/
wmaprodec.c
1618 lines (1412 loc) · 62.7 KB
/
wmaprodec.c
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
/*
* Wmapro compatible decoder
* Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
* Copyright (c) 2008 - 2011 Sascha Sommer, Benjamin Larsson
*
* 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
* @brief wmapro decoder implementation
* Wmapro is an MDCT based codec comparable to wma standard or AAC.
* The decoding therefore consists of the following steps:
* - bitstream decoding
* - reconstruction of per-channel data
* - rescaling and inverse quantization
* - IMDCT
* - windowing and overlapp-add
*
* The compressed wmapro bitstream is split into individual packets.
* Every such packet contains one or more wma frames.
* The compressed frames may have a variable length and frames may
* cross packet boundaries.
* Common to all wmapro frames is the number of samples that are stored in
* a frame.
* The number of samples and a few other decode flags are stored
* as extradata that has to be passed to the decoder.
*
* The wmapro frames themselves are again split into a variable number of
* subframes. Every subframe contains the data for 2^N time domain samples
* where N varies between 7 and 12.
*
* Example wmapro bitstream (in samples):
*
* || packet 0 || packet 1 || packet 2 packets
* ---------------------------------------------------
* || frame 0 || frame 1 || frame 2 || frames
* ---------------------------------------------------
* || | | || | | | || || subframes of channel 0
* ---------------------------------------------------
* || | | || | | | || || subframes of channel 1
* ---------------------------------------------------
*
* The frame layouts for the individual channels of a wma frame does not need
* to be the same.
*
* However, if the offsets and lengths of several subframes of a frame are the
* same, the subframes of the channels can be grouped.
* Every group may then use special coding techniques like M/S stereo coding
* to improve the compression ratio. These channel transformations do not
* need to be applied to a whole subframe. Instead, they can also work on
* individual scale factor bands (see below).
* The coefficients that carry the audio signal in the frequency domain
* are transmitted as huffman-coded vectors with 4, 2 and 1 elements.
* In addition to that, the encoder can switch to a runlevel coding scheme
* by transmitting subframe_length / 128 zero coefficients.
*
* Before the audio signal can be converted to the time domain, the
* coefficients have to be rescaled and inverse quantized.
* A subframe is therefore split into several scale factor bands that get
* scaled individually.
* Scale factors are submitted for every frame but they might be shared
* between the subframes of a channel. Scale factors are initially DPCM-coded.
* Once scale factors are shared, the differences are transmitted as runlevel
* codes.
* Every subframe length and offset combination in the frame layout shares a
* common quantization factor that can be adjusted for every channel by a
* modifier.
* After the inverse quantization, the coefficients get processed by an IMDCT.
* The resulting values are then windowed with a sine window and the first half
* of the values are added to the second half of the output from the previous
* subframe in order to reconstruct the output samples.
*/
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "put_bits.h"
#include "wmaprodata.h"
#include "dsputil.h"
#include "wma.h"
/** current decoder limitations */
#define WMAPRO_MAX_CHANNELS 8 ///< max number of handled channels
#define MAX_SUBFRAMES 32 ///< max number of subframes per channel
#define MAX_BANDS 29 ///< max number of scale factor bands
#define MAX_FRAMESIZE 32768 ///< maximum compressed frame size
#define WMAPRO_BLOCK_MIN_BITS 6 ///< log2 of min block size
#define WMAPRO_BLOCK_MAX_BITS 12 ///< log2 of max block size
#define WMAPRO_BLOCK_MAX_SIZE (1 << WMAPRO_BLOCK_MAX_BITS) ///< maximum block size
#define WMAPRO_BLOCK_SIZES (WMAPRO_BLOCK_MAX_BITS - WMAPRO_BLOCK_MIN_BITS + 1) ///< possible block sizes
#define VLCBITS 9
#define SCALEVLCBITS 8
#define VEC4MAXDEPTH ((HUFF_VEC4_MAXBITS+VLCBITS-1)/VLCBITS)
#define VEC2MAXDEPTH ((HUFF_VEC2_MAXBITS+VLCBITS-1)/VLCBITS)
#define VEC1MAXDEPTH ((HUFF_VEC1_MAXBITS+VLCBITS-1)/VLCBITS)
#define SCALEMAXDEPTH ((HUFF_SCALE_MAXBITS+SCALEVLCBITS-1)/SCALEVLCBITS)
#define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS-1)/VLCBITS)
static VLC sf_vlc; ///< scale factor DPCM vlc
static VLC sf_rl_vlc; ///< scale factor run length vlc
static VLC vec4_vlc; ///< 4 coefficients per symbol
static VLC vec2_vlc; ///< 2 coefficients per symbol
static VLC vec1_vlc; ///< 1 coefficient per symbol
