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1
/*
2
 * WMA compatible decoder
3
 * Copyright (c) 2002 The FFmpeg Project.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
19

    
20
/**
21
 * @file wmadec.c
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 * WMA compatible decoder.
23
 */
24

    
25
#include "avcodec.h"
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#include "dsputil.h"
27

    
28
//#define DEBUG_PARAMS
29
//#define DEBUG_TRACE
30

    
31
/* size of blocks */
32
#define BLOCK_MIN_BITS 7
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#define BLOCK_MAX_BITS 11
34
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
35

    
36
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
37

    
38
/* XXX: find exact max size */
39
#define HIGH_BAND_MAX_SIZE 16
40

    
41
#define NB_LSP_COEFS 10
42

    
43
/* XXX: is it a suitable value ? */
44
#define MAX_CODED_SUPERFRAME_SIZE 4096
45

    
46
#define MAX_CHANNELS 2
47

    
48
#define NOISE_TAB_SIZE 8192
49

    
50
#define LSP_POW_BITS 7
51

    
52
typedef struct WMADecodeContext {
53
    GetBitContext gb;
54
    int sample_rate;
55
    int nb_channels;
56
    int bit_rate;
57
    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
58
    int block_align;
59
    int use_bit_reservoir;
60
    int use_variable_block_len;
61
    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
62
    int use_noise_coding; /* true if perceptual noise is added */
63
    int byte_offset_bits;
64
    VLC exp_vlc;
65
    int exponent_sizes[BLOCK_NB_SIZES];
66
    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
67
    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
68
    int coefs_start;               /* first coded coef */
69
    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
70
    int exponent_high_sizes[BLOCK_NB_SIZES];
71
    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE]; 
72
    VLC hgain_vlc;
73
    
74
    /* coded values in high bands */
75
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
76
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
77

    
78
    /* there are two possible tables for spectral coefficients */
79
    VLC coef_vlc[2];
80
    uint16_t *run_table[2];
81
    uint16_t *level_table[2];
82
    /* frame info */
83
    int frame_len;       /* frame length in samples */
84
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
85
    int nb_block_sizes;  /* number of block sizes */
86
    /* block info */
87
    int reset_block_lengths;
88
    int block_len_bits; /* log2 of current block length */
89
    int next_block_len_bits; /* log2 of next block length */
90
    int prev_block_len_bits; /* log2 of prev block length */
91
    int block_len; /* block length in samples */
92
    int block_num; /* block number in current frame */
93
    int block_pos; /* current position in frame */
94
    uint8_t ms_stereo; /* true if mid/side stereo mode */
95
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
96
    float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
97
    float max_exponent[MAX_CHANNELS];
98
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
99
    float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
100
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
101
    float *windows[BLOCK_NB_SIZES];
102
    FFTSample mdct_tmp[BLOCK_MAX_SIZE] __attribute__((aligned(16))); /* temporary storage for imdct */
103
    /* output buffer for one frame and the last for IMDCT windowing */
104
    float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
105
    /* last frame info */
106
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
107
    int last_bitoffset;
108
    int last_superframe_len;
109
    float noise_table[NOISE_TAB_SIZE];
110
    int noise_index;
111
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
112
    /* lsp_to_curve tables */
113
    float lsp_cos_table[BLOCK_MAX_SIZE];
114
    float lsp_pow_e_table[256];
115
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
116
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
117
} WMADecodeContext;
118

    
119
typedef struct CoefVLCTable {
120
    int n; /* total number of codes */
121
    const uint32_t *huffcodes; /* VLC bit values */
122
    const uint8_t *huffbits;   /* VLC bit size */
123
    const uint16_t *levels; /* table to build run/level tables */
124
} CoefVLCTable;
125

    
126
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
127

    
128
#include "wmadata.h"
129

    
130
#ifdef DEBUG_TRACE
131
#include <stdarg.h>
132
int frame_count;
133

    
134
static FILE *flog;
135

    
136
void trace(const char *fmt, ...)
137
{
138
    va_list ap;
139
    
140

    
141
    if (!flog) {
142
        flog = fopen("/tmp/out.log", "w");
143
        setlinebuf(flog);
144
    }
145

    
146
    va_start(ap, fmt);
147
    vfprintf(flog, fmt, ap);
148
    va_end(ap);
149
}
150

    
151
#define get_bits(s, n) get_bits_trace(s, n)
152
#define get_vlc(s, vlc) get_vlc_trace(s, vlc)
153

    
154
unsigned int get_bits_trace(GetBitContext *s, int n)
155
{
156
    unsigned int val;
157
    val = (get_bits)(s, n);
158
    trace("get_bits(%d) : 0x%x\n", n, val);
159
    return val;
160
}
161

    
162
static int get_vlc_trace(GetBitContext *s, VLC *vlc)
163
{
164
    int code;
165
    code = (get_vlc)(s, vlc);
166
    trace("get_vlc() : %d\n", code);
167
    return code;
168
}
169

    
170
static void dump_shorts(const char *name, const short *tab, int n)
171
{
172
    int i;
173

    
174
    trace("%s[%d]:\n", name, n);
175
    for(i=0;i<n;i++) {
176
        if ((i & 7) == 0)
177
            trace("%4d: ", i);
178
        trace(" %5d.0", tab[i]);
179
        if ((i & 7) == 7)
180
            trace("\n");
181
    }
182
}
183

    
184
static void dump_floats(const char *name, int prec, const float *tab, int n)
185
{
186
    int i;
187

    
188
    trace("%s[%d]:\n", name, n);
189
    for(i=0;i<n;i++) {
190
        if ((i & 7) == 0)
191
            trace("%4d: ", i);
192
        trace(" %8.*f", prec, tab[i]);
193
        if ((i & 7) == 7)
194
            trace("\n");
195
    }
196
    if ((i & 7) != 0)
197
        trace("\n");
198
}
199

