bgmc.c 30.7 KB
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/*
 * Block Gilbert-Moore decoder
3
 * Copyright (c) 2010 Thilo Borgmann <thilo.borgmann _at_ mail.de>
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
23
 * @file
24
 * Block Gilbert-Moore decoder as used by MPEG-4 ALS
25
 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
26 27
 */

28
#include "libavutil/attributes.h"
29 30 31 32 33 34 35 36 37 38 39 40 41 42
#include "bgmc.h"

#define FREQ_BITS  14                      // bits used by frequency counters
#define VALUE_BITS 18                      // bits used to represent the values
#define TOP_VALUE  ((1 << VALUE_BITS) - 1) // maximum value
#define FIRST_QTR  (TOP_VALUE / 4 + 1)     // first quarter of values maximum value
#define HALF       (2 * FIRST_QTR)         // first half of values maximum value
#define THIRD_QTR  (3 * FIRST_QTR)         // third quarter of values maximum value

#define LUT_BITS   (FREQ_BITS - 8)         // number of bits used to index lookup tables
#define LUT_SIZE   (1 << LUT_BITS)         // size of the lookup tables
#define LUT_BUFF   4                       // number of buffered lookup tables


43
/** Cumulative frequency tables for block Gilbert-Moore coding. */
44 45
static const uint16_t cf_tables_1[3][129] = {
    {
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89
        16384, 16066, 15748, 15431, 15114, 14799, 14485, 14173, 13861, 13552,
        13243, 12939, 12635, 12336, 12038, 11745, 11452, 11161, 10870, 10586,
        10303, 10027,  9751,  9483,  9215,  8953,  8692,  8440,  8189,  7946,
         7704,  7472,  7240,  7008,  6776,  6554,  6333,  6122,  5912,  5711,
         5512,  5320,  5128,  4947,  4766,  4595,  4425,  4264,  4104,  3946,
         3788,  3640,  3493,  3355,  3218,  3090,  2963,  2842,  2721,  2609,
         2498,  2395,  2292,  2196,  2100,  2004,  1908,  1820,  1732,  1651,
         1570,  1497,  1424,  1355,  1287,  1223,  1161,  1100,  1044,   988,
          938,   888,   839,   790,   746,   702,   662,   623,   588,   553,
          520,   488,   459,   431,   405,   380,   357,   334,   311,   288,
          268,   248,   230,   213,   197,   182,   168,   154,   142,   130,
          119,   108,    99,    90,    81,    72,    64,    56,    49,    42,
           36,    30,    25,    20,    15,    11,     7,     3,     0
    },
    {
        16384, 16080, 15776, 15473, 15170, 14868, 14567, 14268, 13970, 13674,
        13378, 13086, 12794, 12505, 12218, 11936, 11654, 11373, 11092, 10818,
        10544, 10276, 10008,  9749,  9490,  9236,  8982,  8737,  8492,  8256,
         8020,  7792,  7564,  7336,  7108,  6888,  6669,  6459,  6249,  6050,
         5852,  5660,  5468,  5286,  5104,  4931,  4760,  4598,  4436,  4275,
         4115,  3965,  3816,  3674,  3534,  3403,  3272,  3147,  3023,  2907,
         2792,  2684,  2577,  2476,  2375,  2274,  2173,  2079,  1986,  1897,
         1810,  1724,  1645,  1567,  1493,  1419,  1351,  1284,  1222,  1161,
         1105,  1050,   995,   941,   891,   842,   797,   753,   713,   673,
          636,   599,   566,   533,   503,   473,   446,   419,   392,   365,
          340,   316,   294,   272,   253,   234,   216,   199,   184,   169,
          155,   142,   130,   118,   106,    95,    85,    75,    66,    57,
           49,    41,    34,    27,    21,    15,    10,     5,     0
    },
    {
        16384, 16092, 15801, 15510, 15219, 14930, 14641, 14355, 14069, 13785,
        13501, 13219, 12938, 12661, 12384, 12112, 11841, 11571, 11301, 11037,
        10773, 10514, 10256, 10005,  9754,  9508,  9263,  9025,  8787,  8557,
         8327,  8103,  7879,  7655,  7431,  7215,  7000,  6792,  6585,  6387,
         6190,  5998,  5807,  5625,  5445,  5272,  5100,  4937,  4774,  4613,
         4452,  4301,  4150,  4007,  3865,  3731,  3597,  3469,  3341,  3218,
         3099,  2981,  2869,  2758,  2652,  2546,  2440,  2334,  2234,  2134,
         2041,  1949,  1864,  1779,  1699,  1620,  1547,  1474,  1407,  1340,
         1278,  1217,  1157,  1097,  1043,   989,   940,   891,   846,   801,
          759,   718,   680,   643,   609,   575,   543,   511,   479,   447,
          418,   389,   363,   337,   314,   291,   270,   249,   230,   212,
          195,   179,   164,   149,   135,   121,   108,    96,    85,    74,
          64,     54,    45,    36,    28,    20,    13,     6,     0
    }
90 91 92 93 94
};