static VLC coef_vlc[2]; ///< coefficient run length vlc codes
static float sin64[33]; ///< sinus table for decorrelation
/**
* @brief frame specific decoder context for a single channel
*/
typedef struct {
int16_t prev_block_len; ///< length of the previous block
uint8_t transmit_coefs;
uint8_t num_subframes;
uint16_t subframe_len[MAX_SUBFRAMES]; ///< subframe length in samples
uint16_t subframe_offset[MAX_SUBFRAMES]; ///< subframe positions in the current frame
uint8_t cur_subframe; ///< current subframe number
uint16_t decoded_samples; ///< number of already processed samples
uint8_t grouped; ///< channel is part of a group
int quant_step; ///< quantization step for the current subframe
int8_t reuse_sf; ///< share scale factors between subframes
int8_t scale_factor_step; ///< scaling step for the current subframe
int max_scale_factor; ///< maximum scale factor for the current subframe
int saved_scale_factors[2][MAX_BANDS]; ///< resampled and (previously) transmitted scale factor values
int8_t scale_factor_idx; ///< index for the transmitted scale factor values (used for resampling)
int* scale_factors; ///< pointer to the scale factor values used for decoding
uint8_t table_idx; ///< index in sf_offsets for the scale factor reference block
float* coeffs; ///< pointer to the subframe decode buffer
uint16_t num_vec_coeffs; ///< number of vector coded coefficients
DECLARE_ALIGNED(16, float, out)[WMAPRO_BLOCK_MAX_SIZE + WMAPRO_BLOCK_MAX_SIZE / 2]; ///< output buffer
} WMAProChannelCtx;
/**
* @brief channel group for channel transformations
*/
typedef struct {
uint8_t num_channels; ///< number of channels in the group
int8_t transform; ///< transform on / off
int8_t transform_band[MAX_BANDS]; ///< controls if the transform is enabled for a certain band
float decorrelation_matrix[WMAPRO_MAX_CHANNELS*WMAPRO_MAX_CHANNELS];
float* channel_data[WMAPRO_MAX_CHANNELS]; ///< transformation coefficients
} WMAProChannelGrp;
/**
* @brief main decoder context
*/
typedef struct WMAProDecodeCtx {
/* generic decoder variables */
AVCodecContext* avctx; ///< codec context for av_log
DSPContext dsp; ///< accelerated DSP functions
uint8_t frame_data[MAX_FRAMESIZE +
FF_INPUT_BUFFER_PADDING_SIZE];///< compressed frame data
PutBitContext pb; ///< context for filling the frame_data buffer
FFTContext mdct_ctx[WMAPRO_BLOCK_SIZES]; ///< MDCT context per block size
DECLARE_ALIGNED(16, float, tmp)[WMAPRO_BLOCK_MAX_SIZE]; ///< IMDCT output buffer
float* windows[WMAPRO_BLOCK_SIZES]; ///< windows for the different block sizes
/* frame size dependent frame information (set during initialization) */
uint32_t decode_flags; ///< used compression features
uint8_t len_prefix; ///< frame is prefixed with its length
uint8_t dynamic_range_compression; ///< frame contains DRC data
uint8_t bits_per_sample; ///< integer audio sample size for the unscaled IMDCT output (used to scale to [-1.0, 1.0])
uint16_t samples_per_frame; ///< number of samples to output
uint16_t log2_frame_size;
int8_t num_channels; ///< number of channels in the stream (same as AVCodecContext.num_channels)
int8_t lfe_channel; ///< lfe channel index
uint8_t max_num_subframes;
uint8_t subframe_len_bits; ///< number of bits used for the subframe length
uint8_t max_subframe_len_bit; ///< flag indicating that the subframe is of maximum size when the first subframe length bit is 1
uint16_t min_samples_per_subframe;
int8_t num_sfb[WMAPRO_BLOCK_SIZES]; ///< scale factor bands per block size
int16_t sfb_offsets[WMAPRO_BLOCK_SIZES][MAX_BANDS]; ///< scale factor band offsets (multiples of 4)
int8_t sf_offsets[WMAPRO_BLOCK_SIZES][WMAPRO_BLOCK_SIZES][MAX_BANDS]; ///< scale factor resample matrix
int16_t subwoofer_cutoffs[WMAPRO_BLOCK_SIZES]; ///< subwoofer cutoff values
/* packet decode state */
GetBitContext pgb; ///< bitstream reader context for the packet
int next_packet_start; ///< start offset of the next wma packet in the demuxer packet
uint8_t packet_offset; ///< frame offset in the packet
uint8_t packet_sequence_number; ///< current packet number
int num_saved_bits; ///< saved number of bits
int frame_offset; ///< frame offset in the bit reservoir
int subframe_offset; ///< subframe offset in the bit reservoir
uint8_t packet_loss; ///< set in case of bitstream error
uint8_t packet_done; ///< set when a packet is fully decoded
/* frame decode state */
uint32_t frame_num; ///< current frame number (not used for decoding)
GetBitContext gb; ///< bitstream reader context
int buf_bit_size; ///< buffer size in bits
float* samples; ///< current samplebuffer pointer
float* samples_end; ///< maximum samplebuffer pointer
uint8_t drc_gain; ///< gain for the DRC tool
int8_t skip_frame; ///< skip output step
int8_t parsed_all_subframes; ///< all subframes decoded?
