aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/alsdec.c
blob: fd2f6f022f83a25c20d02f07c2c743c6901c140a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
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
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
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
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
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
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
/*
 * MPEG-4 ALS decoder
 * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ mail.de>
 *
 * 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
 */

/**
 * @file
 * MPEG-4 ALS decoder
 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
 */

#include <inttypes.h>

#include "avcodec.h"
#include "get_bits.h"
#include "unary.h"
#include "mpeg4audio.h"
#include "bgmc.h"
#include "bswapdsp.h"
#include "internal.h"
#include "mlz.h"
#include "libavutil/samplefmt.h"
#include "libavutil/crc.h"
#include "libavutil/softfloat_ieee754.h"
#include "libavutil/intfloat.h"
#include "libavutil/intreadwrite.h"

#include <stdint.h>

/** Rice parameters and corresponding index offsets for decoding the
 *  indices of scaled PARCOR values. The table chosen is set globally
 *  by the encoder and stored in ALSSpecificConfig.
 */
static const int8_t parcor_rice_table[3][20][2] = {
    { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
      { 12, 3}, { -7, 3}, {  9, 3}, { -5, 3}, {  6, 3},
      { -4, 3}, {  3, 3}, { -3, 2}, {  3, 2}, { -2, 2},
      {  3, 2}, { -1, 2}, {  2, 2}, { -1, 2}, {  2, 2} },
    { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
      { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
      {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
      {  7, 3}, { -4, 4}, {  3, 3}, { -1, 3}, {  1, 3} },
    { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
      { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
      {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
      {  3, 3}, {  0, 3}, { -1, 3}, {  2, 3}, { -1, 2} }
};


/** Scaled PARCOR values used for the first two PARCOR coefficients.
 *  To be indexed by the Rice coded indices.
 *  Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
 *  Actual values are divided by 32 in order to be stored in 16 bits.
 */
static const int16_t parcor_scaled_values[] = {
    -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
    -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
    -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
    -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
    -1013728 / 32, -1009376 / 32, -1004768 / 32,  -999904 / 32,
     -994784 / 32,  -989408 / 32,  -983776 / 32,  -977888 / 32,
     -971744 / 32,  -965344 / 32,  -958688 / 32,  -951776 / 32,
     -944608 / 32,  -937184 / 32,  -929504 / 32,  -921568 / 32,
     -913376 / 32,  -904928 / 32,  -896224 / 32,  -887264 / 32,
     -878048 / 32,  -868576 / 32,  -858848 / 32,  -848864 / 32,
     -838624 / 32,  -828128 / 32,  -817376 / 32,  -806368 / 32,
     -795104 / 32,  -783584 / 32,  -771808 / 32,  -759776 / 32,
     -747488 / 32,  -734944 / 32,  -722144 / 32,  -709088 / 32,
     -695776 / 32,  -682208 / 32,  -668384 / 32,  -654304 / 32,
     -639968 / 32,  -625376 / 32,  -610528 / 32,  -595424 / 32,
     -580064 / 32,  -564448 / 32,  -548576 / 32,  -532448 / 32,
     -516064 / 32,  -499424 / 32,  -482528 / 32,  -465376 / 32,
     -447968 / 32,  -430304 / 32,  -412384 / 32,  -394208 / 32,
     -375776 / 32,  -357088 / 32,  -338144 / 32,  -318944 / 32,
     -299488 / 32,  -279776 / 32,  -259808 / 32,  -239584 / 32,
     -219104 / 32,  -198368 / 32,  -177376 / 32,  -156128 / 32,
     -134624 / 32,  -112864 / 32,   -90848 / 32,   -68576 / 32,
      -46048 / 32,   -23264 / 32,     -224 / 32,    23072 / 32,
       46624 / 32,    70432 / 32,    94496 / 32,   118816 / 32,
      143392 / 32,   168224 / 32,   193312 / 32,   218656 / 32,
      244256 / 32,   270112 / 32,   296224 / 32,   322592 / 32,
      349216 / 32,   376096 / 32,   403232 / 32,   430624 / 32,
      458272 / 32,   486176 / 32,   514336 / 32,   542752 / 32,
      571424 / 32,   600352 / 32,   629536 / 32,   658976 / 32,
      688672 / 32,   718624 / 32,   748832 / 32,   779296 / 32,
      810016 / 32,   840992 / 32,   872224 / 32,   903712 / 32,
      935456 / 32,   967456 / 32,   999712 / 32,  1032224 / 32
};


/** Gain values of p(0) for long-term prediction.
 *  To be indexed by the Rice coded indices.
 */
static const uint8_t ltp_gain_values [4][4] = {
    { 0,  8, 16,  24},
    {32, 40, 48,  56},
    {64, 70, 76,  82},
    {88, 92, 96, 100}
};


/** Inter-channel weighting factors for multi-channel correlation.
 *  To be indexed by the Rice coded indices.
 */
static const int16_t mcc_weightings[] = {
    204,  192,  179,  166,  153,  140,  128,  115,
    102,   89,   76,   64,   51,   38,   25,   12,
      0,  -12,  -25,  -38,  -51,  -64,  -76,  -89,
   -102, -115, -128, -140, -153, -166, -179, -192
};


/** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
 */
static const uint8_t tail_code[16][6] = {
    { 74, 44, 25, 13,  7, 3},
    { 68, 42, 24, 13,  7, 3},
    { 58, 39, 23, 13,  7, 3},
    {126, 70, 37, 19, 10, 5},
    {132, 70, 37, 20, 10, 5},
    {124, 70, 38, 20, 10, 5},
    {120, 69, 37, 20, 11, 5},
    {116, 67, 37, 20, 11, 5},
    {108, 66, 36, 20, 10, 5},
    {102, 62, 36, 20, 10, 5},
    { 88, 58, 34, 19, 10, 5},
    {162, 89, 49, 25, 13, 7},
    {156, 87, 49, 26, 14, 7},
    {150, 86, 47, 26, 14, 7},
    {142, 84, 47, 26, 14, 7},
    {131, 79, 46, 26, 14, 7}
};


enum RA_Flag {
    RA_FLAG_NONE,
    RA_FLAG_FRAMES,
    RA_FLAG_HEADER
};


typedef struct ALSSpecificConfig {
    uint32_t samples;         ///< number of samples, 0xFFFFFFFF if unknown
    int resolution;           ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
    int floating;             ///< 1 = IEEE 32-bit floating-point, 0 = integer
    int msb_first;            ///< 1 = original CRC calculated on big-endian system, 0 = little-endian
    int frame_length;         ///< frame length for each frame (last frame may differ)
    int ra_distance;          ///< distance between RA frames (in frames, 0...255)
    enum RA_Flag ra_flag;     ///< indicates where the size of ra units is stored
    int adapt_order;          ///< adaptive order: 1 = on, 0 = off
    int coef_table;           ///< table index of Rice code parameters
    int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
    int max_order;            ///< maximum prediction order (0..1023)
    int block_switching;      ///< number of block switching levels
    int bgmc;                 ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
    int sb_part;              ///< sub-block partition
    int joint_stereo;         ///< joint stereo: 1 = on, 0 = off
    int mc_coding;            ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
    int chan_config;          ///< indicates that a chan_config_info field is present
    int chan_sort;            ///< channel rearrangement: 1 = on, 0 = off
    int rlslms;               ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
    int chan_config_info;     ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
    int *chan_pos;            ///< original channel positions
    int crc_enabled;          ///< enable Cyclic Redundancy Checksum
} ALSSpecificConfig;


typedef struct ALSChannelData {
    int stop_flag;
    int master_channel;
    int time_diff_flag;
    int time_diff_sign;
    int time_diff_index;
    int weighting[6];
} ALSChannelData;


