vpx/vp9/common/vp9_entropy.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "vp9/common/vp9_entropy.h"
#include "vp9/common/vp9_blockd.h"
#include "vp9/common/vp9_onyxc_int.h"
#include "vp9/common/vp9_entropymode.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx/vpx_integer.h"
#include "vp9/common/vp9_coefupdateprobs.h"

DECLARE_ALIGNED(16, const uint8_t, vp9_norm[256]) = {
  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,
  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,
  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,
  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,
  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,
  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,
  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,
  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
};

DECLARE_ALIGNED(16, const uint8_t,
                vp9_coefband_trans_8x8plus[MAXBAND_INDEX + 1]) = {
  0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 5
};

DECLARE_ALIGNED(16, const uint8_t,
                vp9_coefband_trans_4x4[MAXBAND_INDEX + 1]) = {
  0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5,
  5, 5, 5, 5, 5, 5
};

DECLARE_ALIGNED(16, const uint8_t, vp9_pt_energy_class[MAX_ENTROPY_TOKENS]) = {
  0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 5
};

DECLARE_ALIGNED(16, const int, vp9_default_scan_4x4[16]) = {
  0,  4,  1,  5,
  8,  2, 12,  9,
  3,  6, 13, 10,
  7, 14, 11, 15,
};

DECLARE_ALIGNED(16, const int, vp9_col_scan_4x4[16]) = {
  0,  4,  8,  1,
  12,  5,  9,  2,
  13,  6, 10,  3,
  7, 14, 11, 15,
};

DECLARE_ALIGNED(16, const int, vp9_row_scan_4x4[16]) = {
  0,  1,  4,  2,
  5,  3,  6,  8,
  9,  7, 12, 10,
  13, 11, 14, 15,
};

DECLARE_ALIGNED(64, const int, vp9_default_scan_8x8[64]) = {
  0,  8,  1, 16,  9,  2, 17, 24,
  10,  3, 18, 25, 32, 11,  4, 26,
  33, 19, 40, 12, 34, 27,  5, 41,
  20, 48, 13, 35, 42, 28, 21,  6,
  49, 56, 36, 43, 29,  7, 14, 50,
  57, 44, 22, 37, 15, 51, 58, 30,
  45, 23, 52, 59, 38, 31, 60, 53,
  46, 39, 61, 54, 47, 62, 55, 63,
};

DECLARE_ALIGNED(16, const int, vp9_col_scan_8x8[64]) = {
  0,  8, 16,  1, 24,  9, 32, 17,
  2, 40, 25, 10, 33, 18, 48,  3,
  26, 41, 11, 56, 19, 34,  4, 49,
  27, 42, 12, 35, 20, 57, 50, 28,
  5, 43, 13, 36, 58, 51, 21, 44,
  6, 29, 59, 37, 14, 52, 22,  7,
  45, 60, 30, 15, 38, 53, 23, 46,
  31, 61, 39, 54, 47, 62, 55, 63,
};

DECLARE_ALIGNED(16, const int, vp9_row_scan_8x8[64]) = {
  0,  1,  2,  8,  9,  3, 16, 10,
  4, 17, 11, 24,  5, 18, 25, 12,
  19, 26, 32,  6, 13, 20, 33, 27,
  7, 34, 40, 21, 28, 41, 14, 35,
  48, 42, 29, 36, 49, 22, 43, 15,
  56, 37, 50, 44, 30, 57, 23, 51,
  58, 45, 38, 52, 31, 59, 53, 46,
  60, 39, 61, 47, 54, 55, 62, 63,
};

DECLARE_ALIGNED(16, const int, vp9_default_scan_16x16[256]) = {
  0,  16,   1,  32,  17,   2,  48,  33,  18,   3,  64,  34,  49,  19,  65,  80,
  50,   4,  35,  66,  20,  81,  96,  51,   5,  36,  82,  97,  67, 112,  21,  52,
  98,  37,  83, 113,   6,  68, 128,  53,  22,  99, 114,  84,   7, 129,  38,  69,
  100, 115, 144, 130,  85,  54,  23,   8, 145,  39,  70, 116, 101, 131, 160, 146,
  55,  86,  24,  71, 132, 117, 161,  40,   9, 102, 147, 176, 162,  87,  56,  25,
  133, 118, 177, 148,  72, 103,  41, 163,  10, 192, 178,  88,  57, 134, 149, 119,
  26, 164,  73, 104, 193,  42, 179, 208,  11, 135,  89, 165, 120, 150,  58, 194,
  180,  27,  74, 209, 105, 151, 136,  43,  90, 224, 166, 195, 181, 121, 210,  59,
  12, 152, 106, 167, 196,  75, 137, 225, 211, 240, 182, 122,  91,  28, 197,  13,
  226, 168, 183, 153,  44, 212, 138, 107, 241,  60,  29, 123, 198, 184, 227, 169,
  242,  76, 213, 154,  45,  92,  14, 199, 139,  61, 228, 214, 170, 185, 243, 108,
  77, 155,  30,  15, 200, 229, 124, 215, 244,  93,  46, 186, 171, 201, 109, 140,
  230,  62, 216, 245,  31, 125,  78, 156, 231,  47, 187, 202, 217,  94, 246, 141,
  63, 232, 172, 110, 247, 157,  79, 218, 203, 126, 233, 188, 248,  95, 173, 142,
  219, 111, 249, 234, 158, 127, 189, 204, 250, 235, 143, 174, 220, 205, 159, 251,
  190, 221, 175, 236, 237, 191, 206, 252, 222, 253, 207, 238, 223, 254, 239, 255,
};

