequence Parameter Set";
> case V4L2_CID_MPEG_VIDEO_HEVC_PPS: return "HEVC Picture Parameter Set";
> case V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS: return "HEVC Slice Parameters";
> + case V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX: return "HEVC Scaling Matrix";
> case V4L2_CID_MPEG_VIDEO_HEVC_DECODE_PARAMS: return "HEVC Decode Parameters";
> case V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE: return "HEVC Decode Mode";
> case V4L2_CID_MPEG_VIDEO_HEVC_START_CODE: return "HEVC Start Code";
> @@ -1488,6 +1489,9 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> case V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS:
> *type = V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS;
> break;
> + case V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX:
> + *type = V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX;
> + break;
> case V4L2_CID_MPEG_VIDEO_HEVC_DECODE_PARAMS:
> *type = V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS;
> break;
> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> index 53c0038c792b..0e5c4a2eecff 100644
> --- a/include/media/hevc-ctrls.h
> +++ b/include/media/hevc-ctrls.h
> @@ -19,6 +19,7 @@
> #define V4L2_CID_MPEG_VIDEO_HEVC_SPS (V4L2_CID_CODEC_BASE + 1008)
> #define V4L2_CID_MPEG_VIDEO_HEVC_PPS (V4L2_CID_CODEC_BASE + 1009)
> #define V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS (V4L2_CID_CODEC_BASE + 1010)
> +#define V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX (V4L2_CID_CODEC_BASE + 1011)
> #define V4L2_CID_MPEG_VIDEO_HEVC_DECODE_PARAMS (V4L2_CID_CODEC_BASE + 1012)
> #define V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE (V4L2_CID_CODEC_BASE + 1015)
> #define V4L2_CID_MPEG_VIDEO_HEVC_START_CODE (V4L2_CID_CODEC_BASE + 1016)
> @@ -27,6 +28,7 @@
> #define V4L2_CTRL_TYPE_HEVC_SPS 0x0120
> #define V4L2_CTRL_TYPE_HEVC_PPS 0x0121
> #define V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS 0x0122
> +#define V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX 0x0123
> #define V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS 0x0124
>
> enum v4l2_mpeg_video_hevc_decode_mode {
> @@ -224,6 +226,15 @@ struct v4l2_ctrl_hevc_decode_params {
> __u64 flags;
> };
>
> +struct v4l2_ctrl_hevc_scaling_matrix {
> + __u8 scaling_list_4x4[6][16];
> + __u8 scaling_list_8x8[6][64];
> + __u8 scaling_list_16x16[6][64];
> + __u8 scaling_list_32x32[2][64];
> + __u8 scaling_list_dc_coef_16x16[6];
> + __u8 scaling_list_dc_coef_32x32[2];
> +};
> +
> /* MPEG-class control IDs specific to the Hantro driver as defined by V4L2 */
> #define V4L2_CID_CODEC_HANTRO_BASE (V4L2_CTRL_CLASS_CODEC | 0x1200)
> /*
>