jstdhuff.c 5.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144
  1. /*
  2. * jstdhuff.c
  3. *
  4. * This file was part of the Independent JPEG Group's software:
  5. * Copyright (C) 1991-1998, Thomas G. Lane.
  6. * libjpeg-turbo Modifications:
  7. * Copyright (C) 2013, 2022, D. R. Commander.
  8. * For conditions of distribution and use, see the accompanying README.ijg
  9. * file.
  10. *
  11. * This file contains routines to set the default Huffman tables, if they are
  12. * not already set.
  13. */
  14. /*
  15. * Huffman table setup routines
  16. */
  17. LOCAL(void)
  18. add_huff_table(j_common_ptr cinfo, JHUFF_TBL **htblptr, const UINT8 *bits,
  19. const UINT8 *val)
  20. /* Define a Huffman table */
  21. {
  22. int nsymbols, len;
  23. if (*htblptr == NULL)
  24. *htblptr = jpeg_alloc_huff_table(cinfo);
  25. else
  26. return;
  27. /* Copy the number-of-symbols-of-each-code-length counts */
  28. memcpy((*htblptr)->bits, bits, sizeof((*htblptr)->bits));
  29. /* Validate the counts. We do this here mainly so we can copy the right
  30. * number of symbols from the val[] array, without risking marching off
  31. * the end of memory. jchuff.c will do a more thorough test later.
  32. */
  33. nsymbols = 0;
  34. for (len = 1; len <= 16; len++)
  35. nsymbols += bits[len];
  36. if (nsymbols < 1 || nsymbols > 256)
  37. ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
  38. memcpy((*htblptr)->huffval, val, nsymbols * sizeof(UINT8));
  39. memset(&((*htblptr)->huffval[nsymbols]), 0,
  40. (256 - nsymbols) * sizeof(UINT8));
  41. /* Initialize sent_table FALSE so table will be written to JPEG file. */
  42. (*htblptr)->sent_table = FALSE;
  43. }
  44. LOCAL(void)
  45. std_huff_tables(j_common_ptr cinfo)
  46. /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
  47. /* IMPORTANT: these are only valid for 8-bit data precision! */
  48. {
  49. JHUFF_TBL **dc_huff_tbl_ptrs, **ac_huff_tbl_ptrs;
  50. static const UINT8 bits_dc_luminance[17] = {
  51. /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0
  52. };
  53. static const UINT8 val_dc_luminance[] = {
  54. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
  55. };
  56. static const UINT8 bits_dc_chrominance[17] = {
  57. /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0
  58. };
  59. static const UINT8 val_dc_chrominance[] = {
  60. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
  61. };
  62. static const UINT8 bits_ac_luminance[17] = {
  63. /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d
  64. };
  65. static const UINT8 val_ac_luminance[] = {
  66. 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
  67. 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
  68. 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
  69. 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
  70. 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
  71. 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
  72. 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
  73. 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
  74. 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
  75. 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
  76. 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
  77. 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  78. 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
  79. 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
  80. 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
  81. 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
  82. 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
  83. 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
  84. 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
  85. 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  86. 0xf9, 0xfa
  87. };
  88. static const UINT8 bits_ac_chrominance[17] = {
  89. /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77
  90. };
  91. static const UINT8 val_ac_chrominance[] = {
  92. 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
  93. 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
  94. 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
  95. 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
  96. 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
  97. 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
  98. 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
  99. 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
  100. 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
  101. 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
  102. 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
  103. 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  104. 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
  105. 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
  106. 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
  107. 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
  108. 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
  109. 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
  110. 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
  111. 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  112. 0xf9, 0xfa
  113. };
  114. if (cinfo->is_decompressor) {
  115. dc_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->dc_huff_tbl_ptrs;
  116. ac_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->ac_huff_tbl_ptrs;
  117. } else {
  118. dc_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->dc_huff_tbl_ptrs;
  119. ac_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->ac_huff_tbl_ptrs;
  120. }
  121. add_huff_table(cinfo, &dc_huff_tbl_ptrs[0], bits_dc_luminance,
  122. val_dc_luminance);
  123. add_huff_table(cinfo, &ac_huff_tbl_ptrs[0], bits_ac_luminance,
  124. val_ac_luminance);
  125. add_huff_table(cinfo, &dc_huff_tbl_ptrs[1], bits_dc_chrominance,
  126. val_dc_chrominance);
  127. add_huff_table(cinfo, &ac_huff_tbl_ptrs[1], bits_ac_chrominance,
  128. val_ac_chrominance);
  129. }