/* subframe/block decode state */
int16_t subframe_len; ///< current subframe length
int8_t channels_for_cur_subframe; ///< number of channels that contain the subframe
int8_t channel_indexes_for_cur_subframe[WMAPRO_MAX_CHANNELS];
int8_t num_bands; ///< number of scale factor bands
int8_t transmit_num_vec_coeffs; ///< number of vector coded coefficients is part of the bitstream
int16_t* cur_sfb_offsets; ///< sfb offsets for the current block
uint8_t table_idx; ///< index for the num_sfb, sfb_offsets, sf_offsets and subwoofer_cutoffs tables
int8_t esc_len; ///< length of escaped coefficients
uint8_t num_chgroups; ///< number of channel groups
WMAProChannelGrp chgroup[WMAPRO_MAX_CHANNELS]; ///< channel group information
WMAProChannelCtx channel[WMAPRO_MAX_CHANNELS]; ///< per channel data
} WMAProDecodeCtx;
/**
*@brief helper function to print the most important members of the context
*@param s context
*/
static void av_cold dump_context(WMAProDecodeCtx *s)
{
#define PRINT(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %d\n", a, b);
#define PRINT_HEX(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %x\n", a, b);
PRINT("ed sample bit depth", s->bits_per_sample);
PRINT_HEX("ed decode flags", s->decode_flags);
PRINT("samples per frame", s->samples_per_frame);
PRINT("log2 frame size", s->log2_frame_size);
PRINT("max num subframes", s->max_num_subframes);
PRINT("len prefix", s->len_prefix);
PRINT("num channels", s->num_channels);
}
/**
*@brief Uninitialize the decoder and free all resources.
*@param avctx codec context
*@return 0 on success, < 0 otherwise
*/
static av_cold int decode_end(AVCodecContext *avctx)
{
WMAProDecodeCtx *s = avctx->priv_data;
int i;
for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
ff_mdct_end(&s->mdct_ctx[i]);
return 0;
}
/**
*@brief Initialize the decoder.
*@param avctx codec context
*@return 0 on success, -1 otherwise
*/
static av_cold int decode_init(AVCodecContext *avctx)
{
WMAProDecodeCtx *s = avctx->priv_data;
uint8_t *edata_ptr = avctx->extradata;
unsigned int channel_mask;
int i;
int log2_max_num_subframes;
int num_possible_block_sizes;
s->avctx = avctx;
dsputil_init(&s->dsp, avctx);
init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
if (avctx->extradata_size >= 18) {
s->decode_flags = AV_RL16(edata_ptr+14);
channel_mask = AV_RL32(edata_ptr+2);
s->bits_per_sample = AV_RL16(edata_ptr);
/** dump the extradata */
for (i = 0; i < avctx->extradata_size; i++)
dprintf(avctx, "[%x] ", avctx->extradata[i]);
dprintf(avctx, "\n");
} else {
av_log_ask_for_sample(avctx, "Unknown extradata size\n");
return AVERROR_INVALIDDATA;
}
/** generic init */
s->log2_frame_size = av_log2(avctx->block_align) + 4;
/** frame info */
s->skip_frame = 1; /* skip first frame */
s->packet_loss = 1;
s->len_prefix = (s->decode_flags & 0x40);
/** get frame len */
s->samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx->sample_rate,
3, s->decode_flags);
/** init previous block len */
for (i = 0; i < avctx->channels; i++)
s->channel[i].prev_block_len = s->samples_per_frame;
/** subframe info */
log2_max_num_subframes = ((s->decode_flags & 0x38) >> 3);
s->max_num_subframes = 1 << log2_max_num_subframes;
if (s->max_num_subframes == 16 || s->max_num_subframes == 4)
s->max_subframe_len_bit = 1;
s->subframe_len_bits = av_log2(log2_max_num_subframes) + 1;
num_possible_block_sizes = log2_max_num_subframes + 1;
s->min_samples_per_subframe = s->samples_per_frame / s->max_num_subframes;
s->dynamic_range_compression = (s->decode_flags & 0x80);
