jpeg.h (5362B)
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 */ 19static const u8 jpeg_head[] = { 20 0xff, 0xd8, /* jpeg */ 21 22/* quantization table quality 50% */ 23 0xff, 0xdb, 0x00, 0x84, /* DQT */ 240, 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, 341, 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 */ 122static 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 */ 138static 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