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1
/*
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 * WMA compatible decoder
3
 * Copyright (c) 2002 The FFmpeg Project.
4
 *
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 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
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 * 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,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
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 * 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
22
 * WMA compatible decoder.
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 * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
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 * WMA v1 is identified by audio format 0x160 in Microsoft media files
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 * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
26
 *
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 * To use this decoder, a calling application must supply the extra data
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 * bytes provided with the WMA data. These are the extra, codec-specific
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 * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
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 * to the decoder using the extradata[_size] fields in AVCodecContext. There
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 * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
32
 */
33

    
34
#include "avcodec.h"
35
#include "bitstream.h"
36
#include "dsputil.h"
37

    
38
/* size of blocks */
39
#define BLOCK_MIN_BITS 7
40
#define BLOCK_MAX_BITS 11
41
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
42

    
43
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
44

    
45
/* XXX: find exact max size */
46
#define HIGH_BAND_MAX_SIZE 16
47

    
48
#define NB_LSP_COEFS 10
49

    
50
/* XXX: is it a suitable value ? */
51
#define MAX_CODED_SUPERFRAME_SIZE 16384
52

    
53
#define MAX_CHANNELS 2
54

    
55
#define NOISE_TAB_SIZE 8192
56

    
57
#define LSP_POW_BITS 7
58

    
59
typedef struct WMADecodeContext {
60
    GetBitContext gb;
61
    int sample_rate;
62
    int nb_channels;
63
    int bit_rate;
64
    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
65
    int block_align;
66
    int use_bit_reservoir;
67
    int use_variable_block_len;
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    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
69
    int use_noise_coding; /* true if perceptual noise is added */
70
    int byte_offset_bits;
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    VLC exp_vlc;
72
    int exponent_sizes[BLOCK_NB_SIZES];
73
    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
74
    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
75
    int coefs_start;               /* first coded coef */
76
    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
77
    int exponent_high_sizes[BLOCK_NB_SIZES];
78
    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
79
    VLC hgain_vlc;
80

    
81
    /* coded values in high bands */
82
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
83
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
84

    
85
    /* there are two possible tables for spectral coefficients */
86
    VLC coef_vlc[2];
87
    uint16_t *run_table[2];
88
    uint16_t *level_table[2];
89
    /* frame info */
90
    int frame_len;       /* frame length in samples */
91
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
92
    int nb_block_sizes;  /* number of block sizes */
93
    /* block info */
94
    int reset_block_lengths;
95
    int block_len_bits; /* log2 of current block length */
96
    int next_block_len_bits; /* log2 of next block length */
97
    int prev_block_len_bits; /* log2 of prev block length */
98
    int block_len; /* block length in samples */
99
    int block_num; /* block number in current frame */
100
    int block_pos; /* current position in frame */
101
    uint8_t ms_stereo; /* true if mid/side stereo mode */
102
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
103
    float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
104
    float max_exponent[MAX_CHANNELS];
105
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
106
    float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
107
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
108
    float *windows[BLOCK_NB_SIZES];
109
    FFTSample mdct_tmp[BLOCK_MAX_SIZE] __attribute__((aligned(16))); /* temporary storage for imdct */
110
    /* output buffer for one frame and the last for IMDCT windowing */
111
    float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
112
    /* last frame info */
113
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
114
    int last_bitoffset;
115
    int last_superframe_len;
116
    float noise_table[NOISE_TAB_SIZE];
117
    int noise_index;
118
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
119
    /* lsp_to_curve tables */
120
    float lsp_cos_table[BLOCK_MAX_SIZE];
121
    float lsp_pow_e_table[256];
122
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
123
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
124

    
125
#ifdef TRACE
126
    int frame_count;
127
#endif
128
} WMADecodeContext;
129

    
130
typedef struct CoefVLCTable {
131
    int n; /* total number of codes */
132
    const uint32_t *huffcodes; /* VLC bit values */
133
    const uint8_t *huffbits;   /* VLC bit size */
134
    const uint16_t *levels; /* table to build run/level tables */
135
} CoefVLCTable;
136

    
137
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
138

    
139
#include "wmadata.h"
140

    
141
#ifdef TRACE
142
static void dump_shorts(const char *name, const short *tab, int n)
143
{
144
    int i;
145

    
146
    tprintf("%s[%d]:\n", name, n);
147
    for(i=0;i<n;i++) {
148
        if ((i & 7) == 0)
149
            tprintf("%4d: ", i);
150
        tprintf(" %5d.0", tab[i]);
151
        if ((i & 7) == 7)
152
            tprintf("\n");
153
    }
154
}
155

    
156
static void dump_floats(const char *name, int prec, const float *tab, int n)
157
{
158
    int i;
159

