jstdhuff.c (5321B)
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 /* 16 * Huffman table setup routines 17 */ 18 19 LOCAL(void) 20 add_huff_table(j_common_ptr cinfo, JHUFF_TBL **htblptr, const UINT8 *bits, 21 const UINT8 *val) 22 /* Define a Huffman table */ 23 { 24 int nsymbols, len; 25 26 if (*htblptr == NULL) 27 *htblptr = jpeg_alloc_huff_table(cinfo); 28 else 29 return; 30 31 /* Copy the number-of-symbols-of-each-code-length counts */ 32 memcpy((*htblptr)->bits, bits, sizeof((*htblptr)->bits)); 33 34 /* Validate the counts. We do this here mainly so we can copy the right 35 * number of symbols from the val[] array, without risking marching off 36 * the end of memory. jchuff.c will do a more thorough test later. 37 */ 38 nsymbols = 0; 39 for (len = 1; len <= 16; len++) 40 nsymbols += bits[len]; 41 if (nsymbols < 1 || nsymbols > 256) 42 ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); 43 44 memcpy((*htblptr)->huffval, val, nsymbols * sizeof(UINT8)); 45 memset(&((*htblptr)->huffval[nsymbols]), 0, 46 (256 - nsymbols) * sizeof(UINT8)); 47 48 /* Initialize sent_table FALSE so table will be written to JPEG file. */ 49 (*htblptr)->sent_table = FALSE; 50 } 51 52 53 LOCAL(void) 54 std_huff_tables(j_common_ptr cinfo) 55 /* Set up the standard Huffman tables (cf. JPEG standard section K.3) */ 56 /* IMPORTANT: these are only valid for 8-bit data precision! */ 57 { 58 JHUFF_TBL **dc_huff_tbl_ptrs, **ac_huff_tbl_ptrs; 59 60 static const UINT8 bits_dc_luminance[17] = { 61 /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 62 }; 63 static const UINT8 val_dc_luminance[] = { 64 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 65 }; 66 67 static const UINT8 bits_dc_chrominance[17] = { 68 /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 69 }; 70 static const UINT8 val_dc_chrominance[] = { 71 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 72 }; 73 74 static const UINT8 bits_ac_luminance[17] = { 75 /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d 76 }; 77 static const UINT8 val_ac_luminance[] = { 78 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 79 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 80 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, 81 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, 82 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, 83 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, 84 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 85 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 86 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 87 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 88 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 89 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 90 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 91 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 92 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 93 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 94 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, 95 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, 96 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 97 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 98 0xf9, 0xfa 99 }; 100 101 static const UINT8 bits_ac_chrominance[17] = { 102 /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 103 }; 104 static const UINT8 val_ac_chrominance[] = { 105 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 106 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 107 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 108 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, 109 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, 110 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, 111 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, 112 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 113 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 114 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 115 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 116 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 117 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 118 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 119 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 120 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 121 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 122 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 123 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 124 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 125 0xf9, 0xfa 126 }; 127 128 if (cinfo->is_decompressor) { 129 dc_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->dc_huff_tbl_ptrs; 130 ac_huff_tbl_ptrs = ((j_decompress_ptr)cinfo)->ac_huff_tbl_ptrs; 131 } else { 132 dc_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->dc_huff_tbl_ptrs; 133 ac_huff_tbl_ptrs = ((j_compress_ptr)cinfo)->ac_huff_tbl_ptrs; 134 } 135 136 add_huff_table(cinfo, &dc_huff_tbl_ptrs[0], bits_dc_luminance, 137 val_dc_luminance); 138 add_huff_table(cinfo, &ac_huff_tbl_ptrs[0], bits_ac_luminance, 139 val_ac_luminance); 140 add_huff_table(cinfo, &dc_huff_tbl_ptrs[1], bits_dc_chrominance, 141 val_dc_chrominance); 142 add_huff_table(cinfo, &ac_huff_tbl_ptrs[1], bits_ac_chrominance, 143 val_ac_chrominance); 144 }