aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/dca_xll.c
blob: 005a51ed699caa15609de2ded8cd4ea399bf53e0 (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
/*
 * Copyright (C) 2016 foo86
 *
 * 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
 */

#include "avcodec.h"
#include "libavutil/channel_layout.h"
#include "libavutil/mem.h"
#include "dcadec.h"
#include "dcadata.h"
#include "dcamath.h"
#include "dca_syncwords.h"
#include "decode.h"
#include "unary.h"

static int get_linear(GetBitContext *gb, int n)
{
    unsigned int v = get_bits_long(gb, n);
    return (v >> 1) ^ -(v & 1);
}

static int get_rice_un(GetBitContext *gb, int k)
{
    unsigned int v = get_unary(gb, 1, get_bits_left(gb));
    return (v << k) | get_bits_long(gb, k);
}

static int get_rice(GetBitContext *gb, int k)
{
    unsigned int v = get_rice_un(gb, k);
    return (v >> 1) ^ -(v & 1);
}

static void get_array(GetBitContext *gb, int32_t *array, int size, int n)
{
    int i;

    for (i = 0; i < size; i++)
        array[i] = get_bits(gb, n);
}

static void get_linear_array(GetBitContext *gb, int32_t *array, int size, int n)
{
    int i;

    if (n == 0)
        memset(array, 0, sizeof(*array) * size);
    else for (i = 0; i < size; i++)
        array[i] = get_linear(gb, n);
}

static void get_rice_array(GetBitContext *gb, int32_t *array, int size, int k)
{
    int i;

    for (i = 0; i < size; i++)
        array[i] = get_rice(gb, k);
}

static int parse_dmix_coeffs(DCAXllDecoder *s, DCAXllChSet *c)
{
    // Size of downmix coefficient matrix
    int m = c->primary_chset ? ff_dca_dmix_primary_nch[c->dmix_type] : c->hier_ofs;
    int i, j, *coeff_ptr = c->dmix_coeff;

    for (i = 0; i < m; i++) {
        int code, sign, coeff, scale, scale_inv = 0;
        unsigned int index;

        // Downmix scale (only for non-primary channel sets)
        if (!c->primary_chset) {
            code = get_bits(&s->gb, 9);
            sign = (code >> 8) - 1;
            index = (code & 0xff) - FF_DCA_DMIXTABLE_OFFSET;
            if (index >= FF_DCA_INV_DMIXTABLE_SIZE) {
                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL downmix scale index\n");
                return AVERROR_INVALIDDATA;
            }
            scale = ff_dca_dmixtable[index + FF_DCA_DMIXTABLE_OFFSET];
            scale_inv = ff_dca_inv_dmixtable[index];
            c->dmix_scale[i] = (scale ^ sign) - sign;
            c->dmix_scale_inv[i] = (scale_inv ^ sign) - sign;
        }

        // Downmix coefficients
        for (j = 0; j < c->nchannels; j++) {
            code = get_bits(&s->gb, 9);
            sign = (code >> 8) - 1;
            index = code & 0xff;
            if (index >= FF_DCA_DMIXTABLE_SIZE) {
                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL downmix coefficient index\n");
                return AVERROR_INVALIDDATA;
            }
            coeff = ff_dca_dmixtable[index];
            if (!c->primary_chset)
                // Multiply by |InvDmixScale| to get |UndoDmixScale|
                coeff = mul16(scale_inv, coeff);
            *coeff_ptr++ = (coeff ^ sign) - sign;
        }
    }

    return 0;
}

static int chs_parse_header(DCAXllDecoder *s, DCAXllChSet *c, DCAExssAsset *asset)
{
    int i, j, k, ret, band, header_size, header_pos = get_bits_count(&s->gb);
    DCAXllChSet *p = &s->chset[0];
    DCAXllBand *b;

    // Size of channel set sub-header
    header_size = get_bits(&s->gb, 10) + 1;

    // Check CRC
    if (ff_dca_check_crc(s->avctx, &s->gb, header_pos, header_pos + header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL sub-header checksum\n");
        return AVERROR_INVALIDDATA;
    }

    // Number of channels in the channel set
    c->nchannels = get_bits(&s->gb, 4) + 1;
    if (c->nchannels > DCA_XLL_CHANNELS_MAX) {
        avpriv_request_sample(s->avctx, "%d XLL channels", c->nchannels);
        return AVERROR_PATCHWELCOME;
    }

    // Residual type
    c->residual_encode = get_bits(&s->gb, c->nchannels);

    // PCM bit resolution
    c->pcm_bit_res = get_bits(&s->gb, 5) + 1;

    // Storage unit width
    c->storage_bit_res = get_bits(&s->gb, 5) + 1;
    if (c->storage_bit_res != 16 && c->storage_bit_res != 20 && c->storage_bit_res != 24) {
        avpriv_request_sample(s->avctx, "%d-bit XLL storage resolution", c->storage_bit_res);
        return AVERROR_PATCHWELCOME;
    }

    if (c->pcm_bit_res > c->storage_bit_res) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid PCM bit resolution for XLL channel set (%d > %d)\n", c->pcm_bit_res, c->storage_bit_res);
        return AVERROR_INVALIDDATA;
    }

    // Original sampling frequency
    c->freq = ff_dca_sampling_freqs[get_bits(&s->gb, 4)];
    if (c->freq > 192000) {
        avpriv_request_sample(s->avctx, "%d Hz XLL sampling frequency", c->freq);
        return AVERROR_PATCHWELCOME;
    }

    // Sampling frequency modifier
    if (get_bits(&s->gb, 2)) {
        avpriv_request_sample(s->avctx, "XLL sampling frequency modifier");
        return AVERROR_PATCHWELCOME;
    }

    // Which replacement set this channel set is member of
    if (get_bits(&s->gb, 2)) {
        avpriv_request_sample(s->avctx, "XLL replacement set");
        return AVERROR_PATCHWELCOME;
    }

    if (asset->one_to_one_map_ch_to_spkr) {
        // Primary channel set flag
        c->primary_chset = get_bits1(&s->gb);
        if (c->primary_chset != (c == p)) {
            av_log(s->avctx, AV_LOG_ERROR, "The first (and only) XLL channel set must be primary\n");
            return AVERROR_INVALIDDATA;
        }

        // Downmix coefficients present in stream
        c->dmix_coeffs_present = get_bits1(&s->gb);

        // Downmix already performed by encoder
        c->dmix_embedded = c->dmix_coeffs_present && get_bits1(&s->gb);

        // Downmix type
        if (c->dmix_coeffs_present && c->primary_chset) {
            c->dmix_type = get_bits(&s->gb, 3);
            if (c->dmix_type >= DCA_DMIX_TYPE_COUNT) {
                av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL primary channel set downmix type\n");
                return AVERROR_INVALIDDATA;
            }
        }

        // Whether the channel set is part of a hierarchy
        c->hier_chset = get_bits1(&s->gb);
        if (!c->hier_chset && s->nchsets != 1) {
            avpriv_request_sample(s->avctx, "XLL channel set outside of hierarchy");
            return AVERROR_PATCHWELCOME;
        }

