third_party/libwebp/dec/tree.c

   1 // Copyright 2010 Google Inc. All Rights Reserved.
   2 //
   3 // Use of this source code is governed by a BSD-style license
   4 // that can be found in the COPYING file in the root of the source
   5 // tree. An additional intellectual property rights grant can be found
   6 // in the file PATENTS. All contributing project authors may
   7 // be found in the AUTHORS file in the root of the source tree.
   8 // -----------------------------------------------------------------------------
   9 //
  10 // Coding trees and probas
  11 //
  12 // Author: Skal (pascal.massimino@gmail.com)
  13
  14 #include "./vp8i.h"
  15 #include "../utils/bit_reader_inl.h"
  16
  17 #define USE_GENERIC_TREE
  18
  19 #ifdef USE_GENERIC_TREE
  20 static const int8_t kYModesIntra4[18] = {
  21   -B_DC_PRED, 1,
  22     -B_TM_PRED, 2,
  23       -B_VE_PRED, 3,
  24         4, 6,
  25           -B_HE_PRED, 5,
  26             -B_RD_PRED, -B_VR_PRED,
  27         -B_LD_PRED, 7,
  28           -B_VL_PRED, 8,
  29             -B_HD_PRED, -B_HU_PRED
  30 };
  31 #endif
  32
  33 //------------------------------------------------------------------------------
  34 // Default probabilities
  35
  36 // Paragraph 13.5
  37 static const uint8_t
  38   CoeffsProba0[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS] = {
  39   { { { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
  40       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
  41       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }
  42     },
  43     { { 253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128 },
  44       { 189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128 },
  45       { 106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128 }
  46     },
  47     { { 1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128 },
  48       { 181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128 },
  49       { 78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128 },
  50     },
  51     { { 1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128 },
  52       { 184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128 },
  53       { 77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128 },
  54     },
  55     { { 1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128 },
  56       { 170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128 },
  57       { 37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128 }
  58     },
  59     { { 1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128 },
  60       { 207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128 },
  61       { 102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128 }
  62     },
  63     { { 1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128 },
  64       { 177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128 },
  65       { 80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128 }
  66     },
  67     { { 1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
  68       { 246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
  69       { 255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }
  70     }
  71   },
  72   { { { 198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62 },
  73       { 131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1 },
  74       { 68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128 }
  75     },
  76     { { 1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128 },
  77       { 184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128 },
  78       { 81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128 }
  79     },
  80     { { 1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128 },
  81       { 99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128 },
  82       { 23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128 }
  83     },
  84     { { 1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128 },
  85       { 109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128 },
  86       { 44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128 }
