FFmpeg
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bgmc.c
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1 /*
2  * Block Gilbert-Moore decoder
3  * Copyright (c) 2010 Thilo Borgmann <thilo.borgmann _at_ mail.de>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
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 #include "bgmc.h"
30 
31 #define FREQ_BITS 14 // bits used by frequency counters
32 #define VALUE_BITS 18 // bits used to represent the values
33 #define TOP_VALUE ((1 << VALUE_BITS) - 1) // maximum value
34 #define FIRST_QTR (TOP_VALUE / 4 + 1) // first quarter of values maximum value
35 #define HALF (2 * FIRST_QTR) // first half of values maximum value
36 #define THIRD_QTR (3 * FIRST_QTR) // third quarter of values maximum value
37 
38 #define LUT_BITS (FREQ_BITS - 8) // number of bits used to index lookup tables
39 #define LUT_SIZE (1 << LUT_BITS) // size of the lookup tables
40 #define LUT_BUFF 4 // number of buffered lookup tables
41 
42 
43 /** Cumulative frequency tables for block Gilbert-Moore coding. */
44 static const uint16_t cf_tables_1[3][129] = {
45  {
46  16384, 16066, 15748, 15431, 15114, 14799, 14485, 14173, 13861, 13552,
47  13243, 12939, 12635, 12336, 12038, 11745, 11452, 11161, 10870, 10586,
48  10303, 10027, 9751, 9483, 9215, 8953, 8692, 8440, 8189, 7946,
49  7704, 7472, 7240, 7008, 6776, 6554, 6333, 6122, 5912, 5711,
50  5512, 5320, 5128, 4947, 4766, 4595, 4425, 4264, 4104, 3946,
51  3788, 3640, 3493, 3355, 3218, 3090, 2963, 2842, 2721, 2609,
52  2498, 2395, 2292, 2196, 2100, 2004, 1908, 1820, 1732, 1651,
53  1570, 1497, 1424, 1355, 1287, 1223, 1161, 1100, 1044, 988,
54  938, 888, 839, 790, 746, 702, 662, 623, 588, 553,
55  520, 488, 459, 431, 405, 380, 357, 334, 311, 288,
56  268, 248, 230, 213, 197, 182, 168, 154, 142, 130,
57  119, 108, 99, 90, 81, 72, 64, 56, 49, 42,
58  36, 30, 25, 20, 15, 11, 7, 3, 0
59  },
60  {
61  16384, 16080, 15776, 15473, 15170, 14868, 14567, 14268, 13970, 13674,
62  13378, 13086, 12794, 12505, 12218, 11936, 11654, 11373, 11092, 10818,
63  10544, 10276, 10008, 9749, 9490, 9236, 8982, 8737, 8492, 8256,
64  8020, 7792, 7564, 7336, 7108, 6888, 6669, 6459, 6249, 6050,
65  5852, 5660, 5468, 5286, 5104, 4931, 4760, 4598, 4436, 4275,
66  4115, 3965, 3816, 3674, 3534, 3403, 3272, 3147, 3023, 2907,
67  2792, 2684, 2577, 2476, 2375, 2274, 2173, 2079, 1986, 1897,
68  1810, 1724, 1645, 1567, 1493, 1419, 1351, 1284, 1222, 1161,
69  1105, 1050, 995, 941, 891, 842, 797, 753, 713, 673,
70  636, 599, 566, 533, 503, 473, 446, 419, 392, 365,
71  340, 316, 294, 272, 253, 234, 216, 199, 184, 169,
72  155, 142, 130, 118, 106, 95, 85, 75, 66, 57,
73  49, 41, 34, 27, 21, 15, 10, 5, 0
74  },
75  {
76  16384, 16092, 15801, 15510, 15219, 14930, 14641, 14355, 14069, 13785,
77  13501, 13219, 12938, 12661, 12384, 12112, 11841, 11571, 11301, 11037,
78  10773, 10514, 10256, 10005, 9754, 9508, 9263, 9025, 8787, 8557,
79  8327, 8103, 7879, 7655, 7431, 7215, 7000, 6792, 6585, 6387,
80  6190, 5998, 5807, 5625, 5445, 5272, 5100, 4937, 4774, 4613,
81  4452, 4301, 4150, 4007, 3865, 3731, 3597, 3469, 3341, 3218,