    
200
#else
201

    
202
#define trace(fmt, ...)
203

    
204
#endif
205

    
206
/* XXX: use same run/length optimization as mpeg decoders */
207
static void init_coef_vlc(VLC *vlc, 
208
                          uint16_t **prun_table, uint16_t **plevel_table,
209
                          const CoefVLCTable *vlc_table)
210
{
211
    int n = vlc_table->n;
212
    const uint8_t *table_bits = vlc_table->huffbits;
213
    const uint32_t *table_codes = vlc_table->huffcodes;
214
    const uint16_t *levels_table = vlc_table->levels;
215
    uint16_t *run_table, *level_table;
216
    const uint16_t *p;
217
    int i, l, j, level;
218

    
219
    init_vlc(vlc, 9, n, table_bits, 1, 1, table_codes, 4, 4);
220

    
221
    run_table = av_malloc(n * sizeof(uint16_t));
222
    level_table = av_malloc(n * sizeof(uint16_t));
223
    p = levels_table;
224
    i = 2;
225
    level = 1;
226
    while (i < n) {
227
        l = *p++;
228
        for(j=0;j<l;j++) {
229
            run_table[i] = j;
230
            level_table[i] = level;
231
            i++;
232
        }
233
        level++;
234
    }
235
    *prun_table = run_table;
236
    *plevel_table = level_table;
237
}
238

    
239
static int wma_decode_init(AVCodecContext * avctx)
240
{
241
    WMADecodeContext *s = avctx->priv_data;
242
    int i, flags1, flags2;
243
    float *window;
244
    uint8_t *extradata;
245
    float bps1, high_freq, bps;
246
    int sample_rate1;
247
    int coef_vlc_table;
248
    
249
    s->sample_rate = avctx->sample_rate;
250
    s->nb_channels = avctx->channels;
251
    s->bit_rate = avctx->bit_rate;
252
    s->block_align = avctx->block_align;
253

    
254
    if (avctx->codec->id == CODEC_ID_WMAV1) {
255
        s->version = 1;
256
    } else {
257
        s->version = 2;
258
    }
259
    
260
    /* extract flag infos */
261
    flags1 = 0;
262
    flags2 = 0;
263
    extradata = avctx->extradata;
264
    if (s->version == 1 && avctx->extradata_size >= 4) {
265
        flags1 = extradata[0] | (extradata[1] << 8);
266
        flags2 = extradata[2] | (extradata[3] << 8);
267
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
268
        flags1 = extradata[0] | (extradata[1] << 8) | 
269
            (extradata[2] << 16) | (extradata[3] << 24);
270
        flags2 = extradata[4] | (extradata[5] << 8);
271
    }
272
    s->use_exp_vlc = flags2 & 0x0001;
273
    s->use_bit_reservoir = flags2 & 0x0002;
274
    s->use_variable_block_len = flags2 & 0x0004;
275

    
276
    /* compute MDCT block size */
277
    if (s->sample_rate <= 16000) {
278
        s->frame_len_bits = 9;
279
    } else if (s->sample_rate <= 22050 || 
280
               (s->sample_rate <= 32000 && s->version == 1)) {
281
        s->frame_len_bits = 10;
282
    } else {
283
        s->frame_len_bits = 11;
284
    }
285
    s->frame_len = 1 << s->frame_len_bits;
286
    if (s->use_variable_block_len) {
287
        int nb_max, nb;
288
        nb = ((flags2 >> 3) & 3) + 1;
289
        if ((s->bit_rate / s->nb_channels) >= 32000)
290
            nb += 2;
291
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
292
        if (nb > nb_max)
293
            nb = nb_max;
294
        s->nb_block_sizes = nb + 1;
295
    } else {
296
        s->nb_block_sizes = 1;
297
    }
298

    
299
    /* init rate dependant parameters */
300
    s->use_noise_coding = 1;
301
    high_freq = s->sample_rate * 0.5;
302

    
303
    /* if version 2, then the rates are normalized */
304
    sample_rate1 = s->sample_rate;
305
    if (s->version == 2) {
306
        if (sample_rate1 >= 44100) 
307
            sample_rate1 = 44100;
308
        else if (sample_rate1 >= 22050) 
309
            sample_rate1 = 22050;
310
        else if (sample_rate1 >= 16000) 
311
            sample_rate1 = 16000;
312
        else if (sample_rate1 >= 11025) 
313
            sample_rate1 = 11025;
314
        else if (sample_rate1 >= 8000) 
315
            sample_rate1 = 8000;
316
    }
317

    
318
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
319
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0)) + 2;
320

    
321
    /* compute high frequency value and choose if noise coding should
322
       be activated */
323
    bps1 = bps;
324
    if (s->nb_channels == 2)
325
        bps1 = bps * 1.6;
326
    if (sample_rate1 == 44100) {
327
        if (bps1 >= 0.61)
328
            s->use_noise_coding = 0;
329
        else
330
            high_freq = high_freq * 0.4;
331
    } else if (sample_rate1 == 22050) {
332
        if (bps1 >= 1.16)
333
            s->use_noise_coding = 0;
334
        else if (bps1 >= 0.72) 
335
            high_freq = high_freq * 0.7;
336
        else
337
            high_freq = high_freq * 0.6;
338
    } else if (sample_rate1 == 16000) {
339
        if (bps > 0.5)
340
            high_freq = high_freq * 0.5;
341
        else
342
            high_freq = high_freq * 0.3;
343
    } else if (sample_rate1 == 11025) {
344
        high_freq = high_freq * 0.7;
345
    } else if (sample_rate1 == 8000) {
346
        if (bps <= 0.625) {
347
            high_freq = high_freq * 0.5;
348
        } else if (bps > 0.75) {
349
            s->use_noise_coding = 0;
350
        } else {
351
            high_freq = high_freq * 0.65;
352
        }
353
    } else {
354
        if (bps >= 0.8) {
355
            high_freq = high_freq * 0.75;
356
        } else if (bps >= 0.6) {
357
            high_freq = high_freq * 0.6;
358
        } else {
359
            high_freq = high_freq * 0.5;
360
        }
361
    }
362
#ifdef DEBUG_PARAMS
363
    printf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
364
    printf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
365
           s->version, s->nb_channels, s->sample_rate, s->bit_rate, 
366
           s->block_align);
367
    printf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n", 
368
           bps, bps1, high_freq, s->byte_offset_bits);
369
    printf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
370
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
371
#endif
372