  87     },
  88     { { 1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128 },
  89       { 94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128 },
  90       { 22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128 }
  91     },
  92     { { 1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128 },
  93       { 124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128 },
  94       { 35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128 }
  95     },
  96     { { 1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128 },
  97       { 121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128 },
  98       { 45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128 }
  99     },
 100     { { 1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128 },
 101       { 203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128 },
 102       { 137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128 }
 103     }
 104   },
 105   { { { 253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128 },
 106       { 175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128 },
 107       { 73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128 }
 108     },
 109     { { 1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128 },
 110       { 239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128 },
 111       { 155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128 }
 112     },
 113     { { 1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128 },
 114       { 201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128 },
 115       { 69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128 }
 116     },
 117     { { 1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128 },
 118       { 223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128 },
 119       { 141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128 }
 120     },
 121     { { 1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128 },
 122       { 190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128 },
 123       { 149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 }
 124     },
 125     { { 1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
 126       { 247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
 127       { 240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128 }
 128     },
 129     { { 1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128 },
 130       { 213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128 },
 131       { 55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128 }
 132     },
 133     { { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
 134       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
 135       { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 }
 136     }
 137   },
 138   { { { 202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255 },
 139       { 126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128 },
 140       { 61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128 }
 141     },
 142     { { 1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128 },
 143       { 166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128 },
 144       { 39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128 }
 145     },
 146     { { 1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128 },
 147       { 124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128 },
 148       { 24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128 }
 149     },
 150     { { 1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128 },
 151       { 149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128 },
 152       { 28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128 }
 153     },
 154     { { 1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128 },
 155       { 123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128 },
 156       { 20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128 }
 157     },
 158     { { 1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128 },