DECLARE_ALIGNED(16, const int, vp9_col_scan_16x16[256]) = {
  0,  16,  32,  48,   1,  64,  17,  80,  33,  96,  49,   2,  65, 112,  18,  81,
  34, 128,  50,  97,   3,  66, 144,  19, 113,  35,  82, 160,  98,  51, 129,   4,
  67, 176,  20, 114, 145,  83,  36,  99, 130,  52, 192,   5, 161,  68, 115,  21,
  146,  84, 208, 177,  37, 131, 100,  53, 162, 224,  69,   6, 116, 193, 147,  85,
  22, 240, 132,  38, 178, 101, 163,  54, 209, 117,  70,   7, 148, 194,  86, 179,
  225,  23, 133,  39, 164,   8, 102, 210, 241,  55, 195, 118, 149,  71, 180,  24,
  87, 226, 134, 165, 211,  40, 103,  56,  72, 150, 196, 242, 119,   9, 181, 227,
  88, 166,  25, 135,  41, 104, 212,  57, 151, 197, 120,  73, 243, 182, 136, 167,
  213,  89,  10, 228, 105, 152, 198,  26,  42, 121, 183, 244, 168,  58, 137, 229,
  74, 214,  90, 153, 199, 184,  11, 106, 245,  27, 122, 230, 169,  43, 215,  59,
  200, 138, 185, 246,  75,  12,  91, 154, 216, 231, 107,  28,  44, 201, 123, 170,
  60, 247, 232,  76, 139,  13,  92, 217, 186, 248, 155, 108,  29, 124,  45, 202,
  233, 171,  61,  14,  77, 140,  15, 249,  93,  30, 187, 156, 218,  46, 109, 125,
  62, 172,  78, 203,  31, 141, 234,  94,  47, 188,  63, 157, 110, 250, 219,  79,
  126, 204, 173, 142,  95, 189, 111, 235, 158, 220, 251, 127, 174, 143, 205, 236,
  159, 190, 221, 252, 175, 206, 237, 191, 253, 222, 238, 207, 254, 223, 239, 255,
};

DECLARE_ALIGNED(16, const int, vp9_row_scan_16x16[256]) = {
  0,   1,   2,  16,   3,  17,   4,  18,  32,   5,  33,  19,   6,  34,  48,  20,
  49,   7,  35,  21,  50,  64,   8,  36,  65,  22,  51,  37,  80,   9,  66,  52,
  23,  38,  81,  67,  10,  53,  24,  82,  68,  96,  39,  11,  54,  83,  97,  69,
  25,  98,  84,  40, 112,  55,  12,  70,  99, 113,  85,  26,  41,  56, 114, 100,
  13,  71, 128,  86,  27, 115, 101, 129,  42,  57,  72, 116,  14,  87, 130, 102,
  144,  73, 131, 117,  28,  58,  15,  88,  43, 145, 103, 132, 146, 118,  74, 160,
  89, 133, 104,  29,  59, 147, 119,  44, 161, 148,  90, 105, 134, 162, 120, 176,
  75, 135, 149,  30,  60, 163, 177,  45, 121,  91, 106, 164, 178, 150, 192, 136,
  165, 179,  31, 151, 193,  76, 122,  61, 137, 194, 107, 152, 180, 208,  46, 166,
  167, 195,  92, 181, 138, 209, 123, 153, 224, 196,  77, 168, 210, 182, 240, 108,
  197,  62, 154, 225, 183, 169, 211,  47, 139,  93, 184, 226, 212, 241, 198, 170,
  124, 155, 199,  78, 213, 185, 109, 227, 200,  63, 228, 242, 140, 214, 171, 186,
  156, 229, 243, 125,  94, 201, 244, 215, 216, 230, 141, 187, 202,  79, 172, 110,
  157, 245, 217, 231,  95, 246, 232, 126, 203, 247, 233, 173, 218, 142, 111, 158,
  188, 248, 127, 234, 219, 249, 189, 204, 143, 174, 159, 250, 235, 205, 220, 175,
  190, 251, 221, 191, 206, 236, 207, 237, 252, 222, 253, 223, 238, 239, 254, 255,
};