    
373
    /* compute the scale factor band sizes for each MDCT block size */
374
    {
375
        int a, b, pos, lpos, k, block_len, i, j, n;
376
        const uint8_t *table;
377
        
378
        if (s->version == 1) {
379
            s->coefs_start = 3;
380
        } else {
381
            s->coefs_start = 0;
382
        }
383
        for(k = 0; k < s->nb_block_sizes; k++) {
384
            block_len = s->frame_len >> k;
385

    
386
            if (s->version == 1) {
387
                lpos = 0;
388
                for(i=0;i<25;i++) {
389
                    a = wma_critical_freqs[i];
390
                    b = s->sample_rate;
391
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
392
                    if (pos > block_len) 
393
                        pos = block_len;
394
                    s->exponent_bands[0][i] = pos - lpos;
395
                    if (pos >= block_len) {
396
                        i++;
397
                        break;
398
                    }
399
                    lpos = pos;
400
                }
401
                s->exponent_sizes[0] = i;
402
            } else {
403
                /* hardcoded tables */
404
                table = NULL;
405
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
406
                if (a < 3) {
407
                    if (s->sample_rate >= 44100)
408
                        table = exponent_band_44100[a];
409
                    else if (s->sample_rate >= 32000)
410
                        table = exponent_band_32000[a];
411
                    else if (s->sample_rate >= 22050)
412
                        table = exponent_band_22050[a];
413
                }
414
                if (table) {
415
                    n = *table++;
416
                    for(i=0;i<n;i++)
417
                        s->exponent_bands[k][i] = table[i];
418
                    s->exponent_sizes[k] = n;
419
                } else {
420
                    j = 0;
421
                    lpos = 0;
422
                    for(i=0;i<25;i++) {
423
                        a = wma_critical_freqs[i];
424
                        b = s->sample_rate;
425
                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
426
                        pos <<= 2;
427
                        if (pos > block_len) 
428
                            pos = block_len;
429
                        if (pos > lpos)
430
                            s->exponent_bands[k][j++] = pos - lpos;
431
                        if (pos >= block_len)
432
                            break;
433
                        lpos = pos;
434
                    }
435
                    s->exponent_sizes[k] = j;
436
                }
437
            }
438

    
439
            /* max number of coefs */
440
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
441
            /* high freq computation */
442
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) / 
443
                                          s->sample_rate + 0.5);
444
            n = s->exponent_sizes[k];
445
            j = 0;
446
            pos = 0;
447
            for(i=0;i<n;i++) {
448
                int start, end;
449
                start = pos;
450
                pos += s->exponent_bands[k][i];
451
                end = pos;
452
                if (start < s->high_band_start[k])
453
                    start = s->high_band_start[k];
454
                if (end > s->coefs_end[k])
455
                    end = s->coefs_end[k];
456
                if (end > start)
457
                    s->exponent_high_bands[k][j++] = end - start;
458
            }
459
            s->exponent_high_sizes[k] = j;
460
#if 0
461
            trace("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
462
                  s->frame_len >> k, 
463
                  s->coefs_end[k],
464
                  s->high_band_start[k],
465
                  s->exponent_high_sizes[k]);
466
            for(j=0;j<s->exponent_high_sizes[k];j++)
467
                trace(" %d", s->exponent_high_bands[k][j]);
468
            trace("\n");
469
#endif
470
        }
471
    }
472

    
473
#ifdef DEBUG_TRACE
474
    {
475
        int i, j;
476
        for(i = 0; i < s->nb_block_sizes; i++) {
477
            trace("%5d: n=%2d:", 
478
                   s->frame_len >> i, 
479
                   s->exponent_sizes[i]);
480
            for(j=0;j<s->exponent_sizes[i];j++)
481
                trace(" %d", s->exponent_bands[i][j]);
482
            trace("\n");
483
        }
484
    }
485
#endif
486

    
487
    /* init MDCT */
488
    for(i = 0; i < s->nb_block_sizes; i++)
489
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
490
    
491
    /* init MDCT windows : simple sinus window */
492
    for(i = 0; i < s->nb_block_sizes; i++) {
493
        int n, j;
494
        float alpha;
495
        n = 1 << (s->frame_len_bits - i);
496
        window = av_malloc(sizeof(float) * n);
497
        alpha = M_PI / (2.0 * n);
498
        for(j=0;j<n;j++) {
499
            window[n - j - 1] = sin((j + 0.5) * alpha);
500
        }
501
        s->windows[i] = window;
502
    }
503

    
504
    s->reset_block_lengths = 1;
505
    
506
    if (s->use_noise_coding) {
507

    
508
        /* init the noise generator */
509
        if (s->use_exp_vlc)
510
            s->noise_mult = 0.02;
511
        else
512
            s->noise_mult = 0.04;
513
               
514
#if defined(DEBUG_TRACE)
515
        for(i=0;i<NOISE_TAB_SIZE;i++)
516
            s->noise_table[i] = 1.0 * s->noise_mult;
517
#else
518
        {
519
            unsigned int seed;
520
            float norm;
521
            seed = 1;
522
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
523
            for(i=0;i<NOISE_TAB_SIZE;i++) {
524
                seed = seed * 314159 + 1;
525
                s->noise_table[i] = (float)((int)seed) * norm;
526
            }
527
        }
528
#endif
529
        init_vlc(&s->hgain_vlc, 9, sizeof(hgain_huffbits), 
530
                 hgain_huffbits, 1, 1,
531
                 hgain_huffcodes, 2, 2);
532
    }
533