 159       { 168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128 },
 160       { 47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128 }
 161     },
 162     { { 1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128 },
 163       { 141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128 },
 164       { 42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128 }
 165     },
 166     { { 1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
 167       { 244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
 168       { 238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 }
 169     }
 170   }
 171 };
 172
 173 // Paragraph 11.5
 174 static const uint8_t kBModesProba[NUM_BMODES][NUM_BMODES][NUM_BMODES - 1] = {
 175   { { 231, 120, 48, 89, 115, 113, 120, 152, 112 },
 176     { 152, 179, 64, 126, 170, 118, 46, 70, 95 },
 177     { 175, 69, 143, 80, 85, 82, 72, 155, 103 },
 178     { 56, 58, 10, 171, 218, 189, 17, 13, 152 },
 179     { 114, 26, 17, 163, 44, 195, 21, 10, 173 },
 180     { 121, 24, 80, 195, 26, 62, 44, 64, 85 },
 181     { 144, 71, 10, 38, 171, 213, 144, 34, 26 },
 182     { 170, 46, 55, 19, 136, 160, 33, 206, 71 },
 183     { 63, 20, 8, 114, 114, 208, 12, 9, 226 },
 184     { 81, 40, 11, 96, 182, 84, 29, 16, 36 } },
 185   { { 134, 183, 89, 137, 98, 101, 106, 165, 148 },
 186     { 72, 187, 100, 130, 157, 111, 32, 75, 80 },
 187     { 66, 102, 167, 99, 74, 62, 40, 234, 128 },
 188     { 41, 53, 9, 178, 241, 141, 26, 8, 107 },
 189     { 74, 43, 26, 146, 73, 166, 49, 23, 157 },
 190     { 65, 38, 105, 160, 51, 52, 31, 115, 128 },
 191     { 104, 79, 12, 27, 217, 255, 87, 17, 7 },
 192     { 87, 68, 71, 44, 114, 51, 15, 186, 23 },
 193     { 47, 41, 14, 110, 182, 183, 21, 17, 194 },
 194     { 66, 45, 25, 102, 197, 189, 23, 18, 22 } },
 195   { { 88, 88, 147, 150, 42, 46, 45, 196, 205 },
 196     { 43, 97, 183, 117, 85, 38, 35, 179, 61 },
 197     { 39, 53, 200, 87, 26, 21, 43, 232, 171 },
 198     { 56, 34, 51, 104, 114, 102, 29, 93, 77 },
 199     { 39, 28, 85, 171, 58, 165, 90, 98, 64 },
 200     { 34, 22, 116, 206, 23, 34, 43, 166, 73 },
 201     { 107, 54, 32, 26, 51, 1, 81, 43, 31 },
 202     { 68, 25, 106, 22, 64, 171, 36, 225, 114 },
 203     { 34, 19, 21, 102, 132, 188, 16, 76, 124 },
 204     { 62, 18, 78, 95, 85, 57, 50, 48, 51 } },
 205   { { 193, 101, 35, 159, 215, 111, 89, 46, 111 },
 206     { 60, 148, 31, 172, 219, 228, 21, 18, 111 },
 207     { 112, 113, 77, 85, 179, 255, 38, 120, 114 },
 208     { 40, 42, 1, 196, 245, 209, 10, 25, 109 },
 209     { 88, 43, 29, 140, 166, 213, 37, 43, 154 },
 210     { 61, 63, 30, 155, 67, 45, 68, 1, 209 },
 211     { 100, 80, 8, 43, 154, 1, 51, 26, 71 },
 212     { 142, 78, 78, 16, 255, 128, 34, 197, 171 },
 213     { 41, 40, 5, 102, 211, 183, 4, 1, 221 },
 214     { 51, 50, 17, 168, 209, 192, 23, 25, 82 } },
 215   { { 138, 31, 36, 171, 27, 166, 38, 44, 229 },
 216     { 67, 87, 58, 169, 82, 115, 26, 59, 179 },
 217     { 63, 59, 90, 180, 59, 166, 93, 73, 154 },
 218     { 40, 40, 21, 116, 143, 209, 34, 39, 175 },
 219     { 47, 15, 16, 183, 34, 223, 49, 45, 183 },
 220     { 46, 17, 33, 183, 6, 98, 15, 32, 183 },
 221     { 57, 46, 22, 24, 128, 1, 54, 17, 37 },
 222     { 65, 32, 73, 115, 28, 128, 23, 128, 205 },
 223     { 40, 3, 9, 115, 51, 192, 18, 6, 223 },
 224     { 87, 37, 9, 115, 59, 77, 64, 21, 47 } },
 225   { { 104, 55, 44, 218, 9, 54, 53, 130, 226 },
 226     { 64, 90, 70, 205, 40, 41, 23, 26, 57 },
 227     { 54, 57, 112, 184, 5, 41, 38, 166, 213 },
 228     { 30, 34, 26, 133, 152, 116, 10, 32, 134 },
 229     { 39, 19, 53, 221, 26, 114, 32, 73, 255 },
 230     { 31, 9, 65, 234, 2, 15, 1, 118, 73 },
 231     { 75, 32, 12, 51, 192, 255, 160, 43, 51 },
 232     { 88, 31, 35, 67, 102, 85, 55, 186, 85 },
 233     { 56, 21, 23, 111, 59, 205, 45, 37, 192 },
 234     { 55, 38, 70, 124, 73, 102, 1, 34, 98 } },
 235   { { 125, 98, 42, 88, 104, 85, 117, 175, 82 },
 236     { 95, 84, 53, 89, 128, 100, 113, 101, 45 },
 237     { 75, 79, 123, 47, 51, 128, 81, 171, 1 },
 238     { 57, 17, 5, 71, 102, 57, 53, 41, 49 },
 239     { 38, 33, 13, 121, 57, 73, 26, 1, 85 },
