1 /* 2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 12 #include "boolhuff.h" 13 #include "vp8/common/blockd.h" 14 15 16 17 #if defined(SECTIONBITS_OUTPUT) 18 unsigned __int64 Sectionbits[500]; 19 20 #endif 21 22 #ifdef ENTROPY_STATS 23 unsigned int active_section = 0; 24 #endif 25 26 const unsigned int vp8_prob_cost[256] = 27 { 28 2047, 2047, 1791, 1641, 1535, 1452, 1385, 1328, 1279, 1235, 1196, 1161, 1129, 1099, 1072, 1046, 29 1023, 1000, 979, 959, 940, 922, 905, 889, 873, 858, 843, 829, 816, 803, 790, 778, 30 767, 755, 744, 733, 723, 713, 703, 693, 684, 675, 666, 657, 649, 641, 633, 625, 31 617, 609, 602, 594, 587, 580, 573, 567, 560, 553, 547, 541, 534, 528, 522, 516, 32 511, 505, 499, 494, 488, 483, 477, 472, 467, 462, 457, 452, 447, 442, 437, 433, 33 428, 424, 419, 415, 410, 406, 401, 397, 393, 389, 385, 381, 377, 373, 369, 365, 34 361, 357, 353, 349, 346, 342, 338, 335, 331, 328, 324, 321, 317, 314, 311, 307, 35 304, 301, 297, 294, 291, 288, 285, 281, 278, 275, 272, 269, 266, 263, 260, 257, 36 255, 252, 249, 246, 243, 240, 238, 235, 232, 229, 227, 224, 221, 219, 216, 214, 37 211, 208, 206, 203, 201, 198, 196, 194, 191, 189, 186, 184, 181, 179, 177, 174, 38 172, 170, 168, 165, 163, 161, 159, 156, 154, 152, 150, 148, 145, 143, 141, 139, 39 137, 135, 133, 131, 129, 127, 125, 123, 121, 119, 117, 115, 113, 111, 109, 107, 40 105, 103, 101, 99, 97, 95, 93, 92, 90, 88, 86, 84, 82, 81, 79, 77, 41 75, 73, 72, 70, 68, 66, 65, 63, 61, 60, 58, 56, 55, 53, 51, 50, 42 48, 46, 45, 43, 41, 40, 38, 37, 35, 33, 32, 30, 29, 27, 25, 24, 43 22, 21, 19, 18, 16, 15, 13, 12, 10, 9, 7, 6, 4, 3, 1, 1 44 }; 45 46 void vp8_start_encode(BOOL_CODER *br, unsigned char *source) 47 { 48 49 br->lowvalue = 0; 50 br->range = 255; 51 br->value = 0; 52 br->count = -24; 53 br->buffer = source; 54 br->pos = 0; 55 } 56 57 void vp8_stop_encode(BOOL_CODER *br) 58 { 59 int i; 60 61 for (i = 0; i < 32; i++) 62 vp8_encode_bool(br, 0, 128); 63 } 64 65 DECLARE_ALIGNED(16, static const unsigned int, norm[256]) = 66 { 67 0, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 68 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 69 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 70 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 71 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 72 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 73 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 74 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 75 }; 76 77 void vp8_encode_bool(BOOL_CODER *br, int bit, int probability) 78 { 79 unsigned int split; 80 int count = br->count; 81 unsigned int range = br->range; 82 unsigned int lowvalue = br->lowvalue; 83 register unsigned int shift; 84 85 #ifdef ENTROPY_STATS 86 #if defined(SECTIONBITS_OUTPUT) 87 88 if (bit) 89 Sectionbits[active_section] += vp8_prob_cost[255-probability]; 90 else 91 Sectionbits[active_section] += vp8_prob_cost[probability]; 92 93 #endif 94 #endif 95 96 split = 1 + (((range - 1) * probability) >> 8); 97 98 range = split; 99 100 if (bit) 101 { 102 lowvalue += split; 103 range = br->range - split; 104 } 105 106 shift = norm[range]; 107 108 range <<= shift; 109 count += shift; 110 111 if (count >= 0) 112 { 113 int offset = shift - count; 114 115 if ((lowvalue << (offset - 1)) & 0x80000000) 116 { 117 int x = br->pos - 1; 118 119 while (x >= 0 && br->buffer[x] == 0xff) 120 { 121 br->buffer[x] = (unsigned char)0; 122 x--; 123 } 124 125 br->buffer[x] += 1; 126 } 127 128 br->buffer[br->pos++] = (lowvalue >> (24 - offset)); 129 lowvalue <<= offset; 130 shift = count; 131 lowvalue &= 0xffffff; 132 count -= 8 ; 133 } 134 135 lowvalue <<= shift; 136 br->count = count; 137 br->lowvalue = lowvalue; 138 br->range = range; 139 } 140 141 void vp8_encode_value(BOOL_CODER *br, int data, int bits) 142 { 143 int bit; 144 145 for (bit = bits - 1; bit >= 0; bit--) 146 vp8_encode_bool(br, (1 & (data >> bit)), 0x80); 147 148 } 149