if (s->max_num_subframes > MAX_SUBFRAMES) {
av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n",
s->max_num_subframes);
return AVERROR_INVALIDDATA;
}
s->num_channels = avctx->channels;
/** extract lfe channel position */
s->lfe_channel = -1;
if (channel_mask & 8) {
unsigned int mask;
for (mask = 1; mask < 16; mask <<= 1) {
if (channel_mask & mask)
++s->lfe_channel;
}
}
if (s->num_channels < 0) {
av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s->num_channels);
return AVERROR_INVALIDDATA;
} else if (s->num_channels > WMAPRO_MAX_CHANNELS) {
av_log_ask_for_sample(avctx, "unsupported number of channels\n");
return AVERROR_PATCHWELCOME;
}
INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
scale_huffbits, 1, 1,
scale_huffcodes, 2, 2, 616);
INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
scale_rl_huffbits, 1, 1,
scale_rl_huffcodes, 4, 4, 1406);
INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,
coef0_huffbits, 1, 1,
coef0_huffcodes, 4, 4, 2108);
INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,
coef1_huffbits, 1, 1,
coef1_huffcodes, 4, 4, 3912);
INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
vec4_huffbits, 1, 1,
vec4_huffcodes, 2, 2, 604);
INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
vec2_huffbits, 1, 1,
vec2_huffcodes, 2, 2, 562);
INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
vec1_huffbits, 1, 1,
vec1_huffcodes, 2, 2, 562);
/** calculate number of scale factor bands and their offsets
for every possible block size */
for (i = 0; i < num_possible_block_sizes; i++) {
int subframe_len = s->samples_per_frame >> i;
int x;
int band = 1;
s->sfb_offsets[i][0] = 0;
for (x = 0; x < MAX_BANDS-1 && s->sfb_offsets[i][band - 1] < subframe_len; x++) {
int offset = (subframe_len * 2 * critical_freq[x])
/ s->avctx->sample_rate + 2;
offset &= ~3;
if (offset > s->sfb_offsets[i][band - 1])
s->sfb_offsets[i][band++] = offset;
}
s->sfb_offsets[i][band - 1] = subframe_len;
s->num_sfb[i] = band - 1;
}
/** Scale factors can be shared between blocks of different size
as every block has a different scale factor band layout.
The matrix sf_offsets is needed to find the correct scale factor.
*/
for (i = 0; i < num_possible_block_sizes; i++) {
int b;
for (b = 0; b < s->num_sfb[i]; b++) {
int x;
int offset = ((s->sfb_offsets[i][b]
+ s->sfb_offsets[i][b + 1] - 1) << i) >> 1;
for (x = 0; x < num_possible_block_sizes; x++) {
int v = 0;
while (s->sfb_offsets[x][v + 1] << x < offset)
++v;
s->sf_offsets[i][x][b] = v;
}
}
}
/** init MDCT, FIXME: only init needed sizes */
for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
ff_mdct_init(&s->mdct_ctx[i], WMAPRO_BLOCK_MIN_BITS+1+i, 1,
1.0 / (1 << (WMAPRO_BLOCK_MIN_BITS + i - 1))
/ (1 << (s->bits_per_sample - 1)));
/** init MDCT windows: simple sinus window */
for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) {
const int win_idx = WMAPRO_BLOCK_MAX_BITS - i;
ff_init_ff_sine_windows(win_idx);
s->windows[WMAPRO_BLOCK_SIZES - i - 1] = ff_sine_windows[win_idx];
}
/** calculate subwoofer cutoff values */
for (i = 0; i < num_possible_block_sizes; i++) {
int block_size = s->samples_per_frame >> i;
int cutoff = (440*block_size + 3 * (s->avctx->sample_rate >> 1) - 1)
/ s->avctx->sample_rate;
s->subwoofer_cutoffs[i] = av_clip(cutoff, 4, block_size);
}
/** calculate sine values for the decorrelation matrix */
for (i = 0; i < 33; i++)
sin64[i] = sin(i*M_PI / 64.0);
if (avctx->debug & FF_DEBUG_BITSTREAM)
dump_context(s);
avctx->channel_layout = channel_mask;
return 0;
}
/**
*@brief Decode the subframe length.