    
534
    if (s->use_exp_vlc) {
535
        init_vlc(&s->exp_vlc, 9, sizeof(scale_huffbits), 
536
                 scale_huffbits, 1, 1,
537
                 scale_huffcodes, 4, 4);
538
    } else {
539
        wma_lsp_to_curve_init(s, s->frame_len);
540
    }
541

    
542
    /* choose the VLC tables for the coefficients */
543
    coef_vlc_table = 2;
544
    if (s->sample_rate >= 32000) {
545
        if (bps1 < 0.72)
546
            coef_vlc_table = 0;
547
        else if (bps1 < 1.16)
548
            coef_vlc_table = 1;
549
    }
550

    
551
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
552
                  &coef_vlcs[coef_vlc_table * 2]);
553
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
554
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
555
    return 0;
556
}
557

    
558
/* interpolate values for a bigger or smaller block. The block must
559
   have multiple sizes */
560
static void interpolate_array(float *scale, int old_size, int new_size)
561
{
562
    int i, j, jincr, k;
563
    float v;
564

    
565
    if (new_size > old_size) {
566
        jincr = new_size / old_size;
567
        j = new_size;
568
        for(i = old_size - 1; i >=0; i--) {
569
            v = scale[i];
570
            k = jincr;
571
            do {
572
                scale[--j] = v;
573
            } while (--k);
574
        }
575
    } else if (new_size < old_size) {
576
        j = 0;
577
        jincr = old_size / new_size;
578
        for(i = 0; i < new_size; i++) {
579
            scale[i] = scale[j];
580
            j += jincr;
581
        }
582
    }
583
}
584

    
585
/* compute x^-0.25 with an exponent and mantissa table. We use linear
586
   interpolation to reduce the mantissa table size at a small speed
587
   expense (linear interpolation approximately doubles the number of
588
   bits of precision). */
589
static inline float pow_m1_4(WMADecodeContext *s, float x)
590
{
591
    union {
592
        float f;
593
        unsigned int v;
594
    } u, t;
595
    unsigned int e, m;
596
    float a, b;
597

    
598
    u.f = x;
599
    e = u.v >> 23;
600
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
601
    /* build interpolation scale: 1 <= t < 2. */
602
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
603
    a = s->lsp_pow_m_table1[m];
604
    b = s->lsp_pow_m_table2[m];
605
    return s->lsp_pow_e_table[e] * (a + b * t.f);
606
}
607

    
608
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
609
{  
610
    float wdel, a, b;
611
    int i, e, m;
612

    
613
    wdel = M_PI / frame_len;
614
    for(i=0;i<frame_len;i++)
615
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
616

    
617
    /* tables for x^-0.25 computation */
618
    for(i=0;i<256;i++) {
619
        e = i - 126;
620
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
621
    }
622

    
623
    /* NOTE: these two tables are needed to avoid two operations in
624
       pow_m1_4 */
625
    b = 1.0;
626
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
627
        m = (1 << LSP_POW_BITS) + i;
628
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
629
        a = pow(a, -0.25);
630
        s->lsp_pow_m_table1[i] = 2 * a - b;
631
        s->lsp_pow_m_table2[i] = b - a;
632
        b = a;
633
    }
634
#if 0
635
    for(i=1;i<20;i++) {
636
        float v, r1, r2;
637
        v = 5.0 / i;
638
        r1 = pow_m1_4(s, v);
639
        r2 = pow(v,-0.25);
640
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
641
    }
642
#endif
643
}
644

    
645
/* NOTE: We use the same code as Vorbis here */
646
/* XXX: optimize it further with SSE/3Dnow */
647
static void wma_lsp_to_curve(WMADecodeContext *s, 
648
                             float *out, float *val_max_ptr, 
649
                             int n, float *lsp)
650
{
651
    int i, j;
652
    float p, q, w, v, val_max;
653

    
654
    val_max = 0;
655
    for(i=0;i<n;i++) {
656
        p = 0.5f;
657
        q = 0.5f;
658
        w = s->lsp_cos_table[i];
659
        for(j=1;j<NB_LSP_COEFS;j+=2){
660
            q *= w - lsp[j - 1];
661
            p *= w - lsp[j];
662
        }
663
        p *= p * (2.0f - w);
664
        q *= q * (2.0f + w);
665
        v = p + q;
666
        v = pow_m1_4(s, v);
667
        if (v > val_max)
668
            val_max = v;
669
        out[i] = v;
670
    }
671
    *val_max_ptr = val_max;
672
}
673

    
674
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
675
static void decode_exp_lsp(WMADecodeContext *s, int ch)
676
{
677
    float lsp_coefs[NB_LSP_COEFS];
678
    int val, i;
679

    
680
    for(i = 0; i < NB_LSP_COEFS; i++) {
681
        if (i == 0 || i >= 8)
682
            val = get_bits(&s->gb, 3);
683
        else
684
            val = get_bits(&s->gb, 4);
685
        lsp_coefs[i] = lsp_codebook[i][val];
686
    }
687

    
688
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
689
                     s->block_len, lsp_coefs);
690
}
691

    
692
/* decode exponents coded with VLC codes */
693
static int decode_exp_vlc(WMADecodeContext *s, int ch)
694
{
695
    int last_exp, n, code;
696
    const uint16_t *ptr, *band_ptr;
697
    float v, *q, max_scale, *q_end;
698
    