        // Downmix coefficients
        if (c->dmix_coeffs_present && (ret = parse_dmix_coeffs(s, c)) < 0)
            return ret;

        // Channel mask enabled
        if (!get_bits1(&s->gb)) {
            avpriv_request_sample(s->avctx, "Disabled XLL channel mask");
            return AVERROR_PATCHWELCOME;
        }

        // Channel mask for set
        c->ch_mask = get_bits_long(&s->gb, s->ch_mask_nbits);
        if (av_popcount(c->ch_mask) != c->nchannels) {
            av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL channel mask\n");
            return AVERROR_INVALIDDATA;
        }

        // Build the channel to speaker map
        for (i = 0, j = 0; i < s->ch_mask_nbits; i++)
            if (c->ch_mask & (1U << i))
                c->ch_remap[j++] = i;
    } else {
        // Mapping coeffs present flag
        if (c->nchannels != 2 || s->nchsets != 1 || get_bits1(&s->gb)) {
            avpriv_request_sample(s->avctx, "Custom XLL channel to speaker mapping");
            return AVERROR_PATCHWELCOME;
        }

        // Setup for LtRt decoding
        c->primary_chset = 1;
        c->dmix_coeffs_present = 0;
        c->dmix_embedded = 0;
        c->hier_chset = 0;
        c->ch_mask = DCA_SPEAKER_LAYOUT_STEREO;
        c->ch_remap[0] = DCA_SPEAKER_L;
        c->ch_remap[1] = DCA_SPEAKER_R;
    }

    if (c->freq > 96000) {
        // Extra frequency bands flag
        if (get_bits1(&s->gb)) {
            avpriv_request_sample(s->avctx, "Extra XLL frequency bands");
            return AVERROR_PATCHWELCOME;
        }
        c->nfreqbands = 2;
    } else {
        c->nfreqbands = 1;
    }

    // Set the sampling frequency to that of the first frequency band.
    // Frequency will be doubled again after bands assembly.
    c->freq >>= c->nfreqbands - 1;

    // Verify that all channel sets have the same audio characteristics
    if (c != p && (c->nfreqbands != p->nfreqbands || c->freq != p->freq
                   || c->pcm_bit_res != p->pcm_bit_res
                   || c->storage_bit_res != p->storage_bit_res)) {
        avpriv_request_sample(s->avctx, "Different XLL audio characteristics");
        return AVERROR_PATCHWELCOME;
    }

    // Determine number of bits to read bit allocation coding parameter
    if (c->storage_bit_res > 16)
        c->nabits = 5;
    else if (c->storage_bit_res > 8)
        c->nabits = 4;
    else
        c->nabits = 3;

    // Account for embedded downmix and decimator saturation
    if ((s->nchsets > 1 || c->nfreqbands > 1) && c->nabits < 5)
        c->nabits++;

    for (band = 0, b = c->bands; band < c->nfreqbands; band++, b++) {
        // Pairwise channel decorrelation
        if ((b->decor_enabled = get_bits1(&s->gb)) && c->nchannels > 1) {
            int ch_nbits = av_ceil_log2(c->nchannels);

            // Original channel order
            for (i = 0; i < c->nchannels; i++) {
                b->orig_order[i] = get_bits(&s->gb, ch_nbits);
                if (b->orig_order[i] >= c->nchannels) {
                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL original channel order\n");
                    return AVERROR_INVALIDDATA;
                }
            }

            // Pairwise channel coefficients
            for (i = 0; i < c->nchannels / 2; i++)
                b->decor_coeff[i] = get_bits1(&s->gb) ? get_linear(&s->gb, 7) : 0;
        } else {
            for (i = 0; i < c->nchannels; i++)
                b->orig_order[i] = i;
            for (i = 0; i < c->nchannels / 2; i++)
                b->decor_coeff[i] = 0;
        }

        // Adaptive predictor order
        b->highest_pred_order = 0;
        for (i = 0; i < c->nchannels; i++) {
            b->adapt_pred_order[i] = get_bits(&s->gb, 4);
            if (b->adapt_pred_order[i] > b->highest_pred_order)
                b->highest_pred_order = b->adapt_pred_order[i];
        }
        if (b->highest_pred_order > s->nsegsamples) {
            av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL adaptive predicition order\n");
            return AVERROR_INVALIDDATA;
        }

        // Fixed predictor order
        for (i = 0; i < c->nchannels; i++)
            b->fixed_pred_order[i] = b->adapt_pred_order[i] ? 0 : get_bits(&s->gb, 2);

        // Adaptive predictor quantized reflection coefficients
        for (i = 0; i < c->nchannels; i++) {
            for (j = 0; j < b->adapt_pred_order[i]; j++) {
                k = get_linear(&s->gb, 8);
                if (k == -128) {
                    av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL reflection coefficient index\n");
                    return AVERROR_INVALIDDATA;
                }
                if (k < 0)
                    b->adapt_refl_coeff[i][j] = -(int)ff_dca_xll_refl_coeff[-k];
                else
                    b->adapt_refl_coeff[i][j] =  (int)ff_dca_xll_refl_coeff[ k];
            }
        }

        // Downmix performed by encoder in extension frequency band
        b->dmix_embedded = c->dmix_embedded && (band == 0 || get_bits1(&s->gb));

        // MSB/LSB split flag in extension frequency band
        if ((band == 0 && s->scalable_lsbs) || (band != 0 && get_bits1(&s->gb))) {
            // Size of LSB section in any segment
            b->lsb_section_size = get_bits_long(&s->gb, s->seg_size_nbits);
            if (b->lsb_section_size < 0 || b->lsb_section_size > s->frame_size) {
                av_log(s->avctx, AV_LOG_ERROR, "Invalid LSB section size\n");
                return AVERROR_INVALIDDATA;
            }

            // Account for optional CRC bytes after LSB section
            if (b->lsb_section_size && (s->band_crc_present > 2 ||
                                        (band == 0 && s->band_crc_present > 1)))
                b->lsb_section_size += 2;

            // Number of bits to represent the samples in LSB part
            for (i = 0; i < c->nchannels; i++) {
                b->nscalablelsbs[i] = get_bits(&s->gb, 4);
                if (b->nscalablelsbs[i] && !b->lsb_section_size) {
                    av_log(s->avctx, AV_LOG_ERROR, "LSB section missing with non-zero LSB width\n");
                    return AVERROR_INVALIDDATA;
                }
            }
        } else {
            b->lsb_section_size = 0;
            for (i = 0; i < c->nchannels; i++)
                b->nscalablelsbs[i] = 0;
        }

        // Scalable resolution flag in extension frequency band
        if ((band == 0 && s->scalable_lsbs) || (band != 0 && get_bits1(&s->gb))) {
            // Number of bits discarded by authoring
            for (i = 0; i < c->nchannels; i++)
                b->bit_width_adjust[i] = get_bits(&s->gb, 4);
        } else {
            for (i = 0; i < c->nchannels; i++)
                b->bit_width_adjust[i] = 0;
        }
    }