*@param s context
*@param offset sample offset in the frame
*@return decoded subframe length on success, < 0 in case of an error
*/
static int decode_subframe_length(WMAProDecodeCtx *s, int offset)
{
int frame_len_shift = 0;
int subframe_len;
/** no need to read from the bitstream when only one length is possible */
if (offset == s->samples_per_frame - s->min_samples_per_subframe)
return s->min_samples_per_subframe;
/** 1 bit indicates if the subframe is of maximum length */
if (s->max_subframe_len_bit) {
if (get_bits1(&s->gb))
frame_len_shift = 1 + get_bits(&s->gb, s->subframe_len_bits-1);
} else
frame_len_shift = get_bits(&s->gb, s->subframe_len_bits);
subframe_len = s->samples_per_frame >> frame_len_shift;
/** sanity check the length */
if (subframe_len < s->min_samples_per_subframe ||
subframe_len > s->samples_per_frame) {
av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n",
subframe_len);
return AVERROR_INVALIDDATA;
}
return subframe_len;
}
/**
*@brief Decode how the data in the frame is split into subframes.
* Every WMA frame contains the encoded data for a fixed number of
* samples per channel. The data for every channel might be split
* into several subframes. This function will reconstruct the list of
* subframes for every channel.
*
* If the subframes are not evenly split, the algorithm estimates the
* channels with the lowest number of total samples.
* Afterwards, for each of these channels a bit is read from the
* bitstream that indicates if the channel contains a subframe with the
* next subframe size that is going to be read from the bitstream or not.
* If a channel contains such a subframe, the subframe size gets added to
* the channel's subframe list.
* The algorithm repeats these steps until the frame is properly divided
* between the individual channels.
*
*@param s context
*@return 0 on success, < 0 in case of an error
*/
static int decode_tilehdr(WMAProDecodeCtx *s)
{
uint16_t num_samples[WMAPRO_MAX_CHANNELS]; /**< sum of samples for all currently known subframes of a channel */
uint8_t contains_subframe[WMAPRO_MAX_CHANNELS]; /**< flag indicating if a channel contains the current subframe */
int channels_for_cur_subframe = s->num_channels; /**< number of channels that contain the current subframe */
int fixed_channel_layout = 0; /**< flag indicating that all channels use the same subframe offsets and sizes */
int min_channel_len = 0; /**< smallest sum of samples (channels with this length will be processed first) */
int c;
/* Should never consume more than 3073 bits (256 iterations for the
* while loop when always the minimum amount of 128 samples is substracted
* from missing samples in the 8 channel case).
* 1 + BLOCK_MAX_SIZE * MAX_CHANNELS / BLOCK_MIN_SIZE * (MAX_CHANNELS + 4)
*/
/** reset tiling information */
for (c = 0; c < s->num_channels; c++)
s->channel[c].num_subframes = 0;
memset(num_samples, 0, sizeof(num_samples));
if (s->max_num_subframes == 1 || get_bits1(&s->gb))
fixed_channel_layout = 1;
/** loop until the frame data is split between the subframes */
do {
int subframe_len;
/** check which channels contain the subframe */
for (c = 0; c < s->num_channels; c++) {
if (num_samples[c] == min_channel_len) {
if (fixed_channel_layout || channels_for_cur_subframe == 1 ||
(min_channel_len == s->samples_per_frame - s->min_samples_per_subframe))
contains_subframe[c] = 1;
else
contains_subframe[c] = get_bits1(&s->gb);
} else
contains_subframe[c] = 0;
}
/** get subframe length, subframe_len == 0 is not allowed */
if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0)
return AVERROR_INVALIDDATA;
/** add subframes to the individual channels and find new min_channel_len */
min_channel_len += subframe_len;
for (c = 0; c < s->num_channels; c++) {
WMAProChannelCtx* chan = &s->channel[c];
if (contains_subframe[c]) {
if (chan->num_subframes >= MAX_SUBFRAMES) {
av_log(s->avctx, AV_LOG_ERROR,
"broken frame: num subframes > 31\n");
return AVERROR_INVALIDDATA;
}
chan->subframe_len[chan->num_subframes] = subframe_len;
num_samples[c] += subframe_len;
++chan->num_subframes;
if (num_samples[c] > s->samples_per_frame) {
av_log(s->avctx, AV_LOG_ERROR, "broken frame: "
"channel len > samples_per_frame\n");
return AVERROR_INVALIDDATA;
}
} else if (num_samples[c] <= min_channel_len) {
if (num_samples[c] < min_channel_len) {
channels_for_cur_subframe = 0;
min_channel_len = num_samples[c];
}
++channels_for_cur_subframe;
}
}
} while (min_channel_len < s->samples_per_frame);
for (c = 0; c < s->num_channels; c++) {
int i;
int offset = 0;
for (i = 0; i < s->channel[c].num_subframes; i++) {
dprintf(s->avctx, "frame[%i] channel[%i] subframe[%i]"
" len %i\n", s->frame_num, c, i,
s->channel[c].subframe_len[i]);
s->channel[c].subframe_offset[i] = offset;
offset += s->channel[c].subframe_len[i];
}
}
return 0;
}
/**
*@brief Calculate a decorrelation matrix from the bitstream parameters.