 240     { 41, 10, 67, 138, 77, 110, 90, 47, 114 },
 241     { 115, 21, 2, 10, 102, 255, 166, 23, 6 },
 242     { 101, 29, 16, 10, 85, 128, 101, 196, 26 },
 243     { 57, 18, 10, 102, 102, 213, 34, 20, 43 },
 244     { 117, 20, 15, 36, 163, 128, 68, 1, 26 } },
 245   { { 102, 61, 71, 37, 34, 53, 31, 243, 192 },
 246     { 69, 60, 71, 38, 73, 119, 28, 222, 37 },
 247     { 68, 45, 128, 34, 1, 47, 11, 245, 171 },
 248     { 62, 17, 19, 70, 146, 85, 55, 62, 70 },
 249     { 37, 43, 37, 154, 100, 163, 85, 160, 1 },
 250     { 63, 9, 92, 136, 28, 64, 32, 201, 85 },
 251     { 75, 15, 9, 9, 64, 255, 184, 119, 16 },
 252     { 86, 6, 28, 5, 64, 255, 25, 248, 1 },
 253     { 56, 8, 17, 132, 137, 255, 55, 116, 128 },
 254     { 58, 15, 20, 82, 135, 57, 26, 121, 40 } },
 255   { { 164, 50, 31, 137, 154, 133, 25, 35, 218 },
 256     { 51, 103, 44, 131, 131, 123, 31, 6, 158 },
 257     { 86, 40, 64, 135, 148, 224, 45, 183, 128 },
 258     { 22, 26, 17, 131, 240, 154, 14, 1, 209 },
 259     { 45, 16, 21, 91, 64, 222, 7, 1, 197 },
 260     { 56, 21, 39, 155, 60, 138, 23, 102, 213 },
 261     { 83, 12, 13, 54, 192, 255, 68, 47, 28 },
 262     { 85, 26, 85, 85, 128, 128, 32, 146, 171 },
 263     { 18, 11, 7, 63, 144, 171, 4, 4, 246 },
 264     { 35, 27, 10, 146, 174, 171, 12, 26, 128 } },
 265   { { 190, 80, 35, 99, 180, 80, 126, 54, 45 },
 266     { 85, 126, 47, 87, 176, 51, 41, 20, 32 },
 267     { 101, 75, 128, 139, 118, 146, 116, 128, 85 },
 268     { 56, 41, 15, 176, 236, 85, 37, 9, 62 },
 269     { 71, 30, 17, 119, 118, 255, 17, 18, 138 },
 270     { 101, 38, 60, 138, 55, 70, 43, 26, 142 },
 271     { 146, 36, 19, 30, 171, 255, 97, 27, 20 },
 272     { 138, 45, 61, 62, 219, 1, 81, 188, 64 },
 273     { 32, 41, 20, 117, 151, 142, 20, 21, 163 },
 274     { 112, 19, 12, 61, 195, 128, 48, 4, 24 } }
 275 };
 276
 277 void VP8ResetProba(VP8Proba* const proba) {
 278   memset(proba->segments_, 255u, sizeof(proba->segments_));
 279   // proba->bands_[][] is initialized later
 280 }
 281
 282 static void ParseIntraMode(VP8BitReader* const br,
 283                            VP8Decoder* const dec, int mb_x) {
 284   uint8_t* const top = dec->intra_t_ + 4 * mb_x;
 285   uint8_t* const left = dec->intra_l_;
 286   VP8MBData* const block = dec->mb_data_ + mb_x;
 287
 288   // Note: we don't save segment map (yet), as we don't expect
 289   // to decode more than 1 keyframe.
 290   if (dec->segment_hdr_.update_map_) {
 291     // Hardcoded tree parsing
 292     block->segment_ = !VP8GetBit(br, dec->proba_.segments_[0])
 293                     ? VP8GetBit(br, dec->proba_.segments_[1])
 294                     : 2 + VP8GetBit(br, dec->proba_.segments_[2]);
 295   } else {
 296     block->segment_ = 0;  // default for intra
 297   }
 298   if (dec->use_skip_proba_) block->skip_ = VP8GetBit(br, dec->skip_p_);
 299
 300   block->is_i4x4_ = !VP8GetBit(br, 145);   // decide for B_PRED first
 301   if (!block->is_i4x4_) {
 302     // Hardcoded 16x16 intra-mode decision tree.
 303     const int ymode =
 304         VP8GetBit(br, 156) ? (VP8GetBit(br, 128) ? TM_PRED : H_PRED)
 305                            : (VP8GetBit(br, 163) ? V_PRED : DC_PRED);
 306     block->imodes_[0] = ymode;
 307     memset(top, ymode, 4 * sizeof(*top));
 308     memset(left, ymode, 4 * sizeof(*left));
 309   } else {
 310     uint8_t* modes = block->imodes_;
 311     int y;
 312     for (y = 0; y < 4; ++y) {
 313       int ymode = left[y];
 314       int x;
 315       for (x = 0; x < 4; ++x) {
 316         const uint8_t* const prob = kBModesProba[top[x]][ymode];
 317 #ifdef USE_GENERIC_TREE
 318         // Generic tree-parsing
 319         int i = kYModesIntra4[VP8GetBit(br, prob[0])];
 320         while (i > 0) {
 321           i = kYModesIntra4[2 * i + VP8GetBit(br, prob[i])];
 322         }
 323         ymode = -i;
 324 #else
 325         // Hardcoded tree parsing
 326         ymode = !VP8GetBit(br, prob[0]) ? B_DC_PRED :
 327                   !VP8GetBit(br, prob[1]) ? B_TM_PRED :
 328                     !VP8GetBit(br, prob[2]) ? B_VE_PRED :
 329                       !VP8GetBit(br, prob[3]) ?