static const uint16_t cf_tables_2[8][193] = {
    {
95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114
        16384, 16104, 15825, 15546, 15268, 14991, 14714, 14439, 14164, 13891,
        13620, 13350, 13081, 12815, 12549, 12287, 12025, 11765, 11505, 11250,
        10996, 10746, 10497, 10254, 10011,  9772,  9534,  9303,  9072,  8848,
         8624,  8406,  8188,  7970,  7752,  7539,  7327,  7123,  6919,  6724,
         6529,  6339,  6150,  5970,  5790,  5618,  5446,  5282,  5119,  4957,
         4795,  4642,  4490,  4345,  4201,  4065,  3929,  3798,  3669,  3547,
         3425,  3310,  3196,  3086,  2976,  2866,  2756,  2650,  2545,  2447,
         2350,  2260,  2170,  2085,  2000,  1921,  1843,  1770,  1698,  1632,
         1566,  1501,  1436,  1376,  1316,  1261,  1207,  1157,  1108,  1061,
         1015,   973,   931,   893,   855,   819,   783,   747,   711,   677,
          644,   614,   584,   557,   530,   505,   480,   458,   436,   416,
          396,   378,   360,   343,   326,   310,   295,   281,   267,   255,
          243,   232,   221,   211,   201,   192,   183,   174,   166,   158,
          150,   142,   134,   126,   119,   112,   106,   100,    95,    90,
           85,    80,    76,    72,    69,    66,    63,    60,    57,    54,
           51,    48,    46,    44,    42,    40,    38,    36,    34,    33,
           32,    31,    30,    29,    28,    27,    26,    25,    24,    23,
           22,    21,    20,    19,    18,    17,    16,    15,    14,    13,
           12,    11,    10,     9,     8,     7,     6,     5,     4,     3,
            2,     1,     0
115 116
    },
    {
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
        16384, 16116, 15849, 15582, 15316, 15050, 14785, 14521, 14257, 13995,
        13734, 13476, 13218, 12963, 12708, 12457, 12206, 11956, 11706, 11460,
        11215, 10975, 10735, 10500, 10265, 10034,  9803,  9579,  9355,  9136,
         8917,  8703,  8489,  8275,  8061,  7853,  7645,  7444,  7244,  7051,
         6858,  6671,  6484,  6305,  6127,  5956,  5785,  5622,  5459,  5298,
         5137,  4983,  4830,  4684,  4539,  4401,  4263,  4131,  3999,  3874,
         3750,  3632,  3515,  3401,  3287,  3173,  3059,  2949,  2840,  2737,
         2635,  2539,  2444,  2354,  2264,  2181,  2098,  2020,  1943,  1872,
         1801,  1731,  1661,  1596,  1532,  1472,  1412,  1357,  1303,  1251,
         1200,  1153,  1106,  1063,  1020,   979,   938,   897,   856,   818,
          780,   746,   712,   681,   650,   621,   592,   566,   540,   517,
          494,   473,   452,   431,   410,   391,   373,   356,   340,   325,
          310,   296,   282,   270,   258,   247,   236,   225,   214,   203,
          192,   182,   172,   162,   153,   144,   136,   128,   121,   114,
          108,   102,    97,    92,    87,    82,    77,    73,    69,    65,
           62,    59,    56,    53,    50,    47,    45,    43,    41,    39,
           37,    35,    33,    31,    29,    27,    26,    25,    24,    23,
           22,    21,    20,    19,    18,    17,    16,    15,    14,    13,
           12,    11,    10,     9,     8,     7,     6,     5,     4,     3,
            2,     1,     0
137 138
    },
    {
139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158
        16384, 16128, 15872, 15617, 15362, 15107, 14853, 14600, 14347, 14096,
        13846, 13597, 13350, 13105, 12860, 12618, 12376, 12135, 11894, 11657,
        11421, 11189, 10957, 10730, 10503, 10279, 10056,  9838,  9620,  9407,
         9195,  8987,  8779,  8571,  8363,  8159,  7955,  7758,  7561,  7371,
         7182,  6997,  6812,  6635,  6459,  6289,  6120,  5957,  5795,  5634,
         5473,  5319,  5165,  5018,  4871,  4732,  4593,  4458,  4324,  4197,
         4071,  3951,  3831,  3714,  3597,  3480,  3363,  3250,  3138,  3032,
         2927,  2828,  2729,  2635,  2541,  2453,  2366,  2284,  2202,  2126,
         2050,  1975,  1900,  1830,  1761,  1697,  1633,  1574,  1515,  1459,
         1403,  1351,  1300,  1252,  1205,  1160,  1115,  1070,  1025,   982,
          939,   899,   860,   824,   789,   756,   723,   693,   663,   636,
          609,   584,   559,   535,   511,   489,   467,   447,   427,   409,