*@param s codec context
*@param chgroup channel group for which the matrix needs to be calculated
*/
static void decode_decorrelation_matrix(WMAProDecodeCtx *s,
WMAProChannelGrp *chgroup)
{
int i;
int offset = 0;
int8_t rotation_offset[WMAPRO_MAX_CHANNELS * WMAPRO_MAX_CHANNELS];
memset(chgroup->decorrelation_matrix, 0, s->num_channels *
s->num_channels * sizeof(*chgroup->decorrelation_matrix));
for (i = 0; i < chgroup->num_channels * (chgroup->num_channels - 1) >> 1; i++)
rotation_offset[i] = get_bits(&s->gb, 6);
for (i = 0; i < chgroup->num_channels; i++)
chgroup->decorrelation_matrix[chgroup->num_channels * i + i] =
get_bits1(&s->gb) ? 1.0 : -1.0;
for (i = 1; i < chgroup->num_channels; i++) {
int x;
for (x = 0; x < i; x++) {
int y;
for (y = 0; y < i + 1; y++) {
float v1 = chgroup->decorrelation_matrix[x * chgroup->num_channels + y];
float v2 = chgroup->decorrelation_matrix[i * chgroup->num_channels + y];
int n = rotation_offset[offset + x];
float sinv;
float cosv;
if (n < 32) {
sinv = sin64[n];
cosv = sin64[32 - n];
} else {
sinv = sin64[64 - n];
cosv = -sin64[n - 32];
}
chgroup->decorrelation_matrix[y + x * chgroup->num_channels] =
(v1 * sinv) - (v2 * cosv);
chgroup->decorrelation_matrix[y + i * chgroup->num_channels] =
(v1 * cosv) + (v2 * sinv);
}
}
offset += i;
}
}
/**
*@brief Decode channel transformation parameters
*@param s codec context
*@return 0 in case of success, < 0 in case of bitstream errors
*/
static int decode_channel_transform(WMAProDecodeCtx* s)
{
int i;
/* should never consume more than 1921 bits for the 8 channel case
* 1 + MAX_CHANNELS * (MAX_CHANNELS + 2 + 3 * MAX_CHANNELS * MAX_CHANNELS
* + MAX_CHANNELS + MAX_BANDS + 1)
*/
/** in the one channel case channel transforms are pointless */
s->num_chgroups = 0;
if (s->num_channels > 1) {
int remaining_channels = s->channels_for_cur_subframe;
if (get_bits1(&s->gb)) {
av_log_ask_for_sample(s->avctx,
"unsupported channel transform bit\n");
return AVERROR_INVALIDDATA;
}
for (s->num_chgroups = 0; remaining_channels &&
s->num_chgroups < s->channels_for_cur_subframe; s->num_chgroups++) {
WMAProChannelGrp* chgroup = &s->chgroup[s->num_chgroups];
float** channel_data = chgroup->channel_data;
chgroup->num_channels = 0;
chgroup->transform = 0;
/** decode channel mask */
if (remaining_channels > 2) {
for (i = 0; i < s->channels_for_cur_subframe; i++) {
int channel_idx = s->channel_indexes_for_cur_subframe[i];
if (!s->channel[channel_idx].grouped
&& get_bits1(&s->gb)) {
++chgroup->num_channels;
s->channel[channel_idx].grouped = 1;
*channel_data++ = s->channel[channel_idx].coeffs;
}
}
} else {
chgroup->num_channels = remaining_channels;
for (i = 0; i < s->channels_for_cur_subframe; i++) {
int channel_idx = s->channel_indexes_for_cur_subframe[i];
if (!s->channel[channel_idx].grouped)
*channel_data++ = s->channel[channel_idx].coeffs;
s->channel[channel_idx].grouped = 1;
}
}
/** decode transform type */
if (chgroup->num_channels == 2) {
if (get_bits1(&s->gb)) {
if (get_bits1(&s->gb)) {
av_log_ask_for_sample(s->avctx,
"unsupported channel transform type\n");
}
} else {
chgroup->transform = 1;
if (s->num_channels == 2) {
chgroup->decorrelation_matrix[0] = 1.0;
chgroup->decorrelation_matrix[1] = -1.0;
chgroup->decorrelation_matrix[2] = 1.0;
chgroup->decorrelation_matrix[3] = 1.0;
} else {
/** cos(pi/4) */
chgroup->decorrelation_matrix[0] = 0.70703125;
chgroup->decorrelation_matrix[1] = -0.70703125;
chgroup->decorrelation_matrix[2] = 0.70703125;
chgroup->decorrelation_matrix[3] = 0.70703125;
}
}
} else if (chgroup->num_channels > 2) {
if (get_bits1(&s->gb)) {
chgroup->transform = 1;