82  3099, 2981, 2869, 2758, 2652, 2546, 2440, 2334, 2234, 2134,
83  2041, 1949, 1864, 1779, 1699, 1620, 1547, 1474, 1407, 1340,
84  1278, 1217, 1157, 1097, 1043, 989, 940, 891, 846, 801,
85  759, 718, 680, 643, 609, 575, 543, 511, 479, 447,
86  418, 389, 363, 337, 314, 291, 270, 249, 230, 212,
87  195, 179, 164, 149, 135, 121, 108, 96, 85, 74,
88  64, 54, 45, 36, 28, 20, 13, 6, 0
89  }
90 };
91 
92 
93 static const uint16_t cf_tables_2[8][193] = {
94  {
95  16384, 16104, 15825, 15546, 15268, 14991, 14714, 14439, 14164, 13891,
96  13620, 13350, 13081, 12815, 12549, 12287, 12025, 11765, 11505, 11250,
97  10996, 10746, 10497, 10254, 10011, 9772, 9534, 9303, 9072, 8848,
98  8624, 8406, 8188, 7970, 7752, 7539, 7327, 7123, 6919, 6724,
99  6529, 6339, 6150, 5970, 5790, 5618, 5446, 5282, 5119, 4957,
100  4795, 4642, 4490, 4345, 4201, 4065, 3929, 3798, 3669, 3547,
101  3425, 3310, 3196, 3086, 2976, 2866, 2756, 2650, 2545, 2447,
102  2350, 2260, 2170, 2085, 2000, 1921, 1843, 1770, 1698, 1632,
103  1566, 1501, 1436, 1376, 1316, 1261, 1207, 1157, 1108, 1061,
104  1015, 973, 931, 893, 855, 819, 783, 747, 711, 677,
105  644, 614, 584, 557, 530, 505, 480, 458, 436, 416,
106  396, 378, 360, 343, 326, 310, 295, 281, 267, 255,
107  243, 232, 221, 211, 201, 192, 183, 174, 166, 158,
108  150, 142, 134, 126, 119, 112, 106, 100, 95, 90,
109  85, 80, 76, 72, 69, 66, 63, 60, 57, 54,
110  51, 48, 46, 44, 42, 40, 38, 36, 34, 33,
111  32, 31, 30, 29, 28, 27, 26, 25, 24, 23,
112  22, 21, 20, 19, 18, 17, 16, 15, 14, 13,
113  12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
114  2, 1, 0
115  },
116  {
117  16384, 16116, 15849, 15582, 15316, 15050, 14785, 14521, 14257, 13995,
118  13734, 13476, 13218, 12963, 12708, 12457, 12206, 11956, 11706, 11460,
119  11215, 10975, 10735, 10500, 10265, 10034, 9803, 9579, 9355, 9136,
120  8917, 8703, 8489, 8275, 8061, 7853, 7645, 7444, 7244, 7051,
121  6858, 6671, 6484, 6305, 6127, 5956, 5785, 5622, 5459, 5298,
122  5137, 4983, 4830, 4684, 4539, 4401, 4263, 4131, 3999, 3874,
123  3750, 3632, 3515, 3401, 3287, 3173, 3059, 2949, 2840, 2737,
124  2635, 2539, 2444, 2354, 2264, 2181, 2098, 2020, 1943, 1872,
125  1801, 1731, 1661, 1596, 1532, 1472, 1412, 1357, 1303, 1251,
126  1200, 1153, 1106, 1063, 1020, 979, 938, 897, 856, 818,
127  780, 746, 712, 681, 650, 621, 592, 566, 540, 517,
128  494, 473, 452, 431, 410, 391, 373, 356, 340, 325,
129  310, 296, 282, 270, 258, 247, 236, 225, 214, 203,
130  192, 182, 172, 162, 153, 144, 136, 128, 121, 114,
131  108, 102, 97, 92, 87, 82, 77, 73, 69, 65,
132  62, 59, 56, 53, 50, 47, 45, 43, 41, 39,
133  37, 35, 33, 31, 29, 27, 26, 25, 24, 23,
134  22, 21, 20, 19, 18, 17, 16, 15, 14, 13,
135  12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
136  2, 1, 0
137  },
138  {
139  16384, 16128, 15872, 15617, 15362, 15107, 14853, 14600, 14347, 14096,
140  13846, 13597, 13350, 13105, 12860, 12618, 12376, 12135, 11894, 11657,
141  11421, 11189, 10957, 10730, 10503, 10279, 10056, 9838, 9620, 9407,
142  9195, 8987, 8779, 8571, 8363, 8159, 7955, 7758, 7561, 7371,