    
160
    tprintf("%s[%d]:\n", name, n);
161
    for(i=0;i<n;i++) {
162
        if ((i & 7) == 0)
163
            tprintf("%4d: ", i);
164
        tprintf(" %8.*f", prec, tab[i]);
165
        if ((i & 7) == 7)
166
            tprintf("\n");
167
    }
168
    if ((i & 7) != 0)
169
        tprintf("\n");
170
}
171
#endif
172

    
173
/* XXX: use same run/length optimization as mpeg decoders */
174
static void init_coef_vlc(VLC *vlc,
175
                          uint16_t **prun_table, uint16_t **plevel_table,
176
                          const CoefVLCTable *vlc_table)
177
{
178
    int n = vlc_table->n;
179
    const uint8_t *table_bits = vlc_table->huffbits;
180
    const uint32_t *table_codes = vlc_table->huffcodes;
181
    const uint16_t *levels_table = vlc_table->levels;
182
    uint16_t *run_table, *level_table;
183
    const uint16_t *p;
184
    int i, l, j, level;
185

    
186
    init_vlc(vlc, 9, n, table_bits, 1, 1, table_codes, 4, 4, 0);
187

    
188
    run_table = av_malloc(n * sizeof(uint16_t));
189
    level_table = av_malloc(n * sizeof(uint16_t));
190
    p = levels_table;
191
    i = 2;
192
    level = 1;
193
    while (i < n) {
194
        l = *p++;
195
        for(j=0;j<l;j++) {
196
            run_table[i] = j;
197
            level_table[i] = level;
198
            i++;
199
        }
200
        level++;
201
    }
202
    *prun_table = run_table;
203
    *plevel_table = level_table;
204
}
205

    
206
static int wma_decode_init(AVCodecContext * avctx)
207
{
208
    WMADecodeContext *s = avctx->priv_data;
209
    int i, flags1, flags2;
210
    float *window;
211
    uint8_t *extradata;
212
    float bps1, high_freq;
213
    volatile float bps;
214
    int sample_rate1;
215
    int coef_vlc_table;
216

    
217
    s->sample_rate = avctx->sample_rate;
218
    s->nb_channels = avctx->channels;
219
    s->bit_rate = avctx->bit_rate;
220
    s->block_align = avctx->block_align;
221

    
222
    if (avctx->codec->id == CODEC_ID_WMAV1) {
223
        s->version = 1;
224
    } else {
225
        s->version = 2;
226
    }
227

    
228
    /* extract flag infos */
229
    flags1 = 0;
230
    flags2 = 0;
231
    extradata = avctx->extradata;
232
    if (s->version == 1 && avctx->extradata_size >= 4) {
233
        flags1 = extradata[0] | (extradata[1] << 8);
234
        flags2 = extradata[2] | (extradata[3] << 8);
235
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
236
        flags1 = extradata[0] | (extradata[1] << 8) |
237
            (extradata[2] << 16) | (extradata[3] << 24);
238
        flags2 = extradata[4] | (extradata[5] << 8);
239
    }
240
    s->use_exp_vlc = flags2 & 0x0001;
241
    s->use_bit_reservoir = flags2 & 0x0002;
242
    s->use_variable_block_len = flags2 & 0x0004;
243

    
244
    /* compute MDCT block size */
245
    if (s->sample_rate <= 16000) {
246
        s->frame_len_bits = 9;
247
    } else if (s->sample_rate <= 22050 ||
248
               (s->sample_rate <= 32000 && s->version == 1)) {
249
        s->frame_len_bits = 10;
250
    } else {
251
        s->frame_len_bits = 11;
252
    }
253
    s->frame_len = 1 << s->frame_len_bits;
254
    if (s->use_variable_block_len) {
255
        int nb_max, nb;
256
        nb = ((flags2 >> 3) & 3) + 1;
257
        if ((s->bit_rate / s->nb_channels) >= 32000)
258
            nb += 2;
259
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
260
        if (nb > nb_max)
261
            nb = nb_max;
262
        s->nb_block_sizes = nb + 1;
263
    } else {
264
        s->nb_block_sizes = 1;
265
    }
266

    
267
    /* init rate dependant parameters */
268
    s->use_noise_coding = 1;
269
    high_freq = s->sample_rate * 0.5;
270

    
271
    /* if version 2, then the rates are normalized */
272
    sample_rate1 = s->sample_rate;
273
    if (s->version == 2) {
274
        if (sample_rate1 >= 44100)
275
            sample_rate1 = 44100;
276
        else if (sample_rate1 >= 22050)
277
            sample_rate1 = 22050;
278
        else if (sample_rate1 >= 16000)
279
            sample_rate1 = 16000;
280
        else if (sample_rate1 >= 11025)
281
            sample_rate1 = 11025;
282
        else if (sample_rate1 >= 8000)
283
            sample_rate1 = 8000;
284
    }
285

    
286
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
287
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
288