699
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
700
    ptr = band_ptr;
701
    q = s->exponents[ch];
702
    q_end = q + s->block_len;
703
    max_scale = 0;
704
    if (s->version == 1) {
705
        last_exp = get_bits(&s->gb, 5) + 10;
706
        /* XXX: use a table */
707
        v = pow(10, last_exp * (1.0 / 16.0));
708
        max_scale = v;
709
        n = *ptr++;
710
        do {
711
            *q++ = v;
712
        } while (--n);
713
    }
714
    last_exp = 36;
715
    while (q < q_end) {
716
        code = get_vlc(&s->gb, &s->exp_vlc);
717
        if (code < 0)
718
            return -1;
719
        /* NOTE: this offset is the same as MPEG4 AAC ! */
720
        last_exp += code - 60;
721
        /* XXX: use a table */
722
        v = pow(10, last_exp * (1.0 / 16.0));
723
        if (v > max_scale)
724
            max_scale = v;
725
        n = *ptr++;
726
        do {
727
            *q++ = v;
728
        } while (--n);
729
    }
730
    s->max_exponent[ch] = max_scale;
731
    return 0;
732
}
733

    
734
/* return 0 if OK. return 1 if last block of frame. return -1 if
735
   unrecorrable error. */
736
static int wma_decode_block(WMADecodeContext *s)
737
{
738
    int n, v, a, ch, code, bsize;
739
    int coef_nb_bits, total_gain, parse_exponents;
740
    float window[BLOCK_MAX_SIZE * 2];
741
    int nb_coefs[MAX_CHANNELS];
742
    float mdct_norm;
743

    
744
    trace("***decode_block: %d:%d\n", frame_count - 1, s->block_num);
745

    
746
    /* compute current block length */
747
    if (s->use_variable_block_len) {
748
        n = av_log2(s->nb_block_sizes - 1) + 1;
749
    
750
        if (s->reset_block_lengths) {
751
            s->reset_block_lengths = 0;
752
            v = get_bits(&s->gb, n);
753
            if (v >= s->nb_block_sizes)
754
                return -1;
755
            s->prev_block_len_bits = s->frame_len_bits - v;
756
            v = get_bits(&s->gb, n);
757
            if (v >= s->nb_block_sizes)
758
                return -1;
759
            s->block_len_bits = s->frame_len_bits - v;
760
        } else {
761
            /* update block lengths */
762
            s->prev_block_len_bits = s->block_len_bits;
763
            s->block_len_bits = s->next_block_len_bits;
764
        }
765
        v = get_bits(&s->gb, n);
766
        if (v >= s->nb_block_sizes)
767
            return -1;
768
        s->next_block_len_bits = s->frame_len_bits - v;
769
    } else {
770
        /* fixed block len */
771
        s->next_block_len_bits = s->frame_len_bits;
772
        s->prev_block_len_bits = s->frame_len_bits;
773
        s->block_len_bits = s->frame_len_bits;
774
    }
775

    
776
    /* now check if the block length is coherent with the frame length */
777
    s->block_len = 1 << s->block_len_bits;
778
    if ((s->block_pos + s->block_len) > s->frame_len)
779
        return -1;
780

    
781
    if (s->nb_channels == 2) {
782
        s->ms_stereo = get_bits(&s->gb, 1);
783
    }
784
    v = 0;
785
    for(ch = 0; ch < s->nb_channels; ch++) {
786
        a = get_bits(&s->gb, 1);
787
        s->channel_coded[ch] = a;
788
        v |= a;
789
    }
790
    /* if no channel coded, no need to go further */
791
    /* XXX: fix potential framing problems */
792
    if (!v)
793
        goto next;
794

    
795
    bsize = s->frame_len_bits - s->block_len_bits;
796

    
797
    /* read total gain and extract corresponding number of bits for
798
       coef escape coding */
799
    total_gain = 1;
800
    for(;;) {
801
        a = get_bits(&s->gb, 7);
802
        total_gain += a;
803
        if (a != 127)
804
            break;
805
    }
806
    
807
    if (total_gain < 15)
808
        coef_nb_bits = 13;
809
    else if (total_gain < 32)
810
        coef_nb_bits = 12;
811
    else if (total_gain < 40)
812
        coef_nb_bits = 11;
813
    else if (total_gain < 45)
814
        coef_nb_bits = 10;
815
    else
816
        coef_nb_bits = 9;
817

    
818
    /* compute number of coefficients */
819
    n = s->coefs_end[bsize] - s->coefs_start;
820
    for(ch = 0; ch < s->nb_channels; ch++)
821
        nb_coefs[ch] = n;
822

    
823
    /* complex coding */
824
    if (s->use_noise_coding) {
825

    
826
        for(ch = 0; ch < s->nb_channels; ch++) {
827
            if (s->channel_coded[ch]) {
828
                int i, n, a;
829
                n = s->exponent_high_sizes[bsize];
830
                for(i=0;i<n;i++) {
831
                    a = get_bits(&s->gb, 1);
832
                    s->high_band_coded[ch][i] = a;
833
                    /* if noise coding, the coefficients are not transmitted */
834
                    if (a)
835
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
836
                }
837
            }
838
        }
839
        for(ch = 0; ch < s->nb_channels; ch++) {
840
            if (s->channel_coded[ch]) {
841
                int i, n, val, code;
842

    
843
                n = s->exponent_high_sizes[bsize];
844
                val = (int)0x80000000;
845
                for(i=0;i<n;i++) {
846
                    if (s->high_band_coded[ch][i]) {
847
                        if (val == (int)0x80000000) {
848
                            val = get_bits(&s->gb, 7) - 19;
849
                        } else {
850
                            code = get_vlc(&s->gb, &s->hgain_vlc);
851
                            if (code < 0)
852
                                return -1;
853
                            val += code - 18;
854
                        }
855
                        s->high_band_values[ch][i] = val;
856
                    }
857
                }
858
            }
859
        }
860
    }
861
           
