From: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
The format is used on the R-Car VSP1 video queues that carry
2-D histogram statistics data.
Signed-off-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
---
Documentation/media/uapi/v4l/meta-formats.rst | 1 +
.../media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst | 120 +++++++++++++++++++++
drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
include/uapi/linux/videodev2.h | 3 +-
4 files changed, 124 insertions(+), 1 deletion(-)
create mode 100644 Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst
diff --git a/Documentation/media/uapi/v4l/meta-formats.rst
b/Documentation/media/uapi/v4l/meta-formats.rst
index 05ab91e12f10..01e24e3df571 100644
--- a/Documentation/media/uapi/v4l/meta-formats.rst
+++ b/Documentation/media/uapi/v4l/meta-formats.rst
@@ -13,3 +13,4 @@ These formats are used for the :ref:`metadata` interface only.
:maxdepth: 1
pixfmt-meta-vsp1-hgo
+ pixfmt-meta-vsp1-hgt
diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst
b/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst
new file mode 100644
index 000000000000..fb9f79466319
--- /dev/null
+++ b/Documentation/media/uapi/v4l/pixfmt-meta-vsp1-hgt.rst
@@ -0,0 +1,120 @@
+.. -*- 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]
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
b/drivers/media/v4l2-core/v4l2-ioctl.c
index 74885ba0ba68..063ee248b54f 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1233,6 +1233,7 @@ 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 */
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index d402d734afe0..1ddd75afce76 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -678,7 +678,8 @@ 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
--
Regards,
Laurent Pinchart
