drivers/media/usb/gspca/jpeg.h

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This source file includes following definitions.
jpeg_define
jpeg_set_qual
   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 */
 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 */
 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
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root/drivers/media/usb/gspca/jpeg.h

INCLUDED FROM

DEFINITIONS