143  7182, 6997, 6812, 6635, 6459, 6289, 6120, 5957, 5795, 5634,
144  5473, 5319, 5165, 5018, 4871, 4732, 4593, 4458, 4324, 4197,
145  4071, 3951, 3831, 3714, 3597, 3480, 3363, 3250, 3138, 3032,
146  2927, 2828, 2729, 2635, 2541, 2453, 2366, 2284, 2202, 2126,
147  2050, 1975, 1900, 1830, 1761, 1697, 1633, 1574, 1515, 1459,
148  1403, 1351, 1300, 1252, 1205, 1160, 1115, 1070, 1025, 982,
149  939, 899, 860, 824, 789, 756, 723, 693, 663, 636,
150  609, 584, 559, 535, 511, 489, 467, 447, 427, 409,
151  391, 374, 358, 343, 328, 313, 300, 287, 274, 261,
152  248, 235, 223, 211, 200, 189, 179, 169, 160, 151,
153  143, 135, 128, 121, 115, 109, 103, 97, 92, 87,
154  82, 77, 73, 69, 65, 61, 58, 55, 52, 49,
155  46, 43, 40, 37, 35, 33, 31, 29, 27, 25,
156  23, 21, 20, 19, 18, 17, 16, 15, 14, 13,
157  12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
158  2, 1, 0
159  },
160  {
161  16384, 16139, 15894, 15649, 15405, 15162, 14919, 14677, 14435, 14195,
162  13955, 13717, 13479, 13243, 13008, 12775, 12542, 12310, 12079, 11851,
163  11623, 11399, 11176, 10956, 10737, 10521, 10305, 10094, 9883, 9677,
164  9471, 9268, 9065, 8862, 8659, 8459, 8260, 8067, 7874, 7688,
165  7502, 7321, 7140, 6965, 6790, 6621, 6452, 6290, 6128, 5968,
166  5808, 5655, 5503, 5356, 5209, 5069, 4929, 4794, 4660, 4532,
167  4404, 4282, 4160, 4041, 3922, 3803, 3684, 3568, 3452, 3343,
168  3234, 3131, 3029, 2931, 2833, 2741, 2649, 2563, 2477, 2396,
169  2316, 2236, 2157, 2083, 2009, 1940, 1871, 1807, 1743, 1683,
170  1623, 1567, 1511, 1459, 1407, 1357, 1307, 1257, 1207, 1159,
171  1111, 1067, 1023, 983, 943, 905, 868, 834, 800, 769,
172  738, 709, 681, 653, 625, 600, 575, 552, 529, 508,
173  487, 466, 447, 428, 410, 392, 376, 360, 344, 328,
174  313, 298, 283, 268, 255, 242, 230, 218, 207, 196,
175  186, 176, 167, 158, 150, 142, 135, 128, 121, 114,
176  108, 102, 97, 92, 87, 82, 78, 74, 70, 66,
177  62, 58, 54, 50, 47, 44, 41, 38, 35, 32,
178  30, 28, 26, 24, 22, 20, 18, 16, 14, 13,
179  12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
180  2, 1, 0
181  },
182  {
183  16384, 16149, 15915, 15681, 15447, 15214, 14981, 14749, 14517, 14286,
184  14055, 13827, 13599, 13373, 13147, 12923, 12699, 12476, 12253, 12034,
185  11815, 11599, 11383, 11171, 10959, 10750, 10541, 10337, 10133, 9933,
186  9733, 9536, 9339, 9142, 8945, 8751, 8557, 8369, 8181, 7998,
187  7816, 7638, 7460, 7288, 7116, 6950, 6785, 6625, 6465, 6306,
188  6147, 5995, 5843, 5697, 5551, 5411, 5271, 5135, 5000, 4871,
189  4742, 4618, 4495, 4374, 4253, 4132, 4011, 3893, 3775, 3663,
190  3552, 3446, 3340, 3239, 3138, 3043, 2948, 2858, 2768, 2684,
191  2600, 2516, 2433, 2355, 2278, 2205, 2133, 2065, 1997, 1932,
192  1867, 1807, 1747, 1690, 1634, 1580, 1526, 1472, 1418, 1366,
193  1314, 1266, 1218, 1174, 1130, 1088, 1047, 1009, 971, 936,
194  901, 868, 836, 804, 772, 743, 714, 685, 658, 631,
195  606, 582, 559, 536, 515, 494, 475, 456, 437, 418,
196  399, 380, 362, 344, 328, 312, 297, 283, 270, 257,
197  245, 233, 222, 211, 201, 191, 181, 172, 163, 155,
198  147, 139, 132, 125, 119, 113, 107, 101, 96, 91,
199  86, 81, 76, 71, 66, 62, 58, 54, 50, 46,