    // Reserved
    // Byte align
    // CRC16 of channel set sub-header
    if (ff_dca_seek_bits(&s->gb, header_pos + header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL sub-header\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

static int chs_alloc_msb_band_data(DCAXllDecoder *s, DCAXllChSet *c)
{
    int ndecisamples = c->nfreqbands > 1 ? DCA_XLL_DECI_HISTORY_MAX : 0;
    int nchsamples = s->nframesamples + ndecisamples;
    int i, j, nsamples = nchsamples * c->nchannels * c->nfreqbands;
    int32_t *ptr;

    // Reallocate MSB sample buffer
    av_fast_malloc(&c->sample_buffer[0], &c->sample_size[0], nsamples * sizeof(int32_t));
    if (!c->sample_buffer[0])
        return AVERROR(ENOMEM);

    ptr = c->sample_buffer[0] + ndecisamples;
    for (i = 0; i < c->nfreqbands; i++) {
        for (j = 0; j < c->nchannels; j++) {
            c->bands[i].msb_sample_buffer[j] = ptr;
            ptr += nchsamples;
        }
    }

    return 0;
}

static int chs_alloc_lsb_band_data(DCAXllDecoder *s, DCAXllChSet *c)
{
    int i, j, nsamples = 0;
    int32_t *ptr;

    // Determine number of frequency bands that have MSB/LSB split
    for (i = 0; i < c->nfreqbands; i++)
        if (c->bands[i].lsb_section_size)
            nsamples += s->nframesamples * c->nchannels;
    if (!nsamples)
        return 0;

    // Reallocate LSB sample buffer
    av_fast_malloc(&c->sample_buffer[1], &c->sample_size[1], nsamples * sizeof(int32_t));
    if (!c->sample_buffer[1])
        return AVERROR(ENOMEM);

    ptr = c->sample_buffer[1];
    for (i = 0; i < c->nfreqbands; i++) {
        if (c->bands[i].lsb_section_size) {
            for (j = 0; j < c->nchannels; j++) {
                c->bands[i].lsb_sample_buffer[j] = ptr;
                ptr += s->nframesamples;
            }
        } else {
            for (j = 0; j < c->nchannels; j++)
                c->bands[i].lsb_sample_buffer[j] = NULL;
        }
    }

    return 0;
}

static int chs_parse_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band, int seg, int band_data_end)
{
    DCAXllBand *b = &c->bands[band];
    int i, j, k;

    // Start unpacking MSB portion of the segment
    if (!(seg && get_bits1(&s->gb))) {
        // Unpack segment type
        // 0 - distinct coding parameters for each channel
        // 1 - common coding parameters for all channels
        c->seg_common = get_bits1(&s->gb);

        // Determine number of coding parameters encoded in segment
        k = c->seg_common ? 1 : c->nchannels;

        // Unpack Rice coding parameters
        for (i = 0; i < k; i++) {
            // Unpack Rice coding flag
            // 0 - linear code, 1 - Rice code
            c->rice_code_flag[i] = get_bits1(&s->gb);
            // Unpack Hybrid Rice coding flag
            // 0 - Rice code, 1 - Hybrid Rice code
            if (!c->seg_common && c->rice_code_flag[i] && get_bits1(&s->gb))
                // Unpack binary code length for isolated samples
                c->bitalloc_hybrid_linear[i] = get_bits(&s->gb, c->nabits) + 1;
            else
                // 0 indicates no Hybrid Rice coding
                c->bitalloc_hybrid_linear[i] = 0;
        }

        // Unpack coding parameters
        for (i = 0; i < k; i++) {
            if (seg == 0) {
                // Unpack coding parameter for part A of segment 0
                c->bitalloc_part_a[i] = get_bits(&s->gb, c->nabits);

                // Adjust for the linear code
                if (!c->rice_code_flag[i] && c->bitalloc_part_a[i])
                    c->bitalloc_part_a[i]++;

                if (!c->seg_common)
                    c->nsamples_part_a[i] = b->adapt_pred_order[i];
                else
                    c->nsamples_part_a[i] = b->highest_pred_order;
            } else {
                c->bitalloc_part_a[i] = 0;
                c->nsamples_part_a[i] = 0;
            }

            // Unpack coding parameter for part B of segment
            c->bitalloc_part_b[i] = get_bits(&s->gb, c->nabits);

            // Adjust for the linear code
            if (!c->rice_code_flag[i] && c->bitalloc_part_b[i])
                c->bitalloc_part_b[i]++;
        }
    }

    // Unpack entropy codes
    for (i = 0; i < c->nchannels; i++) {
        int32_t *part_a, *part_b;
        int nsamples_part_b;

        // Select index of coding parameters
        k = c->seg_common ? 0 : i;

        // Slice the segment into parts A and B
        part_a = b->msb_sample_buffer[i] + seg * s->nsegsamples;
        part_b = part_a + c->nsamples_part_a[k];
        nsamples_part_b = s->nsegsamples - c->nsamples_part_a[k];

        if (get_bits_left(&s->gb) < 0)
            return AVERROR_INVALIDDATA;

        if (!c->rice_code_flag[k]) {
            // Linear codes
            // Unpack all residuals of part A of segment 0
            get_linear_array(&s->gb, part_a, c->nsamples_part_a[k],
                             c->bitalloc_part_a[k]);

            // Unpack all residuals of part B of segment 0 and others
            get_linear_array(&s->gb, part_b, nsamples_part_b,
                             c->bitalloc_part_b[k]);
        } else {
            // Rice codes
            // Unpack all residuals of part A of segment 0
            get_rice_array(&s->gb, part_a, c->nsamples_part_a[k],
                           c->bitalloc_part_a[k]);

            if (c->bitalloc_hybrid_linear[k]) {
                // Hybrid Rice codes
                // Unpack the number of isolated samples
                int nisosamples = get_bits(&s->gb, s->nsegsamples_log2);

                // Set all locations to 0
                memset(part_b, 0, sizeof(*part_b) * nsamples_part_b);

                // Extract the locations of isolated samples and flag by -1
                for (j = 0; j < nisosamples; j++) {
                    int loc = get_bits(&s->gb, s->nsegsamples_log2);
                    if (loc >= nsamples_part_b) {
                        av_log(s->avctx, AV_LOG_ERROR, "Invalid isolated sample location\n");
                        return AVERROR_INVALIDDATA;
                    }
                    part_b[loc] = -1;
                }

                // Unpack all residuals of part B of segment 0 and others
                for (j = 0; j < nsamples_part_b; j++) {
                    if (part_b[j])
                        part_b[j] = get_linear(&s->gb, c->bitalloc_hybrid_linear[k]);
                    else
                        part_b[j] = get_rice(&s->gb, c->bitalloc_part_b[k]);
                }
            } else {
                // Rice codes
                // Unpack all residuals of part B of segment 0 and others
                get_rice_array(&s->gb, part_b, nsamples_part_b, c->bitalloc_part_b[k]);
            }
        }
    }

