[media] v4l: Define a pixel format for the R-Car VSP1 2-D histogram engine (5deb1c04) · Commits · 戴 / test

Documentation/media/uapi/v4l/meta-formats.rst

+1 −0

Original line number	Diff line number	Diff line
		@@ -13,3 +13,4 @@ These formats are used for the :ref:`metadata` interface only.
		:maxdepth: 1

		pixfmt-meta-vsp1-hgo
		pixfmt-meta-vsp1-hgt

Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst

0 → 100644

+120 −0

Original line number	Diff line number	Diff line
		.. -- coding: utf-8; mode: rst --

		.. _v4l2-meta-fmt-vsp1-hgt:

		*******************************
		V4L2_META_FMT_VSP1_HGT ('VSPT')
		*******************************

		Renesas R-Car VSP1 2-D Histogram Data


		Description
		===========

		This format describes histogram data generated by the Renesas R-Car VSP1
		2-D Histogram (HGT) engine.

		The VSP1 HGT is a histogram computation engine that operates on HSV
		data. It operates on a possibly cropped and subsampled input image and
		computes the sum, maximum and minimum of the S component as well as a
		weighted frequency histogram based on the H and S components.

		The histogram is a matrix of 6 Hue and 32 Saturation buckets, 192 in
		total. Each HSV value is added to one or more buckets with a weight
		between 1 and 16 depending on the Hue areas configuration. Finding the
		corresponding buckets is done by inspecting the H and S value independently.

		The Saturation position n (0 - 31) of the bucket in the matrix is
		found by the expression:

		n = S / 8

		The Hue position m (0 - 5) of the bucket in the matrix depends on
		how the HGT Hue areas are configured. There are 6 user configurable Hue
		Areas which can be configured to cover overlapping Hue values:

		::

		Area 0 Area 1 Area 2 Area 3 Area 4 Area 5
		________ ________ ________ ________ ________ ________
		\ /\| \|\ /\| \|\ /\| \|\ /\| \|\ /\| \|\ /\| \|\ /
		\ / \| \| \ / \| \| \ / \| \| \ / \| \| \ / \| \| \ / \| \| \ /
		X \| \| X \| \| X \| \| X \| \| X \| \| X \| \| X
		/ \ \| \| / \ \| \| / \ \| \| / \ \| \| / \ \| \| / \ \| \| / \
		/ \\| \|/ \\| \|/ \\| \|/ \\| \|/ \\| \|/ \\| \|/ \
		5U 0L 0U 1L 1U 2L 2U 3L 3U 4L 4U 5L 5U 0L
		<0..............................Hue Value............................255>

		When two consecutive areas don't overlap (n+1L is equal to nU) the boundary
		value is considered as part of the lower area.

		Pixels with a hue value included in the centre of an area (between nL and nU
		included) are attributed to that single area and given a weight of 16. Pixels
		with a hue value included in the overlapping region between two areas (between
		n+1L and nU excluded) are attributed to both areas and given a weight for each
		of these areas proportional to their position along the diagonal lines
		(rounded down).

		The Hue area setup must match one of the following constrains:

		::

		0L <= 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U

		::

		0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U <= 0L

		Byte Order.
		All data is stored in memory in little endian format. Each cell in the tables
		contains one byte.

		.. flat-table:: VSP1 HGT Data - (776 bytes)
		:header-rows: 2
		:stub-columns: 0

		* - Offset
		- :cspan:`4` Memory
		* -
		- [31:24]
		- [23:16]
		- [15:8]
		- [7:0]
		* - 0
		- -
		- S max [7:0]
		- -
		- S min [7:0]
		* - 4
		- :cspan:`4` S sum [31:0]
		* - 8
		- :cspan:`4` Histogram bucket (m=0, n=0) [31:0]
		* - 12
		- :cspan:`4` Histogram bucket (m=0, n=1) [31:0]
		* -
		- :cspan:`4` ...
		* - 132
		- :cspan:`4` Histogram bucket (m=0, n=31) [31:0]
		* - 136
		- :cspan:`4` Histogram bucket (m=1, n=0) [31:0]
		* -
		- :cspan:`4` ...
		* - 264
		- :cspan:`4` Histogram bucket (m=2, n=0) [31:0]
		* -
		- :cspan:`4` ...
		* - 392
		- :cspan:`4` Histogram bucket (m=3, n=0) [31:0]
		* -
		- :cspan:`4` ...
		* - 520
		- :cspan:`4` Histogram bucket (m=4, n=0) [31:0]
		* -
		- :cspan:`4` ...
		* - 648
		- :cspan:`4` Histogram bucket (m=5, n=0) [31:0]
		* -
		- :cspan:`4` ...
		* - 772
		- :cspan:`4` Histogram bucket (m=5, n=31) [31:0]

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

+1 −0

Original line number	Diff line number	Diff line
		@@ -1234,6 +1234,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
		case V4L2_TCH_FMT_TU16: descr = "16-bit unsigned touch data"; break;
		case V4L2_TCH_FMT_TU08: descr = "8-bit unsigned touch data"; break;
		case V4L2_META_FMT_VSP1_HGO: descr = "R-Car VSP1 1-D Histogram"; break;
		case V4L2_META_FMT_VSP1_HGT: descr = "R-Car VSP1 2-D Histogram"; break;

		default:
		/* Compressed formats */

include/uapi/linux/videodev2.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -677,7 +677,8 @@ struct v4l2_pix_format {
		#define V4L2_TCH_FMT_TU08 v4l2_fourcc('T', 'U', '0', '8') /* 8-bit unsigned touch data */

		/* Meta-data formats */
		#define V4L2_META_FMT_VSP1_HGO v4l2_fourcc('V', 'S', 'P', 'H') /* R-Car VSP1 Histogram */
		#define V4L2_META_FMT_VSP1_HGO v4l2_fourcc('V', 'S', 'P', 'H') /* R-Car VSP1 1-D Histogram */
		#define V4L2_META_FMT_VSP1_HGT v4l2_fourcc('V', 'S', 'P', 'T') /* R-Car VSP1 2-D Histogram */

		/* priv field value to indicates that subsequent fields are valid. */
		#define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe

Admin message