200  43, 40, 37, 34, 31, 28, 26, 24, 22, 20,
201  18, 16, 14, 12, 10, 8, 6, 5, 4, 3,
202  2, 1, 0
203  },
204  {
205  16384, 16159, 15934, 15709, 15485, 15261, 15038, 14816, 14594, 14373,
206  14152, 13933, 13714, 13497, 13280, 13065, 12850, 12636, 12422, 12211,
207  12000, 11791, 11583, 11378, 11173, 10971, 10769, 10571, 10373, 10179,
208  9985, 9793, 9601, 9409, 9217, 9029, 8842, 8658, 8475, 8297,
209  8120, 7946, 7773, 7604, 7435, 7271, 7108, 6950, 6792, 6634,
210  6477, 6326, 6175, 6029, 5883, 5742, 5602, 5466, 5330, 5199,
211  5068, 4943, 4818, 4696, 4574, 4452, 4330, 4211, 4093, 3979,
212  3866, 3759, 3652, 3549, 3446, 3348, 3250, 3157, 3065, 2977,
213  2889, 2802, 2716, 2634, 2553, 2476, 2399, 2326, 2254, 2185,
214  2117, 2052, 1987, 1926, 1866, 1808, 1750, 1692, 1634, 1578,
215  1522, 1470, 1418, 1369, 1321, 1275, 1229, 1187, 1145, 1105,
216  1066, 1027, 991, 955, 919, 883, 850, 817, 786, 756,
217  728, 700, 674, 648, 624, 600, 578, 556, 534, 512,
218  490, 468, 447, 426, 407, 388, 371, 354, 338, 322,
219  307, 293, 280, 267, 255, 243, 231, 219, 209, 199,
220  189, 179, 170, 161, 153, 145, 138, 131, 124, 117,
221  111, 105, 99, 93, 87, 81, 76, 71, 66, 61,
222  57, 53, 49, 45, 42, 39, 36, 33, 30, 27,
223  24, 21, 19, 17, 15, 13, 11, 9, 7, 5,
224  3, 1, 0
225  },
226  {
227  16384, 16169, 15954, 15739, 15524, 15310, 15096, 14883, 14670, 14458,
228  14246, 14035, 13824, 13614, 13405, 13198, 12991, 12785, 12579, 12376,
229  12173, 11972, 11772, 11574, 11377, 11182, 10987, 10795, 10603, 10414,
230  10226, 10040, 9854, 9668, 9482, 9299, 9116, 8937, 8759, 8585,
231  8411, 8241, 8071, 7906, 7741, 7580, 7419, 7263, 7107, 6952,
232  6797, 6647, 6497, 6353, 6209, 6070, 5931, 5796, 5661, 5531,
233  5401, 5275, 5150, 5027, 4904, 4781, 4658, 4538, 4419, 4304,
234  4190, 4081, 3972, 3867, 3762, 3662, 3562, 3467, 3372, 3281,
235  3191, 3101, 3012, 2928, 2844, 2764, 2684, 2608, 2533, 2460,
236  2387, 2318, 2250, 2185, 2121, 2059, 1997, 1935, 1873, 1813,
237  1754, 1698, 1642, 1588, 1535, 1483, 1433, 1384, 1338, 1292,
238  1249, 1206, 1165, 1125, 1085, 1045, 1008, 971, 937, 903,
239  871, 840, 810, 780, 752, 724, 698, 672, 647, 622,
240  597, 572, 548, 524, 502, 480, 460, 440, 421, 403,
241  386, 369, 353, 337, 323, 309, 295, 281, 268, 255,
242  243, 231, 220, 209, 199, 189, 180, 171, 163, 155,
243  147, 139, 131, 123, 116, 109, 102, 95, 89, 83,
244  77, 72, 67, 62, 57, 52, 48, 44, 40, 36,
245  32, 28, 25, 22, 19, 16, 13, 10, 8, 6,
246  4, 2, 0
247  },
248  {
249  16384, 16177, 15970, 15764, 15558, 15353, 15148, 14944, 14740, 14537,
250  14334, 14132, 13930, 13729, 13529, 13330, 13131, 12933, 12735, 12539,
251  12343, 12150, 11957, 11766, 11576, 11388, 11200, 11015, 10830, 10647,
252  10465, 10285, 10105, 9925, 9745, 9568, 9391, 9218, 9045, 8876,
253  8707, 8541, 8375, 8213, 8051, 7894, 7737, 7583, 7429, 7277,
254  7125, 6977, 6830, 6687, 6544, 6406, 6268, 6133, 5998, 5868,
255  5738, 5612, 5487, 5364, 5241, 5118, 4995, 4875, 4755, 4640,
256  4525, 4414, 4304, 4198, 4092, 3990, 3888, 3790, 3693, 3600,
257  3507, 3415, 3323, 3235, 3147, 3064, 2981, 2902, 2823, 2746,