    
289
    /* compute high frequency value and choose if noise coding should
290
       be activated */
291
    bps1 = bps;
292
    if (s->nb_channels == 2)
293
        bps1 = bps * 1.6;
294
    if (sample_rate1 == 44100) {
295
        if (bps1 >= 0.61)
296
            s->use_noise_coding = 0;
297
        else
298
            high_freq = high_freq * 0.4;
299
    } else if (sample_rate1 == 22050) {
300
        if (bps1 >= 1.16)
301
            s->use_noise_coding = 0;
302
        else if (bps1 >= 0.72)
303
            high_freq = high_freq * 0.7;
304
        else
305
            high_freq = high_freq * 0.6;
306
    } else if (sample_rate1 == 16000) {
307
        if (bps > 0.5)
308
            high_freq = high_freq * 0.5;
309
        else
310
            high_freq = high_freq * 0.3;
311
    } else if (sample_rate1 == 11025) {
312
        high_freq = high_freq * 0.7;
313
    } else if (sample_rate1 == 8000) {
314
        if (bps <= 0.625) {
315
            high_freq = high_freq * 0.5;
316
        } else if (bps > 0.75) {
317
            s->use_noise_coding = 0;
318
        } else {
319
            high_freq = high_freq * 0.65;
320
        }
321
    } else {
322
        if (bps >= 0.8) {
323
            high_freq = high_freq * 0.75;
324
        } else if (bps >= 0.6) {
325
            high_freq = high_freq * 0.6;
326
        } else {
327
            high_freq = high_freq * 0.5;
328
        }
329
    }
330
    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
331
    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
332
           s->version, s->nb_channels, s->sample_rate, s->bit_rate,
333
           s->block_align);
334
    dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
335
           bps, bps1, high_freq, s->byte_offset_bits);
336
    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
337
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
338

    
339
    /* compute the scale factor band sizes for each MDCT block size */
340
    {
341
        int a, b, pos, lpos, k, block_len, i, j, n;
342
        const uint8_t *table;
343

    
344
        if (s->version == 1) {
345
            s->coefs_start = 3;
346
        } else {
347
            s->coefs_start = 0;
348
        }
349
        for(k = 0; k < s->nb_block_sizes; k++) {
350
            block_len = s->frame_len >> k;
351

    
352
            if (s->version == 1) {
353
                lpos = 0;
354
                for(i=0;i<25;i++) {
355
                    a = wma_critical_freqs[i];
356
                    b = s->sample_rate;
357
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
358
                    if (pos > block_len)
359
                        pos = block_len;
360
                    s->exponent_bands[0][i] = pos - lpos;
361
                    if (pos >= block_len) {
362
                        i++;
363
                        break;
364
                    }
365
                    lpos = pos;
366
                }
367
                s->exponent_sizes[0] = i;
368
            } else {
369
                /* hardcoded tables */
370
                table = NULL;
371
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
372
                if (a < 3) {
373
                    if (s->sample_rate >= 44100)
374
                        table = exponent_band_44100[a];
375
                    else if (s->sample_rate >= 32000)
376
                        table = exponent_band_32000[a];
377
                    else if (s->sample_rate >= 22050)
378
                        table = exponent_band_22050[a];
379
                }
380
                if (table) {
381
                    n = *table++;
382
                    for(i=0;i<n;i++)
383
                        s->exponent_bands[k][i] = table[i];
384
                    s->exponent_sizes[k] = n;
385
                } else {
386
                    j = 0;
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)) / (4 * b);
392
                        pos <<= 2;
393
                        if (pos > block_len)
394
                            pos = block_len;
395
                        if (pos > lpos)
396
                            s->exponent_bands[k][j++] = pos - lpos;
397
                        if (pos >= block_len)
398
                            break;
399
                        lpos = pos;
400
                    }
401
                    s->exponent_sizes[k] = j;
402
                }
403
            }
404

    
405
            /* max number of coefs */
406
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
407
            /* high freq computation */
408
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
409
                                          s->sample_rate + 0.5);
410
            n = s->exponent_sizes[k];
411
            j = 0;
412
            pos = 0;
413
            for(i=0;i<n;i++) {
414
                int start, end;
415
                start = pos;
416
                pos += s->exponent_bands[k][i];
417
                end = pos;
418
                if (start < s->high_band_start[k])
419
                    start = s->high_band_start[k];
420
                if (end > s->coefs_end[k])
421
                    end = s->coefs_end[k];
422
                if (end > start)
423
                    s->exponent_high_bands[k][j++] = end - start;
424
            }
425
            s->exponent_high_sizes[k] = j;
426
#if 0
427
            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
428
                  s->frame_len >> k,
429
                  s->coefs_end[k],
430
                  s->high_band_start[k],
431
                  s->exponent_high_sizes[k]);
432
            for(j=0;j<s->exponent_high_sizes[k];j++)
433
                tprintf(" %d", s->exponent_high_bands[k][j]);
434
            tprintf("\n");
435
#endif
436
        }
437
    }
438

