media: uapi: hevc: Add scaling matrix control

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

Taken from https://patchwork.linuxtv.org/patch/60728/
Changes (mainly documentation) have been requested.

HEVC has a scaling matrix concept. Add support for it.
Signed-off-by: NJernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

@@ -4316,6 +4316,47 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
       - ``padding[6]``
       - Applications and drivers must set this to zero.
 
+``V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX (struct)``
+    Specifies the scaling matrix (as extracted from the bitstream) for
+    the associated HEVC slice data. The bitstream parameters are
+    defined according to :ref:`hevc`, section 7.4.5 "Scaling list
+    data semantics". For further documentation, refer to the above
+    specification, unless there is an explicit comment stating
+    otherwise.
+
+    .. note::
+
+       This compound control is not yet part of the public kernel API and
+       it is expected to change.
+
+.. c:type:: v4l2_ctrl_hevc_scaling_matrix
+
+.. 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]``
+      -
+
 ``V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE (enum)``
     Specifies the decoding mode to use. Currently exposes slice-based and
     frame-based decoding but new modes might be added later on.

Documentation/userspace-api/media/v4l/pixfmt-compressed.rst

@@ -200,6 +200,7 @@ Compressed Formats
         * ``V4L2_CID_MPEG_VIDEO_HEVC_SPS``
         * ``V4L2_CID_MPEG_VIDEO_HEVC_PPS``
         * ``V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS``
+        * ``V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX``
 	See the :ref:`associated Codec Control IDs <v4l2-mpeg-hevc>`.
 	Buffers associated with this pixel format must contain the appropriate
 	number of macroblocks to decode a full corresponding frame.

drivers/media/v4l2-core/v4l2-ctrls.c

@@ -1022,6 +1022,7 @@ 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_MODE:		return "HEVC Decode Mode";
 	case V4L2_CID_MPEG_VIDEO_HEVC_START_CODE:		return "HEVC Start Code";
 
@@ -1462,6 +1463,9 @@ 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_UNIT_CELL_SIZE:
 		*type = V4L2_CTRL_TYPE_AREA;
 		*flags |= V4L2_CTRL_FLAG_READ_ONLY;
@@ -1935,6 +1939,9 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 		zero_padding(*p_hevc_slice_params);
 		break;
 
+	case V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX:
+		break;
+
 	case V4L2_CTRL_TYPE_AREA:
 		area = p;
 		if (!area->width || !area->height)
@@ -2627,6 +2634,9 @@ 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_AREA:
 		elem_size = sizeof(struct v4l2_area);
 		break;

include/media/hevc-ctrls.h

@@ -19,6 +19,7 @@
 #define V4L2_CID_MPEG_VIDEO_HEVC_SPS		(V4L2_CID_MPEG_BASE + 1008)
 #define V4L2_CID_MPEG_VIDEO_HEVC_PPS		(V4L2_CID_MPEG_BASE + 1009)
 #define V4L2_CID_MPEG_VIDEO_HEVC_SLICE_PARAMS	(V4L2_CID_MPEG_BASE + 1010)
+#define V4L2_CID_MPEG_VIDEO_HEVC_SCALING_MATRIX	(V4L2_CID_MPEG_BASE + 1011)
 #define V4L2_CID_MPEG_VIDEO_HEVC_DECODE_MODE	(V4L2_CID_MPEG_BASE + 1015)
 #define V4L2_CID_MPEG_VIDEO_HEVC_START_CODE	(V4L2_CID_MPEG_BASE + 1016)
 
@@ -26,6 +27,7 @@
 #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
 
 enum v4l2_mpeg_video_hevc_decode_mode {
 	V4L2_MPEG_VIDEO_HEVC_DECODE_MODE_SLICE_BASED,
@@ -209,4 +211,13 @@ struct v4l2_ctrl_hevc_slice_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];
+};
+
 #endif