258  2670, 2594, 2522, 2450, 2382, 2314, 2248, 2182, 2116, 2050,
259  1987, 1924, 1864, 1804, 1748, 1692, 1638, 1585, 1534, 1484,
260  1437, 1390, 1346, 1302, 1258, 1215, 1174, 1133, 1095, 1057,
261  1021, 986, 952, 918, 887, 856, 827, 798, 770, 742,
262  714, 686, 659, 632, 607, 582, 559, 536, 514, 492,
263  472, 452, 433, 415, 398, 381, 364, 348, 333, 318,
264  304, 290, 277, 264, 252, 240, 229, 218, 208, 198,
265  188, 178, 168, 158, 149, 140, 132, 124, 116, 108,
266  101, 94, 87, 81, 75, 69, 64, 59, 54, 49,
267  44, 39, 35, 31, 27, 23, 19, 15, 12, 9,
268  6, 3, 0
269  }
270 };
271 
272 
273 static const uint16_t cf_tables_3[5][257] = {
274  {
275  16384, 16187, 15990, 15793, 15597, 15401, 15205, 15009, 14813, 14618,
276  14423, 14230, 14037, 13845, 13653, 13463, 13273, 13083, 12894, 12706,
277  12518, 12332, 12146, 11962, 11778, 11597, 11416, 11237, 11059, 10882,
278  10706, 10532, 10358, 10184, 10010, 9838, 9666, 9497, 9328, 9163,
279  8999, 8837, 8675, 8517, 8359, 8205, 8051, 7901, 7751, 7602,
280  7453, 7308, 7163, 7022, 6882, 6745, 6609, 6476, 6343, 6214,
281  6085, 5960, 5835, 5712, 5589, 5466, 5343, 5223, 5103, 4987,
282  4872, 4761, 4650, 4542, 4435, 4332, 4229, 4130, 4031, 3936,
283  3841, 3747, 3653, 3563, 3473, 3387, 3302, 3220, 3138, 3059,
284  2980, 2905, 2830, 2759, 2688, 2619, 2550, 2481, 2412, 2345,
285  2278, 2215, 2152, 2092, 2032, 1974, 1917, 1863, 1809, 1758,
286  1707, 1659, 1611, 1564, 1517, 1473, 1429, 1387, 1346, 1307,
287  1268, 1230, 1193, 1158, 1123, 1090, 1058, 1026, 994, 962,
288  930, 899, 869, 841, 813, 786, 760, 735, 710, 687,
289  664, 643, 622, 602, 582, 562, 543, 525, 507, 490,
290  473, 457, 442, 427, 412, 398, 385, 373, 361, 349,
291  337, 325, 313, 301, 290, 279, 269, 259, 249, 240,
292  231, 222, 214, 206, 199, 192, 185, 178, 171, 165,
293  159, 153, 148, 143, 138, 133, 128, 123, 119, 115,
294  111, 107, 103, 99, 95, 91, 87, 83, 80, 77,
295  74, 71, 68, 65, 63, 61, 59, 57, 55, 53,
296  51, 49, 47, 45, 43, 41, 40, 39, 38, 37,
297  36, 35, 34, 33, 32, 31, 30, 29, 28, 27,
298  26, 25, 24, 23, 22, 21, 20, 19, 18, 17,
299  16, 15, 14, 13, 12, 11, 10, 9, 8, 7,
300  6, 5, 4, 3, 2, 1, 0
301  },
302  {
303  16384, 16195, 16006, 15817, 15629, 15441, 15253, 15065, 14878, 14692,
304  14506, 14321, 14136, 13952, 13768, 13585, 13402, 13219, 13037, 12857,
305  12677, 12499, 12321, 12144, 11967, 11792, 11617, 11444, 11271, 11100,
306  10930, 10762, 10594, 10426, 10258, 10091, 9925, 9761, 9598, 9438,
307  9278, 9120, 8963, 8809, 8655, 8504, 8354, 8207, 8060, 7914,
308  7769, 7627, 7485, 7347, 7209, 7074, 6939, 6807, 6676, 6548,
309  6420, 6296, 6172, 6050, 5928, 5806, 5684, 5564, 5444, 5328,
310  5212, 5100, 4988, 4879, 4771, 4667, 4563, 4462, 4362, 4265,
311  4169, 4073, 3978, 3886, 3795, 3707, 3619, 3535, 3451, 3369,
312  3288, 3210, 3133, 3059, 2985, 2913, 2841, 2769, 2697, 2627,
313  2557, 2490, 2424, 2360, 2297, 2237, 2177, 2119, 2062, 2007,
314  1953, 1901, 1849, 1798, 1748, 1700, 1652, 1607, 1562, 1519,
315  1476, 1435, 1394, 1355, 1317, 1281, 1245, 1210, 1175, 1140,