862
    /* exposant can be interpolated in short blocks. */
863
    parse_exponents = 1;
864
    if (s->block_len_bits != s->frame_len_bits) {
865
        parse_exponents = get_bits(&s->gb, 1);
866
    }
867
    
868
    if (parse_exponents) {
869
        for(ch = 0; ch < s->nb_channels; ch++) {
870
            if (s->channel_coded[ch]) {
871
                if (s->use_exp_vlc) {
872
                    if (decode_exp_vlc(s, ch) < 0)
873
                        return -1;
874
                } else {
875
                    decode_exp_lsp(s, ch);
876
                }
877
            }
878
        }
879
    } else {
880
        for(ch = 0; ch < s->nb_channels; ch++) {
881
            if (s->channel_coded[ch]) {
882
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits, 
883
                                  s->block_len);
884
            }
885
        }
886
    }
887

    
888
    /* parse spectral coefficients : just RLE encoding */
889
    for(ch = 0; ch < s->nb_channels; ch++) {
890
        if (s->channel_coded[ch]) {
891
            VLC *coef_vlc;
892
            int level, run, sign, tindex;
893
            int16_t *ptr, *eptr;
894
            const int16_t *level_table, *run_table;
895

    
896
            /* special VLC tables are used for ms stereo because
897
               there is potentially less energy there */
898
            tindex = (ch == 1 && s->ms_stereo);
899
            coef_vlc = &s->coef_vlc[tindex];
900
            run_table = s->run_table[tindex];
901
            level_table = s->level_table[tindex];
902
            /* XXX: optimize */
903
            ptr = &s->coefs1[ch][0];
904
            eptr = ptr + nb_coefs[ch];
905
            memset(ptr, 0, s->block_len * sizeof(int16_t));
906
            for(;;) {
907
                code = get_vlc(&s->gb, coef_vlc);
908
                if (code < 0)
909
                    return -1;
910
                if (code == 1) {
911
                    /* EOB */
912
                    break;
913
                } else if (code == 0) {
914
                    /* escape */
915
                    level = get_bits(&s->gb, coef_nb_bits);
916
                    /* NOTE: this is rather suboptimal. reading
917
                       block_len_bits would be better */
918
                    run = get_bits(&s->gb, s->frame_len_bits);
919
                } else {
920
                    /* normal code */
921
                    run = run_table[code];
922
                    level = level_table[code];
923
                }
924
                sign = get_bits(&s->gb, 1);
925
                if (!sign)
926
                    level = -level;
927
                ptr += run;
928
                if (ptr >= eptr)
929
                    return -1;
930
                *ptr++ = level;
931
                /* NOTE: EOB can be omitted */
932
                if (ptr >= eptr)
933
                    break;
934
            }
935
        }
936
        if (s->version == 1 && s->nb_channels >= 2) {
937
            align_get_bits(&s->gb);
938
        }
939
    }
940
     
941
    /* normalize */
942
    {
943
        int n4 = s->block_len / 2;
944
        mdct_norm = 1.0 / (float)n4;
945
        if (s->version == 1) {
946
            mdct_norm *= sqrt(n4);
947
        }
948
    }
949

    
950
    /* finally compute the MDCT coefficients */
951
    for(ch = 0; ch < s->nb_channels; ch++) {
952
        if (s->channel_coded[ch]) {
953
            int16_t *coefs1;
954
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
955
            int i, j, n, n1, last_high_band;
956
            float exp_power[HIGH_BAND_MAX_SIZE];
957

    
958
            coefs1 = s->coefs1[ch];
959
            exponents = s->exponents[ch];
960
            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
961
            mult *= mdct_norm;
962
            coefs = s->coefs[ch];
963
            if (s->use_noise_coding) {
964
                mult1 = mult;
965
                /* very low freqs : noise */
966
                for(i = 0;i < s->coefs_start; i++) {
967
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
968
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
969
                }
970
                
971
                n1 = s->exponent_high_sizes[bsize];
972

    
973
                /* compute power of high bands */
974
                exp_ptr = exponents + 
975
                    s->high_band_start[bsize] - 
976
                    s->coefs_start;
977
                last_high_band = 0; /* avoid warning */
978
                for(j=0;j<n1;j++) {
979
                    n = s->exponent_high_bands[s->frame_len_bits - 
980
                                              s->block_len_bits][j];
981
                    if (s->high_band_coded[ch][j]) {
982
                        float e2, v;
983
                        e2 = 0;
984
                        for(i = 0;i < n; i++) {
985
                            v = exp_ptr[i];
986
                            e2 += v * v;
987
                        }
988
                        exp_power[j] = e2 / n;
989
                        last_high_band = j;
990
                        trace("%d: power=%f (%d)\n", j, exp_power[j], n);
991
                    }
992
                    exp_ptr += n;
993
                }
994

    
995
                /* main freqs and high freqs */
996
                for(j=-1;j<n1;j++) {
997
                    if (j < 0) {
998
                        n = s->high_band_start[bsize] - 
999
                            s->coefs_start;
1000
                    } else {
1001
                        n = s->exponent_high_bands[s->frame_len_bits - 
1002
                                                  s->block_len_bits][j];
1003
                    }
1004
                    if (j >= 0 && s->high_band_coded[ch][j]) {
1005
                        /* use noise with specified power */
1006
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
1007
                        /* XXX: use a table */
1008
                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
1009
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
1010
                        mult1 *= mdct_norm;
1011
                        for(i = 0;i < n; i++) {
1012
                            noise = s->noise_table[s->noise_index];
1013
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1014
                            *coefs++ = (*exponents++) * noise * mult1;
1015
                        }
1016
                    } else {
1017
                        /* coded values + small noise */
1018
                        for(i = 0;i < n; i++) {
1019
                            noise = s->noise_table[s->noise_index];
1020
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1021
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
1022
                        }
1023
                    }
1024
                }
1025