          391,   374,   358,   343,   328,   313,   300,   287,   274,   261,
          248,   235,   223,   211,   200,   189,   179,   169,   160,   151,
          143,   135,   128,   121,   115,   109,   103,    97,    92,    87,
           82,    77,    73,    69,    65,    61,    58,    55,    52,    49,
           46,    43,    40,    37,    35,    33,    31,    29,    27,    25,
           23,    21,    20,    19,    18,    17,    16,    15,    14,    13,
           12,    11,    10,     9,     8,     7,     6,     5,     4,     3,
            2,     1,     0
159 160
    },
    {
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
        16384, 16139, 15894, 15649, 15405, 15162, 14919, 14677, 14435, 14195,
        13955, 13717, 13479, 13243, 13008, 12775, 12542, 12310, 12079, 11851,
        11623, 11399, 11176, 10956, 10737, 10521, 10305, 10094,  9883,  9677,
         9471,  9268,  9065,  8862,  8659,  8459,  8260,  8067,  7874,  7688,
         7502,  7321,  7140,  6965,  6790,  6621,  6452,  6290,  6128,  5968,
         5808,  5655,  5503,  5356,  5209,  5069,  4929,  4794,  4660,  4532,
         4404,  4282,  4160,  4041,  3922,  3803,  3684,  3568,  3452,  3343,
         3234,  3131,  3029,  2931,  2833,  2741,  2649,  2563,  2477,  2396,
         2316,  2236,  2157,  2083,  2009,  1940,  1871,  1807,  1743,  1683,
         1623,  1567,  1511,  1459,  1407,  1357,  1307,  1257,  1207,  1159,
         1111,  1067,  1023,   983,   943,   905,   868,   834,   800,   769,
          738,   709,   681,   653,   625,   600,   575,   552,   529,   508,
          487,   466,   447,   428,   410,   392,   376,   360,   344,   328,
          313,   298,   283,   268,   255,   242,   230,   218,   207,   196,
          186,   176,   167,   158,   150,   142,   135,   128,   121,   114,
          108,   102,    97,    92,    87,    82,    78,    74,    70,    66,
           62,    58,    54,    50,    47,    44,    41,    38,    35,    32,
           30,    28,    26,    24,    22,    20,    18,    16,    14,    13,
           12,    11,    10,     9,     8,     7,     6,     5,     4,     3,
            2,     1,     0
181 182
    },
    {
183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
        16384, 16149, 15915, 15681, 15447, 15214, 14981, 14749, 14517, 14286,
        14055, 13827, 13599, 13373, 13147, 12923, 12699, 12476, 12253, 12034,
        11815, 11599, 11383, 11171, 10959, 10750, 10541, 10337, 10133,  9933,
         9733,  9536,  9339,  9142,  8945,  8751,  8557,  8369,  8181,  7998,
         7816,  7638,  7460,  7288,  7116,  6950,  6785,  6625,  6465,  6306,
         6147,  5995,  5843,  5697,  5551,  5411,  5271,  5135,  5000,  4871,
         4742,  4618,  4495,  4374,  4253,  4132,  4011,  3893,  3775,  3663,
         3552,  3446,  3340,  3239,  3138,  3043,  2948,  2858,  2768,  2684,
         2600,  2516,  2433,  2355,  2278,  2205,  2133,  2065,  1997,  1932,
         1867,  1807,  1747,  1690,  1634,  1580,  1526,  1472,  1418,  1366,
         1314,  1266,  1218,  1174,  1130,  1088,  1047,  1009,   971,   936,
          901,   868,   836,   804,   772,   743,   714,   685,   658,   631,
          606,   582,   559,   536,   515,   494,   475,   456,   437,   418,
          399,   380,   362,   344,   328,   312,   297,   283,   270,   257,
          245,   233,   222,   211,   201,   191,   181,   172,   163,   155,
          147,   139,   132,   125,   119,   113,   107,   101,    96,    91,
           86,    81,    76,    71,    66,    62,    58,    54,    50,    46,
           43,    40,    37,    34,    31,    28,    26,    24,    22,    20,
           18,    16,    14,    12,    10,     8,     6,     5,     4,     3,
            2,     1,     0
203 204
    },
    {
205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224
        16384, 16159, 15934, 15709, 15485, 15261, 15038, 14816, 14594, 14373,
        14152, 13933, 13714, 13497, 13280, 13065, 12850, 12636, 12422, 12211,
        12000, 11791, 11583, 11378, 11173, 10971, 10769, 10571, 10373, 10179,
         9985,  9793,  9601,  9409,  9217,  9029,  8842,  8658,  8475,  8297,
         8120,  7946,  7773,  7604,  7435,  7271,  7108,  6950,  6792,  6634,
         6477,  6326,  6175,  6029,  5883,  5742,  5602,  5466,  5330,  5199,