316  1105, 1071, 1037, 1005, 973, 943, 913, 885, 857, 830,
317  804, 779, 754, 731, 708, 685, 663, 642, 621, 601,
318  581, 563, 545, 528, 511, 495, 479, 463, 448, 433,
319  419, 405, 391, 377, 364, 351, 338, 326, 314, 302,
320  291, 280, 270, 260, 251, 242, 234, 226, 218, 210,
321  202, 195, 188, 181, 174, 168, 162, 156, 150, 144,
322  139, 134, 129, 124, 119, 114, 109, 104, 100, 96,
323  92, 88, 84, 80, 77, 74, 71, 68, 65, 62,
324  59, 56, 54, 52, 50, 48, 46, 44, 42, 40,
325  38, 36, 34, 33, 32, 31, 30, 29, 28, 27,
326  26, 25, 24, 23, 22, 21, 20, 19, 18, 17,
327  16, 15, 14, 13, 12, 11, 10, 9, 8, 7,
328  6, 5, 4, 3, 2, 1, 0
329  },
330  {
331  16384, 16203, 16022, 15842, 15662, 15482, 15302, 15122, 14942, 14763,
332  14584, 14406, 14228, 14051, 13874, 13698, 13522, 13347, 13172, 12998,
333  12824, 12652, 12480, 12310, 12140, 11971, 11803, 11637, 11471, 11307,
334  11143, 10980, 10817, 10654, 10491, 10330, 10169, 10011, 9853, 9697,
335  9542, 9389, 9236, 9086, 8936, 8789, 8642, 8498, 8355, 8212,
336  8070, 7931, 7792, 7656, 7520, 7388, 7256, 7126, 6996, 6870,
337  6744, 6621, 6498, 6377, 6256, 6135, 6014, 5895, 5776, 5660,
338  5545, 5433, 5321, 5212, 5104, 4999, 4895, 4793, 4692, 4594,
339  4496, 4400, 4304, 4211, 4118, 4028, 3939, 3853, 3767, 3684,
340  3601, 3521, 3441, 3364, 3287, 3212, 3137, 3062, 2987, 2915,
341  2843, 2773, 2704, 2638, 2572, 2508, 2445, 2384, 2324, 2266,
342  2208, 2153, 2098, 2044, 1990, 1939, 1888, 1839, 1791, 1745,
343  1699, 1655, 1611, 1569, 1527, 1487, 1448, 1409, 1370, 1331,
344  1292, 1255, 1218, 1183, 1148, 1115, 1082, 1051, 1020, 990,
345  960, 932, 904, 878, 852, 826, 801, 777, 753, 731,
346  709, 687, 666, 645, 625, 605, 586, 567, 550, 533,
347  516, 499, 482, 465, 449, 433, 418, 403, 389, 375,
348  362, 349, 337, 325, 314, 303, 293, 283, 273, 263,
349  254, 245, 236, 227, 219, 211, 204, 197, 190, 183,
350  177, 171, 165, 159, 153, 147, 141, 135, 130, 125,
351  120, 115, 110, 105, 101, 97, 93, 89, 85, 81,
352  77, 74, 71, 68, 65, 62, 59, 56, 53, 51,
353  49, 47, 45, 43, 41, 39, 37, 35, 33, 31,
354  29, 27, 25, 23, 22, 21, 20, 19, 18, 17,
355  16, 15, 14, 13, 12, 11, 10, 9, 8, 7,
356  6, 5, 4, 3, 2, 1, 0
357  },
358  {
359  16384, 16210, 16036, 15863, 15690, 15517, 15344, 15172, 15000, 14828,
360  14656, 14485, 14314, 14145, 13976, 13808, 13640, 13472, 13304, 13137,
361  12970, 12804, 12639, 12475, 12312, 12149, 11987, 11827, 11667, 11508,
362  11349, 11192, 11035, 10878, 10721, 10565, 10410, 10257, 10104, 9953,
363  9802, 9654, 9506, 9359, 9213, 9070, 8927, 8787, 8647, 8508,
364  8369, 8233, 8097, 7964, 7831, 7700, 7570, 7442, 7315, 7190,
365  7065, 6943, 6821, 6701, 6581, 6461, 6341, 6223, 6105, 5990,
366  5876, 5764, 5653, 5545, 5437, 5331, 5226, 5124, 5022, 4924,
367  4826, 4729, 4632, 4538, 4444, 4353, 4262, 4174, 4087, 4002,
368  3917, 3835, 3753, 3674, 3595, 3518, 3441, 3364, 3287, 3212,
369  3138, 3066, 2995, 2926, 2858, 2792, 2726, 2662, 2599, 2538,
370  2478, 2420, 2362, 2305, 2249, 2195, 2141, 2089, 2037, 1988,
371  1939, 1891, 1844, 1799, 1754, 1711, 1668, 1626, 1584, 1542,
