metafmt-vsp1-hgo.rst

  1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
  2.. c:namespace:: V4L
  3
  4.. _v4l2-meta-fmt-vsp1-hgo:
  5
  6*******************************
  7V4L2_META_FMT_VSP1_HGO ('VSPH')
  8*******************************
  9
 10Renesas R-Car VSP1 1-D Histogram Data
 11
 12
 13Description
 14===========
 15
 16This format describes histogram data generated by the Renesas R-Car VSP1 1-D
 17Histogram (HGO) engine.
 18
 19The VSP1 HGO is a histogram computation engine that can operate on RGB, YCrCb
 20or HSV data. It operates on a possibly cropped and subsampled input image and
 21computes the minimum, maximum and sum of all pixels as well as per-channel
 22histograms.
 23
 24The HGO can compute histograms independently per channel, on the maximum of the
 25three channels (RGB data only) or on the Y channel only (YCbCr only). It can
 26additionally output the histogram with 64 or 256 bins, resulting in four
 27possible modes of operation.
 28
 29- In *64 bins normal mode*, the HGO operates on the three channels independently
 30  to compute three 64-bins histograms. RGB, YCbCr and HSV image formats are
 31  supported.
 32- In *64 bins maximum mode*, the HGO operates on the maximum of the (R, G, B)
 33  channels to compute a single 64-bins histogram. Only the RGB image format is
 34  supported.
 35- In *256 bins normal mode*, the HGO operates on the Y channel to compute a
 36  single 256-bins histogram. Only the YCbCr image format is supported.
 37- In *256 bins maximum mode*, the HGO operates on the maximum of the (R, G, B)
 38  channels to compute a single 256-bins histogram. Only the RGB image format is
 39  supported.
 40
 41**Byte Order.**
 42All data is stored in memory in little endian format. Each cell in the tables
 43contains one byte.
 44
 45.. flat-table:: VSP1 HGO Data - 64 Bins, Normal Mode (792 bytes)
 46    :header-rows:  2
 47    :stub-columns: 0
 48
 49    * - Offset
 50      - :cspan:`4` Memory
 51    * -
 52      - [31:24]
 53      - [23:16]
 54      - [15:8]
 55      - [7:0]
 56    * - 0
 57      -
 58      - R/Cr/H max [7:0]
 59      -
 60      - R/Cr/H min [7:0]
 61    * - 4
 62      -
 63      - G/Y/S max [7:0]
 64      -
 65      - G/Y/S min [7:0]
 66    * - 8
 67      -
 68      - B/Cb/V max [7:0]
 69      -
 70      - B/Cb/V min [7:0]
 71    * - 12
 72      - :cspan:`4` R/Cr/H sum [31:0]
 73    * - 16
 74      - :cspan:`4` G/Y/S sum [31:0]
 75    * - 20
 76      - :cspan:`4` B/Cb/V sum [31:0]
 77    * - 24
 78      - :cspan:`4` R/Cr/H bin 0 [31:0]
 79    * -
 80      - :cspan:`4` ...
 81    * - 276
 82      - :cspan:`4` R/Cr/H bin 63 [31:0]
 83    * - 280
 84      - :cspan:`4` G/Y/S bin 0 [31:0]
 85    * -
 86      - :cspan:`4` ...
 87    * - 532
 88      - :cspan:`4` G/Y/S bin 63 [31:0]
 89    * - 536
 90      - :cspan:`4` B/Cb/V bin 0 [31:0]
 91    * -
 92      - :cspan:`4` ...
 93    * - 788
 94      - :cspan:`4` B/Cb/V bin 63 [31:0]
 95
 96.. flat-table:: VSP1 HGO Data - 64 Bins, Max Mode (264 bytes)
 97    :header-rows:  2
 98    :stub-columns: 0
 99
100    * - Offset
101      - :cspan:`4` Memory
102    * -
103      - [31:24]
104      - [23:16]
105      - [15:8]
106      - [7:0]
107    * - 0
108      -
109      - max(R,G,B) max [7:0]
110      -
111      - max(R,G,B) min [7:0]
112    * - 4
113      - :cspan:`4` max(R,G,B) sum [31:0]
114    * - 8
115      - :cspan:`4` max(R,G,B) bin 0 [31:0]
116    * -
117      - :cspan:`4` ...
118    * - 260
119      - :cspan:`4` max(R,G,B) bin 63 [31:0]
120
121.. flat-table:: VSP1 HGO Data - 256 Bins, Normal Mode (1032 bytes)
122    :header-rows:  2
123    :stub-columns: 0
124
125    * - Offset
126      - :cspan:`4` Memory
127    * -
128      - [31:24]
129      - [23:16]
130      - [15:8]
131      - [7:0]
132    * - 0
133      -
134      - Y max [7:0]
135      -
136      - Y min [7:0]
137    * - 4
138      - :cspan:`4` Y sum [31:0]
139    * - 8
140      - :cspan:`4` Y bin 0 [31:0]
141    * -
142      - :cspan:`4` ...
143    * - 1028
144      - :cspan:`4` Y bin 255 [31:0]
145
146.. flat-table:: VSP1 HGO Data - 256 Bins, Max Mode (1032 bytes)
147    :header-rows:  2
148    :stub-columns: 0
149
150    * - Offset
151      - :cspan:`4` Memory
152    * -
153      - [31:24]
154      - [23:16]
155      - [15:8]
156      - [7:0]
157    * - 0
158      -
159      - max(R,G,B) max [7:0]
160      -
161      - max(R,G,B) min [7:0]
162    * - 4
163      - :cspan:`4` max(R,G,B) sum [31:0]
164    * - 8
165      - :cspan:`4` max(R,G,B) bin 0 [31:0]
166    * -
167      - :cspan:`4` ...
168    * - 1028
169      - :cspan:`4` max(R,G,B) bin 255 [31:0]