DECLARE_ALIGNED(16, const int, vp9_default_scan_32x32[1024]) = {
  0,   32,    1,   64,   33,    2,   96,   65,   34,  128,    3,   97,   66,  160,  129,   35,   98,    4,   67,  130,  161,  192,   36,   99,  224,    5,  162,  193,   68,  131,   37,  100,
  225,  194,  256,  163,   69,  132,    6,  226,  257,  288,  195,  101,  164,   38,  258,    7,  227,  289,  133,  320,   70,  196,  165,  290,  259,  228,   39,  321,  102,  352,    8,  197,
  71,  134,  322,  291,  260,  353,  384,  229,  166,  103,   40,  354,  323,  292,  135,  385,  198,  261,   72,    9,  416,  167,  386,  355,  230,  324,  104,  293,   41,  417,  199,  136,
  262,  387,  448,  325,  356,   10,   73,  418,  231,  168,  449,  294,  388,  105,  419,  263,   42,  200,  357,  450,  137,  480,   74,  326,  232,   11,  389,  169,  295,  420,  106,  451,
  481,  358,  264,  327,  201,   43,  138,  512,  482,  390,  296,  233,  170,  421,   75,  452,  359,   12,  513,  265,  483,  328,  107,  202,  514,  544,  422,  391,  453,  139,   44,  234,
  484,  297,  360,  171,   76,  515,  545,  266,  329,  454,   13,  423,  392,  203,  108,  546,  485,  576,  298,  235,  140,  361,  516,  330,  172,  547,   45,  424,  455,  267,  393,  577,
  486,   77,  204,  517,  362,  548,  608,   14,  456,  299,  578,  109,  236,  425,  394,  487,  609,  331,  141,  579,  518,   46,  268,   15,  173,  549,  610,  640,  363,   78,  519,  488,
  300,  205,   16,  457,  580,  426,  550,  395,  110,  237,  611,  641,  332,  672,  142,  642,  269,  458,   47,  581,  427,  489,  174,  364,  520,  612,  551,  673,   79,  206,  301,  643,
  704,   17,  111,  490,  674,  238,  582,   48,  521,  613,  333,  396,  459,  143,  270,  552,  644,  705,  736,  365,   80,  675,  583,  175,  428,  706,  112,  302,  207,  614,  553,   49,
  645,  522,  737,  397,  768,  144,  334,   18,  676,  491,  239,  615,  707,  584,   81,  460,  176,  271,  738,  429,  113,  800,  366,  208,  523,  708,  646,  554,  677,  769,   19,  145,
  585,  739,  240,  303,   50,  461,  616,  398,  647,  335,  492,  177,   82,  770,  832,  555,  272,  430,  678,  209,  709,  114,  740,  801,  617,   51,  304,  679,  524,  367,  586,  241,
  20,  146,  771,  864,   83,  802,  648,  493,  399,  273,  336,  710,  178,  462,  833,  587,  741,  115,  305,  711,  368,  525,  618,  803,  210,  896,  680,  834,  772,   52,  649,  147,
  431,  494,  556,  242,  400,  865,  337,   21,  928,  179,  742,   84,  463,  274,  369,  804,  650,  557,  743,  960,  835,  619,  773,  306,  211,  526,  432,  992,  588,  712,  116,  243,
  866,  495,  681,  558,  805,  589,  401,  897,   53,  338,  148,  682,  867,  464,  275,   22,  370,  433,  307,  620,  527,  836,  774,  651,  713,  744,   85,  180,  621,  465,  929,  775,
  496,  898,  212,  339,  244,  402,  590,  117,  559,  714,  434,   23,  868,  930,  806,  683,  528,  652,  371,  961,  149,  837,   54,  899,  745,  276,  993,  497,  403,  622,  181,  776,
  746,  529,  560,  435,   86,  684,  466,  308,  591,  653,  715,  807,  340,  869,  213,  962,  245,  838,  561,  931,  808,  592,  118,  498,  372,  623,  685,  994,  467,  654,  747,  900,
  716,  277,  150,   55,   24,  404,  530,  839,  777,  655,  182,  963,  840,  686,  778,  309,  870,  341,   87,  499,  809,  624,  593,  436,  717,  932,  214,  246,  995,  718,  625,  373,
  562,   25,  119,  901,  531,  468,  964,  748,  810,  278,  779,  500,  563,  656,  405,  687,  871,  872,  594,  151,  933,  749,  841,  310,  657,  626,  595,  437,  688,  183,  996,  965,
  902,  811,  342,  750,  689,  719,  532,   56,  215,  469,  934,  374,  247,  720,  780,  564,  781,  842,  406,   26,  751,  903,  873,   57,  279,  627,  501,  658,  843,  997,  812,  904,
  88,  813,  438,  752,  935,  936,  311,  596,  533,  690,  343,  966,  874,   89,  120,  470,  721,  875,  659,  782,  565,  998,  375,  844,  845,   27,  628,  967,  121,  905,  968,  152,
  937,  814,  753,  502,  691,  783,  184,  153,  722,  407,   58,  815,  999,  660,  597,  723,  534,  906,  216,  439,  907,  248,  185,  876,  846,  692,  784,  629,   90,  969,  280,  754,
  938,  939,  217,  847,  566,  471,  785,  816,  877, 1000,  249,  878,  661,  503,  312,  970,  755,  122,  817,  281,  344,  786,  598,  724,   28,   59,   29,  154,  535,  630,  376, 1001,
  313,  908,  186,   91,  848,  849,  345,  909,  940,  879,  408,  818,  693, 1002,  971,  941,  567,  377,  218,  756,  910,  787,  440,  123,  880,  725,  662,  250,  819, 1003,  282,  972,
  850,  599,  472,  409,  155,  441,  942,  757,  788,  694,  911,  881,  314,  631,  973,  504,  187, 1004,  346,  473,  851,  943,  820,  726,   60,  505,  219,  378,  912,  974,   30,   31,
  536,  882, 1005,   92,  251,  663,  944,  913,  283,  695,  883,  568, 1006,  975,  410,  442,  945,  789,  852,  537, 1007,  124,  315,   61,  758,  821,  600,  914,  976,  569,  474,  347,
  156, 1008,  915,   93,  977,  506,  946,  727,  379,  884,  188,  632,  601, 1009,  790,  853,  978,  947,  220,  411,  125,  633,  664,  759,  252,  443,  916,  538,  157,  822,   62,  570,
  979,  284, 1010,  885,  948,  189,  475,   94,  316,  665,  696, 1011,  854,  791,  980,  221,  348,   63,  917,  602,  380,  507,  253,  126,  697,  823,  634,  285,  728,  949,  886,   95,
  158,  539, 1012,  317,  412,  444,  760,  571,  190,  981,  729,  918,  127,  666,  349,  381,  476,  855,  761, 1013,  603,  222,  159,  698,  950,  508,  254,  792,  286,  635,  887,  793,
  413,  191,  982,  445,  540,  318,  730,  667,  223,  824,  919, 1014,  350,  477,  572,  255,  825,  951,  762,  509,  604,  856,  382,  699,  287,  319,  636,  983,  794,  414,  541,  731,
  857,  888,  351,  446,  573, 1015,  668,  889,  478,  826,  383,  763,  605,  920,  510,  637,  415,  700,  921,  858,  447,  952,  542,  795,  479,  953,  732,  890,  669,  574,  511,  984,
  827,  985,  922, 1016,  764,  606,  543,  701,  859,  638, 1017,  575,  796,  954,  733,  891,  670,  607,  828,  986,  765,  923,  639, 1018,  702,  860,  955,  671,  892,  734,  797,  703,
  987,  829, 1019,  766,  924,  735,  861,  956,  988,  893,  767,  798,  830, 1020,  925,  957,  799,  862,  831,  989,  894, 1021,  863,  926,  895,  958,  990, 1022,  927,  959,  991, 1023,
};