         5068,  4943,  4818,  4696,  4574,  4452,  4330,  4211,  4093,  3979,
         3866,  3759,  3652,  3549,  3446,  3348,  3250,  3157,  3065,  2977,
         2889,  2802,  2716,  2634,  2553,  2476,  2399,  2326,  2254,  2185,
         2117,  2052,  1987,  1926,  1866,  1808,  1750,  1692,  1634,  1578,
         1522,  1470,  1418,  1369,  1321,  1275,  1229,  1187,  1145,  1105,
         1066,  1027,   991,   955,   919,   883,   850,   817,   786,   756,
          728,   700,   674,   648,   624,   600,   578,   556,   534,   512,
          490,   468,   447,   426,   407,   388,   371,   354,   338,   322,
          307,   293,   280,   267,   255,   243,   231,   219,   209,   199,
          189,   179,   170,   161,   153,   145,   138,   131,   124,   117,
          111,   105,    99,    93,    87,    81,    76,    71,    66,    61,
           57,    53,    49,    45,    42,    39,    36,    33,    30,    27,
           24,    21,    19,    17,    15,    13,    11,     9,     7,     5,
            3,     1,     0
225 226
    },
    {
227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
        16384, 16169, 15954, 15739, 15524, 15310, 15096, 14883, 14670, 14458,
        14246, 14035, 13824, 13614, 13405, 13198, 12991, 12785, 12579, 12376,
        12173, 11972, 11772, 11574, 11377, 11182, 10987, 10795, 10603, 10414,
        10226, 10040,  9854,  9668,  9482,  9299,  9116,  8937,  8759,  8585,
         8411,  8241,  8071,  7906,  7741,  7580,  7419,  7263,  7107,  6952,
         6797,  6647,  6497,  6353,  6209,  6070,  5931,  5796,  5661,  5531,
         5401,  5275,  5150,  5027,  4904,  4781,  4658,  4538,  4419,  4304,
         4190,  4081,  3972,  3867,  3762,  3662,  3562,  3467,  3372,  3281,
         3191,  3101,  3012,  2928,  2844,  2764,  2684,  2608,  2533,  2460,
         2387,  2318,  2250,  2185,  2121,  2059,  1997,  1935,  1873,  1813,
         1754,  1698,  1642,  1588,  1535,  1483,  1433,  1384,  1338,  1292,
         1249,  1206,  1165,  1125,  1085,  1045,  1008,   971,   937,   903,
          871,   840,   810,   780,   752,   724,   698,   672,   647,   622,
          597,   572,   548,   524,   502,   480,   460,   440,   421,   403,
          386,   369,   353,   337,   323,   309,   295,   281,   268,   255,
          243,   231,   220,   209,   199,   189,   180,   171,   163,   155,
          147,   139,   131,   123,   116,   109,   102,    95,    89,    83,
           77,    72,    67,    62,    57,    52,    48,    44,    40,    36,
           32,    28,    25,    22,    19,    16,    13,    10,     8,     6,
            4,     2,     0
247 248
    },
    {
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268
        16384, 16177, 15970, 15764, 15558, 15353, 15148, 14944, 14740, 14537,
        14334, 14132, 13930, 13729, 13529, 13330, 13131, 12933, 12735, 12539,
        12343, 12150, 11957, 11766, 11576, 11388, 11200, 11015, 10830, 10647,
        10465, 10285, 10105,  9925,  9745,  9568,  9391,  9218,  9045,  8876,
         8707,  8541,  8375,  8213,  8051,  7894,  7737,  7583,  7429,  7277,
         7125,  6977,  6830,  6687,  6544,  6406,  6268,  6133,  5998,  5868,
         5738,  5612,  5487,  5364,  5241,  5118,  4995,  4875,  4755,  4640,
         4525,  4414,  4304,  4198,  4092,  3990,  3888,  3790,  3693,  3600,
         3507,  3415,  3323,  3235,  3147,  3064,  2981,  2902,  2823,  2746,
         2670,  2594,  2522,  2450,  2382,  2314,  2248,  2182,  2116,  2050,
         1987,  1924,  1864,  1804,  1748,  1692,  1638,  1585,  1534,  1484,
         1437,  1390,  1346,  1302,  1258,  1215,  1174,  1133,  1095,  1057,
         1021,   986,   952,   918,   887,   856,   827,   798,   770,   742,
          714,   686,   659,   632,   607,   582,   559,   536,   514,   492,
          472,   452,   433,   415,   398,   381,   364,   348,   333,   318,
          304,   290,   277,   264,   252,   240,   229,   218,   208,   198,
          188,   178,   168,   158,   149,   140,   132,   124,   116,   108,
          101,    94,    87,    81,    75,    69,    64,    59,    54,    49,
           44,    39,    35,    31,    27,    23,    19,    15,    12,     9,
            6,     3,     0
269 270 271 272 273 274
    }
};