    
1026
                /* very high freqs : noise */
1027
                n = s->block_len - s->coefs_end[bsize];
1028
                mult1 = mult * exponents[-1];
1029
                for(i = 0; i < n; i++) {
1030
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
1031
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1032
                }
1033
            } else {
1034
                /* XXX: optimize more */
1035
                for(i = 0;i < s->coefs_start; i++)
1036
                    *coefs++ = 0.0;
1037
                n = nb_coefs[ch];
1038
                for(i = 0;i < n; i++) {
1039
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1040
                }
1041
                n = s->block_len - s->coefs_end[bsize];
1042
                for(i = 0;i < n; i++)
1043
                    *coefs++ = 0.0;
1044
            }
1045
        }
1046
    }
1047

    
1048
#ifdef DEBUG_TRACE
1049
    for(ch = 0; ch < s->nb_channels; ch++) {
1050
        if (s->channel_coded[ch]) {
1051
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1052
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1053
        }
1054
    }
1055
#endif
1056
    
1057
    if (s->ms_stereo && s->channel_coded[1]) {
1058
        float a, b;
1059
        int i;
1060

    
1061
        /* nominal case for ms stereo: we do it before mdct */
1062
        /* no need to optimize this case because it should almost
1063
           never happen */
1064
        if (!s->channel_coded[0]) {
1065
#ifdef DEBUG_TRACE
1066
            trace("rare ms-stereo case happened\n");
1067
#endif
1068
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1069
            s->channel_coded[0] = 1;
1070
        }
1071
        
1072
        for(i = 0; i < s->block_len; i++) {
1073
            a = s->coefs[0][i];
1074
            b = s->coefs[1][i];
1075
            s->coefs[0][i] = a + b;
1076
            s->coefs[1][i] = a - b;
1077
        }
1078
    }
1079

    
1080
    /* build the window : we ensure that when the windows overlap
1081
       their squared sum is always 1 (MDCT reconstruction rule) */
1082
    /* XXX: merge with output */
1083
    {
1084
        int i, next_block_len, block_len, prev_block_len, n;
1085
        float *wptr;
1086

    
1087
        block_len = s->block_len;
1088
        prev_block_len = 1 << s->prev_block_len_bits;
1089
        next_block_len = 1 << s->next_block_len_bits;
1090

    
1091
        /* right part */
1092
        wptr = window + block_len;
1093
        if (block_len <= next_block_len) {
1094
            for(i=0;i<block_len;i++)
1095
                *wptr++ = s->windows[bsize][i];
1096
        } else {
1097
            /* overlap */
1098
            n = (block_len / 2) - (next_block_len / 2);
1099
            for(i=0;i<n;i++)
1100
                *wptr++ = 1.0;
1101
            for(i=0;i<next_block_len;i++)
1102
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1103
            for(i=0;i<n;i++)
1104
                *wptr++ = 0.0;
1105
        }
1106

    
1107
        /* left part */
1108
        wptr = window + block_len;
1109
        if (block_len <= prev_block_len) {
1110
            for(i=0;i<block_len;i++)
1111
                *--wptr = s->windows[bsize][i];
1112
        } else {
1113
            /* overlap */
1114
            n = (block_len / 2) - (prev_block_len / 2);
1115
            for(i=0;i<n;i++)
1116
                *--wptr = 1.0;
1117
            for(i=0;i<prev_block_len;i++)
1118
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1119
            for(i=0;i<n;i++)
1120
                *--wptr = 0.0;
1121
        }
1122
    }
1123

    
1124
    
1125
    for(ch = 0; ch < s->nb_channels; ch++) {
1126
        if (s->channel_coded[ch]) {
1127
            FFTSample output[BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
1128
            float *ptr;
1129
            int i, n4, index, n;
1130

    
1131
            n = s->block_len;
1132
            n4 = s->block_len / 2;
1133
            ff_imdct_calc(&s->mdct_ctx[bsize], 
1134
                          output, s->coefs[ch], s->mdct_tmp);
1135

    
1136
            /* XXX: optimize all that by build the window and
1137
               multipying/adding at the same time */
1138
            /* multiply by the window */
1139
            for(i=0;i<n * 2;i++) {
1140
                output[i] *= window[i];
1141
            }
1142

    
1143
            /* add in the frame */
1144
            index = (s->frame_len / 2) + s->block_pos - n4;
1145
            ptr = &s->frame_out[ch][index];
1146
            for(i=0;i<n * 2;i++) {
1147
                *ptr += output[i];
1148
                ptr++;
1149
            }
1150

    
1151
            /* specific fast case for ms-stereo : add to second
1152
               channel if it is not coded */
1153
            if (s->ms_stereo && !s->channel_coded[1]) {
1154
                ptr = &s->frame_out[1][index];
1155
                for(i=0;i<n * 2;i++) {
1156
                    *ptr += output[i];
1157
                    ptr++;
1158
                }
1159
            }
1160
        }
1161
    }
1162
 next:
1163
    /* update block number */
1164
    s->block_num++;
1165
    s->block_pos += s->block_len;
1166
    if (s->block_pos >= s->frame_len)
1167
        return 1;
1168
    else
1169
        return 0;
1170
}
1171

    
1172
/* decode a frame of frame_len samples */
1173
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1174
{
1175
    int ret, i, n, a, ch, incr;
1176
    int16_t *ptr;
1177
    float *iptr;
1178

    
1179
    trace("***decode_frame: %d size=%d\n", frame_count++, s->frame_len);
1180

    
1181
    /* read each block */
1182
    s->block_num = 0;
1183
    s->block_pos = 0;
1184
    for(;;) {
1185
        ret = wma_decode_block(s);
1186
        if (ret < 0) 
1187
            return -1;
1188
        if (ret)
1189
            break;
1190
    }
1191