if (get_bits1(&s->gb)) {
decode_decorrelation_matrix(s, chgroup);
} else {
/** FIXME: more than 6 coupled channels not supported */
if (chgroup->num_channels > 6) {
av_log_ask_for_sample(s->avctx,
"coupled channels > 6\n");
} else {
memcpy(chgroup->decorrelation_matrix,
default_decorrelation[chgroup->num_channels],
chgroup->num_channels * chgroup->num_channels *
sizeof(*chgroup->decorrelation_matrix));
}
}
}
}
/** decode transform on / off */
if (chgroup->transform) {
if (!get_bits1(&s->gb)) {
int i;
/** transform can be enabled for individual bands */
for (i = 0; i < s->num_bands; i++) {
chgroup->transform_band[i] = get_bits1(&s->gb);
}
} else {
memset(chgroup->transform_band, 1, s->num_bands);
}
}
remaining_channels -= chgroup->num_channels;
}
}
return 0;
}
/**
*@brief Extract the coefficients from the bitstream.
*@param s codec context
*@param c current channel number
*@return 0 on success, < 0 in case of bitstream errors
*/
static int decode_coeffs(WMAProDecodeCtx *s, int c)
{
/* Integers 0..15 as single-precision floats. The table saves a
costly int to float conversion, and storing the values as
integers allows fast sign-flipping. */
static const int fval_tab[16] = {
0x00000000, 0x3f800000, 0x40000000, 0x40400000,
0x40800000, 0x40a00000, 0x40c00000, 0x40e00000,
0x41000000, 0x41100000, 0x41200000, 0x41300000,
0x41400000, 0x41500000, 0x41600000, 0x41700000,
};
int vlctable;
VLC* vlc;
WMAProChannelCtx* ci = &s->channel[c];
int rl_mode = 0;
int cur_coeff = 0;
int num_zeros = 0;
const uint16_t* run;
const float* level;
dprintf(s->avctx, "decode coefficients for channel %i\n", c);
vlctable = get_bits1(&s->gb);
vlc = &coef_vlc[vlctable];
if (vlctable) {
run = coef1_run;
level = coef1_level;
} else {
run = coef0_run;
level = coef0_level;
}
/** decode vector coefficients (consumes up to 167 bits per iteration for
4 vector coded large values) */
while ((s->transmit_num_vec_coeffs || !rl_mode) &&
(cur_coeff + 3 < ci->num_vec_coeffs)) {
int vals[4];
int i;
unsigned int idx;
idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
if (idx == HUFF_VEC4_SIZE - 1) {
for (i = 0; i < 4; i += 2) {
idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
if (idx == HUFF_VEC2_SIZE - 1) {
int v0, v1;
v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
if (v0 == HUFF_VEC1_SIZE - 1)
v0 += ff_wma_get_large_val(&s->gb);
v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
if (v1 == HUFF_VEC1_SIZE - 1)
v1 += ff_wma_get_large_val(&s->gb);
((float*)vals)[i ] = v0;
((float*)vals)[i+1] = v1;
} else {
vals[i] = fval_tab[symbol_to_vec2[idx] >> 4 ];
vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF];
}
}
} else {
vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12 ];
vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF];
vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF];
vals[3] = fval_tab[ symbol_to_vec4[idx] & 0xF];
}
/** decode sign */
for (i = 0; i < 4; i++) {
if (vals[i]) {
int sign = get_bits1(&s->gb) - 1;
*(uint32_t*)&ci->coeffs[cur_coeff] = vals[i] ^ sign<<31;
num_zeros = 0;
} else {
ci->coeffs[cur_coeff] = 0;
/** switch to run level mode when subframe_len / 128 zeros
were found in a row */
rl_mode |= (++num_zeros > s->subframe_len >> 8);
}
++cur_coeff;
}
}
/** decode run level coded coefficients */
if (cur_coeff < s->subframe_len) {
memset(&ci->coeffs[cur_coeff], 0,
sizeof(*ci->coeffs) * (s->subframe_len - cur_coeff));
if (ff_wma_run_level_decode(s->avctx, &s->gb, vlc,
level, run, 1, ci->coeffs,
cur_coeff, s->subframe_len,
s->subframe_len, s->esc_len, 0))
return AVERROR_INVALIDDATA;
}
return 0;
}
/**
*@brief Extract scale factors from the bitstream.