/* Array indices are identical to previously-existing CONTEXT_NODE indices */

const vp9_tree_index vp9_coef_tree[ 22] =     /* corresponding _CONTEXT_NODEs */
{
  -DCT_EOB_TOKEN, 2,                        /* 0 = EOB */
  -ZERO_TOKEN, 4,                           /* 1 = ZERO */
  -ONE_TOKEN, 6,                            /* 2 = ONE */
  8, 12,                                    /* 3 = LOW_VAL */
  -TWO_TOKEN, 10,                           /* 4 = TWO */
  -THREE_TOKEN, -FOUR_TOKEN,                /* 5 = THREE */
  14, 16,                                   /* 6 = HIGH_LOW */
  -DCT_VAL_CATEGORY1, -DCT_VAL_CATEGORY2,   /* 7 = CAT_ONE */
  18, 20,                                   /* 8 = CAT_THREEFOUR */
  -DCT_VAL_CATEGORY3, -DCT_VAL_CATEGORY4,   /* 9 = CAT_THREE */
  -DCT_VAL_CATEGORY5, -DCT_VAL_CATEGORY6    /* 10 = CAT_FIVE */
};

struct vp9_token vp9_coef_encodings[MAX_ENTROPY_TOKENS];

/* Trees for extra bits.  Probabilities are constant and
   do not depend on previously encoded bits */

static const vp9_prob Pcat1[] = { 159};
static const vp9_prob Pcat2[] = { 165, 145};
static const vp9_prob Pcat3[] = { 173, 148, 140};
static const vp9_prob Pcat4[] = { 176, 155, 140, 135};
static const vp9_prob Pcat5[] = { 180, 157, 141, 134, 130};
static const vp9_prob Pcat6[] = {
  254, 254, 254, 252, 249, 243, 230, 196, 177, 153, 140, 133, 130, 129
};

const vp9_tree_index vp9_coefmodel_tree[6] = {
  -DCT_EOB_MODEL_TOKEN, 2,                      /* 0 = EOB */
  -ZERO_TOKEN, 4,                               /* 1 = ZERO */
  -ONE_TOKEN, -TWO_TOKEN,                       /* 2 = ONE */
};

// Model obtained from a 2-sided zero-centerd distribuition derived
// from a Pareto distribution. The cdf of the distribution is:
// cdf(x) = 0.5 + 0.5 * sgn(x) * [1 - {alpha/(alpha + |x|)} ^ beta]
//
// For a given beta and a given probablity of the 1-node, the alpha
// is first solved, and then the {alpha, beta} pair is used to generate
// the probabilities for the rest of the nodes.