 330                         (!VP8GetBit(br, prob[4]) ? B_HE_PRED :
 331                           (!VP8GetBit(br, prob[5]) ? B_RD_PRED : B_VR_PRED)) :
 332                         (!VP8GetBit(br, prob[6]) ? B_LD_PRED :
 333                           (!VP8GetBit(br, prob[7]) ? B_VL_PRED :
 334                             (!VP8GetBit(br, prob[8]) ? B_HD_PRED : B_HU_PRED)));
 335 #endif    // USE_GENERIC_TREE
 336         top[x] = ymode;
 337       }
 338       memcpy(modes, top, 4 * sizeof(*top));
 339       modes += 4;
 340       left[y] = ymode;
 341     }
 342   }
 343   // Hardcoded UVMode decision tree
 344   block->uvmode_ = !VP8GetBit(br, 142) ? DC_PRED
 345                  : !VP8GetBit(br, 114) ? V_PRED
 346                  : VP8GetBit(br, 183) ? TM_PRED : H_PRED;
 347 }
 348
 349 int VP8ParseIntraModeRow(VP8BitReader* const br, VP8Decoder* const dec) {
 350   int mb_x;
 351   for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
 352     ParseIntraMode(br, dec, mb_x);
 353   }
 354   return !dec->br_.eof_;
 355 }
 356
 357 //------------------------------------------------------------------------------
 358 // Paragraph 13
 359
 360 static const uint8_t
 361     CoeffsUpdateProba[NUM_TYPES][NUM_BANDS][NUM_CTX][NUM_PROBAS] = {
 362   { { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 363       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 364       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 365     },
 366     { { 176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 367       { 223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
 368       { 249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 }
 369     },
 370     { { 255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
 371       { 234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 372       { 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 373     },
 374     { { 255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 375       { 239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 376       { 254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 }
 377     },
 378     { { 255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 379       { 251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 380       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 381     },
 382     { { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 383       { 251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 384       { 254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 }
 385     },
 386     { { 255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255 },
 387       { 250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255 },
 388       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 389     },
 390     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 391       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 392       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 393     }
 394   },
 395   { { { 217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 396       { 225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255 },
 397       { 234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255 }
 398     },
 399     { { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 400       { 223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 401       { 238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255 }
 402     },
 403     { { 255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 404       { 249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 405       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 406     },
 407     { { 255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 408       { 247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 409       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 410     },
 411     { { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 412       { 252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 413       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 414     },
 415     { { 255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 416       { 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 417       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 418     },
 419     { { 255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 420       { 250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 421       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 422     },
 423     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 424       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 425       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 426     }
 427   },
 428   { { { 186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255 },
 429       { 234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255 },
 430       { 251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255 }
 431     },
 432     { { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 433       { 236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 434       { 251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255 }
 435     },
 436     { { 255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 437       { 254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 438       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 439     },
 440     { { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 441       { 254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 442       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 443     },
 444     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 445       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 446       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 447     },
 448     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 449       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 450       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 451     },
 452     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 453       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 454       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 455     },
 456     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 457       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 458       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 459     }
 460   },
 461   { { { 248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 462       { 250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255 },
 463       { 248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255 }
 464     },
 465     { { 255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 466       { 246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 467       { 252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255 }
 468     },
 469     { { 255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
 470       { 248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 471       { 253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255 }
 472     },
 473     { { 255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 474       { 245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 475       { 253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 }
 476     },
 477     { { 255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 478       { 252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 479       { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 480     },
 481     { { 255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 482       { 249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
 483       { 255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 }
 484     },
 485     { { 255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
 486       { 250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 487       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 488     },
 489     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 490       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
 491       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
 492     }
 493   }
 494 };
 495
 496 // Paragraph 9.9
 497 void VP8ParseProba(VP8BitReader* const br, VP8Decoder* const dec) {
 498   VP8Proba* const proba = &dec->proba_;
 499   int t, b, c, p;
 500   for (t = 0; t < NUM_TYPES; ++t) {
 501     for (b = 0; b < NUM_BANDS; ++b) {
 502       for (c = 0; c < NUM_CTX; ++c) {
 503         for (p = 0; p < NUM_PROBAS; ++p) {
 504           const int v = VP8GetBit(br, CoeffsUpdateProba[t][b][c][p]) ?
 505                         VP8GetValue(br, 8) : CoeffsProba0[t][b][c][p];
 506           proba->bands_[t][b].probas_[c][p] = v;
 507         }
 508       }
 509     }
 510   }
 511   dec->use_skip_proba_ = VP8Get(br);
 512   if (dec->use_skip_proba_) {
 513     dec->skip_p_ = VP8GetValue(br, 8);
 514   }
 515 }
 516