    
439
#ifdef TRACE
440
    {
441
        int i, j;
442
        for(i = 0; i < s->nb_block_sizes; i++) {
443
            tprintf("%5d: n=%2d:",
444
                   s->frame_len >> i,
445
                   s->exponent_sizes[i]);
446
            for(j=0;j<s->exponent_sizes[i];j++)
447
                tprintf(" %d", s->exponent_bands[i][j]);
448
            tprintf("\n");
449
        }
450
    }
451
#endif
452

    
453
    /* init MDCT */
454
    for(i = 0; i < s->nb_block_sizes; i++)
455
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
456

    
457
    /* init MDCT windows : simple sinus window */
458
    for(i = 0; i < s->nb_block_sizes; i++) {
459
        int n, j;
460
        float alpha;
461
        n = 1 << (s->frame_len_bits - i);
462
        window = av_malloc(sizeof(float) * n);
463
        alpha = M_PI / (2.0 * n);
464
        for(j=0;j<n;j++) {
465
            window[n - j - 1] = sin((j + 0.5) * alpha);
466
        }
467
        s->windows[i] = window;
468
    }
469

    
470
    s->reset_block_lengths = 1;
471

    
472
    if (s->use_noise_coding) {
473

    
474
        /* init the noise generator */
475
        if (s->use_exp_vlc)
476
            s->noise_mult = 0.02;
477
        else
478
            s->noise_mult = 0.04;
479

    
480
#ifdef TRACE
481
        for(i=0;i<NOISE_TAB_SIZE;i++)
482
            s->noise_table[i] = 1.0 * s->noise_mult;
483
#else
484
        {
485
            unsigned int seed;
486
            float norm;
487
            seed = 1;
488
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
489
            for(i=0;i<NOISE_TAB_SIZE;i++) {
490
                seed = seed * 314159 + 1;
491
                s->noise_table[i] = (float)((int)seed) * norm;
492
            }
493
        }
494
#endif
495
        init_vlc(&s->hgain_vlc, 9, sizeof(hgain_huffbits),
496
                 hgain_huffbits, 1, 1,
497
                 hgain_huffcodes, 2, 2, 0);
498
    }
499

    
500
    if (s->use_exp_vlc) {
501
        init_vlc(&s->exp_vlc, 9, sizeof(scale_huffbits),
502
                 scale_huffbits, 1, 1,
503
                 scale_huffcodes, 4, 4, 0);
504
    } else {
505
        wma_lsp_to_curve_init(s, s->frame_len);
506
    }
507

    
508
    /* choose the VLC tables for the coefficients */
509
    coef_vlc_table = 2;
510
    if (s->sample_rate >= 32000) {
511
        if (bps1 < 0.72)
512
            coef_vlc_table = 0;
513
        else if (bps1 < 1.16)
514
            coef_vlc_table = 1;
515
    }
516

    
517
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
518
                  &coef_vlcs[coef_vlc_table * 2]);
519
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
520
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
521
    return 0;
522
}
523

    
524
/* interpolate values for a bigger or smaller block. The block must
525
   have multiple sizes */
526
static void interpolate_array(float *scale, int old_size, int new_size)
527
{
528
    int i, j, jincr, k;
529
    float v;
530

    
531
    if (new_size > old_size) {
532
        jincr = new_size / old_size;
533
        j = new_size;
534
        for(i = old_size - 1; i >=0; i--) {
535
            v = scale[i];
536
            k = jincr;
537
            do {
538
                scale[--j] = v;
539
            } while (--k);
540
        }
541
    } else if (new_size < old_size) {
542
        j = 0;
543
        jincr = old_size / new_size;
544
        for(i = 0; i < new_size; i++) {
545
            scale[i] = scale[j];
546
            j += jincr;
547
        }
548
    }
549
}
550

    
551
/* compute x^-0.25 with an exponent and mantissa table. We use linear
552
   interpolation to reduce the mantissa table size at a small speed
553
   expense (linear interpolation approximately doubles the number of
554
   bits of precision). */
555
static inline float pow_m1_4(WMADecodeContext *s, float x)
556
{
557
    union {
558
        float f;
559
        unsigned int v;
560
    } u, t;
561
    unsigned int e, m;
562
    float a, b;
563

    
564
    u.f = x;
565
    e = u.v >> 23;
566
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
567
    /* build interpolation scale: 1 <= t < 2. */
568
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
569
    a = s->lsp_pow_m_table1[m];
570
    b = s->lsp_pow_m_table2[m];
571
    return s->lsp_pow_e_table[e] * (a + b * t.f);
572
}
573

    
574
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
575
{
576
    float wdel, a, b;
577
    int i, e, m;
578

    
579
    wdel = M_PI / frame_len;
580
    for(i=0;i<frame_len;i++)
581
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
582

    
583
    /* tables for x^-0.25 computation */
584
    for(i=0;i<256;i++) {
585
        e = i - 126;
586
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
587
    }
588