typedef struct ALSDecContext {
    AVCodecContext *avctx;
    ALSSpecificConfig sconf;
    GetBitContext gb;
    BswapDSPContext bdsp;
    const AVCRC *crc_table;
    uint32_t crc_org;               ///< CRC value of the original input data
    uint32_t crc;                   ///< CRC value calculated from decoded data
    unsigned int cur_frame_length;  ///< length of the current frame to decode
    unsigned int frame_id;          ///< the frame ID / number of the current frame
    unsigned int js_switch;         ///< if true, joint-stereo decoding is enforced
    unsigned int cs_switch;         ///< if true, channel rearrangement is done
    unsigned int num_blocks;        ///< number of blocks used in the current frame
    unsigned int s_max;             ///< maximum Rice parameter allowed in entropy coding
    uint8_t *bgmc_lut;              ///< pointer at lookup tables used for BGMC
    int *bgmc_lut_status;           ///< pointer at lookup table status flags used for BGMC
    int ltp_lag_length;             ///< number of bits used for ltp lag value
    int *const_block;               ///< contains const_block flags for all channels
    unsigned int *shift_lsbs;       ///< contains shift_lsbs flags for all channels
    unsigned int *opt_order;        ///< contains opt_order flags for all channels
    int *store_prev_samples;        ///< contains store_prev_samples flags for all channels
    int *use_ltp;                   ///< contains use_ltp flags for all channels
    int *ltp_lag;                   ///< contains ltp lag values for all channels
    int **ltp_gain;                 ///< gain values for ltp 5-tap filter for a channel
    int *ltp_gain_buffer;           ///< contains all gain values for ltp 5-tap filter
    int32_t **quant_cof;            ///< quantized parcor coefficients for a channel
    int32_t *quant_cof_buffer;      ///< contains all quantized parcor coefficients
    int32_t **lpc_cof;              ///< coefficients of the direct form prediction filter for a channel
    int32_t *lpc_cof_buffer;        ///< contains all coefficients of the direct form prediction filter
    int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
    ALSChannelData **chan_data;     ///< channel data for multi-channel correlation
    ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
    int *reverted_channels;         ///< stores a flag for each reverted channel
    int32_t *prev_raw_samples;      ///< contains unshifted raw samples from the previous block
    int32_t **raw_samples;          ///< decoded raw samples for each channel
    int32_t *raw_buffer;            ///< contains all decoded raw samples including carryover samples
    uint8_t *crc_buffer;            ///< buffer of byte order corrected samples used for CRC check
    MLZ* mlz;                       ///< masked lz decompression structure
    SoftFloat_IEEE754 *acf;         ///< contains common multiplier for all channels
    int *last_acf_mantissa;         ///< contains the last acf mantissa data of common multiplier for all channels
    int *shift_value;               ///< value by which the binary point is to be shifted for all channels
    int *last_shift_value;          ///< contains last shift value for all channels
    int **raw_mantissa;             ///< decoded mantissa bits of the difference signal
    unsigned char *larray;          ///< buffer to store the output of masked lz decompression
    int *nbits;                     ///< contains the number of bits to read for masked lz decompression for all samples
    int highest_decoded_channel;
} ALSDecContext;


typedef struct ALSBlockData {
    unsigned int block_length;      ///< number of samples within the block
    unsigned int ra_block;          ///< if true, this is a random access block
    int          *const_block;      ///< if true, this is a constant value block
    int          js_blocks;         ///< true if this block contains a difference signal
    unsigned int *shift_lsbs;       ///< shift of values for this block
    unsigned int *opt_order;        ///< prediction order of this block
    int          *store_prev_samples;///< if true, carryover samples have to be stored
    int          *use_ltp;          ///< if true, long-term prediction is used
    int          *ltp_lag;          ///< lag value for long-term prediction
    int          *ltp_gain;         ///< gain values for ltp 5-tap filter
    int32_t      *quant_cof;        ///< quantized parcor coefficients
    int32_t      *lpc_cof;          ///< coefficients of the direct form prediction
    int32_t      *raw_samples;      ///< decoded raw samples / residuals for this block
    int32_t      *prev_raw_samples; ///< contains unshifted raw samples from the previous block
    int32_t      *raw_other;        ///< decoded raw samples of the other channel of a channel pair
} ALSBlockData;


static av_cold void dprint_specific_config(ALSDecContext *ctx)
{
#ifdef DEBUG
    AVCodecContext *avctx    = ctx->avctx;
    ALSSpecificConfig *sconf = &ctx->sconf;

    ff_dlog(avctx, "resolution = %i\n",           sconf->resolution);
    ff_dlog(avctx, "floating = %i\n",             sconf->floating);
    ff_dlog(avctx, "frame_length = %i\n",         sconf->frame_length);
    ff_dlog(avctx, "ra_distance = %i\n",          sconf->ra_distance);
    ff_dlog(avctx, "ra_flag = %i\n",              sconf->ra_flag);
    ff_dlog(avctx, "adapt_order = %i\n",          sconf->adapt_order);
    ff_dlog(avctx, "coef_table = %i\n",           sconf->coef_table);
    ff_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
    ff_dlog(avctx, "max_order = %i\n",            sconf->max_order);
    ff_dlog(avctx, "block_switching = %i\n",      sconf->block_switching);
    ff_dlog(avctx, "bgmc = %i\n",                 sconf->bgmc);
    ff_dlog(avctx, "sb_part = %i\n",              sconf->sb_part);
    ff_dlog(avctx, "joint_stereo = %i\n",         sconf->joint_stereo);
    ff_dlog(avctx, "mc_coding = %i\n",            sconf->mc_coding);
    ff_dlog(avctx, "chan_config = %i\n",          sconf->chan_config);
    ff_dlog(avctx, "chan_sort = %i\n",            sconf->chan_sort);
    ff_dlog(avctx, "RLSLMS = %i\n",               sconf->rlslms);
    ff_dlog(avctx, "chan_config_info = %i\n",     sconf->chan_config_info);
#endif
}


/** Read an ALSSpecificConfig from a buffer into the output struct.
 */
static av_cold int read_specific_config(ALSDecContext *ctx)
{
    GetBitContext gb;
    uint64_t ht_size;
    int i, config_offset;
    MPEG4AudioConfig m4ac = {0};
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    uint32_t als_id, header_size, trailer_size;
    int ret;

    if ((ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size)) < 0)
        return ret;

    config_offset = avpriv_mpeg4audio_get_config2(&m4ac, avctx->extradata,
                                                  avctx->extradata_size, 1, avctx);

    if (config_offset < 0)
        return AVERROR_INVALIDDATA;

    skip_bits_long(&gb, config_offset);

    if (get_bits_left(&gb) < (30 << 3))
        return AVERROR_INVALIDDATA;

    // read the fixed items
    als_id                      = get_bits_long(&gb, 32);
    avctx->sample_rate          = m4ac.sample_rate;
    skip_bits_long(&gb, 32); // sample rate already known
    sconf->samples              = get_bits_long(&gb, 32);
    avctx->channels             = m4ac.channels;
    skip_bits(&gb, 16);      // number of channels already known
    skip_bits(&gb, 3);       // skip file_type
    sconf->resolution           = get_bits(&gb, 3);
    sconf->floating             = get_bits1(&gb);
    sconf->msb_first            = get_bits1(&gb);
    sconf->frame_length         = get_bits(&gb, 16) + 1;
    sconf->ra_distance          = get_bits(&gb, 8);
    sconf->ra_flag              = get_bits(&gb, 2);
    sconf->adapt_order          = get_bits1(&gb);
    sconf->coef_table           = get_bits(&gb, 2);
    sconf->long_term_prediction = get_bits1(&gb);
    sconf->max_order            = get_bits(&gb, 10);
    sconf->block_switching      = get_bits(&gb, 2);
    sconf->bgmc                 = get_bits1(&gb);
    sconf->sb_part              = get_bits1(&gb);
    sconf->joint_stereo         = get_bits1(&gb);
    sconf->mc_coding            = get_bits1(&gb);
    sconf->chan_config          = get_bits1(&gb);
    sconf->chan_sort            = get_bits1(&gb);
    sconf->crc_enabled          = get_bits1(&gb);
    sconf->rlslms               = get_bits1(&gb);
    skip_bits(&gb, 5);       // skip 5 reserved bits
    skip_bits1(&gb);         // skip aux_data_enabled


    // check for ALSSpecificConfig struct
    if (als_id != MKBETAG('A','L','S','\0'))
        return AVERROR_INVALIDDATA;

    if (avctx->channels > FF_SANE_NB_CHANNELS) {
        avpriv_request_sample(avctx, "Huge number of channels\n");
        return AVERROR_PATCHWELCOME;
    }

    ctx->cur_frame_length = sconf->frame_length;

    // read channel config
    if (sconf->chan_config)
        sconf->chan_config_info = get_bits(&gb, 16);
    // TODO: use this to set avctx->channel_layout


    // read channel sorting
    if (sconf->chan_sort && avctx->channels > 1) {
        int chan_pos_bits = av_ceil_log2(avctx->channels);
        int bits_needed  = avctx->channels * chan_pos_bits + 7;
        if (get_bits_left(&gb) < bits_needed)
            return AVERROR_INVALIDDATA;

        if (!(sconf->chan_pos = av_malloc_array(avctx->channels, sizeof(*sconf->chan_pos))))
            return AVERROR(ENOMEM);

        ctx->cs_switch = 1;

        for (i = 0; i < avctx->channels; i++) {
            sconf->chan_pos[i] = -1;
        }

        for (i = 0; i < avctx->channels; i++) {
            int idx;

            idx = get_bits(&gb, chan_pos_bits);
            if (idx >= avctx->channels || sconf->chan_pos[idx] != -1) {
                av_log(avctx, AV_LOG_WARNING, "Invalid channel reordering.\n");
                ctx->cs_switch = 0;
                break;
            }
            sconf->chan_pos[idx] = i;
        }

        align_get_bits(&gb);
    }


    // read fixed header and trailer sizes,
    // if size = 0xFFFFFFFF then there is no data field!
    if (get_bits_left(&gb) < 64)
        return AVERROR_INVALIDDATA;

    header_size  = get_bits_long(&gb, 32);
    trailer_size = get_bits_long(&gb, 32);
    if (header_size  == 0xFFFFFFFF)
        header_size  = 0;
    if (trailer_size == 0xFFFFFFFF)
        trailer_size = 0;

    ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;


    // skip the header and trailer data
    if (get_bits_left(&gb) < ht_size)
        return AVERROR_INVALIDDATA;

    if (ht_size > INT32_MAX)
        return AVERROR_PATCHWELCOME;

    skip_bits_long(&gb, ht_size);


    // initialize CRC calculation
    if (sconf->crc_enabled) {
        if (get_bits_left(&gb) < 32)
            return AVERROR_INVALIDDATA;

        if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {
            ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
            ctx->crc       = 0xFFFFFFFF;
            ctx->crc_org   = ~get_bits_long(&gb, 32);
        } else
            skip_bits_long(&gb, 32);
    }


    // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)

    dprint_specific_config(ctx);

    return 0;
}


/** Check the ALSSpecificConfig for unsupported features.
 */
static int check_specific_config(ALSDecContext *ctx)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    int error = 0;

    // report unsupported feature and set error value
    #define MISSING_ERR(cond, str, errval)              \
    {                                                   \
        if (cond) {                                     \
            avpriv_report_missing_feature(ctx->avctx,   \
                                          str);         \
            error = errval;                             \
        }                                               \
    }

    MISSING_ERR(sconf->rlslms,    "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);

    return error;
}


/** Parse the bs_info field to extract the block partitioning used in
 *  block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
 */
static void parse_bs_info(const uint32_t bs_info, unsigned int n,
                          unsigned int div, unsigned int **div_blocks,
                          unsigned int *num_blocks)
{
    if (n < 31 && ((bs_info << n) & 0x40000000)) {
        // if the level is valid and the investigated bit n is set
        // then recursively check both children at bits (2n+1) and (2n+2)
        n   *= 2;
        div += 1;
        parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
        parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
    } else {
        // else the bit is not set or the last level has been reached
        // (bit implicitly not set)
        **div_blocks = div;
        (*div_blocks)++;
        (*num_blocks)++;
    }
}


/** Read and decode a Rice codeword.
 */
static int32_t decode_rice(GetBitContext *gb, unsigned int k)
{
    int max = get_bits_left(gb) - k;
    unsigned q = get_unary(gb, 0, max);
    int r   = k ? get_bits1(gb) : !(q & 1);

    if (k > 1) {
        q <<= (k - 1);
        q  += get_bits_long(gb, k - 1);
    } else if (!k) {
        q >>= 1;
    }
    return r ? q : ~q;
}


/** Convert PARCOR coefficient k to direct filter coefficient.
 */
static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
{
    int i, j;

    for (i = 0, j = k - 1; i < j; i++, j--) {
        unsigned tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
        cof[j]  += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
        cof[i]  += tmp1;
    }
    if (i == j)
        cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

    cof[k] = par[k];
}


/** Read block switching field if necessary and set actual block sizes.
 *  Also assure that the block sizes of the last frame correspond to the
 *  actual number of samples.
 */
static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
                            uint32_t *bs_info)
{
    ALSSpecificConfig *sconf     = &ctx->sconf;
    GetBitContext *gb            = &ctx->gb;
    unsigned int *ptr_div_blocks = div_blocks;
    unsigned int b;

    if (sconf->block_switching) {
        unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
        *bs_info = get_bits_long(gb, bs_info_len);
        *bs_info <<= (32 - bs_info_len);
    }

    ctx->num_blocks = 0;
    parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);

    // The last frame may have an overdetermined block structure given in
    // the bitstream. In that case the defined block structure would need
    // more samples than available to be consistent.
    // The block structure is actually used but the block sizes are adapted
    // to fit the actual number of available samples.
    // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
    // This results in the actual block sizes:    2 2 1 0.
    // This is not specified in 14496-3 but actually done by the reference
    // codec RM22 revision 2.
    // This appears to happen in case of an odd number of samples in the last
    // frame which is actually not allowed by the block length switching part
    // of 14496-3.
    // The ALS conformance files feature an odd number of samples in the last
    // frame.

    for (b = 0; b < ctx->num_blocks; b++)
        div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];

    if (ctx->cur_frame_length != ctx->sconf.frame_length) {
        unsigned int remaining = ctx->cur_frame_length;

        for (b = 0; b < ctx->num_blocks; b++) {
            if (remaining <= div_blocks[b]) {
                div_blocks[b] = remaining;
                ctx->num_blocks = b + 1;
                break;
            }

            remaining -= div_blocks[b];
        }
    }
}


/** Read the block data for a constant block
 */
static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb        = &ctx->gb;

    if (bd->block_length <= 0)
        return AVERROR_INVALIDDATA;

    *bd->raw_samples = 0;
    *bd->const_block = get_bits1(gb);    // 1 = constant value, 0 = zero block (silence)
    bd->js_blocks    = get_bits1(gb);

    // skip 5 reserved bits
    skip_bits(gb, 5);

    if (*bd->const_block) {
        unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
        *bd->raw_samples = get_sbits_long(gb, const_val_bits);
    }

    // ensure constant block decoding by reusing this field
    *bd->const_block = 1;

    return 0;
}


/** Decode the block data for a constant block
 */
static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
    int      smp = bd->block_length - 1;
    int32_t  val = *bd->raw_samples;
    int32_t *dst = bd->raw_samples + 1;

    // write raw samples into buffer
    for (; smp; smp--)
        *dst++ = val;
}


/** Read the block data for a non-constant block
 */
static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb        = &ctx->gb;
    unsigned int k;
    unsigned int s[8];
    unsigned int sx[8];
    unsigned int sub_blocks, log2_sub_blocks, sb_length;
    unsigned int start      = 0;
    unsigned int opt_order;
    int          sb;
    int32_t      *quant_cof = bd->quant_cof;
    int32_t      *current_res;


    // ensure variable block decoding by reusing this field
    *bd->const_block = 0;

    *bd->opt_order  = 1;
    bd->js_blocks   = get_bits1(gb);

    opt_order       = *bd->opt_order;

    // determine the number of subblocks for entropy decoding
    if (!sconf->bgmc && !sconf->sb_part) {
        log2_sub_blocks = 0;
    } else {
        if (sconf->bgmc && sconf->sb_part)
            log2_sub_blocks = get_bits(gb, 2);
        else
            log2_sub_blocks = 2 * get_bits1(gb);
    }

    sub_blocks = 1 << log2_sub_blocks;

    // do not continue in case of a damaged stream since
    // block_length must be evenly divisible by sub_blocks
    if (bd->block_length & (sub_blocks - 1) || bd->block_length <= 0) {
        av_log(avctx, AV_LOG_WARNING,
               "Block length is not evenly divisible by the number of subblocks.\n");
        return AVERROR_INVALIDDATA;
    }

    sb_length = bd->block_length >> log2_sub_blocks;

    if (sconf->bgmc) {
        s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
        for (k = 1; k < sub_blocks; k++)
            s[k] = s[k - 1] + decode_rice(gb, 2);

        for (k = 0; k < sub_blocks; k++) {
            sx[k]   = s[k] & 0x0F;
            s [k] >>= 4;
        }
    } else {
        s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
        for (k = 1; k < sub_blocks; k++)
            s[k] = s[k - 1] + decode_rice(gb, 0);
    }
    for (k = 1; k < sub_blocks; k++)
        if (s[k] > 32) {
            av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
            return AVERROR_INVALIDDATA;
        }

    if (get_bits1(gb))
        *bd->shift_lsbs = get_bits(gb, 4) + 1;

    *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;


    if (!sconf->rlslms) {
        if (sconf->adapt_order && sconf->max_order) {
            int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
                                                2, sconf->max_order + 1));
            *bd->opt_order       = get_bits(gb, opt_order_length);
            if (*bd->opt_order > sconf->max_order) {
                *bd->opt_order = sconf->max_order;
                av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
                return AVERROR_INVALIDDATA;
            }
        } else {
            *bd->opt_order = sconf->max_order;
        }
        opt_order = *bd->opt_order;

        if (opt_order) {
            int add_base;

            if (sconf->coef_table == 3) {
                add_base = 0x7F;

                // read coefficient 0
                quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];

                // read coefficient 1
                if (opt_order > 1)
                    quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];

                // read coefficients 2 to opt_order
                for (k = 2; k < opt_order; k++)
                    quant_cof[k] = get_bits(gb, 7);
            } else {
                int k_max;
                add_base = 1;

                // read coefficient 0 to 19
                k_max = FFMIN(opt_order, 20);
                for (k = 0; k < k_max; k++) {
                    int rice_param = parcor_rice_table[sconf->coef_table][k][1];
                    int offset     = parcor_rice_table[sconf->coef_table][k][0];
                    quant_cof[k] = decode_rice(gb, rice_param) + offset;
                    if (quant_cof[k] < -64 || quant_cof[k] > 63) {
                        av_log(avctx, AV_LOG_ERROR,
                               "quant_cof %"PRId32" is out of range.\n",
                               quant_cof[k]);
                        return AVERROR_INVALIDDATA;
                    }
                }

