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