1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef JPEG_H
3 #define JPEG_H 1
4 /*
5 * Insert a JPEG header at start of frame
6 *
7 * This module is used by the gspca subdrivers.
8 * A special case is done for Conexant webcams.
9 *
10 * Copyright (C) Jean-Francois Moine (http://moinejf.free.fr)
11 */
12
13 /*
14 * generation options
15 * CONEX_CAM Conexant if present
16 */
17
18 /* JPEG header */
19 static const u8 jpeg_head[] = {
20 0xff, 0xd8, /* jpeg */
21
22 /* quantization table quality 50% */
23 0xff, 0xdb, 0x00, 0x84, /* DQT */
24 0,
25 #define JPEG_QT0_OFFSET 7
26 0x10, 0x0b, 0x0c, 0x0e, 0x0c, 0x0a, 0x10, 0x0e,
27 0x0d, 0x0e, 0x12, 0x11, 0x10, 0x13, 0x18, 0x28,
28 0x1a, 0x18, 0x16, 0x16, 0x18, 0x31, 0x23, 0x25,
29 0x1d, 0x28, 0x3a, 0x33, 0x3d, 0x3c, 0x39, 0x33,
30 0x38, 0x37, 0x40, 0x48, 0x5c, 0x4e, 0x40, 0x44,
31 0x57, 0x45, 0x37, 0x38, 0x50, 0x6d, 0x51, 0x57,
32 0x5f, 0x62, 0x67, 0x68, 0x67, 0x3e, 0x4d, 0x71,
33 0x79, 0x70, 0x64, 0x78, 0x5c, 0x65, 0x67, 0x63,
34 1,
35 #define JPEG_QT1_OFFSET 72
36 0x11, 0x12, 0x12, 0x18, 0x15, 0x18, 0x2f, 0x1a,
37 0x1a, 0x2f, 0x63, 0x42, 0x38, 0x42, 0x63, 0x63,
38 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
39 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
40 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
41 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
42 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
43 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
44
45 /* huffman table */
46 0xff, 0xc4, 0x01, 0xa2,
47 0x00, 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01,
48 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
49 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
50 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x01, 0x00, 0x03,
51 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
52 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
53 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
54 0x0a, 0x0b, 0x10, 0x00, 0x02, 0x01, 0x03, 0x03,
55 0x02, 0x04, 0x03, 0x05, 0x05, 0x04, 0x04, 0x00,
56 0x00, 0x01, 0x7d, 0x01, 0x02, 0x03, 0x00, 0x04,
57 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06, 0x13,
58 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81,
59 0x91, 0xa1, 0x08, 0x23, 0x42, 0xb1, 0xc1, 0x15,
60 0x52, 0xd1, 0xf0, 0x24, 0x33, 0x62, 0x72, 0x82,
61 0x09, 0x0a, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x25,
62 0x26, 0x27, 0x28, 0x29, 0x2a, 0x34, 0x35, 0x36,
63 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46,
64 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56,
65 0x57, 0x58, 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66,
66 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76,
67 0x77, 0x78, 0x79, 0x7a, 0x83, 0x84, 0x85, 0x86,
68 0x87, 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95,
69 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4,
70 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3,
71 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2,
72 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca,
73 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9,
74 0xda, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
75 0xe8, 0xe9, 0xea, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5,
76 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0x11, 0x00, 0x02,
77 0x01, 0x02, 0x04, 0x04, 0x03, 0x04, 0x07, 0x05,
78 0x04, 0x04, 0x00, 0x01, 0x02, 0x77, 0x00, 0x01,
79 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31, 0x06,
80 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 0x13, 0x22,
81 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 0xa1, 0xb1,
82 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 0x15, 0x62,
83 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25,
84 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, 0x27, 0x28,
85 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a,
86 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
87 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a,
88 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a,
89 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a,
90 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
91 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
92 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
93 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
94 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
95 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
96 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe2, 0xe3,
97 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf2,
98 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa,
99 #ifdef CONEX_CAM
100 /* the Conexant frames start with SOF0 */
101 #define JPEG_HDR_SZ 556
102 #else
103 0xff, 0xc0, 0x00, 0x11, /* SOF0 (start of frame 0 */
104 0x08, /* data precision */
105 #define JPEG_HEIGHT_OFFSET 561
106 0x01, 0xe0, /* height */
107 0x02, 0x80, /* width */
108 0x03, /* component number */
109 0x01,
110 0x21, /* samples Y */
111 0x00, /* quant Y */
112 0x02, 0x11, 0x01, /* samples CbCr - quant CbCr */
113 0x03, 0x11, 0x01,
114
115 0xff, 0xda, 0x00, 0x0c, /* SOS (start of scan) */
116 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00
117 #define JPEG_HDR_SZ 589
118 #endif
119 };
120
121 /* define the JPEG header */
jpeg_define(u8 * jpeg_hdr,int height,int width,int samplesY)122 static void jpeg_define(u8 *jpeg_hdr,
123 int height,
124 int width,
125 int samplesY)
126 {
127 memcpy(jpeg_hdr, jpeg_head, sizeof jpeg_head);
128 #ifndef CONEX_CAM
129 jpeg_hdr[JPEG_HEIGHT_OFFSET + 0] = height >> 8;
130 jpeg_hdr[JPEG_HEIGHT_OFFSET + 1] = height;
131 jpeg_hdr[JPEG_HEIGHT_OFFSET + 2] = width >> 8;
132 jpeg_hdr[JPEG_HEIGHT_OFFSET + 3] = width;
133 jpeg_hdr[JPEG_HEIGHT_OFFSET + 6] = samplesY;
134 #endif
135 }
136
137 /* set the JPEG quality */
jpeg_set_qual(u8 * jpeg_hdr,int quality)138 static void jpeg_set_qual(u8 *jpeg_hdr,
139 int quality)
140 {
141 int i, sc;
142
143 if (quality <= 0)
144 sc = 5000;
145 else if (quality < 50)
146 sc = 5000 / quality;
147 else
148 sc = 200 - quality * 2;
149 for (i = 0; i < 64; i++) {
150 jpeg_hdr[JPEG_QT0_OFFSET + i] =
151 (jpeg_head[JPEG_QT0_OFFSET + i] * sc + 50) / 100;
152 jpeg_hdr[JPEG_QT1_OFFSET + i] =
153 (jpeg_head[JPEG_QT1_OFFSET + i] * sc + 50) / 100;
154 }
155 }
156 #endif
157