                // read coefficients 20 to 126
                k_max = FFMIN(opt_order, 127);
                for (; k < k_max; k++)
                    quant_cof[k] = decode_rice(gb, 2) + (k & 1);

                // read coefficients 127 to opt_order
                for (; k < opt_order; k++)
                    quant_cof[k] = decode_rice(gb, 1);

                quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];

                if (opt_order > 1)
                    quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
            }

            for (k = 2; k < opt_order; k++)
                quant_cof[k] = (quant_cof[k] * (1U << 14)) + (add_base << 13);
        }
    }

    // read LTP gain and lag values
    if (sconf->long_term_prediction) {
        *bd->use_ltp = get_bits1(gb);

        if (*bd->use_ltp) {
            int r, c;

            bd->ltp_gain[0]   = decode_rice(gb, 1) * 8;
            bd->ltp_gain[1]   = decode_rice(gb, 2) * 8;

            r                 = get_unary(gb, 0, 4);
            c                 = get_bits(gb, 2);
            if (r >= 4) {
                av_log(avctx, AV_LOG_ERROR, "r overflow\n");
                return AVERROR_INVALIDDATA;
            }

            bd->ltp_gain[2]   = ltp_gain_values[r][c];

            bd->ltp_gain[3]   = decode_rice(gb, 2) * 8;
            bd->ltp_gain[4]   = decode_rice(gb, 1) * 8;

            *bd->ltp_lag      = get_bits(gb, ctx->ltp_lag_length);
            *bd->ltp_lag     += FFMAX(4, opt_order + 1);
        }
    }

    // read first value and residuals in case of a random access block
    if (bd->ra_block) {
        start = FFMIN(opt_order, 3);
        av_assert0(sb_length <= sconf->frame_length);
        if (sb_length <= start) {
            // opt_order or sb_length may be corrupted, either way this is unsupported and not well defined in the specification
            av_log(avctx, AV_LOG_ERROR, "Sub block length smaller or equal start\n");
            return AVERROR_PATCHWELCOME;
        }

        if (opt_order)
            bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
        if (opt_order > 1)
            bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
        if (opt_order > 2)
            bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
    }

    // read all residuals
    if (sconf->bgmc) {
        int          delta[8];
        unsigned int k    [8];
        unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);

        // read most significant bits
        unsigned int high;
        unsigned int low;
        unsigned int value;

        int ret = ff_bgmc_decode_init(gb, &high, &low, &value);
        if (ret < 0)
            return ret;

        current_res = bd->raw_samples + start;

        for (sb = 0; sb < sub_blocks; sb++) {
            unsigned int sb_len  = sb_length - (sb ? 0 : start);

            k    [sb] = s[sb] > b ? s[sb] - b : 0;
            delta[sb] = 5 - s[sb] + k[sb];

            if (k[sb] >= 32)
                return AVERROR_INVALIDDATA;

            ff_bgmc_decode(gb, sb_len, current_res,
                        delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);

            current_res += sb_len;
        }

        ff_bgmc_decode_end(gb);


        // read least significant bits and tails
        current_res = bd->raw_samples + start;

        for (sb = 0; sb < sub_blocks; sb++, start = 0) {
            unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
            unsigned int cur_k         = k[sb];
            unsigned int cur_s         = s[sb];

            for (; start < sb_length; start++) {
                int32_t res = *current_res;

                if (res == cur_tail_code) {
                    unsigned int max_msb =   (2 + (sx[sb] > 2) + (sx[sb] > 10))
                                          << (5 - delta[sb]);

                    res = decode_rice(gb, cur_s);

                    if (res >= 0) {
                        res += (max_msb    ) << cur_k;
                    } else {
                        res -= (max_msb - 1) << cur_k;
                    }
                } else {
                    if (res > cur_tail_code)
                        res--;

                    if (res & 1)
                        res = -res;

                    res >>= 1;

                    if (cur_k) {
                        res  *= 1U << cur_k;
                        res  |= get_bits_long(gb, cur_k);
                    }
                }

                *current_res++ = res;
            }
        }
    } else {
        current_res = bd->raw_samples + start;

        for (sb = 0; sb < sub_blocks; sb++, start = 0)
            for (; start < sb_length; start++)
                *current_res++ = decode_rice(gb, s[sb]);
     }

    return 0;
}


/** Decode the block data for a non-constant block
 */
static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    unsigned int block_length = bd->block_length;
    unsigned int smp = 0;
    unsigned int k;
    int opt_order             = *bd->opt_order;
    int sb;
    int64_t y;
    int32_t *quant_cof        = bd->quant_cof;
    int32_t *lpc_cof          = bd->lpc_cof;
    int32_t *raw_samples      = bd->raw_samples;
    int32_t *raw_samples_end  = bd->raw_samples + bd->block_length;
    int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

    // reverse long-term prediction
    if (*bd->use_ltp) {
        int ltp_smp;

        for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
            int center = ltp_smp - *bd->ltp_lag;
            int begin  = FFMAX(0, center - 2);
            int end    = center + 3;
            int tab    = 5 - (end - begin);
            int base;

            y = 1 << 6;

            for (base = begin; base < end; base++, tab++)
                y += (uint64_t)MUL64(bd->ltp_gain[tab], raw_samples[base]);

            raw_samples[ltp_smp] += y >> 7;
        }
    }

    // reconstruct all samples from residuals
    if (bd->ra_block) {
        for (smp = 0; smp < FFMIN(opt_order, block_length); smp++) {
            y = 1 << 19;

            for (sb = 0; sb < smp; sb++)
                y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);

            *raw_samples++ -= y >> 20;
            parcor_to_lpc(smp, quant_cof, lpc_cof);
        }
    } else {
        for (k = 0; k < opt_order; k++)
            parcor_to_lpc(k, quant_cof, lpc_cof);

        // store previous samples in case that they have to be altered
        if (*bd->store_prev_samples)
            memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
                   sizeof(*bd->prev_raw_samples) * sconf->max_order);

        // reconstruct difference signal for prediction (joint-stereo)
        if (bd->js_blocks && bd->raw_other) {
            uint32_t *left, *right;

            if (bd->raw_other > raw_samples) {  // D = R - L
                left  = raw_samples;
                right = bd->raw_other;
            } else {                                // D = R - L
                left  = bd->raw_other;
                right = raw_samples;
            }

            for (sb = -1; sb >= -sconf->max_order; sb--)
                raw_samples[sb] = right[sb] - left[sb];
        }

        // reconstruct shifted signal
        if (*bd->shift_lsbs)
            for (sb = -1; sb >= -sconf->max_order; sb--)
                raw_samples[sb] >>= *bd->shift_lsbs;
    }

    // reverse linear prediction coefficients for efficiency
    lpc_cof = lpc_cof + opt_order;

    for (sb = 0; sb < opt_order; sb++)
        lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];

    // reconstruct raw samples
    raw_samples = bd->raw_samples + smp;
    lpc_cof     = lpc_cof_reversed + opt_order;

    for (; raw_samples < raw_samples_end; raw_samples++) {
        y = 1 << 19;

        for (sb = -opt_order; sb < 0; sb++)
            y += (uint64_t)MUL64(lpc_cof[sb], raw_samples[sb]);

        *raw_samples -= y >> 20;
    }

    raw_samples = bd->raw_samples;

    // restore previous samples in case that they have been altered
    if (*bd->store_prev_samples)
        memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
               sizeof(*raw_samples) * sconf->max_order);

    return 0;
}


/** Read the block data.
 */
static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    int ret;
    GetBitContext *gb        = &ctx->gb;
    ALSSpecificConfig *sconf = &ctx->sconf;

    *bd->shift_lsbs = 0;

    if (get_bits_left(gb) < 7)
        return AVERROR_INVALIDDATA;

    // read block type flag and read the samples accordingly
    if (get_bits1(gb)) {
        ret = read_var_block_data(ctx, bd);
    } else {
        ret = read_const_block_data(ctx, bd);
    }

    if (!sconf->mc_coding || ctx->js_switch)
        align_get_bits(gb);

    return ret;
}


/** Decode the block data.
 */
static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    unsigned int smp;
    int ret = 0;

    // read block type flag and read the samples accordingly
    if (*bd->const_block)
        decode_const_block_data(ctx, bd);
    else
        ret = decode_var_block_data(ctx, bd); // always return 0

    if (ret < 0)
        return ret;