static const uint16_t cf_tables_3[5][257] = {
    {
275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300
        16384, 16187, 15990, 15793, 15597, 15401, 15205, 15009, 14813, 14618,
        14423, 14230, 14037, 13845, 13653, 13463, 13273, 13083, 12894, 12706,
        12518, 12332, 12146, 11962, 11778, 11597, 11416, 11237, 11059, 10882,
        10706, 10532, 10358, 10184, 10010,  9838,  9666,  9497,  9328,  9163,
         8999,  8837,  8675,  8517,  8359,  8205,  8051,  7901,  7751,  7602,
         7453,  7308,  7163,  7022,  6882,  6745,  6609,  6476,  6343,  6214,
         6085,  5960,  5835,  5712,  5589,  5466,  5343,  5223,  5103,  4987,
         4872,  4761,  4650,  4542,  4435,  4332,  4229,  4130,  4031,  3936,
         3841,  3747,  3653,  3563,  3473,  3387,  3302,  3220,  3138,  3059,
         2980,  2905,  2830,  2759,  2688,  2619,  2550,  2481,  2412,  2345,
         2278,  2215,  2152,  2092,  2032,  1974,  1917,  1863,  1809,  1758,
         1707,  1659,  1611,  1564,  1517,  1473,  1429,  1387,  1346,  1307,
         1268,  1230,  1193,  1158,  1123,  1090,  1058,  1026,   994,   962,
          930,   899,   869,   841,   813,   786,   760,   735,   710,   687,
          664,   643,   622,   602,   582,   562,   543,   525,   507,   490,
          473,   457,   442,   427,   412,   398,   385,   373,   361,   349,
          337,   325,   313,   301,   290,   279,   269,   259,   249,   240,
          231,   222,   214,   206,   199,   192,   185,   178,   171,   165,
          159,   153,   148,   143,   138,   133,   128,   123,   119,   115,
          111,   107,   103,    99,    95,    91,    87,    83,    80,    77,
           74,    71,    68,    65,    63,    61,    59,    57,    55,    53,
           51,    49,    47,    45,    43,    41,    40,    39,    38,    37,
           36,    35,    34,    33,    32,    31,    30,    29,    28,    27,
           26,    25,    24,    23,    22,    21,    20,    19,    18,    17,
           16,    15,    14,    13,    12,    11,    10,     9,     8,     7,
            6,     5,     4,     3,     2,     1,     0
301 302
    },
    {
303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
        16384, 16195, 16006, 15817, 15629, 15441, 15253, 15065, 14878, 14692,
        14506, 14321, 14136, 13952, 13768, 13585, 13402, 13219, 13037, 12857,
        12677, 12499, 12321, 12144, 11967, 11792, 11617, 11444, 11271, 11100,
        10930, 10762, 10594, 10426, 10258, 10091,  9925,  9761,  9598,  9438,
         9278,  9120,  8963,  8809,  8655,  8504,  8354,  8207,  8060,  7914,
         7769,  7627,  7485,  7347,  7209,  7074,  6939,  6807,  6676,  6548,
         6420,  6296,  6172,  6050,  5928,  5806,  5684,  5564,  5444,  5328,
         5212,  5100,  4988,  4879,  4771,  4667,  4563,  4462,  4362,  4265,
         4169,  4073,  3978,  3886,  3795,  3707,  3619,  3535,  3451,  3369,
         3288,  3210,  3133,  3059,  2985,  2913,  2841,  2769,  2697,  2627,
         2557,  2490,  2424,  2360,  2297,  2237,  2177,  2119,  2062,  2007,
         1953,  1901,  1849,  1798,  1748,  1700,  1652,  1607,  1562,  1519,
         1476,  1435,  1394,  1355,  1317,  1281,  1245,  1210,  1175,  1140,
         1105,  1071,  1037,  1005,   973,   943,   913,   885,   857,   830,
          804,   779,   754,   731,   708,   685,   663,   642,   621,   601,
          581,   563,   545,   528,   511,   495,   479,   463,   448,   433,
          419,   405,   391,   377,   364,   351,   338,   326,   314,   302,