// beta = 8
const vp9_prob vp9_modelcoefprobs_pareto8[COEFPROB_MODELS][MODEL_NODES] = {
  {  3,  86, 128,   6,  86,  23,  88,  29},
  {  9,  86, 129,  17,  88,  61,  94,  76},
  { 15,  87, 129,  28,  89,  93, 100, 110},
  { 20,  88, 130,  38,  91, 118, 106, 136},
  { 26,  89, 131,  48,  92, 139, 111, 156},
  { 31,  90, 131,  58,  94, 156, 117, 171},
  { 37,  90, 132,  66,  95, 171, 122, 184},
  { 42,  91, 132,  75,  97, 183, 127, 194},
  { 47,  92, 133,  83,  98, 193, 132, 202},
  { 52,  93, 133,  90, 100, 201, 137, 208},
  { 57,  94, 134,  98, 101, 208, 142, 214},
  { 62,  94, 135, 105, 103, 214, 146, 218},
  { 66,  95, 135, 111, 104, 219, 151, 222},
  { 71,  96, 136, 117, 106, 224, 155, 225},
  { 76,  97, 136, 123, 107, 227, 159, 228},
  { 80,  98, 137, 129, 109, 231, 162, 231},
  { 84,  98, 138, 134, 110, 234, 166, 233},
  { 89,  99, 138, 140, 112, 236, 170, 235},
  { 93, 100, 139, 145, 113, 238, 173, 236},
  { 97, 101, 140, 149, 115, 240, 176, 238},
  {101, 102, 140, 154, 116, 242, 179, 239},
  {105, 103, 141, 158, 118, 243, 182, 240},
  {109, 104, 141, 162, 119, 244, 185, 241},
  {113, 104, 142, 166, 120, 245, 187, 242},
  {116, 105, 143, 170, 122, 246, 190, 243},
  {120, 106, 143, 173, 123, 247, 192, 244},
  {123, 107, 144, 177, 125, 248, 195, 244},
  {127, 108, 145, 180, 126, 249, 197, 245},
  {130, 109, 145, 183, 128, 249, 199, 245},
  {134, 110, 146, 186, 129, 250, 201, 246},
  {137, 111, 147, 189, 131, 251, 203, 246},
  {140, 112, 147, 192, 132, 251, 205, 247},
  {143, 113, 148, 194, 133, 251, 207, 247},
  {146, 114, 149, 197, 135, 252, 208, 248},
  {149, 115, 149, 199, 136, 252, 210, 248},
  {152, 115, 150, 201, 138, 252, 211, 248},
  {155, 116, 151, 204, 139, 253, 213, 249},
  {158, 117, 151, 206, 140, 253, 214, 249},
  {161, 118, 152, 208, 142, 253, 216, 249},
  {163, 119, 153, 210, 143, 253, 217, 249},
  {166, 120, 153, 212, 144, 254, 218, 250},
  {168, 121, 154, 213, 146, 254, 220, 250},
  {171, 122, 155, 215, 147, 254, 221, 250},
  {173, 123, 155, 217, 148, 254, 222, 250},
  {176, 124, 156, 218, 150, 254, 223, 250},
  {178, 125, 157, 220, 151, 254, 224, 251},
  {180, 126, 157, 221, 152, 254, 225, 251},
  {183, 127, 158, 222, 153, 254, 226, 251},
  {185, 128, 159, 224, 155, 255, 227, 251},
  {187, 129, 160, 225, 156, 255, 228, 251},
  {189, 131, 160, 226, 157, 255, 228, 251},
  {191, 132, 161, 227, 159, 255, 229, 251},
  {193, 133, 162, 228, 160, 255, 230, 252},
  {195, 134, 163, 230, 161, 255, 231, 252},
  {197, 135, 163, 231, 162, 255, 231, 252},
  {199, 136, 164, 232, 163, 255, 232, 252},
  {201, 137, 165, 233, 165, 255, 233, 252},
  {202, 138, 166, 233, 166, 255, 233, 252},
  {204, 139, 166, 234, 167, 255, 234, 252},
  {206, 140, 167, 235, 168, 255, 235, 252},
  {207, 141, 168, 236, 169, 255, 235, 252},
  {209, 142, 169, 237, 171, 255, 236, 252},
  {210, 144, 169, 237, 172, 255, 236, 252},
  {212, 145, 170, 238, 173, 255, 237, 252},
  {214, 146, 171, 239, 174, 255, 237, 253},
  {215, 147, 172, 240, 175, 255, 238, 253},
  {216, 148, 173, 240, 176, 255, 238, 253},
  {218, 149, 173, 241, 177, 255, 239, 253},
  {219, 150, 174, 241, 179, 255, 239, 253},
  {220, 152, 175, 242, 180, 255, 240, 253},
  {222, 153, 176, 242, 181, 255, 240, 253},
  {223, 154, 177, 243, 182, 255, 240, 253},
  {224, 155, 178, 244, 183, 255, 241, 253},
  {225, 156, 178, 244, 184, 255, 241, 253},
  {226, 158, 179, 244, 185, 255, 242, 253},
  {228, 159, 180, 245, 186, 255, 242, 253},
  {229, 160, 181, 245, 187, 255, 242, 253},
  {230, 161, 182, 246, 188, 255, 243, 253},
  {231, 163, 183, 246, 189, 255, 243, 253},
  {232, 164, 184, 247, 190, 255, 243, 253},
  {233, 165, 185, 247, 191, 255, 244, 253},
  {234, 166, 185, 247, 192, 255, 244, 253},
  {235, 168, 186, 248, 193, 255, 244, 253},
  {236, 169, 187, 248, 194, 255, 244, 253},
  {236, 170, 188, 248, 195, 255, 245, 253},
  {237, 171, 189, 249, 196, 255, 245, 254},
  {238, 173, 190, 249, 197, 255, 245, 254},
  {239, 174, 191, 249, 198, 255, 245, 254},
  {240, 175, 192, 249, 199, 255, 246, 254},
  {240, 177, 193, 250, 200, 255, 246, 254},
  {241, 178, 194, 250, 201, 255, 246, 254},
  {242, 179, 195, 250, 202, 255, 246, 254},
  {242, 181, 196, 250, 203, 255, 247, 254},
  {243, 182, 197, 251, 204, 255, 247, 254},
  {244, 184, 198, 251, 205, 255, 247, 254},
  {244, 185, 199, 251, 206, 255, 247, 254},
  {245, 186, 200, 251, 207, 255, 247, 254},
  {246, 188, 201, 252, 207, 255, 248, 254},
  {246, 189, 202, 252, 208, 255, 248, 254},
  {247, 191, 203, 252, 209, 255, 248, 254},
  {247, 192, 204, 252, 210, 255, 248, 254},
  {248, 194, 205, 252, 211, 255, 248, 254},
  {248, 195, 206, 252, 212, 255, 249, 254},
  {249, 197, 207, 253, 213, 255, 249, 254},
  {249, 198, 208, 253, 214, 255, 249, 254},
  {250, 200, 210, 253, 215, 255, 249, 254},
  {250, 201, 211, 253, 215, 255, 249, 254},
  {250, 203, 212, 253, 216, 255, 249, 254},
  {251, 204, 213, 253, 217, 255, 250, 254},
  {251, 206, 214, 254, 218, 255, 250, 254},
  {252, 207, 216, 254, 219, 255, 250, 254},
  {252, 209, 217, 254, 220, 255, 250, 254},
  {252, 211, 218, 254, 221, 255, 250, 254},
  {253, 213, 219, 254, 222, 255, 250, 254},
  {253, 214, 221, 254, 223, 255, 250, 254},
  {253, 216, 222, 254, 224, 255, 251, 254},
  {253, 218, 224, 254, 225, 255, 251, 254},
  {254, 220, 225, 254, 225, 255, 251, 254},
  {254, 222, 227, 255, 226, 255, 251, 254},
  {254, 224, 228, 255, 227, 255, 251, 254},
  {254, 226, 230, 255, 228, 255, 251, 254},
  {255, 228, 231, 255, 230, 255, 251, 254},
  {255, 230, 233, 255, 231, 255, 252, 254},
  {255, 232, 235, 255, 232, 255, 252, 254},
  {255, 235, 237, 255, 233, 255, 252, 254},
  {255, 238, 240, 255, 235, 255, 252, 255},
  {255, 241, 243, 255, 236, 255, 252, 254},
  {255, 246, 247, 255, 239, 255, 253, 255}
};