    
589
    /* NOTE: these two tables are needed to avoid two operations in
590
       pow_m1_4 */
591
    b = 1.0;
592
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
593
        m = (1 << LSP_POW_BITS) + i;
594
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
595
        a = pow(a, -0.25);
596
        s->lsp_pow_m_table1[i] = 2 * a - b;
597
        s->lsp_pow_m_table2[i] = b - a;
598
        b = a;
599
    }
600
#if 0
601
    for(i=1;i<20;i++) {
602
        float v, r1, r2;
603
        v = 5.0 / i;
604
        r1 = pow_m1_4(s, v);
605
        r2 = pow(v,-0.25);
606
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
607
    }
608
#endif
609
}
610

    
611
/* NOTE: We use the same code as Vorbis here */
612
/* XXX: optimize it further with SSE/3Dnow */
613
static void wma_lsp_to_curve(WMADecodeContext *s,
614
                             float *out, float *val_max_ptr,
615
                             int n, float *lsp)
616
{
617
    int i, j;
618
    float p, q, w, v, val_max;
619

    
620
    val_max = 0;
621
    for(i=0;i<n;i++) {
622
        p = 0.5f;
623
        q = 0.5f;
624
        w = s->lsp_cos_table[i];
625
        for(j=1;j<NB_LSP_COEFS;j+=2){
626
            q *= w - lsp[j - 1];
627
            p *= w - lsp[j];
628
        }
629
        p *= p * (2.0f - w);
630
        q *= q * (2.0f + w);
631
        v = p + q;
632
        v = pow_m1_4(s, v);
633
        if (v > val_max)
634
            val_max = v;
635
        out[i] = v;
636
    }
637
    *val_max_ptr = val_max;
638
}
639

    
640
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
641
static void decode_exp_lsp(WMADecodeContext *s, int ch)
642
{
643
    float lsp_coefs[NB_LSP_COEFS];
644
    int val, i;
645

    
646
    for(i = 0; i < NB_LSP_COEFS; i++) {
647
        if (i == 0 || i >= 8)
648
            val = get_bits(&s->gb, 3);
649
        else
650
            val = get_bits(&s->gb, 4);
651
        lsp_coefs[i] = lsp_codebook[i][val];
652
    }
653

    
654
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
655
                     s->block_len, lsp_coefs);
656
}
657

    
658
/* decode exponents coded with VLC codes */
659
static int decode_exp_vlc(WMADecodeContext *s, int ch)
660
{
661
    int last_exp, n, code;
662
    const uint16_t *ptr, *band_ptr;
663
    float v, *q, max_scale, *q_end;
664

    
665
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
666
    ptr = band_ptr;
667
    q = s->exponents[ch];
668
    q_end = q + s->block_len;
669
    max_scale = 0;
670
    if (s->version == 1) {
671
        last_exp = get_bits(&s->gb, 5) + 10;
672
        /* XXX: use a table */
673
        v = pow(10, last_exp * (1.0 / 16.0));
674
        max_scale = v;
675
        n = *ptr++;
676
        do {
677
            *q++ = v;
678
        } while (--n);
679
    }
680
    last_exp = 36;
681
    while (q < q_end) {
682
        code = get_vlc(&s->gb, &s->exp_vlc);
683
        if (code < 0)
684
            return -1;
685
        /* NOTE: this offset is the same as MPEG4 AAC ! */
686
        last_exp += code - 60;
687
        /* XXX: use a table */
688
        v = pow(10, last_exp * (1.0 / 16.0));
689
        if (v > max_scale)
690
            max_scale = v;
691
        n = *ptr++;
692
        do {
693
            *q++ = v;
694
        } while (--n);
695
    }
696
    s->max_exponent[ch] = max_scale;
697
    return 0;
698
}
699

    
700
/* return 0 if OK. return 1 if last block of frame. return -1 if
701
   unrecorrable error. */
702
static int wma_decode_block(WMADecodeContext *s)
703
{
704
    int n, v, a, ch, code, bsize;
705
    int coef_nb_bits, total_gain, parse_exponents;
706
    float window[BLOCK_MAX_SIZE * 2];
707
// XXX: FIXME!! there's a bug somewhere which makes this mandatory under altivec
708
#ifdef HAVE_ALTIVEC
709
    volatile int nb_coefs[MAX_CHANNELS] __attribute__((aligned(16)));
710
#else
711
    int nb_coefs[MAX_CHANNELS];
712
#endif
713
    float mdct_norm;
714

    
715
#ifdef TRACE
716
    tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
717
#endif
718

    
719
    /* compute current block length */
720
    if (s->use_variable_block_len) {
721
        n = av_log2(s->nb_block_sizes - 1) + 1;
722