          291,   280,   270,   260,   251,   242,   234,   226,   218,   210,
          202,   195,   188,   181,   174,   168,   162,   156,   150,   144,
          139,   134,   129,   124,   119,   114,   109,   104,   100,    96,
           92,    88,    84,    80,    77,    74,    71,    68,    65,    62,
           59,    56,    54,    52,    50,    48,    46,    44,    42,    40,
           38,    36,    34,    33,    32,    31,    30,    29,    28,    27,
           26,    25,    24,    23,    22,    21,    20,    19,    18,    17,
           16,    15,    14,    13,    12,    11,    10,     9,     8,     7,
            6,     5,     4,     3,     2,     1,     0
329 330
    },
    {
331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356
        16384, 16203, 16022, 15842, 15662, 15482, 15302, 15122, 14942, 14763,
        14584, 14406, 14228, 14051, 13874, 13698, 13522, 13347, 13172, 12998,
        12824, 12652, 12480, 12310, 12140, 11971, 11803, 11637, 11471, 11307,
        11143, 10980, 10817, 10654, 10491, 10330, 10169, 10011,  9853,  9697,
         9542,  9389,  9236,  9086,  8936,  8789,  8642,  8498,  8355,  8212,
         8070,  7931,  7792,  7656,  7520,  7388,  7256,  7126,  6996,  6870,
         6744,  6621,  6498,  6377,  6256,  6135,  6014,  5895,  5776,  5660,
         5545,  5433,  5321,  5212,  5104,  4999,  4895,  4793,  4692,  4594,
         4496,  4400,  4304,  4211,  4118,  4028,  3939,  3853,  3767,  3684,
         3601,  3521,  3441,  3364,  3287,  3212,  3137,  3062,  2987,  2915,
         2843,  2773,  2704,  2638,  2572,  2508,  2445,  2384,  2324,  2266,
         2208,  2153,  2098,  2044,  1990,  1939,  1888,  1839,  1791,  1745,
         1699,  1655,  1611,  1569,  1527,  1487,  1448,  1409,  1370,  1331,
         1292,  1255,  1218,  1183,  1148,  1115,  1082,  1051,  1020,   990,
          960,   932,   904,   878,   852,   826,   801,   777,   753,   731,
          709,   687,   666,   645,   625,   605,   586,   567,   550,   533,
          516,   499,   482,   465,   449,   433,   418,   403,   389,   375,
          362,   349,   337,   325,   314,   303,   293,   283,   273,   263,
          254,   245,   236,   227,   219,   211,   204,   197,   190,   183,
          177,   171,   165,   159,   153,   147,   141,   135,   130,   125,
          120,   115,   110,   105,   101,    97,    93,    89,    85,    81,
           77,    74,    71,    68,    65,    62,    59,    56,    53,    51,
           49,    47,    45,    43,    41,    39,    37,    35,    33,    31,
           29,    27,    25,    23,    22,    21,    20,    19,    18,    17,
           16,    15,    14,    13,    12,    11,    10,     9,     8,     7,
            6,     5,     4,     3,     2,     1,     0
357 358
    },
    {
359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384
        16384, 16210, 16036, 15863, 15690, 15517, 15344, 15172, 15000, 14828,
        14656, 14485, 14314, 14145, 13976, 13808, 13640, 13472, 13304, 13137,
        12970, 12804, 12639, 12475, 12312, 12149, 11987, 11827, 11667, 11508,
        11349, 11192, 11035, 10878, 10721, 10565, 10410, 10257, 10104,  9953,
         9802,  9654,  9506,  9359,  9213,  9070,  8927,  8787,  8647,  8508,
         8369,  8233,  8097,  7964,  7831,  7700,  7570,  7442,  7315,  7190,
         7065,  6943,  6821,  6701,  6581,  6461,  6341,  6223,  6105,  5990,
         5876,  5764,  5653,  5545,  5437,  5331,  5226,  5124,  5022,  4924,