    // Unpack decimator history for frequency band 1
    if (seg == 0 && band == 1) {
        int nbits = get_bits(&s->gb, 5) + 1;
        for (i = 0; i < c->nchannels; i++)
            for (j = 1; j < DCA_XLL_DECI_HISTORY_MAX; j++)
                c->deci_history[i][j] = get_sbits_long(&s->gb, nbits);
    }

    // Start unpacking LSB portion of the segment
    if (b->lsb_section_size) {
        // Skip to the start of LSB portion
        if (ff_dca_seek_bits(&s->gb, band_data_end - b->lsb_section_size * 8)) {
            av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL band data\n");
            return AVERROR_INVALIDDATA;
        }

        // Unpack all LSB parts of residuals of this segment
        for (i = 0; i < c->nchannels; i++) {
            if (b->nscalablelsbs[i]) {
                get_array(&s->gb,
                          b->lsb_sample_buffer[i] + seg * s->nsegsamples,
                          s->nsegsamples, b->nscalablelsbs[i]);
            }
        }
    }

    // Skip to the end of band data
    if (ff_dca_seek_bits(&s->gb, band_data_end)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL band data\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

static av_cold void chs_clear_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band, int seg)
{
    DCAXllBand *b = &c->bands[band];
    int i, offset, nsamples;

    if (seg < 0) {
        offset = 0;
        nsamples = s->nframesamples;
    } else {
        offset = seg * s->nsegsamples;
        nsamples = s->nsegsamples;
    }

    for (i = 0; i < c->nchannels; i++) {
        memset(b->msb_sample_buffer[i] + offset, 0, nsamples * sizeof(int32_t));
        if (b->lsb_section_size)
            memset(b->lsb_sample_buffer[i] + offset, 0, nsamples * sizeof(int32_t));
    }

    if (seg <= 0 && band)
        memset(c->deci_history, 0, sizeof(c->deci_history));

    if (seg < 0) {
        memset(b->nscalablelsbs, 0, sizeof(b->nscalablelsbs));
        memset(b->bit_width_adjust, 0, sizeof(b->bit_width_adjust));
    }
}

static void chs_filter_band_data(DCAXllDecoder *s, DCAXllChSet *c, int band)
{
    DCAXllBand *b = &c->bands[band];
    int nsamples = s->nframesamples;
    int i, j, k;

    // Inverse adaptive or fixed prediction
    for (i = 0; i < c->nchannels; i++) {
        int32_t *buf = b->msb_sample_buffer[i];
        int order = b->adapt_pred_order[i];
        if (order > 0) {
            int coeff[DCA_XLL_ADAPT_PRED_ORDER_MAX];
            // Conversion from reflection coefficients to direct form coefficients
            for (j = 0; j < order; j++) {
                int rc = b->adapt_refl_coeff[i][j];
                for (k = 0; k < (j + 1) / 2; k++) {
                    int tmp1 = coeff[    k    ];
                    int tmp2 = coeff[j - k - 1];
                    coeff[    k    ] = tmp1 + mul16(rc, tmp2);
                    coeff[j - k - 1] = tmp2 + mul16(rc, tmp1);
                }
                coeff[j] = rc;
            }
            // Inverse adaptive prediction
            for (j = 0; j < nsamples - order; j++) {
                int64_t err = 0;
                for (k = 0; k < order; k++)
                    err += (int64_t)buf[j + k] * coeff[order - k - 1];
                buf[j + k] -= (SUINT)clip23(norm16(err));
            }
        } else {
            // Inverse fixed coefficient prediction
            for (j = 0; j < b->fixed_pred_order[i]; j++)
                for (k = 1; k < nsamples; k++)
                    buf[k] += (unsigned)buf[k - 1];
        }
    }

    // Inverse pairwise channel decorrellation
    if (b->decor_enabled) {
        int32_t *tmp[DCA_XLL_CHANNELS_MAX];

        for (i = 0; i < c->nchannels / 2; i++) {
            int coeff = b->decor_coeff[i];
            if (coeff) {
                s->dcadsp->decor(b->msb_sample_buffer[i * 2 + 1],
                                 b->msb_sample_buffer[i * 2    ],
                                 coeff, nsamples);
            }
        }

        // Reorder channel pointers to the original order
        for (i = 0; i < c->nchannels; i++)
            tmp[i] = b->msb_sample_buffer[i];

        for (i = 0; i < c->nchannels; i++)
            b->msb_sample_buffer[b->orig_order[i]] = tmp[i];
    }

    // Map output channel pointers for frequency band 0
    if (c->nfreqbands == 1)
        for (i = 0; i < c->nchannels; i++)
            s->output_samples[c->ch_remap[i]] = b->msb_sample_buffer[i];
}

static int chs_get_lsb_width(DCAXllDecoder *s, DCAXllChSet *c, int band, int ch)
{
    int adj = c->bands[band].bit_width_adjust[ch];
    int shift = c->bands[band].nscalablelsbs[ch];

    if (s->fixed_lsb_width)
        shift = s->fixed_lsb_width;
    else if (shift && adj)
        shift += adj - 1;
    else
        shift += adj;

    return shift;
}

static void chs_assemble_msbs_lsbs(DCAXllDecoder *s, DCAXllChSet *c, int band)
{
    DCAXllBand *b = &c->bands[band];
    int n, ch, nsamples = s->nframesamples;

    for (ch = 0; ch < c->nchannels; ch++) {
        int shift = chs_get_lsb_width(s, c, band, ch);
        if (shift) {
            int32_t *msb = b->msb_sample_buffer[ch];
            if (b->nscalablelsbs[ch]) {
                int32_t *lsb = b->lsb_sample_buffer[ch];
                int adj = b->bit_width_adjust[ch];
                for (n = 0; n < nsamples; n++)
                    msb[n] = msb[n] * (SUINT)(1 << shift) + (lsb[n] << adj);
            } else {
                for (n = 0; n < nsamples; n++)
                    msb[n] = msb[n] * (SUINT)(1 << shift);
            }
        }
    }
}

static int chs_assemble_freq_bands(DCAXllDecoder *s, DCAXllChSet *c)
{
    int ch, nsamples = s->nframesamples;
    int32_t *ptr;

    av_assert1(c->nfreqbands > 1);

    // Reallocate frequency band assembly buffer
    av_fast_malloc(&c->sample_buffer[2], &c->sample_size[2],
                   2 * nsamples * c->nchannels * sizeof(int32_t));
    if (!c->sample_buffer[2])
        return AVERROR(ENOMEM);

    // Assemble frequency bands 0 and 1
    ptr = c->sample_buffer[2];
    for (ch = 0; ch < c->nchannels; ch++) {
        int32_t *band0 = c->bands[0].msb_sample_buffer[ch];
        int32_t *band1 = c->bands[1].msb_sample_buffer[ch];

        // Copy decimator history
        memcpy(band0 - DCA_XLL_DECI_HISTORY_MAX,
               c->deci_history[ch], sizeof(c->deci_history[0]));