    // TODO: read RLSLMS extension data

    if (*bd->shift_lsbs)
        for (smp = 0; smp < bd->block_length; smp++)
            bd->raw_samples[smp] = (unsigned)bd->raw_samples[smp] << *bd->shift_lsbs;

    return 0;
}


/** Read and decode block data successively.
 */
static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
{
    int ret;

    if ((ret = read_block(ctx, bd)) < 0)
        return ret;

    return decode_block(ctx, bd);
}


/** Compute the number of samples left to decode for the current frame and
 *  sets these samples to zero.
 */
static void zero_remaining(unsigned int b, unsigned int b_max,
                           const unsigned int *div_blocks, int32_t *buf)
{
    unsigned int count = 0;

    while (b < b_max)
        count += div_blocks[b++];

    if (count)
        memset(buf, 0, sizeof(*buf) * count);
}


/** Decode blocks independently.
 */
static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
                             unsigned int c, const unsigned int *div_blocks,
                             unsigned int *js_blocks)
{
    int ret;
    unsigned int b;
    ALSBlockData bd = { 0 };

    bd.ra_block         = ra_frame;
    bd.const_block      = ctx->const_block;
    bd.shift_lsbs       = ctx->shift_lsbs;
    bd.opt_order        = ctx->opt_order;
    bd.store_prev_samples = ctx->store_prev_samples;
    bd.use_ltp          = ctx->use_ltp;
    bd.ltp_lag          = ctx->ltp_lag;
    bd.ltp_gain         = ctx->ltp_gain[0];
    bd.quant_cof        = ctx->quant_cof[0];
    bd.lpc_cof          = ctx->lpc_cof[0];
    bd.prev_raw_samples = ctx->prev_raw_samples;
    bd.raw_samples      = ctx->raw_samples[c];


    for (b = 0; b < ctx->num_blocks; b++) {
        bd.block_length     = div_blocks[b];

        if ((ret = read_decode_block(ctx, &bd)) < 0) {
            // damaged block, write zero for the rest of the frame
            zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
            return ret;
        }
        bd.raw_samples += div_blocks[b];
        bd.ra_block     = 0;
    }

    return 0;
}


/** Decode blocks dependently.
 */
static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
                         unsigned int c, const unsigned int *div_blocks,
                         unsigned int *js_blocks)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    unsigned int offset = 0;
    unsigned int b;
    int ret;
    ALSBlockData bd[2] = { { 0 } };

    bd[0].ra_block         = ra_frame;
    bd[0].const_block      = ctx->const_block;
    bd[0].shift_lsbs       = ctx->shift_lsbs;
    bd[0].opt_order        = ctx->opt_order;
    bd[0].store_prev_samples = ctx->store_prev_samples;
    bd[0].use_ltp          = ctx->use_ltp;
    bd[0].ltp_lag          = ctx->ltp_lag;
    bd[0].ltp_gain         = ctx->ltp_gain[0];
    bd[0].quant_cof        = ctx->quant_cof[0];
    bd[0].lpc_cof          = ctx->lpc_cof[0];
    bd[0].prev_raw_samples = ctx->prev_raw_samples;
    bd[0].js_blocks        = *js_blocks;

    bd[1].ra_block         = ra_frame;
    bd[1].const_block      = ctx->const_block;
    bd[1].shift_lsbs       = ctx->shift_lsbs;
    bd[1].opt_order        = ctx->opt_order;
    bd[1].store_prev_samples = ctx->store_prev_samples;
    bd[1].use_ltp          = ctx->use_ltp;
    bd[1].ltp_lag          = ctx->ltp_lag;
    bd[1].ltp_gain         = ctx->ltp_gain[0];
    bd[1].quant_cof        = ctx->quant_cof[0];
    bd[1].lpc_cof          = ctx->lpc_cof[0];
    bd[1].prev_raw_samples = ctx->prev_raw_samples;
    bd[1].js_blocks        = *(js_blocks + 1);

    // decode all blocks
    for (b = 0; b < ctx->num_blocks; b++) {
        unsigned int s;

        bd[0].block_length = div_blocks[b];
        bd[1].block_length = div_blocks[b];

        bd[0].raw_samples  = ctx->raw_samples[c    ] + offset;
        bd[1].raw_samples  = ctx->raw_samples[c + 1] + offset;

        bd[0].raw_other    = bd[1].raw_samples;
        bd[1].raw_other    = bd[0].raw_samples;

        if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||
            (ret = read_decode_block(ctx, &bd[1])) < 0)
            goto fail;

        // reconstruct joint-stereo blocks
        if (bd[0].js_blocks) {
            if (bd[1].js_blocks)
                av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");

            for (s = 0; s < div_blocks[b]; s++)
                bd[0].raw_samples[s] = bd[1].raw_samples[s] - (unsigned)bd[0].raw_samples[s];
        } else if (bd[1].js_blocks) {
            for (s = 0; s < div_blocks[b]; s++)
                bd[1].raw_samples[s] = bd[1].raw_samples[s] + (unsigned)bd[0].raw_samples[s];
        }

        offset  += div_blocks[b];
        bd[0].ra_block = 0;
        bd[1].ra_block = 0;
    }

    // store carryover raw samples,
    // the others channel raw samples are stored by the calling function.
    memmove(ctx->raw_samples[c] - sconf->max_order,
            ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
            sizeof(*ctx->raw_samples[c]) * sconf->max_order);

    return 0;
fail:
    // damaged block, write zero for the rest of the frame
    zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
    zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
    return ret;
}

static inline int als_weighting(GetBitContext *gb, int k, int off)
{
    int idx = av_clip(decode_rice(gb, k) + off,
                      0, FF_ARRAY_ELEMS(mcc_weightings) - 1);
    return mcc_weightings[idx];
}

/** Read the channel data.
  */
static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
{
    GetBitContext *gb       = &ctx->gb;
    ALSChannelData *current = cd;
    unsigned int channels   = ctx->avctx->channels;
    int entries             = 0;

    while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
        current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

        if (current->master_channel >= channels) {
            av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");
            return AVERROR_INVALIDDATA;
        }

        if (current->master_channel != c) {
            current->time_diff_flag = get_bits1(gb);
            current->weighting[0]   = als_weighting(gb, 1, 16);
            current->weighting[1]   = als_weighting(gb, 2, 14);
            current->weighting[2]   = als_weighting(gb, 1, 16);

            if (current->time_diff_flag) {
                current->weighting[3] = als_weighting(gb, 1, 16);
                current->weighting[4] = als_weighting(gb, 1, 16);
                current->weighting[5] = als_weighting(gb, 1, 16);

                current->time_diff_sign  = get_bits1(gb);
                current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
            }
        }

        current++;
        entries++;
    }

    if (entries == channels) {
        av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");
        return AVERROR_INVALIDDATA;
    }

    align_get_bits(gb);
    return 0;
}


/** Recursively reverts the inter-channel correlation for a block.
 */
static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
                                       ALSChannelData **cd, int *reverted,
                                       unsigned int offset, int c)
{
    ALSChannelData *ch = cd[c];
    unsigned int   dep = 0;
    unsigned int channels = ctx->avctx->channels;
    unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;

    if (reverted[c])
        return 0;

    reverted[c] = 1;

    while (dep < channels && !ch[dep].stop_flag) {
        revert_channel_correlation(ctx, bd, cd, reverted, offset,
                                   ch[dep].master_channel);

        dep++;
    }

    if (dep == channels) {
        av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");
        return AVERROR_INVALIDDATA;
    }

    bd->const_block = ctx->const_block + c;
    bd->shift_lsbs  = ctx->shift_lsbs + c;
    bd->opt_order   = ctx->opt_order + c;
    bd->store_prev_samples = ctx->store_prev_samples + c;
    bd->use_ltp     = ctx->use_ltp + c;
    bd->ltp_lag     = ctx->ltp_lag + c;
    bd->ltp_gain    = ctx->ltp_gain[c];
    bd->lpc_cof     = ctx->lpc_cof[c];
    bd->quant_cof   = ctx->quant_cof[c];
    bd->raw_samples = ctx->raw_samples[c] + offset;

    for (dep = 0; !ch[dep].stop_flag; dep++) {
        ptrdiff_t smp;
        ptrdiff_t begin = 1;
        ptrdiff_t end   = bd->block_length - 1;
        int64_t y;
        int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

        if (ch[dep].master_channel == c)
            continue;

        if (ch[dep].time_diff_flag) {
            int t = ch[dep].time_diff_index;

            if (ch[dep].time_diff_sign) {
                t      = -t;
                if (begin < t) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "begin %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", begin, t);
                    return AVERROR_INVALIDDATA;
                }
                begin -= t;
            } else {
                if (end < t) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "end %"PTRDIFF_SPECIFIER" smaller than time diff index %d.\n", end, t);
                    return AVERROR_INVALIDDATA;
                }
                end   -= t;
            }

            if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||
                FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {
                av_log(ctx->avctx, AV_LOG_ERROR,
                       "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                       master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),
                       ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);
                return AVERROR_INVALIDDATA;
            }

            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
                     MUL64(ch[dep].weighting[1], master[smp        ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
                     MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
                     MUL64(ch[dep].weighting[4], master[smp     + t]) +
                     MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

                bd->raw_samples[smp] += y >> 7;
            }
        } else {

            if (begin - 1 < ctx->raw_buffer - master ||
                end   + 1 > ctx->raw_buffer + channels * channel_size - master) {
                av_log(ctx->avctx, AV_LOG_ERROR,
                       "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                       master + begin - 1, master + end + 1,
                       ctx->raw_buffer, ctx->raw_buffer + channels * channel_size);
                return AVERROR_INVALIDDATA;
            }