static void extend_model_to_full_distribution(vp9_prob p,
                                              vp9_prob *tree_probs) {
  const int l = ((p - 1) / 2);
  const vp9_prob (*model)[MODEL_NODES];
  model = vp9_modelcoefprobs_pareto8;
  if (p & 1) {
    vpx_memcpy(tree_probs + UNCONSTRAINED_NODES,
               model[l], MODEL_NODES * sizeof(vp9_prob));
  } else {
    // interpolate
    int i;
    for (i = UNCONSTRAINED_NODES; i < ENTROPY_NODES; ++i)
      tree_probs[i] = (model[l][i - UNCONSTRAINED_NODES] +
                       model[l + 1][i - UNCONSTRAINED_NODES]) >> 1;
  }
}

void vp9_model_to_full_probs(const vp9_prob *model, vp9_prob *full) {
  if (full != model)
    vpx_memcpy(full, model, sizeof(vp9_prob) * UNCONSTRAINED_NODES);
  extend_model_to_full_distribution(model[PIVOT_NODE], full);
}

void vp9_model_to_full_probs_sb(
    vp9_prob model[COEF_BANDS][PREV_COEF_CONTEXTS][UNCONSTRAINED_NODES],
    vp9_prob full[COEF_BANDS][PREV_COEF_CONTEXTS][ENTROPY_NODES]) {
  int c, p;
  for (c = 0; c < COEF_BANDS; ++c)
    for (p = 0; p < PREV_COEF_CONTEXTS; ++p) {
      vp9_model_to_full_probs(model[c][p], full[c][p]);
    }
}

static vp9_tree_index cat1[2], cat2[4], cat3[6], cat4[8], cat5[10], cat6[28];

static void init_bit_tree(vp9_tree_index *p, int n) {
  int i = 0;

  while (++i < n) {
    p[0] = p[1] = i << 1;
    p += 2;
  }

  p[0] = p[1] = 0;
}

static void init_bit_trees() {
  init_bit_tree(cat1, 1);
  init_bit_tree(cat2, 2);
  init_bit_tree(cat3, 3);
  init_bit_tree(cat4, 4);
  init_bit_tree(cat5, 5);
  init_bit_tree(cat6, 14);
}

vp9_extra_bit vp9_extra_bits[12] = {
  { 0, 0, 0, 0},
  { 0, 0, 0, 1},
  { 0, 0, 0, 2},
  { 0, 0, 0, 3},
  { 0, 0, 0, 4},
  { cat1, Pcat1, 1, 5},
  { cat2, Pcat2, 2, 7},
  { cat3, Pcat3, 3, 11},
  { cat4, Pcat4, 4, 19},
  { cat5, Pcat5, 5, 35},
  { cat6, Pcat6, 14, 67},
  { 0, 0, 0, 0}
};

#include "vp9/common/vp9_default_coef_probs.h"

// This function updates and then returns n AC coefficient context
// This is currently a placeholder function to allow experimentation
// using various context models based on the energy earlier tokens
// within the current block.
//
// For now it just returns the previously used context.
#define MAX_NEIGHBORS 2
int vp9_get_coef_context(const int *scan, const int *neighbors,
                         int nb_pad, uint8_t *token_cache, int c, int l) {
  int eob = l;
  assert(nb_pad == MAX_NEIGHBORS);
  if (c == eob) {
    return 0;
  } else {
    int ctx;
    assert(neighbors[MAX_NEIGHBORS * c + 0] >= 0);
    if (neighbors[MAX_NEIGHBORS * c + 1] >= 0) {
      ctx = (1 + token_cache[scan[neighbors[MAX_NEIGHBORS * c + 0]]] +
             token_cache[scan[neighbors[MAX_NEIGHBORS * c + 1]]]) >> 1;
    } else {
      ctx = token_cache[scan[neighbors[MAX_NEIGHBORS * c + 0]]];
    }
    return vp9_pt_energy_class[ctx];
  }
};

void vp9_default_coef_probs(VP9_COMMON *pc) {
  vpx_memcpy(pc->fc.coef_probs_4x4, default_coef_probs_4x4,
             sizeof(pc->fc.coef_probs_4x4));
  vpx_memcpy(pc->fc.coef_probs_8x8, default_coef_probs_8x8,
             sizeof(pc->fc.coef_probs_8x8));
  vpx_memcpy(pc->fc.coef_probs_16x16, default_coef_probs_16x16,
             sizeof(pc->fc.coef_probs_16x16));
  vpx_memcpy(pc->fc.coef_probs_32x32, default_coef_probs_32x32,
             sizeof(pc->fc.coef_probs_32x32));
}