        // Filter
        s->dcadsp->assemble_freq_bands(ptr, band0, band1,
                                       ff_dca_xll_band_coeff,
                                       nsamples);

        // Remap output channel pointer to assembly buffer
        s->output_samples[c->ch_remap[ch]] = ptr;
        ptr += nsamples * 2;
    }

    return 0;
}

static int parse_common_header(DCAXllDecoder *s)
{
    int stream_ver, header_size, frame_size_nbits, nframesegs_log2;

    // XLL extension sync word
    if (get_bits_long(&s->gb, 32) != DCA_SYNCWORD_XLL) {
        av_log(s->avctx, AV_LOG_VERBOSE, "Invalid XLL sync word\n");
        return AVERROR(EAGAIN);
    }

    // Version number
    stream_ver = get_bits(&s->gb, 4) + 1;
    if (stream_ver > 1) {
        avpriv_request_sample(s->avctx, "XLL stream version %d", stream_ver);
        return AVERROR_PATCHWELCOME;
    }

    // Lossless frame header length
    header_size = get_bits(&s->gb, 8) + 1;

    // Check CRC
    if (ff_dca_check_crc(s->avctx, &s->gb, 32, header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL common header checksum\n");
        return AVERROR_INVALIDDATA;
    }

    // Number of bits used to read frame size
    frame_size_nbits = get_bits(&s->gb, 5) + 1;

    // Number of bytes in a lossless frame
    s->frame_size = get_bits_long(&s->gb, frame_size_nbits);
    if (s->frame_size < 0 || s->frame_size >= DCA_XLL_PBR_BUFFER_MAX) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid XLL frame size (%d bytes)\n", s->frame_size);
        return AVERROR_INVALIDDATA;
    }
    s->frame_size++;

    // Number of channels sets per frame
    s->nchsets = get_bits(&s->gb, 4) + 1;
    if (s->nchsets > DCA_XLL_CHSETS_MAX) {
        avpriv_request_sample(s->avctx, "%d XLL channel sets", s->nchsets);
        return AVERROR_PATCHWELCOME;
    }

    // Number of segments per frame
    nframesegs_log2 = get_bits(&s->gb, 4);
    s->nframesegs = 1 << nframesegs_log2;
    if (s->nframesegs > 1024) {
        av_log(s->avctx, AV_LOG_ERROR, "Too many segments per XLL frame\n");
        return AVERROR_INVALIDDATA;
    }

    // Samples in segment per one frequency band for the first channel set
    // Maximum value is 256 for sampling frequencies <= 48 kHz
    // Maximum value is 512 for sampling frequencies > 48 kHz
    s->nsegsamples_log2 = get_bits(&s->gb, 4);
    if (!s->nsegsamples_log2) {
        av_log(s->avctx, AV_LOG_ERROR, "Too few samples per XLL segment\n");
        return AVERROR_INVALIDDATA;
    }
    s->nsegsamples = 1 << s->nsegsamples_log2;
    if (s->nsegsamples > 512) {
        av_log(s->avctx, AV_LOG_ERROR, "Too many samples per XLL segment\n");
        return AVERROR_INVALIDDATA;
    }

    // Samples in frame per one frequency band for the first channel set
    s->nframesamples_log2 = s->nsegsamples_log2 + nframesegs_log2;
    s->nframesamples = 1 << s->nframesamples_log2;
    if (s->nframesamples > 65536) {
        av_log(s->avctx, AV_LOG_ERROR, "Too many samples per XLL frame\n");
        return AVERROR_INVALIDDATA;
    }

    // Number of bits used to read segment size
    s->seg_size_nbits = get_bits(&s->gb, 5) + 1;

    // Presence of CRC16 within each frequency band
    // 0 - No CRC16 within band
    // 1 - CRC16 placed at the end of MSB0
    // 2 - CRC16 placed at the end of MSB0 and LSB0
    // 3 - CRC16 placed at the end of MSB0 and LSB0 and other frequency bands
    s->band_crc_present = get_bits(&s->gb, 2);

    // MSB/LSB split flag
    s->scalable_lsbs = get_bits1(&s->gb);

    // Channel position mask
    s->ch_mask_nbits = get_bits(&s->gb, 5) + 1;

    // Fixed LSB width
    if (s->scalable_lsbs)
        s->fixed_lsb_width = get_bits(&s->gb, 4);
    else
        s->fixed_lsb_width = 0;

    // Reserved
    // Byte align
    // Header CRC16 protection
    if (ff_dca_seek_bits(&s->gb, header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL common header\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

static int is_hier_dmix_chset(DCAXllChSet *c)
{
    return !c->primary_chset && c->dmix_embedded && c->hier_chset;
}

static DCAXllChSet *find_next_hier_dmix_chset(DCAXllDecoder *s, DCAXllChSet *c)
{
    if (c->hier_chset)
        while (++c < &s->chset[s->nchsets])
            if (is_hier_dmix_chset(c))
                return c;

    return NULL;
}

static void prescale_down_mix(DCAXllChSet *c, DCAXllChSet *o)
{
    int i, j, *coeff_ptr = c->dmix_coeff;

    for (i = 0; i < c->hier_ofs; i++) {
        int scale = o->dmix_scale[i];
        int scale_inv = o->dmix_scale_inv[i];
        c->dmix_scale[i] = mul15(c->dmix_scale[i], scale);
        c->dmix_scale_inv[i] = mul16(c->dmix_scale_inv[i], scale_inv);
        for (j = 0; j < c->nchannels; j++) {
            int coeff = mul16(*coeff_ptr, scale_inv);
            *coeff_ptr++ = mul15(coeff, o->dmix_scale[c->hier_ofs + j]);
        }
    }
}

static int parse_sub_headers(DCAXllDecoder *s, DCAExssAsset *asset)
{
    DCAContext *dca = s->avctx->priv_data;
    DCAXllChSet *c;
    int i, ret;

    // Parse channel set headers
    s->nfreqbands = 0;
    s->nchannels = 0;
    s->nreschsets = 0;
    for (i = 0, c = s->chset; i < s->nchsets; i++, c++) {
        c->hier_ofs = s->nchannels;
        if ((ret = chs_parse_header(s, c, asset)) < 0)
            return ret;
        if (c->nfreqbands > s->nfreqbands)
            s->nfreqbands = c->nfreqbands;
        if (c->hier_chset)
            s->nchannels += c->nchannels;
        if (c->residual_encode != (1 << c->nchannels) - 1)
            s->nreschsets++;
    }

    // Pre-scale downmixing coefficients for all non-primary channel sets
    for (i = s->nchsets - 1, c = &s->chset[i]; i > 0; i--, c--) {
        if (is_hier_dmix_chset(c)) {
            DCAXllChSet *o = find_next_hier_dmix_chset(s, c);
            if (o)
                prescale_down_mix(c, o);
        }
    }