    
1192
    /* convert frame to integer */
1193
    n = s->frame_len;
1194
    incr = s->nb_channels;
1195
    for(ch = 0; ch < s->nb_channels; ch++) {
1196
        ptr = samples + ch;
1197
        iptr = s->frame_out[ch];
1198

    
1199
        for(i=0;i<n;i++) {
1200
            a = lrintf(*iptr++);
1201
            if (a > 32767)
1202
                a = 32767;
1203
            else if (a < -32768)
1204
                a = -32768;
1205
            *ptr = a;
1206
            ptr += incr;
1207
        }
1208
        /* prepare for next block */
1209
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1210
                s->frame_len * sizeof(float));
1211
        /* XXX: suppress this */
1212
        memset(&s->frame_out[ch][s->frame_len], 0, 
1213
               s->frame_len * sizeof(float));
1214
    }
1215

    
1216
#ifdef DEBUG_TRACE
1217
    dump_shorts("samples", samples, n * s->nb_channels);
1218
#endif
1219
    return 0;
1220
}
1221

    
1222
static int wma_decode_superframe(AVCodecContext *avctx, 
1223
                                 void *data, int *data_size,
1224
                                 uint8_t *buf, int buf_size)
1225
{
1226
    WMADecodeContext *s = avctx->priv_data;
1227
    int nb_frames, bit_offset, i, pos, len;
1228
    uint8_t *q;
1229
    int16_t *samples;
1230
    
1231
    trace("***decode_superframe:\n");
1232

    
1233
    samples = data;
1234

    
1235
    init_get_bits(&s->gb, buf, buf_size*8);
1236
    
1237
    if (s->use_bit_reservoir) {
1238
        /* read super frame header */
1239
        get_bits(&s->gb, 4); /* super frame index */
1240
        nb_frames = get_bits(&s->gb, 4) - 1;
1241

    
1242
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1243

    
1244
        if (s->last_superframe_len > 0) {
1245
            //        printf("skip=%d\n", s->last_bitoffset);
1246
            /* add bit_offset bits to last frame */
1247
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) > 
1248
                MAX_CODED_SUPERFRAME_SIZE)
1249
                goto fail;
1250
            q = s->last_superframe + s->last_superframe_len;
1251
            len = bit_offset;
1252
            while (len > 0) {
1253
                *q++ = (get_bits)(&s->gb, 8);
1254
                len -= 8;
1255
            }
1256
            if (len > 0) {
1257
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1258
            }
1259
            
1260
            /* XXX: bit_offset bits into last frame */
1261
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1262
            /* skip unused bits */
1263
            if (s->last_bitoffset > 0)
1264
                skip_bits(&s->gb, s->last_bitoffset);
1265
            /* this frame is stored in the last superframe and in the
1266
               current one */
1267
            if (wma_decode_frame(s, samples) < 0)
1268
                goto fail;
1269
            samples += s->nb_channels * s->frame_len;
1270
        }
1271

    
1272
        /* read each frame starting from bit_offset */
1273
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1274
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1275
        len = pos & 7;
1276
        if (len > 0)
1277
            skip_bits(&s->gb, len);
1278
    
1279
        s->reset_block_lengths = 1;
1280
        for(i=0;i<nb_frames;i++) {
1281
            if (wma_decode_frame(s, samples) < 0)
1282
                goto fail;
1283
            samples += s->nb_channels * s->frame_len;
1284
        }
1285

    
1286
        /* we copy the end of the frame in the last frame buffer */
1287
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1288
        s->last_bitoffset = pos & 7;
1289
        pos >>= 3;
1290
        len = buf_size - pos;
1291
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1292
            goto fail;
1293
        }
1294
        s->last_superframe_len = len;
1295
        memcpy(s->last_superframe, buf + pos, len);
1296
    } else {
1297
        /* single frame decode */
1298
        if (wma_decode_frame(s, samples) < 0)
1299
            goto fail;
1300
        samples += s->nb_channels * s->frame_len;
1301
    }
1302
    *data_size = (int8_t *)samples - (int8_t *)data;
1303
    return s->block_align;
1304
 fail:
1305
    /* when error, we reset the bit reservoir */
1306
    s->last_superframe_len = 0;
1307
    return -1;
1308
}
1309

    
1310
static int wma_decode_end(AVCodecContext *avctx)
1311
{
1312
    WMADecodeContext *s = avctx->priv_data;
1313
    int i;
1314

    
1315
    for(i = 0; i < s->nb_block_sizes; i++)
1316
        ff_mdct_end(&s->mdct_ctx[i]);
1317
    for(i = 0; i < s->nb_block_sizes; i++)
1318
        av_free(s->windows[i]);
1319

    
1320
    if (s->use_exp_vlc) {
1321
        free_vlc(&s->exp_vlc);
1322
    }
1323
    if (s->use_noise_coding) {
1324
        free_vlc(&s->hgain_vlc);
1325
    }
1326
    for(i = 0;i < 2; i++) {
1327
        free_vlc(&s->coef_vlc[i]);
1328
        av_free(s->run_table[i]);
1329
        av_free(s->level_table[i]);
1330
    }
1331
    
1332
    return 0;
1333
}
1334

    
1335
AVCodec wmav1_decoder =
1336
{
1337
    "wmav1",
1338
    CODEC_TYPE_AUDIO,
1339
    CODEC_ID_WMAV1,
1340
    sizeof(WMADecodeContext),
1341
    wma_decode_init,
1342
    NULL,
1343
    wma_decode_end,
1344
    wma_decode_superframe,
1345
};
1346

    
1347
AVCodec wmav2_decoder =
1348
{
1349
    "wmav2",
1350
    CODEC_TYPE_AUDIO,
1351
    CODEC_ID_WMAV2,
1352
    sizeof(WMADecodeContext),
1353
    wma_decode_init,
1354
    NULL,
1355
    wma_decode_end,
1356
    wma_decode_superframe,
1357
};