372  1500, 1459, 1418, 1380, 1342, 1305, 1269, 1234, 1199, 1166,
373  1133, 1102, 1071, 1041, 1012, 983, 954, 926, 899, 872,
374  847, 822, 798, 774, 751, 728, 707, 686, 666, 646,
375  627, 608, 589, 570, 552, 534, 517, 500, 484, 468,
376  453, 438, 424, 410, 397, 384, 372, 360, 348, 336,
377  325, 314, 303, 293, 283, 273, 264, 255, 246, 237,
378  229, 221, 213, 205, 197, 189, 181, 174, 167, 160,
379  154, 148, 142, 136, 131, 126, 121, 116, 111, 106,
380  101, 97, 93, 89, 85, 81, 77, 73, 70, 67,
381  64, 61, 58, 55, 52, 49, 46, 43, 40, 37,
382  35, 33, 31, 29, 27, 25, 23, 21, 19, 17,
383  16, 15, 14, 13, 12, 11, 10, 9, 8, 7,
384  6, 5, 4, 3, 2, 1, 0
385  },
386  {
387  16384, 16218, 16052, 15886, 15720, 15554, 15389, 15224, 15059, 14895,
388  14731, 14567, 14403, 14240, 14077, 13915, 13753, 13591, 13429, 13269,
389  13109, 12950, 12791, 12633, 12476, 12320, 12164, 12009, 11854, 11701,
390  11548, 11396, 11244, 11092, 10940, 10790, 10640, 10492, 10344, 10198,
391  10052, 9908, 9764, 9622, 9481, 9342, 9203, 9066, 8929, 8793,
392  8657, 8524, 8391, 8261, 8131, 8003, 7875, 7749, 7624, 7502,
393  7380, 7260, 7140, 7022, 6904, 6786, 6668, 6551, 6435, 6322,
394  6209, 6099, 5989, 5881, 5773, 5668, 5563, 5461, 5359, 5260,
395  5161, 5063, 4965, 4871, 4777, 4686, 4595, 4506, 4417, 4331,
396  4245, 4162, 4079, 3999, 3919, 3841, 3763, 3685, 3607, 3530,
397  3454, 3380, 3307, 3236, 3166, 3097, 3029, 2963, 2897, 2834,
398  2771, 2710, 2650, 2591, 2532, 2475, 2418, 2363, 2309, 2257,
399  2205, 2155, 2105, 2057, 2009, 1963, 1918, 1873, 1828, 1783,
400  1738, 1694, 1650, 1607, 1565, 1524, 1484, 1445, 1407, 1369,
401  1333, 1297, 1263, 1229, 1197, 1165, 1134, 1103, 1073, 1043,
402  1015, 987, 960, 933, 907, 882, 858, 834, 811, 788,
403  766, 744, 722, 700, 679, 658, 638, 618, 599, 581,
404  563, 545, 528, 511, 495, 480, 465, 451, 437, 423,
405  410, 397, 384, 372, 360, 348, 337, 326, 315, 305,
406  295, 285, 275, 265, 255, 245, 236, 227, 219, 211,
407  203, 195, 188, 181, 174, 167, 161, 155, 149, 143,
408  137, 131, 126, 121, 116, 111, 106, 101, 97, 93,
409  89, 85, 81, 77, 73, 69, 65, 61, 58, 55,
410  52, 49, 46, 43, 40, 37, 34, 32, 30, 28,
411  26, 24, 22, 20, 18, 16, 14, 12, 10, 8,
412  6, 5, 4, 3, 2, 1, 0
413  }
414 };
415 
416 
417 static const uint16_t *const cf_table[16] = {
418  cf_tables_1[0], cf_tables_1[1], cf_tables_1[2], cf_tables_2[0],
419  cf_tables_2[1], cf_tables_2[2], cf_tables_2[3], cf_tables_2[4],
420  cf_tables_2[5], cf_tables_2[6], cf_tables_2[7], cf_tables_3[0],
421  cf_tables_3[1], cf_tables_3[2], cf_tables_3[3], cf_tables_3[4]
422 };
423 
424 
425 /** Initialize a given lookup table using a given delta */
426 static void bgmc_lut_fillp(uint8_t *lut, int *lut_status, int delta)
427 {
428  unsigned int sx, i;
429 
430  for (sx = 0; sx < 16; sx++)
431  for (i = 0; i < LUT_SIZE; i++) {
432  unsigned int target = (i + 1) << (FREQ_BITS - LUT_BITS);
433  unsigned int symbol = 1 << delta;
434 
435  while (cf_table[sx][symbol] > target)
436  symbol += 1 << delta;
437 
438  *lut++ = symbol >> delta;
439  }
440 
441  *lut_status = delta;
442 }
443 
444 