    // Determine number of active channel sets to decode
    switch (dca->request_channel_layout) {
    case DCA_SPEAKER_LAYOUT_STEREO:
        s->nactivechsets = 1;
        break;
    case DCA_SPEAKER_LAYOUT_5POINT0:
    case DCA_SPEAKER_LAYOUT_5POINT1:
        s->nactivechsets = (s->chset[0].nchannels < 5 && s->nchsets > 1) ? 2 : 1;
        break;
    default:
        s->nactivechsets = s->nchsets;
        break;
    }

    return 0;
}

static int parse_navi_table(DCAXllDecoder *s)
{
    int chs, seg, band, navi_nb, navi_pos, *navi_ptr;
    DCAXllChSet *c;

    // Determine size of NAVI table
    navi_nb = s->nfreqbands * s->nframesegs * s->nchsets;
    if (navi_nb > 1024) {
        av_log(s->avctx, AV_LOG_ERROR, "Too many NAVI entries (%d)\n", navi_nb);
        return AVERROR_INVALIDDATA;
    }

    // Reallocate NAVI table
    av_fast_malloc(&s->navi, &s->navi_size, navi_nb * sizeof(*s->navi));
    if (!s->navi)
        return AVERROR(ENOMEM);

    // Parse NAVI
    navi_pos = get_bits_count(&s->gb);
    navi_ptr = s->navi;
    for (band = 0; band < s->nfreqbands; band++) {
        for (seg = 0; seg < s->nframesegs; seg++) {
            for (chs = 0, c = s->chset; chs < s->nchsets; chs++, c++) {
                int size = 0;
                if (c->nfreqbands > band) {
                    size = get_bits_long(&s->gb, s->seg_size_nbits);
                    if (size < 0 || size >= s->frame_size) {
                        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI segment size (%d bytes)\n", size);
                        return AVERROR_INVALIDDATA;
                    }
                    size++;
                }
                *navi_ptr++ = size;
            }
        }
    }

    // Byte align
    // CRC16
    skip_bits(&s->gb, -get_bits_count(&s->gb) & 7);
    skip_bits(&s->gb, 16);

    // Check CRC
    if (ff_dca_check_crc(s->avctx, &s->gb, navi_pos, get_bits_count(&s->gb))) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI checksum\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

static int parse_band_data(DCAXllDecoder *s)
{
    int ret, chs, seg, band, navi_pos, *navi_ptr;
    DCAXllChSet *c;

    for (chs = 0, c = s->chset; chs < s->nactivechsets; chs++, c++) {
        if ((ret = chs_alloc_msb_band_data(s, c)) < 0)
            return ret;
        if ((ret = chs_alloc_lsb_band_data(s, c)) < 0)
            return ret;
    }

    navi_pos = get_bits_count(&s->gb);
    navi_ptr = s->navi;
    for (band = 0; band < s->nfreqbands; band++) {
        for (seg = 0; seg < s->nframesegs; seg++) {
            for (chs = 0, c = s->chset; chs < s->nchsets; chs++, c++) {
                if (c->nfreqbands > band) {
                    navi_pos += *navi_ptr * 8;
                    if (navi_pos > s->gb.size_in_bits) {
                        av_log(s->avctx, AV_LOG_ERROR, "Invalid NAVI position\n");
                        return AVERROR_INVALIDDATA;
                    }
                    if (chs < s->nactivechsets &&
                        (ret = chs_parse_band_data(s, c, band, seg, navi_pos)) < 0) {
                        if (s->avctx->err_recognition & AV_EF_EXPLODE)
                            return ret;
                        chs_clear_band_data(s, c, band, seg);
                    }
                    skip_bits_long(&s->gb, navi_pos - get_bits_count(&s->gb));
                }
                navi_ptr++;
            }
        }
    }

    return 0;
}

static int parse_frame(DCAXllDecoder *s, const uint8_t *data, int size, DCAExssAsset *asset)
{
    int ret;

    if ((ret = init_get_bits8(&s->gb, data, size)) < 0)
        return ret;
    if ((ret = parse_common_header(s)) < 0)
        return ret;
    if ((ret = parse_sub_headers(s, asset)) < 0)
        return ret;
    if ((ret = parse_navi_table(s)) < 0)
        return ret;
    if ((ret = parse_band_data(s)) < 0)
        return ret;

     if (s->frame_size * 8 > FFALIGN(get_bits_count(&s->gb), 32)) {
        unsigned int extradata_syncword;

        // Align to dword
        skip_bits_long(&s->gb, -get_bits_count(&s->gb) & 31);

        extradata_syncword = show_bits_long(&s->gb, 32);

        if (extradata_syncword == DCA_SYNCWORD_XLL_X) {
            s->x_syncword_present = 1;
        } else if ((extradata_syncword >> 1) == (DCA_SYNCWORD_XLL_X_IMAX >> 1)) {
            s->x_imax_syncword_present = 1;
        }
    }

    if (ff_dca_seek_bits(&s->gb, s->frame_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of XLL frame\n");
        return AVERROR_INVALIDDATA;
    }
    return ret;
}

static void clear_pbr(DCAXllDecoder *s)
{
    s->pbr_length = 0;
    s->pbr_delay = 0;
}

static int copy_to_pbr(DCAXllDecoder *s, const uint8_t *data, int size, int delay)
{
    if (size > DCA_XLL_PBR_BUFFER_MAX)
        return AVERROR(ENOSPC);

    if (!s->pbr_buffer && !(s->pbr_buffer = av_malloc(DCA_XLL_PBR_BUFFER_MAX + AV_INPUT_BUFFER_PADDING_SIZE)))
        return AVERROR(ENOMEM);

    memcpy(s->pbr_buffer, data, size);
    s->pbr_length = size;
    s->pbr_delay = delay;
    return 0;
}

static int parse_frame_no_pbr(DCAXllDecoder *s, const uint8_t *data, int size, DCAExssAsset *asset)
{
    int ret = parse_frame(s, data, size, asset);

    // If XLL packet data didn't start with a sync word, we must have jumped
    // right into the middle of PBR smoothing period
    if (ret == AVERROR(EAGAIN) && asset->xll_sync_present && asset->xll_sync_offset < size) {
        // Skip to the next sync word in this packet
        data += asset->xll_sync_offset;
        size -= asset->xll_sync_offset;

        // If decoding delay is set, put the frame into PBR buffer and return
        // failure code. Higher level decoder is expected to switch to lossy
        // core decoding or mute its output until decoding delay expires.
        if (asset->xll_delay_nframes > 0) {
            if ((ret = copy_to_pbr(s, data, size, asset->xll_delay_nframes)) < 0)
                return ret;
            return AVERROR(EAGAIN);
        }

        // No decoding delay, just parse the frame in place
        ret = parse_frame(s, data, size, asset);
    }

    if (ret < 0)
        return ret;

    if (s->frame_size > size)
        return AVERROR(EINVAL);