            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1]) +
                     MUL64(ch[dep].weighting[1], master[smp    ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1]);

                bd->raw_samples[smp] += y >> 7;
            }
        }
    }

    return 0;
}


/** multiply two softfloats and handle the rounding off
 */
static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a, SoftFloat_IEEE754 b) {
    uint64_t mantissa_temp;
    uint64_t mask_64;
    int cutoff_bit_count;
    unsigned char last_2_bits;
    unsigned int mantissa;
    int32_t sign;
    uint32_t return_val = 0;
    int bit_count       = 48;

    sign = a.sign ^ b.sign;

    // Multiply mantissa bits in a 64-bit register
    mantissa_temp = (uint64_t)a.mant * (uint64_t)b.mant;
    mask_64       = (uint64_t)0x1 << 47;

    if (!mantissa_temp)
        return FLOAT_0;

    // Count the valid bit count
    while (!(mantissa_temp & mask_64) && mask_64) {
        bit_count--;
        mask_64 >>= 1;
    }

    // Round off
    cutoff_bit_count = bit_count - 24;
    if (cutoff_bit_count > 0) {
        last_2_bits = (unsigned char)(((unsigned int)mantissa_temp >> (cutoff_bit_count - 1)) & 0x3 );
        if ((last_2_bits == 0x3) || ((last_2_bits == 0x1) && ((unsigned int)mantissa_temp & ((0x1UL << (cutoff_bit_count - 1)) - 1)))) {
            // Need to round up
            mantissa_temp += (uint64_t)0x1 << cutoff_bit_count;
        }
    }

    if (cutoff_bit_count >= 0) {
        mantissa = (unsigned int)(mantissa_temp >> cutoff_bit_count);
    } else {
        mantissa = (unsigned int)(mantissa_temp <<-cutoff_bit_count);
    }

    // Need one more shift?
    if (mantissa & 0x01000000ul) {
        bit_count++;
        mantissa >>= 1;
    }

    if (!sign) {
        return_val = 0x80000000U;
    }

    return_val |= ((unsigned)av_clip(a.exp + b.exp + bit_count - 47, -126, 127) << 23) & 0x7F800000;
    return_val |= mantissa;
    return av_bits2sf_ieee754(return_val);
}


/** Read and decode the floating point sample data
 */
static int read_diff_float_data(ALSDecContext *ctx, unsigned int ra_frame) {
    AVCodecContext *avctx   = ctx->avctx;
    GetBitContext *gb       = &ctx->gb;
    SoftFloat_IEEE754 *acf  = ctx->acf;
    int *shift_value        = ctx->shift_value;
    int *last_shift_value   = ctx->last_shift_value;
    int *last_acf_mantissa  = ctx->last_acf_mantissa;
    int **raw_mantissa      = ctx->raw_mantissa;
    int *nbits              = ctx->nbits;
    unsigned char *larray   = ctx->larray;
    int frame_length        = ctx->cur_frame_length;
    SoftFloat_IEEE754 scale = av_int2sf_ieee754(0x1u, 23);
    unsigned int partA_flag;
    unsigned int highest_byte;
    unsigned int shift_amp;
    uint32_t tmp_32;
    int use_acf;
    int nchars;
    int i;
    int c;
    long k;
    long nbits_aligned;
    unsigned long acc;
    unsigned long j;
    uint32_t sign;
    uint32_t e;
    uint32_t mantissa;

    skip_bits_long(gb, 32); //num_bytes_diff_float
    use_acf = get_bits1(gb);

    if (ra_frame) {
        memset(last_acf_mantissa, 0, avctx->channels * sizeof(*last_acf_mantissa));
        memset(last_shift_value,  0, avctx->channels * sizeof(*last_shift_value) );
        ff_mlz_flush_dict(ctx->mlz);
    }

    if (avctx->channels * 8 > get_bits_left(gb))
        return AVERROR_INVALIDDATA;

    for (c = 0; c < avctx->channels; ++c) {
        if (use_acf) {
            //acf_flag
            if (get_bits1(gb)) {
                tmp_32 = get_bits(gb, 23);
                last_acf_mantissa[c] = tmp_32;
            } else {
                tmp_32 = last_acf_mantissa[c];
            }
            acf[c] = av_bits2sf_ieee754(tmp_32);
        } else {
            acf[c] = FLOAT_1;
        }

        highest_byte = get_bits(gb, 2);
        partA_flag   = get_bits1(gb);
        shift_amp    = get_bits1(gb);

        if (shift_amp) {
            shift_value[c] = get_bits(gb, 8);
            last_shift_value[c] = shift_value[c];
        } else {
            shift_value[c] = last_shift_value[c];
        }

        if (partA_flag) {
            if (!get_bits1(gb)) { //uncompressed
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] == 0) {
                        ctx->raw_mantissa[c][i] = get_bits_long(gb, 32);
                    }
                }
            } else { //compressed
                nchars = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] == 0) {
                        nchars += 4;
                    }
                }

                tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);
                if(tmp_32 != nchars) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
                    return AVERROR_INVALIDDATA;
                }

                for (i = 0; i < frame_length; ++i) {
                    ctx->raw_mantissa[c][i] = AV_RB32(larray);
                }
            }
        }

        //decode part B
        if (highest_byte) {
            for (i = 0; i < frame_length; ++i) {
                if (ctx->raw_samples[c][i] != 0) {
                    //The following logic is taken from Tabel 14.45 and 14.46 from the ISO spec
                    if (av_cmp_sf_ieee754(acf[c], FLOAT_1)) {
                        nbits[i] = 23 - av_log2(abs(ctx->raw_samples[c][i]));
                    } else {
                        nbits[i] = 23;
                    }
                    nbits[i] = FFMIN(nbits[i], highest_byte*8);
                }
            }

            if (!get_bits1(gb)) { //uncompressed
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i] != 0) {
                        raw_mantissa[c][i] = get_bitsz(gb, nbits[i]);
                    }
                }
            } else { //compressed
                nchars = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i]) {
                        nchars += (int) nbits[i] / 8;
                        if (nbits[i] & 7) {
                            ++nchars;
                        }
                    }
                }

                tmp_32 = ff_mlz_decompression(ctx->mlz, gb, nchars, larray);
                if(tmp_32 != nchars) {
                    av_log(ctx->avctx, AV_LOG_ERROR, "Error in MLZ decompression (%"PRId32", %d).\n", tmp_32, nchars);
                    return AVERROR_INVALIDDATA;
                }

                j = 0;
                for (i = 0; i < frame_length; ++i) {
                    if (ctx->raw_samples[c][i]) {
                        if (nbits[i] & 7) {
                            nbits_aligned = 8 * ((unsigned int)(nbits[i] / 8) + 1);
                        } else {
                            nbits_aligned = nbits[i];
                        }
                        acc = 0;
                        for (k = 0; k < nbits_aligned/8; ++k) {
                            acc = (acc << 8) + larray[j++];
                        }
                        acc >>= (nbits_aligned - nbits[i]);
                        raw_mantissa[c][i] = acc;
                    }
                }
            }
        }

        for (i = 0; i < frame_length; ++i) {
            SoftFloat_IEEE754 pcm_sf = av_int2sf_ieee754(ctx->raw_samples[c][i], 0);
            pcm_sf = av_div_sf_ieee754(pcm_sf, scale);

            if (ctx->raw_samples[c][i] != 0) {
                if (!av_cmp_sf_ieee754(acf[c], FLOAT_1)) {
                    pcm_sf = multiply(acf[c], pcm_sf);
                }

                sign = pcm_sf.sign;
                e = pcm_sf.exp;
                mantissa = (pcm_sf.mant | 0x800000) + raw_mantissa[c][i];

                while(mantissa >= 0x1000000) {
                    e++;
                    mantissa >>= 1;
                }

                if (mantissa) e += (shift_value[c] - 127);
                mantissa &= 0x007fffffUL;

                tmp_32 = (sign << 31) | ((e + EXP_BIAS) << 23) | (mantissa);
                ctx->raw_samples[c][i] = tmp_32;
            } else {
                ctx->raw_samples[c][i] = raw_mantissa[c][i] & 0x007fffffUL;
            }
        }
        align_get_bits(gb);
    }
    return 0;
}


/** Read the frame data.
 */
static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
{
    ALSSpecificConfig *sconf = &ctx->sconf;
    AVCodecContext *avctx    = ctx->avctx;
    GetBitContext *gb = &ctx->gb;
    unsigned int div_blocks[32];                ///< block sizes.
    int c;
    unsigned int js_blocks[2];
    uint32_t bs_info = 0;
    int ret;

    // skip the size of the ra unit if present in the frame
    if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
        skip_bits_long(gb, 32);

    if (sconf->mc_coding && sconf->joint_stereo) {
        ctx->js_switch = get_bits1(gb);
        align_get_bits(gb);
    }

    if (!sconf->mc_coding || ctx->js_switch) {
        int independent_bs = !sconf->joint_stereo;

        for (c = 0; c < avctx->channels; c++) {
            js_blocks[0] = 0;
            js_blocks[1] = 0;

            get_block_sizes(ctx, div_blocks, &bs_info);