445 /** Retune the index of a suitable lookup table for a given delta */
446 static uint8_t *bgmc_lut_getp(uint8_t *lut, int *lut_status, int delta)
447 {
448  unsigned int i = av_clip(delta, 0, LUT_BUFF - 1);
449 
450  lut += (i * LUT_SIZE) << 4;
451 
452  if (lut_status[i] != delta)
453  bgmc_lut_fillp(lut, &lut_status[i], delta);
454 
455  return lut;
456 }
457 
458 
459 /** Initialize the lookup table arrays */
460 av_cold int ff_bgmc_init(AVCodecContext *avctx,
461  uint8_t **cf_lut, int **cf_lut_status)
462 {
463  *cf_lut = av_malloc(sizeof(**cf_lut) * LUT_BUFF * 16 * LUT_SIZE);
464  *cf_lut_status = av_malloc(sizeof(**cf_lut_status) * LUT_BUFF);
465 
466  if (!*cf_lut || !*cf_lut_status) {
467  ff_bgmc_end(cf_lut, cf_lut_status);
468  av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
469  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  return 0;
476 }
477 
478 
479 /** Release the lookup table arrays */
480 av_cold void ff_bgmc_end(uint8_t **cf_lut, int **cf_lut_status)
481 {
482  av_freep(cf_lut);
483  av_freep(cf_lut_status);
484 }
485 
486 
487 /** Initialize decoding and reads the first value */
488 void ff_bgmc_decode_init(GetBitContext *gb, unsigned int *h,
489  unsigned int *l, unsigned int *v)
490 {
491  *h = TOP_VALUE;
492  *l = 0;
493  *v = get_bits_long(gb, VALUE_BITS);
494 }
495 
496 
497 /** Finish decoding */
498 void ff_bgmc_decode_end(GetBitContext *gb)
499 {
500  skip_bits_long(gb, -(VALUE_BITS - 2));
501 }
502 
503 
504 /** Read and decode a block Gilbert-Moore coded symbol */
505 void ff_bgmc_decode(GetBitContext *gb, unsigned int num, int32_t *dst,
506  int delta, unsigned int sx,
507  unsigned int *h, unsigned int *l, unsigned int *v,
508  uint8_t *cf_lut, int *cf_lut_status)
509 {
510  unsigned int i;
511  uint8_t *lut = bgmc_lut_getp(cf_lut, cf_lut_status, delta);
512 
513  // read current state
514  unsigned int high = *h;
515  unsigned int low = *l;
516  unsigned int value = *v;
517 
518  lut += sx * LUT_SIZE;
519 
520  // decode num samples
521  for (i = 0; i < num; i++) {
522  unsigned int range = high - low + 1;
523  unsigned int target = (((value - low + 1) << FREQ_BITS) - 1) / range;
524  unsigned int symbol = lut[target >> (FREQ_BITS - LUT_BITS)] << delta;
525 
526  while (cf_table[sx][symbol] > target)
527  symbol += 1 << delta;
528 
529  symbol = (symbol >> delta) - 1;
530 
531  high = low + ((range * cf_table[sx][(symbol) << delta] - (1 << FREQ_BITS)) >> FREQ_BITS);
532  low = low + ((range * cf_table[sx][(symbol + 1) << delta]) >> FREQ_BITS);
533 
534  while (1) {
535  if (high >= HALF) {
536  if (low >= HALF) {
537  value -= HALF;
538  low -= HALF;
539  high -= HALF;
540  } else if (low >= FIRST_QTR && high < THIRD_QTR) {
541  value -= FIRST_QTR;
542  low -= FIRST_QTR;
543  high -= FIRST_QTR;
544  } else
545  break;
546  }
547 
548  low *= 2;
549  high = 2 * high + 1;
550  value = 2 * value + get_bits1(gb);
551  }
552 
553  *dst++ = symbol;
554  }
555 
556  // save current state
557  *h = high;
558  *l = low;
559  *v = value;
560 }
Generated on Sun Mar 23 2014 23:49:52 for FFmpeg by   doxygen 1.8.2