         4826,  4729,  4632,  4538,  4444,  4353,  4262,  4174,  4087,  4002,
         3917,  3835,  3753,  3674,  3595,  3518,  3441,  3364,  3287,  3212,
         3138,  3066,  2995,  2926,  2858,  2792,  2726,  2662,  2599,  2538,
         2478,  2420,  2362,  2305,  2249,  2195,  2141,  2089,  2037,  1988,
         1939,  1891,  1844,  1799,  1754,  1711,  1668,  1626,  1584,  1542,
         1500,  1459,  1418,  1380,  1342,  1305,  1269,  1234,  1199,  1166,
         1133,  1102,  1071,  1041,  1012,   983,   954,   926,   899,   872,
          847,   822,   798,   774,   751,   728,   707,   686,   666,   646,
          627,   608,   589,   570,   552,   534,   517,   500,   484,   468,
          453,   438,   424,   410,   397,   384,   372,   360,   348,   336,
          325,   314,   303,   293,   283,   273,   264,   255,   246,   237,
          229,   221,   213,   205,   197,   189,   181,   174,   167,   160,
          154,   148,   142,   136,   131,   126,   121,   116,   111,   106,
          101,    97,    93,    89,    85,    81,    77,    73,    70,    67,
           64,    61,    58,    55,    52,    49,    46,    43,    40,    37,
           35,    33,    31,    29,    27,    25,    23,    21,    19,    17,
           16,    15,    14,    13,    12,    11,    10,     9,     8,     7,
            6,     5,     4,     3,     2,     1,     0
385 386
    },
    {
387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
        16384, 16218, 16052, 15886, 15720, 15554, 15389, 15224, 15059, 14895,
        14731, 14567, 14403, 14240, 14077, 13915, 13753, 13591, 13429, 13269,
        13109, 12950, 12791, 12633, 12476, 12320, 12164, 12009, 11854, 11701,
        11548, 11396, 11244, 11092, 10940, 10790, 10640, 10492, 10344, 10198,
        10052,  9908,  9764,  9622,  9481,  9342,  9203,  9066,  8929,  8793,
         8657,  8524,  8391,  8261,  8131,  8003,  7875,  7749,  7624,  7502,
         7380,  7260,  7140,  7022,  6904,  6786,  6668,  6551,  6435,  6322,
         6209,  6099,  5989,  5881,  5773,  5668,  5563,  5461,  5359,  5260,
         5161,  5063,  4965,  4871,  4777,  4686,  4595,  4506,  4417,  4331,
         4245,  4162,  4079,  3999,  3919,  3841,  3763,  3685,  3607,  3530,
         3454,  3380,  3307,  3236,  3166,  3097,  3029,  2963,  2897,  2834,
         2771,  2710,  2650,  2591,  2532,  2475,  2418,  2363,  2309,  2257,
         2205,  2155,  2105,  2057,  2009,  1963,  1918,  1873,  1828,  1783,
         1738,  1694,  1650,  1607,  1565,  1524,  1484,  1445,  1407,  1369,
         1333,  1297,  1263,  1229,  1197,  1165,  1134,  1103,  1073,  1043,
         1015,   987,   960,   933,   907,   882,   858,   834,   811,   788,
          766,   744,   722,   700,   679,   658,   638,   618,   599,   581,
          563,   545,   528,   511,   495,   480,   465,   451,   437,   423,
          410,   397,   384,   372,   360,   348,   337,   326,   315,   305,
          295,   285,   275,   265,   255,   245,   236,   227,   219,   211,
          203,   195,   188,   181,   174,   167,   161,   155,   149,   143,
          137,   131,   126,   121,   116,   111,   106,   101,    97,    93,
           89,    85,    81,    77,    73,    69,    65,    61,    58,    55,
           52,    49,    46,    43,    40,    37,    34,    32,    30,    28,
           26,    24,    22,    20,    18,    16,    14,    12,    10,     8,
            6,     5,     4,     3,     2,     1,     0
413 414 415 416
    }
};