            // if joint_stereo and block_switching is set, independent decoding
            // is signaled via the first bit of bs_info
            if (sconf->joint_stereo && sconf->block_switching)
                if (bs_info >> 31)
                    independent_bs = 2;

            // if this is the last channel, it has to be decoded independently
            if (c == avctx->channels - 1 || (c & 1))
                independent_bs = 1;

            if (independent_bs) {
                ret = decode_blocks_ind(ctx, ra_frame, c,
                                        div_blocks, js_blocks);
                if (ret < 0)
                    return ret;
                independent_bs--;
            } else {
                ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);
                if (ret < 0)
                    return ret;

                c++;
            }

            // store carryover raw samples
            memmove(ctx->raw_samples[c] - sconf->max_order,
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
            ctx->highest_decoded_channel = c;
        }
    } else { // multi-channel coding
        ALSBlockData   bd = { 0 };
        int            b, ret;
        int            *reverted_channels = ctx->reverted_channels;
        unsigned int   offset             = 0;

        for (c = 0; c < avctx->channels; c++)
            if (ctx->chan_data[c] < ctx->chan_data_buffer) {
                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");
                return AVERROR_INVALIDDATA;
            }

        memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

        bd.ra_block         = ra_frame;
        bd.prev_raw_samples = ctx->prev_raw_samples;

        get_block_sizes(ctx, div_blocks, &bs_info);

        for (b = 0; b < ctx->num_blocks; b++) {
            bd.block_length = div_blocks[b];
            if (bd.block_length <= 0) {
                av_log(ctx->avctx, AV_LOG_WARNING,
                       "Invalid block length %u in channel data!\n",
                       bd.block_length);
                continue;
            }

            for (c = 0; c < avctx->channels; c++) {
                bd.const_block = ctx->const_block + c;
                bd.shift_lsbs  = ctx->shift_lsbs + c;
                bd.opt_order   = ctx->opt_order + c;
                bd.store_prev_samples = ctx->store_prev_samples + c;
                bd.use_ltp     = ctx->use_ltp + c;
                bd.ltp_lag     = ctx->ltp_lag + c;
                bd.ltp_gain    = ctx->ltp_gain[c];
                bd.lpc_cof     = ctx->lpc_cof[c];
                bd.quant_cof   = ctx->quant_cof[c];
                bd.raw_samples = ctx->raw_samples[c] + offset;
                bd.raw_other   = NULL;

                if ((ret = read_block(ctx, &bd)) < 0)
                    return ret;
                if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
                    return ret;
            }

            for (c = 0; c < avctx->channels; c++) {
                ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,
                                                 reverted_channels, offset, c);
                if (ret < 0)
                    return ret;
            }
            for (c = 0; c < avctx->channels; c++) {
                bd.const_block = ctx->const_block + c;
                bd.shift_lsbs  = ctx->shift_lsbs + c;
                bd.opt_order   = ctx->opt_order + c;
                bd.store_prev_samples = ctx->store_prev_samples + c;
                bd.use_ltp     = ctx->use_ltp + c;
                bd.ltp_lag     = ctx->ltp_lag + c;
                bd.ltp_gain    = ctx->ltp_gain[c];
                bd.lpc_cof     = ctx->lpc_cof[c];
                bd.quant_cof   = ctx->quant_cof[c];
                bd.raw_samples = ctx->raw_samples[c] + offset;

                if ((ret = decode_block(ctx, &bd)) < 0)
                    return ret;

                ctx->highest_decoded_channel = FFMAX(ctx->highest_decoded_channel, c);
            }

            memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
            offset      += div_blocks[b];
            bd.ra_block  = 0;
        }

        // store carryover raw samples
        for (c = 0; c < avctx->channels; c++)
            memmove(ctx->raw_samples[c] - sconf->max_order,
                    ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
                    sizeof(*ctx->raw_samples[c]) * sconf->max_order);
    }

    if (sconf->floating) {
        read_diff_float_data(ctx, ra_frame);
    }

    if (get_bits_left(gb) < 0) {
        av_log(ctx->avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));
        return AVERROR_INVALIDDATA;
    }

    return 0;
}


/** Decode an ALS frame.
 */
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
                        AVPacket *avpkt)
{
    ALSDecContext *ctx       = avctx->priv_data;
    AVFrame *frame           = data;
    ALSSpecificConfig *sconf = &ctx->sconf;
    const uint8_t *buffer    = avpkt->data;
    int buffer_size          = avpkt->size;
    int invalid_frame, ret;
    unsigned int c, sample, ra_frame, bytes_read, shift;

    if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)
        return ret;

    // In the case that the distance between random access frames is set to zero
    // (sconf->ra_distance == 0) no frame is treated as a random access frame.
    // For the first frame, if prediction is used, all samples used from the
    // previous frame are assumed to be zero.
    ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

    // the last frame to decode might have a different length
    if (sconf->samples != 0xFFFFFFFF)
        ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
                                      sconf->frame_length);
    else
        ctx->cur_frame_length = sconf->frame_length;

    ctx->highest_decoded_channel = -1;
    // decode the frame data
    if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
        av_log(ctx->avctx, AV_LOG_WARNING,
               "Reading frame data failed. Skipping RA unit.\n");

    if (ctx->highest_decoded_channel == -1) {
        av_log(ctx->avctx, AV_LOG_WARNING,
               "No channel data decoded.\n");
        return AVERROR_INVALIDDATA;
    }

    ctx->frame_id++;

    /* get output buffer */
    frame->nb_samples = ctx->cur_frame_length;
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;

    // transform decoded frame into output format
    #define INTERLEAVE_OUTPUT(bps)                                                   \
    {                                                                                \
        int##bps##_t *dest = (int##bps##_t*)frame->data[0];                          \
        int channels = avctx->channels;                                              \
        int32_t *raw_samples = ctx->raw_samples[0];                                  \
        int raw_step = channels > 1 ? ctx->raw_samples[1] - raw_samples : 1;         \
        shift = bps - ctx->avctx->bits_per_raw_sample;                               \
        if (!ctx->cs_switch) {                                                       \
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
                for (c = 0; c < channels; c++)                                       \
                    *dest++ = raw_samples[c*raw_step + sample] * (1U << shift);      \
        } else {                                                                     \
            for (sample = 0; sample < ctx->cur_frame_length; sample++)               \
                for (c = 0; c < channels; c++)                                       \
                    *dest++ = raw_samples[sconf->chan_pos[c]*raw_step + sample] * (1U << shift);\
        }                                                                            \
    }

    if (ctx->avctx->bits_per_raw_sample <= 16) {
        INTERLEAVE_OUTPUT(16)
    } else {
        INTERLEAVE_OUTPUT(32)
    }

    // update CRC
    if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
        int swap = HAVE_BIGENDIAN != sconf->msb_first;

        if (ctx->avctx->bits_per_raw_sample == 24) {
            int32_t *src = (int32_t *)frame->data[0];

            for (sample = 0;
                 sample < ctx->cur_frame_length * avctx->channels;
                 sample++) {
                int32_t v;

                if (swap)
                    v = av_bswap32(src[sample]);
                else
                    v = src[sample];
                if (!HAVE_BIGENDIAN)
                    v >>= 8;

                ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
            }
        } else {
            uint8_t *crc_source;

            if (swap) {
                if (ctx->avctx->bits_per_raw_sample <= 16) {
                    int16_t *src  = (int16_t*) frame->data[0];
                    int16_t *dest = (int16_t*) ctx->crc_buffer;
                    for (sample = 0;
                         sample < ctx->cur_frame_length * avctx->channels;
                         sample++)
                        *dest++ = av_bswap16(src[sample]);
                } else {
                    ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,
                                        (uint32_t *) frame->data[0],
                                        ctx->cur_frame_length * avctx->channels);
                }
                crc_source = ctx->crc_buffer;
            } else {
                crc_source = frame->data[0];
            }

            ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
                              ctx->cur_frame_length * avctx->channels *
                              av_get_bytes_per_sample(avctx->sample_fmt));
        }


        // check CRC sums if this is the last frame
        if (ctx->cur_frame_length != sconf->frame_length &&
            ctx->crc_org != ctx->crc) {
            av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
            if (avctx->err_recognition & AV_EF_EXPLODE)
                return AVERROR_INVALIDDATA;
        }
    }

    *got_frame_ptr = 1;

    bytes_read = invalid_frame ? buffer_size :
                                 (get_bits_count(&ctx->gb) + 7) >> 3;

    return bytes_read;
}


/** Uninitialize the ALS decoder.
 */
static av_cold int decode_end(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;
    int i;

    av_freep(&ctx->sconf.chan_pos);

    ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

    av_freep(&ctx->const_block);
    av_freep(&ctx->shift_lsbs);
    av_freep(&ctx->opt_order);
    av_freep(&ctx->store_prev_samples);
    av_freep(&ctx->use_ltp);
    av_freep(&ctx->ltp_lag);
    av_freep(&ctx->ltp_gain);
    av_freep(&ctx->ltp_gain_buffer);
    av_freep(&ctx->quant_cof);
    av_freep(&ctx->lpc_cof);
    av_freep(&ctx->quant_cof_buffer);
    av_freep(&ctx->lpc_cof_buffer);
    av_freep(&ctx->lpc_cof_reversed_buffer);
    av_freep(&ctx->prev_raw_samples);
    av_freep(&ctx->raw_samples);
    av_freep(&ctx->raw_buffer);
    av_freep(&ctx->chan_data);
    av_freep(&ctx->chan_data_buffer);
    av_freep(&ctx->reverted_channels);
    av_freep(&ctx->crc_buffer);
    if (ctx->mlz) {
        av_freep(&ctx->mlz->dict);
        av_freep(&ctx->mlz);
    }
    av_freep(&ctx->acf);
    av_freep(&ctx->last_acf_mantissa);
    av_freep(&ctx->shift_value);
    av_freep(&ctx->last_shift_value);
    if (ctx->raw_mantissa) {
        for (i = 0; i < avctx->channels; i++) {
            av_freep(&ctx->raw_mantissa[i]);
        }
        av_freep(&ctx->raw_mantissa);
    }
    av_freep(&ctx->larray);
    av_freep(&ctx->nbits);

    return 0;
}


/** Initialize the ALS decoder.
 */
static av_cold int decode_init(AVCodecContext *avctx)
{
    unsigned int c;
    unsigned int channel_size;
    int num_buffers, ret;
    ALSDecContext *ctx = avctx->priv_data;
    ALSSpecificConfig *sconf = &ctx->sconf;
    ctx->avctx = avctx;

    if (!avctx->extradata) {
        av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
        return AVERROR_INVALIDDATA;
    }

    if ((ret = read_specific_config(ctx)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
        goto fail;
    }

    if ((ret = check_specific_config(ctx)) < 0) {
        goto fail;
    }

    if (sconf->bgmc) {
        ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
        if (ret < 0)
            goto fail;
    }
    if (sconf->floating) {
        avctx->sample_fmt          = AV_SAMPLE_FMT_FLT;
        avctx->bits_per_raw_sample = 32;
    } else {
        avctx->sample_fmt          = sconf->resolution > 1
                                     ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
        avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
        if (avctx->bits_per_raw_sample > 32) {
            av_log(avctx, AV_LOG_ERROR, "Bits per raw sample %d larger than 32.\n",
                   avctx->bits_per_raw_sample);
            ret = AVERROR_INVALIDDATA;
            goto fail;
        }
    }

    // set maximum Rice parameter for progressive decoding based on resolution
    // This is not specified in 14496-3 but actually done by the reference
    // codec RM22 revision 2.
    ctx->s_max = sconf->resolution > 1 ? 31 : 15;

    // set lag value for long-term prediction
    ctx->ltp_lag_length = 8 + (avctx->sample_rate >=  96000) +
                              (avctx->sample_rate >= 192000);

    // allocate quantized parcor coefficient buffer
    num_buffers = sconf->mc_coding ? avctx->channels : 1;
    if (num_buffers * (uint64_t)num_buffers > INT_MAX) // protect chan_data_buffer allocation
        return AVERROR_INVALIDDATA;

    ctx->quant_cof        = av_malloc_array(num_buffers, sizeof(*ctx->quant_cof));
    ctx->lpc_cof          = av_malloc_array(num_buffers, sizeof(*ctx->lpc_cof));
    ctx->quant_cof_buffer = av_malloc_array(num_buffers * sconf->max_order,
                                            sizeof(*ctx->quant_cof_buffer));
    ctx->lpc_cof_buffer   = av_malloc_array(num_buffers * sconf->max_order,
                                            sizeof(*ctx->lpc_cof_buffer));
    ctx->lpc_cof_reversed_buffer = av_malloc_array(sconf->max_order,
                                                   sizeof(*ctx->lpc_cof_buffer));

    if (!ctx->quant_cof              || !ctx->lpc_cof        ||
        !ctx->quant_cof_buffer       || !ctx->lpc_cof_buffer ||
        !ctx->lpc_cof_reversed_buffer) {
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
        ret = AVERROR(ENOMEM);
        goto fail;
    }

    // assign quantized parcor coefficient buffers
    for (c = 0; c < num_buffers; c++) {
        ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
        ctx->lpc_cof[c]   = ctx->lpc_cof_buffer   + c * sconf->max_order;
    }

    // allocate and assign lag and gain data buffer for ltp mode
    ctx->const_block     = av_malloc_array(num_buffers, sizeof(*ctx->const_block));
    ctx->shift_lsbs      = av_malloc_array(num_buffers, sizeof(*ctx->shift_lsbs));
    ctx->opt_order       = av_malloc_array(num_buffers, sizeof(*ctx->opt_order));
    ctx->store_prev_samples = av_malloc_array(num_buffers, sizeof(*ctx->store_prev_samples));
    ctx->use_ltp         = av_mallocz_array(num_buffers, sizeof(*ctx->use_ltp));
    ctx->ltp_lag         = av_malloc_array(num_buffers, sizeof(*ctx->ltp_lag));
    ctx->ltp_gain        = av_malloc_array(num_buffers, sizeof(*ctx->ltp_gain));
    ctx->ltp_gain_buffer = av_malloc_array(num_buffers * 5, sizeof(*ctx->ltp_gain_buffer));

    if (!ctx->const_block || !ctx->shift_lsbs ||
        !ctx->opt_order || !ctx->store_prev_samples ||
        !ctx->use_ltp  || !ctx->ltp_lag ||
        !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
        ret = AVERROR(ENOMEM);
        goto fail;
    }

    for (c = 0; c < num_buffers; c++)
        ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

    // allocate and assign channel data buffer for mcc mode
    if (sconf->mc_coding) {
        ctx->chan_data_buffer  = av_mallocz_array(num_buffers * num_buffers,
                                                 sizeof(*ctx->chan_data_buffer));
        ctx->chan_data         = av_mallocz_array(num_buffers,
                                                 sizeof(*ctx->chan_data));
        ctx->reverted_channels = av_malloc_array(num_buffers,
                                                 sizeof(*ctx->reverted_channels));

        if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
            ret = AVERROR(ENOMEM);
            goto fail;
        }

        for (c = 0; c < num_buffers; c++)
            ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
    } else {
        ctx->chan_data         = NULL;
        ctx->chan_data_buffer  = NULL;
        ctx->reverted_channels = NULL;
    }

    channel_size      = sconf->frame_length + sconf->max_order;

    ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));
    ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));
    ctx->raw_samples      = av_malloc_array(avctx->channels, sizeof(*ctx->raw_samples));

    if (sconf->floating) {
        ctx->acf               = av_malloc_array(avctx->channels, sizeof(*ctx->acf));
        ctx->shift_value       = av_malloc_array(avctx->channels, sizeof(*ctx->shift_value));
        ctx->last_shift_value  = av_malloc_array(avctx->channels, sizeof(*ctx->last_shift_value));
        ctx->last_acf_mantissa = av_malloc_array(avctx->channels, sizeof(*ctx->last_acf_mantissa));
        ctx->raw_mantissa      = av_mallocz_array(avctx->channels, sizeof(*ctx->raw_mantissa));

        ctx->larray = av_malloc_array(ctx->cur_frame_length * 4, sizeof(*ctx->larray));
        ctx->nbits  = av_malloc_array(ctx->cur_frame_length, sizeof(*ctx->nbits));
        ctx->mlz    = av_mallocz(sizeof(*ctx->mlz));

        if (!ctx->mlz || !ctx->acf || !ctx->shift_value || !ctx->last_shift_value
            || !ctx->last_acf_mantissa || !ctx->raw_mantissa) {
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
            ret = AVERROR(ENOMEM);
            goto fail;
        }

        ff_mlz_init_dict(avctx, ctx->mlz);
        ff_mlz_flush_dict(ctx->mlz);

        for (c = 0; c < avctx->channels; ++c) {
            ctx->raw_mantissa[c] = av_mallocz_array(ctx->cur_frame_length, sizeof(**ctx->raw_mantissa));
        }
    }

    // allocate previous raw sample buffer
    if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
        av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
        ret = AVERROR(ENOMEM);
        goto fail;
    }

    // assign raw samples buffers
    ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
    for (c = 1; c < avctx->channels; c++)
        ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

    // allocate crc buffer
    if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
        (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
        ctx->crc_buffer = av_malloc_array(ctx->cur_frame_length *
                                          avctx->channels *
                                          av_get_bytes_per_sample(avctx->sample_fmt),
                                          sizeof(*ctx->crc_buffer));
        if (!ctx->crc_buffer) {
            av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
            ret = AVERROR(ENOMEM);
            goto fail;
        }
    }

    ff_bswapdsp_init(&ctx->bdsp);

    return 0;

fail:
    return ret;
}


/** Flush (reset) the frame ID after seeking.
 */
static av_cold void flush(AVCodecContext *avctx)
{
    ALSDecContext *ctx = avctx->priv_data;

    ctx->frame_id = 0;
}


AVCodec ff_als_decoder = {
    .name           = "als",
    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_MP4ALS,
    .priv_data_size = sizeof(ALSDecContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .flush          = flush,
    .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
};