jpeg.h 5.2 KB

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