    
723
        if (s->reset_block_lengths) {
724
            s->reset_block_lengths = 0;
725
            v = get_bits(&s->gb, n);
726
            if (v >= s->nb_block_sizes)
727
                return -1;
728
            s->prev_block_len_bits = s->frame_len_bits - v;
729
            v = get_bits(&s->gb, n);
730
            if (v >= s->nb_block_sizes)
731
                return -1;
732
            s->block_len_bits = s->frame_len_bits - v;
733
        } else {
734
            /* update block lengths */
735
            s->prev_block_len_bits = s->block_len_bits;
736
            s->block_len_bits = s->next_block_len_bits;
737
        }
738
        v = get_bits(&s->gb, n);
739
        if (v >= s->nb_block_sizes)
740
            return -1;
741
        s->next_block_len_bits = s->frame_len_bits - v;
742
    } else {
743
        /* fixed block len */
744
        s->next_block_len_bits = s->frame_len_bits;
745
        s->prev_block_len_bits = s->frame_len_bits;
746
        s->block_len_bits = s->frame_len_bits;
747
    }
748

    
749
    /* now check if the block length is coherent with the frame length */
750
    s->block_len = 1 << s->block_len_bits;
751
    if ((s->block_pos + s->block_len) > s->frame_len)
752
        return -1;
753

    
754
    if (s->nb_channels == 2) {
755
        s->ms_stereo = get_bits(&s->gb, 1);
756
    }
757
    v = 0;
758
    for(ch = 0; ch < s->nb_channels; ch++) {
759
        a = get_bits(&s->gb, 1);
760
        s->channel_coded[ch] = a;
761
        v |= a;
762
    }
763
    /* if no channel coded, no need to go further */
764
    /* XXX: fix potential framing problems */
765
    if (!v)
766
        goto next;
767

    
768
    bsize = s->frame_len_bits - s->block_len_bits;
769

    
770
    /* read total gain and extract corresponding number of bits for
771
       coef escape coding */
772
    total_gain = 1;
773
    for(;;) {
774
        a = get_bits(&s->gb, 7);
775
        total_gain += a;
776
        if (a != 127)
777
            break;
778
    }
779

    
780
    if (total_gain < 15)
781
        coef_nb_bits = 13;
782
    else if (total_gain < 32)
783
        coef_nb_bits = 12;
784
    else if (total_gain < 40)
785
        coef_nb_bits = 11;
786
    else if (total_gain < 45)
787
        coef_nb_bits = 10;
788
    else
789
        coef_nb_bits = 9;
790

    
791
    /* compute number of coefficients */
792
    n = s->coefs_end[bsize] - s->coefs_start;
793
    for(ch = 0; ch < s->nb_channels; ch++)
794
        nb_coefs[ch] = n;
795

    
796
    /* complex coding */
797
    if (s->use_noise_coding) {
798

    
799
        for(ch = 0; ch < s->nb_channels; ch++) {
800
            if (s->channel_coded[ch]) {
801
                int i, n, a;
802
                n = s->exponent_high_sizes[bsize];
803
                for(i=0;i<n;i++) {
804
                    a = get_bits(&s->gb, 1);
805
                    s->high_band_coded[ch][i] = a;
806
                    /* if noise coding, the coefficients are not transmitted */
807
                    if (a)
808
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
809
                }
810
            }
811
        }
812
        for(ch = 0; ch < s->nb_channels; ch++) {
813
            if (s->channel_coded[ch]) {
814
                int i, n, val, code;
815

    
816
                n = s->exponent_high_sizes[bsize];
817
                val = (int)0x80000000;
818
                for(i=0;i<n;i++) {
819
                    if (s->high_band_coded[ch][i]) {
820
                        if (val == (int)0x80000000) {
821
                            val = get_bits(&s->gb, 7) - 19;
822
                        } else {
823
                            code = get_vlc(&s->gb, &s->hgain_vlc);
824
                            if (code < 0)
825
                                return -1;
826
                            val += code - 18;
827
                        }
828
                        s->high_band_values[ch][i] = val;
829
                    }
830
                }
831
            }
832
        }
833
    }
834

    
835
    /* exposant can be interpolated in short blocks. */
836
    parse_exponents = 1;
837
    if (s->block_len_bits != s->frame_len_bits) {
838
        parse_exponents = get_bits(&s->gb, 1);
839
    }
840

    
841
    if (parse_exponents) {
842
        for(ch = 0; ch < s->nb_channels; ch++) {
843
            if (s->channel_coded[ch]) {
844
                if (s->use_exp_vlc) {
845
                    if (decode_exp_vlc(s, ch) < 0)
846
                        return -1;
847
                } else {
848
                    decode_exp_lsp(s, ch);
849
                }
850
            }
851
        }
852
    } else {
853
        for(ch = 0; ch < s->nb_channels; ch++) {
854
            if (s->channel_coded[ch]) {
855
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
856
                                  s->block_len);
857
            }
858
        }
859
    }
860