417
static const uint16_t *const cf_table[16] = {
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    cf_tables_1[0], cf_tables_1[1], cf_tables_1[2], cf_tables_2[0],
    cf_tables_2[1], cf_tables_2[2], cf_tables_2[3], cf_tables_2[4],
    cf_tables_2[5], cf_tables_2[6], cf_tables_2[7], cf_tables_3[0],
    cf_tables_3[1], cf_tables_3[2], cf_tables_3[3], cf_tables_3[4]
};


425 426
/** Initialize a given lookup table using a given delta */
static void bgmc_lut_fillp(uint8_t *lut, int *lut_status, int delta)
427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444
{
    unsigned int sx, i;

    for (sx = 0; sx < 16; sx++)
        for (i = 0; i < LUT_SIZE; i++) {
            unsigned int target = (i + 1) << (FREQ_BITS - LUT_BITS);
            unsigned int symbol = 1 << delta;

            while (cf_table[sx][symbol] > target)
                symbol += 1 << delta;

            *lut++ = symbol >> delta;
        }

    *lut_status = delta;
}


445 446
/** Retune the index of a suitable lookup table for a given delta */
static uint8_t *bgmc_lut_getp(uint8_t *lut, int *lut_status, int delta)
447 448 449 450 451 452 453 454 455 456 457 458
{
    unsigned int i = av_clip(delta, 0, LUT_BUFF - 1);

    lut += (i * LUT_SIZE) << 4;

    if (lut_status[i] != delta)
        bgmc_lut_fillp(lut, &lut_status[i], delta);

    return lut;
}


459
/** Initialize the lookup table arrays */
460 461
av_cold int ff_bgmc_init(AVCodecContext *avctx,
                         uint8_t **cf_lut, int **cf_lut_status)
462
{
463 464
    *cf_lut        = av_malloc(sizeof(**cf_lut)        * LUT_BUFF * 16 * LUT_SIZE);
    *cf_lut_status = av_malloc(sizeof(**cf_lut_status) * LUT_BUFF);
465

466
    if (!*cf_lut || !*cf_lut_status) {
467 468 469
        ff_bgmc_end(cf_lut, cf_lut_status);
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
        return AVERROR(ENOMEM);
470
    } else {
471
        // initialize lut_status buffer to a value never used to compare against
472
        memset(*cf_lut_status, -1, sizeof(**cf_lut_status) * LUT_BUFF);
473 474 475 476 477 478
    }

    return 0;
}


479
/** Release the lookup table arrays */
480
av_cold void ff_bgmc_end(uint8_t **cf_lut, int **cf_lut_status)
481 482 483 484 485 486
{
    av_freep(cf_lut);
    av_freep(cf_lut_status);
}


487
/** Initialize decoding and reads the first value */
488 489
void ff_bgmc_decode_init(GetBitContext *gb, unsigned int *h,
                         unsigned int *l, unsigned int *v)
490 491 492 493 494 495 496
{
    *h = TOP_VALUE;
    *l = 0;
    *v = get_bits_long(gb, VALUE_BITS);
}


497
/** Finish decoding */
498 499 500 501 502 503
void ff_bgmc_decode_end(GetBitContext *gb)
{
    skip_bits_long(gb, -(VALUE_BITS - 2));
}


504
/** Read and decode a block Gilbert-Moore coded symbol */
505
void ff_bgmc_decode(GetBitContext *gb, unsigned int num, int32_t *dst,
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506 507 508
                    int delta, unsigned int sx,
                    unsigned int *h, unsigned int *l, unsigned int *v,
                    uint8_t *cf_lut, int *cf_lut_status)
509 510 511 512 513
{
    unsigned int i;
    uint8_t *lut = bgmc_lut_getp(cf_lut, cf_lut_status, delta);

    // read current state
514 515 516
    unsigned int high  = *h;
    unsigned int low   = *l;
    unsigned int value = *v;
517 518 519 520 521 522 523 524 525 526 527 528 529 530

    lut += sx * LUT_SIZE;

    // decode num samples
    for (i = 0; i < num; i++) {
        unsigned int range  = high - low + 1;
        unsigned int target = (((value - low + 1) << FREQ_BITS) - 1) / range;
        unsigned int symbol = lut[target >> (FREQ_BITS - LUT_BITS)] << delta;

        while (cf_table[sx][symbol] > target)
            symbol += 1 << delta;

        symbol = (symbol >> delta) - 1;

531 532
        high = low + ((range * cf_table[sx][(symbol)     << delta] - (1 << FREQ_BITS)) >> FREQ_BITS);
        low  = low + ((range * cf_table[sx][(symbol + 1) << delta])                    >> FREQ_BITS);
533 534 535

        while (1) {
            if (high >= HALF) {
536
                if (low >= HALF) {
537 538 539 540 541 542 543
                    value -= HALF;
                    low   -= HALF;
                    high  -= HALF;
                } else if (low >= FIRST_QTR && high < THIRD_QTR) {
                    value -= FIRST_QTR;
                    low   -= FIRST_QTR;
                    high  -= FIRST_QTR;
544 545
                } else
                    break;
546 547
            }

548 549 550
            low  *= 2;
            high  = 2 * high + 1;
            value = 2 * value + get_bits1(gb);
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        }

        *dst++ = symbol;
    }

    // save current state
    *h = high;
    *l = low;
    *v = value;
}