jpeg.h 5.7 KB

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  1. #ifndef JPEG_H
  2. #define JPEG_H 1
  3. /*
  4. * Insert a JPEG header at start of frame
  5. *
  6. * This module is used by the gspca subdrivers.
  7. * A special case is done for Conexant webcams.
  8. *
  9. * Copyright (C) Jean-Francois Moine (http://moinejf.free.fr)
  10. *
  11. * This program is free software; you can redistribute it and/or modify
  12. * it under the terms of the GNU General Public License as published by
  13. * the Free Software Foundation; either version 2 of the License, or
  14. * any later version.
  15. *
  16. * This program is distributed in the hope that it will be useful,
  17. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19. * GNU General Public License for more details.
  20. *
  21. */
  22. /*
  23. * generation options
  24. * CONEX_CAM Conexant if present
  25. */
  26. /* JPEG header */
  27. static const u8 jpeg_head[] = {
  28. 0xff, 0xd8, /* jpeg */
  29. /* quantization table quality 50% */
  30. 0xff, 0xdb, 0x00, 0x84, /* DQT */
  31. 0,
  32. #define JPEG_QT0_OFFSET 7
  33. 0x10, 0x0b, 0x0c, 0x0e, 0x0c, 0x0a, 0x10, 0x0e,
  34. 0x0d, 0x0e, 0x12, 0x11, 0x10, 0x13, 0x18, 0x28,
  35. 0x1a, 0x18, 0x16, 0x16, 0x18, 0x31, 0x23, 0x25,
  36. 0x1d, 0x28, 0x3a, 0x33, 0x3d, 0x3c, 0x39, 0x33,
  37. 0x38, 0x37, 0x40, 0x48, 0x5c, 0x4e, 0x40, 0x44,
  38. 0x57, 0x45, 0x37, 0x38, 0x50, 0x6d, 0x51, 0x57,
  39. 0x5f, 0x62, 0x67, 0x68, 0x67, 0x3e, 0x4d, 0x71,
  40. 0x79, 0x70, 0x64, 0x78, 0x5c, 0x65, 0x67, 0x63,
  41. 1,
  42. #define JPEG_QT1_OFFSET 72
  43. 0x11, 0x12, 0x12, 0x18, 0x15, 0x18, 0x2f, 0x1a,
  44. 0x1a, 0x2f, 0x63, 0x42, 0x38, 0x42, 0x63, 0x63,
  45. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  46. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  47. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  48. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  49. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  50. 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63, 0x63,
  51. /* huffman table */
  52. 0xff, 0xc4, 0x01, 0xa2,
  53. 0x00, 0x00, 0x01, 0x05, 0x01, 0x01, 0x01, 0x01,
  54. 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  55. 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
  56. 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x01, 0x00, 0x03,
  57. 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
  58. 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
  59. 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
  60. 0x0a, 0x0b, 0x10, 0x00, 0x02, 0x01, 0x03, 0x03,
  61. 0x02, 0x04, 0x03, 0x05, 0x05, 0x04, 0x04, 0x00,
  62. 0x00, 0x01, 0x7d, 0x01, 0x02, 0x03, 0x00, 0x04,
  63. 0x11, 0x05, 0x12, 0x21, 0x31, 0x41, 0x06, 0x13,
  64. 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32, 0x81,
  65. 0x91, 0xa1, 0x08, 0x23, 0x42, 0xb1, 0xc1, 0x15,
  66. 0x52, 0xd1, 0xf0, 0x24, 0x33, 0x62, 0x72, 0x82,
  67. 0x09, 0x0a, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x25,
  68. 0x26, 0x27, 0x28, 0x29, 0x2a, 0x34, 0x35, 0x36,
  69. 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46,
  70. 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56,
  71. 0x57, 0x58, 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66,
  72. 0x67, 0x68, 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76,
  73. 0x77, 0x78, 0x79, 0x7a, 0x83, 0x84, 0x85, 0x86,
  74. 0x87, 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95,
  75. 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4,
  76. 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3,
  77. 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2,
  78. 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca,
  79. 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9,
  80. 0xda, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
  81. 0xe8, 0xe9, 0xea, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5,
  82. 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0x11, 0x00, 0x02,
  83. 0x01, 0x02, 0x04, 0x04, 0x03, 0x04, 0x07, 0x05,
  84. 0x04, 0x04, 0x00, 0x01, 0x02, 0x77, 0x00, 0x01,
  85. 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31, 0x06,
  86. 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 0x13, 0x22,
  87. 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 0xa1, 0xb1,
  88. 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 0x15, 0x62,
  89. 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25,
  90. 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, 0x27, 0x28,
  91. 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a,
  92. 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
  93. 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a,
  94. 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a,
  95. 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a,
  96. 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  97. 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
  98. 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
  99. 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
  100. 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
  101. 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
  102. 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe2, 0xe3,
  103. 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf2,
  104. 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa,
  105. #ifdef CONEX_CAM
  106. /* the Conexant frames start with SOF0 */
  107. #define JPEG_HDR_SZ 556
  108. #else
  109. 0xff, 0xc0, 0x00, 0x11, /* SOF0 (start of frame 0 */
  110. 0x08, /* data precision */
  111. #define JPEG_HEIGHT_OFFSET 561
  112. 0x01, 0xe0, /* height */
  113. 0x02, 0x80, /* width */
  114. 0x03, /* component number */
  115. 0x01,
  116. 0x21, /* samples Y */
  117. 0x00, /* quant Y */
  118. 0x02, 0x11, 0x01, /* samples CbCr - quant CbCr */
  119. 0x03, 0x11, 0x01,
  120. 0xff, 0xda, 0x00, 0x0c, /* SOS (start of scan) */
  121. 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00
  122. #define JPEG_HDR_SZ 589
  123. #endif
  124. };
  125. /* define the JPEG header */
  126. static void jpeg_define(u8 *jpeg_hdr,
  127. int height,
  128. int width,
  129. int samplesY)
  130. {
  131. memcpy(jpeg_hdr, jpeg_head, sizeof jpeg_head);
  132. #ifndef CONEX_CAM
  133. jpeg_hdr[JPEG_HEIGHT_OFFSET + 0] = height >> 8;
  134. jpeg_hdr[JPEG_HEIGHT_OFFSET + 1] = height;
  135. jpeg_hdr[JPEG_HEIGHT_OFFSET + 2] = width >> 8;
  136. jpeg_hdr[JPEG_HEIGHT_OFFSET + 3] = width;
  137. jpeg_hdr[JPEG_HEIGHT_OFFSET + 6] = samplesY;
  138. #endif
  139. }
  140. /* set the JPEG quality */
  141. static void jpeg_set_qual(u8 *jpeg_hdr,
  142. int quality)
  143. {
  144. int i, sc;
  145. if (quality <= 0)
  146. sc = 5000;
  147. else if (quality < 50)
  148. sc = 5000 / quality;
  149. else
  150. sc = 200 - quality * 2;
  151. for (i = 0; i < 64; i++) {
  152. jpeg_hdr[JPEG_QT0_OFFSET + i] =
  153. (jpeg_head[JPEG_QT0_OFFSET + i] * sc + 50) / 100;
  154. jpeg_hdr[JPEG_QT1_OFFSET + i] =
  155. (jpeg_head[JPEG_QT1_OFFSET + i] * sc + 50) / 100;
  156. }
  157. }
  158. #endif