    // If the XLL decoder didn't consume full packet, start PBR smoothing period
    if (s->frame_size < size)
        if ((ret = copy_to_pbr(s, data + s->frame_size, size - s->frame_size, 0)) < 0)
            return ret;

    return 0;
}

static int parse_frame_pbr(DCAXllDecoder *s, const uint8_t *data, int size, DCAExssAsset *asset)
{
    int ret;

    if (size > DCA_XLL_PBR_BUFFER_MAX - s->pbr_length) {
        ret = AVERROR(ENOSPC);
        goto fail;
    }

    memcpy(s->pbr_buffer + s->pbr_length, data, size);
    s->pbr_length += size;

    // Respect decoding delay after synchronization error
    if (s->pbr_delay > 0 && --s->pbr_delay)
        return AVERROR(EAGAIN);

    if ((ret = parse_frame(s, s->pbr_buffer, s->pbr_length, asset)) < 0)
        goto fail;

    if (s->frame_size > s->pbr_length) {
        ret = AVERROR(EINVAL);
        goto fail;
    }

    if (s->frame_size == s->pbr_length) {
        // End of PBR smoothing period
        clear_pbr(s);
    } else {
        s->pbr_length -= s->frame_size;
        memmove(s->pbr_buffer, s->pbr_buffer + s->frame_size, s->pbr_length);
    }

    return 0;

fail:
    // For now, throw out all PBR state on failure.
    // Perhaps we can be smarter and try to resync somehow.
    clear_pbr(s);
    return ret;
}

int ff_dca_xll_parse(DCAXllDecoder *s, const uint8_t *data, DCAExssAsset *asset)
{
    int ret;

    if (s->hd_stream_id != asset->hd_stream_id) {
        clear_pbr(s);
        s->hd_stream_id = asset->hd_stream_id;
    }

    if (s->pbr_length)
        ret = parse_frame_pbr(s, data + asset->xll_offset, asset->xll_size, asset);
    else
        ret = parse_frame_no_pbr(s, data + asset->xll_offset, asset->xll_size, asset);

    return ret;
}

static void undo_down_mix(DCAXllDecoder *s, DCAXllChSet *o, int band)
{
    int i, j, k, nchannels = 0, *coeff_ptr = o->dmix_coeff;
    DCAXllChSet *c;

    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
        if (!c->hier_chset)
            continue;

        av_assert1(band < c->nfreqbands);
        for (j = 0; j < c->nchannels; j++) {
            for (k = 0; k < o->nchannels; k++) {
                int coeff = *coeff_ptr++;
                if (coeff) {
                    s->dcadsp->dmix_sub(c->bands[band].msb_sample_buffer[j],
                                        o->bands[band].msb_sample_buffer[k],
                                        coeff, s->nframesamples);
                    if (band)
                        s->dcadsp->dmix_sub(c->deci_history[j],
                                            o->deci_history[k],
                                            coeff, DCA_XLL_DECI_HISTORY_MAX);
                }
            }
        }

        nchannels += c->nchannels;
        if (nchannels >= o->hier_ofs)
            break;
    }
}

static void scale_down_mix(DCAXllDecoder *s, DCAXllChSet *o, int band)
{
    int i, j, nchannels = 0;
    DCAXllChSet *c;

    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
        if (!c->hier_chset)
            continue;

        av_assert1(band < c->nfreqbands);
        for (j = 0; j < c->nchannels; j++) {
            int scale = o->dmix_scale[nchannels++];
            if (scale != (1 << 15)) {
                s->dcadsp->dmix_scale(c->bands[band].msb_sample_buffer[j],
                                      scale, s->nframesamples);
                if (band)
                    s->dcadsp->dmix_scale(c->deci_history[j],
                                          scale, DCA_XLL_DECI_HISTORY_MAX);
            }
        }

        if (nchannels >= o->hier_ofs)
            break;
    }
}

// Clear all band data and replace non-residual encoded channels with lossy
// counterparts
static av_cold void force_lossy_output(DCAXllDecoder *s, DCAXllChSet *c)
{
    DCAContext *dca = s->avctx->priv_data;
    int band, ch;

    for (band = 0; band < c->nfreqbands; band++)
        chs_clear_band_data(s, c, band, -1);

    for (ch = 0; ch < c->nchannels; ch++) {
        if (!(c->residual_encode & (1 << ch)))
            continue;
        if (ff_dca_core_map_spkr(&dca->core, c->ch_remap[ch]) < 0)
            continue;
        c->residual_encode &= ~(1 << ch);
    }
}

static int combine_residual_frame(DCAXllDecoder *s, DCAXllChSet *c)
{
    DCAContext *dca = s->avctx->priv_data;
    int ch, nsamples = s->nframesamples;
    DCAXllChSet *o;

    // Verify that core is compatible
    if (!(dca->packet & DCA_PACKET_CORE)) {
        av_log(s->avctx, AV_LOG_ERROR, "Residual encoded channels are present without core\n");
        return AVERROR(EINVAL);
    }

    if (c->freq != dca->core.output_rate) {
        av_log(s->avctx, AV_LOG_WARNING, "Sample rate mismatch between core (%d Hz) and XLL (%d Hz)\n", dca->core.output_rate, c->freq);
        return AVERROR_INVALIDDATA;
    }

    if (nsamples != dca->core.npcmsamples) {
        av_log(s->avctx, AV_LOG_WARNING, "Number of samples per frame mismatch between core (%d) and XLL (%d)\n", dca->core.npcmsamples, nsamples);
        return AVERROR_INVALIDDATA;
    }

    // See if this channel set is downmixed and find the next channel set in
    // hierarchy. If downmixed, undo core pre-scaling before combining with
    // residual (residual is not scaled).
    o = find_next_hier_dmix_chset(s, c);

    // Reduce core bit width and combine with residual
    for (ch = 0; ch < c->nchannels; ch++) {
        int n, spkr, shift, round;
        int32_t *src, *dst;

        if (c->residual_encode & (1 << ch))
            continue;

        // Map this channel to core speaker
        spkr = ff_dca_core_map_spkr(&dca->core, c->ch_remap[ch]);
        if (spkr < 0) {
            av_log(s->avctx, AV_LOG_WARNING, "Residual encoded channel (%d) references unavailable core channel\n", c->ch_remap[ch]);
            return AVERROR_INVALIDDATA;
        }

        // Account for LSB width
        shift = 24 - c->pcm_bit_res + chs_get_lsb_width(s, c, 0, ch);
        if (shift > 24) {
            av_log(s->avctx, AV_LOG_WARNING, "Invalid core shift (%d bits)\n", shift);
            return AVERROR_INVALIDDATA;
        }

        round = shift > 0 ? 1 << (shift - 1) : 0;

        src = dca->core.output_samples[spkr];
        dst = c->bands[0].msb_sample_buffer[ch];
        if (o) {
            // Undo embedded core downmix pre-scaling
            int scale_inv = o->dmix_scale_inv[c->hier_ofs + ch];
            for (n = 0; n < nsamples; n++)
                dst[n] += (SUINT)clip23((mul16(src[n], scale_inv) + round) >> shift);
        } else {
            // No downmix scaling
            for (n = 0; n < nsamples; n++)
                dst[n] += (unsigned)((src[n] + round) >> shift);
        }
    }

    return 0;
}

int ff_dca_xll_filter_frame(DCAXllDecoder *s, AVFrame *frame)
{
    AVCodecContext *avctx = s->avctx;
    DCAContext *dca = avctx->priv_data;
    DCAExssAsset *asset = &dca->exss.assets[0];
    DCAXllChSet *p = &s->chset[0], *c;
    enum AVMatrixEncoding matrix_encoding = AV_MATRIX_ENCODING_NONE;
    int i, j, k, ret, shift, nsamples, request_mask;
    int ch_remap[DCA_SPEAKER_COUNT];