*@param s codec context
*@return 0 on success, < 0 in case of bitstream errors
*/
static int decode_scale_factors(WMAProDecodeCtx* s)
{
int i;
/** should never consume more than 5344 bits
* MAX_CHANNELS * (1 + MAX_BANDS * 23)
*/
for (i = 0; i < s->channels_for_cur_subframe; i++) {
int c = s->channel_indexes_for_cur_subframe[i];
int* sf;
int* sf_end;
s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx];
sf_end = s->channel[c].scale_factors + s->num_bands;
/** resample scale factors for the new block size
* as the scale factors might need to be resampled several times
* before some new values are transmitted, a backup of the last
* transmitted scale factors is kept in saved_scale_factors
*/
if (s->channel[c].reuse_sf) {
const int8_t* sf_offsets = s->sf_offsets[s->table_idx][s->channel[c].table_idx];
int b;
for (b = 0; b < s->num_bands; b++)
s->channel[c].scale_factors[b] =
s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++];
}
if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) {
if (!s->channel[c].reuse_sf) {
int val;
/** decode DPCM coded scale factors */
s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1;
val = 45 / s->channel[c].scale_factor_step;
for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) {
val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH) - 60;
*sf = val;
}
} else {
int i;
/** run level decode differences to the resampled factors */
for (i = 0; i < s->num_bands; i++) {
int idx;
int skip;
int val;
int sign;
idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH);
if (!idx) {
uint32_t code = get_bits(&s->gb, 14);
val = code >> 6;
sign = (code & 1) - 1;
skip = (code & 0x3f) >> 1;
} else if (idx == 1) {
break;
} else {
skip = scale_rl_run[idx];
val = scale_rl_level[idx];
sign = get_bits1(&s->gb)-1;
}
i += skip;
if (i >= s->num_bands) {
av_log(s->avctx, AV_LOG_ERROR,
"invalid scale factor coding\n");
return AVERROR_INVALIDDATA;
}
s->channel[c].scale_factors[i] += (val ^ sign) - sign;
}
}
/** swap buffers */
s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx;
s->channel[c].table_idx = s->table_idx;
s->channel[c].reuse_sf = 1;
}
/** calculate new scale factor maximum */
s->channel[c].max_scale_factor = s->channel[c].scale_factors[0];
for (sf = s->channel[c].scale_factors + 1; sf < sf_end; sf++) {
s->channel[c].max_scale_factor =
FFMAX(s->channel[c].max_scale_factor, *sf);
}
}
return 0;
}
/**
*@brief Reconstruct the individual channel data.
*@param s codec context
*/
static void inverse_channel_transform(WMAProDecodeCtx *s)
{
int i;
for (i = 0; i < s->num_chgroups; i++) {
if (s->chgroup[i].transform) {
float data[WMAPRO_MAX_CHANNELS];
const int num_channels = s->chgroup[i].num_channels;
float** ch_data = s->chgroup[i].channel_data;
float** ch_end = ch_data + num_channels;
const int8_t* tb = s->chgroup[i].transform_band;
int16_t* sfb;
/** multichannel decorrelation */
for (sfb = s->cur_sfb_offsets;
sfb < s->cur_sfb_offsets + s->num_bands; sfb++) {
int y;
if (*tb++ == 1) {
/** multiply values with the decorrelation_matrix */
for (y = sfb[0]; y < FFMIN(sfb[1], s->subframe_len); y++) {
const float* mat = s->chgroup[i].decorrelation_matrix;
const float* data_end = data + num_channels;
float* data_ptr = data;
float** ch;
for (ch = ch_data; ch < ch_end; ch++)
*data_ptr++ = (*ch)[y];
for (ch = ch_data; ch < ch_end; ch++) {
float sum = 0;
data_ptr = data;
while (data_ptr < data_end)
sum += *data_ptr++ * *mat++;
(*ch)[y] = sum;
}
}
} else if (s->num_channels == 2) {
int len = FFMIN(sfb[1], s->subframe_len) - sfb[0];
s->dsp.vector_fmul_scalar(ch_data[0] + sfb[0],
ch_data[0] + sfb[0],