// Neighborhood 5-tuples for various scans and blocksizes,
// in {top, left, topleft, topright, bottomleft} order
// for each position in raster scan order.
// -1 indicates the neighbor does not exist.
DECLARE_ALIGNED(16, int,
                vp9_default_scan_4x4_neighbors[16 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_col_scan_4x4_neighbors[16 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_row_scan_4x4_neighbors[16 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_col_scan_8x8_neighbors[64 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_row_scan_8x8_neighbors[64 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_default_scan_8x8_neighbors[64 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_col_scan_16x16_neighbors[256 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_row_scan_16x16_neighbors[256 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_default_scan_16x16_neighbors[256 * MAX_NEIGHBORS]);
DECLARE_ALIGNED(16, int,
                vp9_default_scan_32x32_neighbors[1024 * MAX_NEIGHBORS]);

static int find_in_scan(const int *scan, int l, int idx) {
  int n, l2 = l * l;
  for (n = 0; n < l2; n++) {
    int rc = scan[n];
    if (rc == idx)
      return  n;
  }
  assert(0);
  return -1;
}
static void init_scan_neighbors(const int *scan, int l, int *neighbors,
                                int max_neighbors) {
  int l2 = l * l;
  int n, i, j;

  for (n = 0; n < l2; n++) {
    int rc = scan[n];
    assert(max_neighbors == MAX_NEIGHBORS);
    i = rc / l;
    j = rc % l;
    if (i > 0 && j > 0) {
      // col/row scan is used for adst/dct, and generally means that
      // energy decreases to zero much faster in the dimension in
      // which ADST is used compared to the direction in which DCT
      // is used. Likewise, we find much higher correlation between
      // coefficients within the direction in which DCT is used.
      // Therefore, if we use ADST/DCT, prefer the DCT neighbor coeff
      // as a context. If ADST or DCT is used in both directions, we
      // use the combination of the two as a context.
      int a = find_in_scan(scan, l, (i - 1) * l + j);
      int b = find_in_scan(scan, l,  i      * l + j - 1);
      if (scan == vp9_col_scan_4x4 || scan == vp9_col_scan_8x8 ||
          scan == vp9_col_scan_16x16) {
        neighbors[max_neighbors * n + 0] = a;
        neighbors[max_neighbors * n + 1] = -1;
      } else if (scan == vp9_row_scan_4x4 || scan == vp9_row_scan_8x8 ||
                 scan == vp9_row_scan_16x16) {
        neighbors[max_neighbors * n + 0] = b;
        neighbors[max_neighbors * n + 1] = -1;
      } else {
        neighbors[max_neighbors * n + 0] = a;
        neighbors[max_neighbors * n + 1] = b;
      }
    } else if (i > 0) {
      neighbors[max_neighbors * n + 0] = find_in_scan(scan, l, (i - 1) * l + j);
      neighbors[max_neighbors * n + 1] = -1;
    } else if (j > 0) {
      neighbors[max_neighbors * n + 0] =
          find_in_scan(scan, l,  i      * l + j - 1);
      neighbors[max_neighbors * n + 1] = -1;
    } else {
      assert(n == 0);
      // dc predictor doesn't use previous tokens
      neighbors[max_neighbors * n + 0] = -1;
    }
    assert(neighbors[max_neighbors * n + 0] < n);
  }
}

void vp9_init_neighbors() {
  init_scan_neighbors(vp9_default_scan_4x4, 4,
                      vp9_default_scan_4x4_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_row_scan_4x4, 4,
                      vp9_row_scan_4x4_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_col_scan_4x4, 4,
                      vp9_col_scan_4x4_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_default_scan_8x8, 8,
                      vp9_default_scan_8x8_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_row_scan_8x8, 8,
                      vp9_row_scan_8x8_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_col_scan_8x8, 8,
                      vp9_col_scan_8x8_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_default_scan_16x16, 16,
                      vp9_default_scan_16x16_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_row_scan_16x16, 16,
                      vp9_row_scan_16x16_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_col_scan_16x16, 16,
                      vp9_col_scan_16x16_neighbors, MAX_NEIGHBORS);
  init_scan_neighbors(vp9_default_scan_32x32, 32,
                      vp9_default_scan_32x32_neighbors, MAX_NEIGHBORS);
}

const int *vp9_get_coef_neighbors_handle(const int *scan, int *pad) {
  if (scan == vp9_default_scan_4x4) {
    *pad = MAX_NEIGHBORS;
    return vp9_default_scan_4x4_neighbors;
  } else if (scan == vp9_row_scan_4x4) {
    *pad = MAX_NEIGHBORS;
    return vp9_row_scan_4x4_neighbors;
  } else if (scan == vp9_col_scan_4x4) {
    *pad = MAX_NEIGHBORS;
    return vp9_col_scan_4x4_neighbors;
  } else if (scan == vp9_default_scan_8x8) {
    *pad = MAX_NEIGHBORS;
    return vp9_default_scan_8x8_neighbors;
  } else if (scan == vp9_row_scan_8x8) {
    *pad = 2;
    return vp9_row_scan_8x8_neighbors;
  } else if (scan == vp9_col_scan_8x8) {
    *pad = 2;
    return vp9_col_scan_8x8_neighbors;
  } else if (scan == vp9_default_scan_16x16) {
    *pad = MAX_NEIGHBORS;
    return vp9_default_scan_16x16_neighbors;
  } else if (scan == vp9_row_scan_16x16) {
    *pad = 2;
    return vp9_row_scan_16x16_neighbors;
  } else if (scan == vp9_col_scan_16x16) {
    *pad = 2;
    return vp9_col_scan_16x16_neighbors;
  } else if (scan == vp9_default_scan_32x32) {
    *pad = MAX_NEIGHBORS;
    return vp9_default_scan_32x32_neighbors;
  } else {
    assert(0);
    return NULL;
  }
}

void vp9_coef_tree_initialize() {
  vp9_init_neighbors();
  init_bit_trees();
  vp9_tokens_from_tree(vp9_coef_encodings, vp9_coef_tree);
}