    // Force lossy downmixed output during recovery
    if (dca->packet & DCA_PACKET_RECOVERY) {
        for (i = 0, c = s->chset; i < s->nchsets; i++, c++) {
            if (i < s->nactivechsets)
                force_lossy_output(s, c);

            if (!c->primary_chset)
                c->dmix_embedded = 0;
        }

        s->scalable_lsbs = 0;
        s->fixed_lsb_width = 0;
    }

    // Filter frequency bands for active channel sets
    s->output_mask = 0;
    for (i = 0, c = s->chset; i < s->nactivechsets; i++, c++) {
        chs_filter_band_data(s, c, 0);

        if (c->residual_encode != (1 << c->nchannels) - 1
            && (ret = combine_residual_frame(s, c)) < 0)
            return ret;

        if (s->scalable_lsbs)
            chs_assemble_msbs_lsbs(s, c, 0);

        if (c->nfreqbands > 1) {
            chs_filter_band_data(s, c, 1);
            chs_assemble_msbs_lsbs(s, c, 1);
        }

        s->output_mask |= c->ch_mask;
    }

    // Undo hierarchial downmix and/or apply scaling
    for (i = 1, c = &s->chset[1]; i < s->nchsets; i++, c++) {
        if (!is_hier_dmix_chset(c))
            continue;

        if (i >= s->nactivechsets) {
            for (j = 0; j < c->nfreqbands; j++)
                if (c->bands[j].dmix_embedded)
                    scale_down_mix(s, c, j);
            break;
        }

        for (j = 0; j < c->nfreqbands; j++)
            if (c->bands[j].dmix_embedded)
                undo_down_mix(s, c, j);
    }

    // Assemble frequency bands for active channel sets
    if (s->nfreqbands > 1) {
        for (i = 0; i < s->nactivechsets; i++)
            if ((ret = chs_assemble_freq_bands(s, &s->chset[i])) < 0)
                return ret;
    }

    // Normalize to regular 5.1 layout if downmixing
    if (dca->request_channel_layout) {
        if (s->output_mask & DCA_SPEAKER_MASK_Lss) {
            s->output_samples[DCA_SPEAKER_Ls] = s->output_samples[DCA_SPEAKER_Lss];
            s->output_mask = (s->output_mask & ~DCA_SPEAKER_MASK_Lss) | DCA_SPEAKER_MASK_Ls;
        }
        if (s->output_mask & DCA_SPEAKER_MASK_Rss) {
            s->output_samples[DCA_SPEAKER_Rs] = s->output_samples[DCA_SPEAKER_Rss];
            s->output_mask = (s->output_mask & ~DCA_SPEAKER_MASK_Rss) | DCA_SPEAKER_MASK_Rs;
        }
    }

    // Handle downmixing to stereo request
    if (dca->request_channel_layout == DCA_SPEAKER_LAYOUT_STEREO
        && DCA_HAS_STEREO(s->output_mask) && p->dmix_embedded
        && (p->dmix_type == DCA_DMIX_TYPE_LoRo ||
            p->dmix_type == DCA_DMIX_TYPE_LtRt))
        request_mask = DCA_SPEAKER_LAYOUT_STEREO;
    else
        request_mask = s->output_mask;
    if (!ff_dca_set_channel_layout(avctx, ch_remap, request_mask))
        return AVERROR(EINVAL);

    avctx->sample_rate = p->freq << (s->nfreqbands - 1);

    switch (p->storage_bit_res) {
    case 16:
        avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
        shift = 16 - p->pcm_bit_res;
        break;
    case 20:
    case 24:
        avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
        shift = 24 - p->pcm_bit_res;
        break;
    default:
        return AVERROR(EINVAL);
    }

    if (s->x_imax_syncword_present) {
        avctx->profile = AV_PROFILE_DTS_HD_MA_X_IMAX;
    } else if (s->x_syncword_present) {
        avctx->profile = AV_PROFILE_DTS_HD_MA_X;
    } else {
        avctx->profile = AV_PROFILE_DTS_HD_MA;
    }

    avctx->bits_per_raw_sample = p->storage_bit_res;
    avctx->bit_rate = 0;

    frame->nb_samples = nsamples = s->nframesamples << (s->nfreqbands - 1);
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;

    // Downmix primary channel set to stereo
    if (request_mask != s->output_mask) {
        ff_dca_downmix_to_stereo_fixed(s->dcadsp, s->output_samples,
                                       p->dmix_coeff, nsamples,
                                       s->output_mask);
    }

    for (i = 0; i < avctx->ch_layout.nb_channels; i++) {
        int32_t *samples = s->output_samples[ch_remap[i]];
        if (frame->format == AV_SAMPLE_FMT_S16P) {
            int16_t *plane = (int16_t *)frame->extended_data[i];
            for (k = 0; k < nsamples; k++)
                plane[k] = av_clip_int16(samples[k] * (SUINT)(1 << shift));
        } else {
            int32_t *plane = (int32_t *)frame->extended_data[i];
            for (k = 0; k < nsamples; k++)
                plane[k] = clip23(samples[k] * (SUINT)(1 << shift)) * (1 << 8);
        }
    }

    if (!asset->one_to_one_map_ch_to_spkr) {
        if (asset->representation_type == DCA_REPR_TYPE_LtRt)
            matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
        else if (asset->representation_type == DCA_REPR_TYPE_LhRh)
            matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
    } else if (request_mask != s->output_mask && p->dmix_type == DCA_DMIX_TYPE_LtRt) {
        matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
    }
    if ((ret = ff_side_data_update_matrix_encoding(frame, matrix_encoding)) < 0)
        return ret;

    return 0;
}

av_cold void ff_dca_xll_flush(DCAXllDecoder *s)
{
    clear_pbr(s);
}

av_cold void ff_dca_xll_close(DCAXllDecoder *s)
{
    DCAXllChSet *c;
    int i, j;

    for (i = 0, c = s->chset; i < DCA_XLL_CHSETS_MAX; i++, c++) {
        for (j = 0; j < DCA_XLL_SAMPLE_BUFFERS_MAX; j++) {
            av_freep(&c->sample_buffer[j]);
            c->sample_size[j] = 0;
        }
    }

    av_freep(&s->navi);
    s->navi_size = 0;

    av_freep(&s->pbr_buffer);
    clear_pbr(s);
}