    
861
    /* parse spectral coefficients : just RLE encoding */
862
    for(ch = 0; ch < s->nb_channels; ch++) {
863
        if (s->channel_coded[ch]) {
864
            VLC *coef_vlc;
865
            int level, run, sign, tindex;
866
            int16_t *ptr, *eptr;
867
            const int16_t *level_table, *run_table;
868

    
869
            /* special VLC tables are used for ms stereo because
870
               there is potentially less energy there */
871
            tindex = (ch == 1 && s->ms_stereo);
872
            coef_vlc = &s->coef_vlc[tindex];
873
            run_table = s->run_table[tindex];
874
            level_table = s->level_table[tindex];
875
            /* XXX: optimize */
876
            ptr = &s->coefs1[ch][0];
877
            eptr = ptr + nb_coefs[ch];
878
            memset(ptr, 0, s->block_len * sizeof(int16_t));
879
            for(;;) {
880
                code = get_vlc(&s->gb, coef_vlc);
881
                if (code < 0)
882
                    return -1;
883
                if (code == 1) {
884
                    /* EOB */
885
                    break;
886
                } else if (code == 0) {
887
                    /* escape */
888
                    level = get_bits(&s->gb, coef_nb_bits);
889
                    /* NOTE: this is rather suboptimal. reading
890
                       block_len_bits would be better */
891
                    run = get_bits(&s->gb, s->frame_len_bits);
892
                } else {
893
                    /* normal code */
894
                    run = run_table[code];
895
                    level = level_table[code];
896
                }
897
                sign = get_bits(&s->gb, 1);
898
                if (!sign)
899
                    level = -level;
900
                ptr += run;
901
                if (ptr >= eptr)
902
                    return -1;
903
                *ptr++ = level;
904
                /* NOTE: EOB can be omitted */
905
                if (ptr >= eptr)
906
                    break;
907
            }
908
        }
909
        if (s->version == 1 && s->nb_channels >= 2) {
910
            align_get_bits(&s->gb);
911
        }
912
    }
913

    
914
    /* normalize */
915
    {
916
        int n4 = s->block_len / 2;
917
        mdct_norm = 1.0 / (float)n4;
918
        if (s->version == 1) {
919
            mdct_norm *= sqrt(n4);
920
        }
921
    }
922

    
923
    /* finally compute the MDCT coefficients */
924
    for(ch = 0; ch < s->nb_channels; ch++) {
925
        if (s->channel_coded[ch]) {
926
            int16_t *coefs1;
927
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
928
            int i, j, n, n1, last_high_band;
929
            float exp_power[HIGH_BAND_MAX_SIZE];
930

    
931
            coefs1 = s->coefs1[ch];
932
            exponents = s->exponents[ch];
933
            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
934
            mult *= mdct_norm;
935
            coefs = s->coefs[ch];
936
            if (s->use_noise_coding) {
937
                mult1 = mult;
938
                /* very low freqs : noise */
939
                for(i = 0;i < s->coefs_start; i++) {
940
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
941
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
942
                }
943

    
944
                n1 = s->exponent_high_sizes[bsize];
945

    
946
                /* compute power of high bands */
947
                exp_ptr = exponents +
948
                    s->high_band_start[bsize] -
949
                    s->coefs_start;
950
                last_high_band = 0; /* avoid warning */
951
                for(j=0;j<n1;j++) {
952
                    n = s->exponent_high_bands[s->frame_len_bits -
953
                                              s->block_len_bits][j];
954
                    if (s->high_band_coded[ch][j]) {
955
                        float e2, v;
956
                        e2 = 0;
957
                        for(i = 0;i < n; i++) {
958
                            v = exp_ptr[i];
959
                            e2 += v * v;
960
                        }
961
                        exp_power[j] = e2 / n;
962
                        last_high_band = j;
963
                        tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
964
                    }
965
                    exp_ptr += n;
966
                }
967

    
968
                /* main freqs and high freqs */
969
                for(j=-1;j<n1;j++) {
970
                    if (j < 0) {
971
                        n = s->high_band_start[bsize] -
972
                            s->coefs_start;
973
                    } else {
974
                        n = s->exponent_high_bands[s->frame_len_bits -
975
                                                  s->block_len_bits][j];
976
                    }
977
                    if (j >= 0 && s->high_band_coded[ch][j]) {
978
                        /* use noise with specified power */
979
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
980
                        /* XXX: use a table */
981
                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
982
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
983
                        mult1 *= mdct_norm;
984
                        for(i = 0;i < n; i++) {
985
                            noise = s->noise_table[s->noise_index];
986
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
987
                            *coefs++ = (*exponents++) * noise * mult1;
988
                        }
989
                    } else {
990
                        /* coded values + small noise */
991
                        for(i = 0;i < n; i++) {
992
                            noise = s->noise_table[s->noise_index];
993
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
994
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
995
                        }
996
                    }
997
                }
998