// #define COEF_COUNT_TESTING

#define COEF_COUNT_SAT 24
#define COEF_MAX_UPDATE_FACTOR 112
#define COEF_COUNT_SAT_KEY 24
#define COEF_MAX_UPDATE_FACTOR_KEY 112
#define COEF_COUNT_SAT_AFTER_KEY 24
#define COEF_MAX_UPDATE_FACTOR_AFTER_KEY 128

void vp9_full_to_model_count(unsigned int *model_count,
                             unsigned int *full_count) {
  int n;
  model_count[ZERO_TOKEN] = full_count[ZERO_TOKEN];
  model_count[ONE_TOKEN] = full_count[ONE_TOKEN];
  model_count[TWO_TOKEN] = full_count[TWO_TOKEN];
  for (n = THREE_TOKEN; n < DCT_EOB_TOKEN; ++n)
    model_count[TWO_TOKEN] += full_count[n];
  model_count[DCT_EOB_MODEL_TOKEN] = full_count[DCT_EOB_TOKEN];
}

void vp9_full_to_model_counts(
    vp9_coeff_count_model *model_count, vp9_coeff_count *full_count) {
  int i, j, k, l;
  for (i = 0; i < BLOCK_TYPES; ++i)
    for (j = 0; j < REF_TYPES; ++j)
      for (k = 0; k < COEF_BANDS; ++k)
        for (l = 0; l < PREV_COEF_CONTEXTS; ++l) {
          if (l >= 3 && k == 0)
            continue;
          vp9_full_to_model_count(model_count[i][j][k][l],
                                  full_count[i][j][k][l]);
        }
}

static void adapt_coef_probs(
    vp9_coeff_probs_model *dst_coef_probs,
    vp9_coeff_probs_model *pre_coef_probs,
    vp9_coeff_count_model *coef_counts,
    unsigned int (*eob_branch_count)[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS],
    int count_sat,
    int update_factor) {
  int t, i, j, k, l, count;
  int factor;
  unsigned int branch_ct[UNCONSTRAINED_NODES][2];
  vp9_prob coef_probs[UNCONSTRAINED_NODES];
  int entropy_nodes_adapt = UNCONSTRAINED_NODES;

  for (i = 0; i < BLOCK_TYPES; ++i)
    for (j = 0; j < REF_TYPES; ++j)
      for (k = 0; k < COEF_BANDS; ++k)
        for (l = 0; l < PREV_COEF_CONTEXTS; ++l) {
          if (l >= 3 && k == 0)
            continue;
          vp9_tree_probs_from_distribution(
              vp9_coefmodel_tree,
              coef_probs, branch_ct,
              coef_counts[i][j][k][l], 0);
          branch_ct[0][1] = eob_branch_count[i][j][k][l] - branch_ct[0][0];
          coef_probs[0] = get_binary_prob(branch_ct[0][0], branch_ct[0][1]);
          for (t = 0; t < entropy_nodes_adapt; ++t) {
            count = branch_ct[t][0] + branch_ct[t][1];
            count = count > count_sat ? count_sat : count;
            factor = (update_factor * count / count_sat);
            dst_coef_probs[i][j][k][l][t] =
                weighted_prob(pre_coef_probs[i][j][k][l][t],
                              coef_probs[t], factor);
          }
        }
}

void vp9_adapt_coef_probs(VP9_COMMON *cm) {
  int count_sat;
  int update_factor; /* denominator 256 */

  if (cm->frame_type == KEY_FRAME) {
    update_factor = COEF_MAX_UPDATE_FACTOR_KEY;
    count_sat = COEF_COUNT_SAT_KEY;
  } else if (cm->last_frame_type == KEY_FRAME) {
    update_factor = COEF_MAX_UPDATE_FACTOR_AFTER_KEY;  /* adapt quickly */
    count_sat = COEF_COUNT_SAT_AFTER_KEY;
  } else {
    update_factor = COEF_MAX_UPDATE_FACTOR;
    count_sat = COEF_COUNT_SAT;
  }
  adapt_coef_probs(cm->fc.coef_probs_4x4, cm->fc.pre_coef_probs_4x4,
                   cm->fc.coef_counts_4x4,
                   cm->fc.eob_branch_counts[TX_4X4],
                   count_sat, update_factor);
  adapt_coef_probs(cm->fc.coef_probs_8x8, cm->fc.pre_coef_probs_8x8,
                   cm->fc.coef_counts_8x8,
                   cm->fc.eob_branch_counts[TX_8X8],
                   count_sat, update_factor);
  adapt_coef_probs(cm->fc.coef_probs_16x16, cm->fc.pre_coef_probs_16x16,
                   cm->fc.coef_counts_16x16,
                   cm->fc.eob_branch_counts[TX_16X16],
                   count_sat, update_factor);
  adapt_coef_probs(cm->fc.coef_probs_32x32, cm->fc.pre_coef_probs_32x32,
                   cm->fc.coef_counts_32x32,
                   cm->fc.eob_branch_counts[TX_32X32],
                   count_sat, update_factor);
}