    
999
                /* very high freqs : noise */
1000
                n = s->block_len - s->coefs_end[bsize];
1001
                mult1 = mult * exponents[-1];
1002
                for(i = 0; i < n; i++) {
1003
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
1004
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1005
                }
1006
            } else {
1007
                /* XXX: optimize more */
1008
                for(i = 0;i < s->coefs_start; i++)
1009
                    *coefs++ = 0.0;
1010
                n = nb_coefs[ch];
1011
                for(i = 0;i < n; i++) {
1012
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1013
                }
1014
                n = s->block_len - s->coefs_end[bsize];
1015
                for(i = 0;i < n; i++)
1016
                    *coefs++ = 0.0;
1017
            }
1018
        }
1019
    }
1020

    
1021
#ifdef TRACE
1022
    for(ch = 0; ch < s->nb_channels; ch++) {
1023
        if (s->channel_coded[ch]) {
1024
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1025
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1026
        }
1027
    }
1028
#endif
1029

    
1030
    if (s->ms_stereo && s->channel_coded[1]) {
1031
        float a, b;
1032
        int i;
1033

    
1034
        /* nominal case for ms stereo: we do it before mdct */
1035
        /* no need to optimize this case because it should almost
1036
           never happen */
1037
        if (!s->channel_coded[0]) {
1038
            tprintf("rare ms-stereo case happened\n");
1039
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1040
            s->channel_coded[0] = 1;
1041
        }
1042

    
1043
        for(i = 0; i < s->block_len; i++) {
1044
            a = s->coefs[0][i];
1045
            b = s->coefs[1][i];
1046
            s->coefs[0][i] = a + b;
1047
            s->coefs[1][i] = a - b;
1048
        }
1049
    }
1050

    
1051
    /* build the window : we ensure that when the windows overlap
1052
       their squared sum is always 1 (MDCT reconstruction rule) */
1053
    /* XXX: merge with output */
1054
    {
1055
        int i, next_block_len, block_len, prev_block_len, n;
1056
        float *wptr;
1057

    
1058
        block_len = s->block_len;
1059
        prev_block_len = 1 << s->prev_block_len_bits;
1060
        next_block_len = 1 << s->next_block_len_bits;
1061

    
1062
        /* right part */
1063
        wptr = window + block_len;
1064
        if (block_len <= next_block_len) {
1065
            for(i=0;i<block_len;i++)
1066
                *wptr++ = s->windows[bsize][i];
1067
        } else {
1068
            /* overlap */
1069
            n = (block_len / 2) - (next_block_len / 2);
1070
            for(i=0;i<n;i++)
1071
                *wptr++ = 1.0;
1072
            for(i=0;i<next_block_len;i++)
1073
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1074
            for(i=0;i<n;i++)
1075
                *wptr++ = 0.0;
1076
        }
1077

    
1078
        /* left part */
1079
        wptr = window + block_len;
1080
        if (block_len <= prev_block_len) {
1081
            for(i=0;i<block_len;i++)
1082
                *--wptr = s->windows[bsize][i];
1083
        } else {
1084
            /* overlap */
1085
            n = (block_len / 2) - (prev_block_len / 2);
1086
            for(i=0;i<n;i++)
1087
                *--wptr = 1.0;
1088
            for(i=0;i<prev_block_len;i++)
1089
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1090
            for(i=0;i<n;i++)
1091
                *--wptr = 0.0;
1092
        }
1093
    }
1094

    
1095

    
1096
    for(ch = 0; ch < s->nb_channels; ch++) {
1097
        if (s->channel_coded[ch]) {
1098
            FFTSample output[BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
1099
            float *ptr;
1100
            int i, n4, index, n;
1101

    
1102
            n = s->block_len;
1103
            n4 = s->block_len / 2;
1104
            ff_imdct_calc(&s->mdct_ctx[bsize],
1105
                          output, s->coefs[ch], s->mdct_tmp);
1106

    
1107
            /* XXX: optimize all that by build the window and
1108
               multipying/adding at the same time */
1109
            /* multiply by the window */
1110
            for(i=0;i<n * 2;i++) {
1111
                output[i] *= window[i];
1112
            }
1113

    
1114
            /* add in the frame */
1115
            index = (s->frame_len / 2) + s->block_pos - n4;
1116
            ptr = &s->frame_out[ch][index];
1117
            for(i=0;i<n * 2;i++) {
1118
                *ptr += output[i];
1119
                ptr++;
1120
            }
1121

    
1122
            /* specific fast case for ms-stereo : add to second
1123
               channel if it is not coded */
1124
            if (s->ms_stereo && !s->channel_coded[1]) {
1125
                ptr = &s->frame_out[1][index];
1126
                for(i=0;i<n * 2;i++) {
1127
                    *ptr += output[i];
1128
                    ptr++;
1129
                }
1130
            }
1131
        }
1132
    }
1133
 next:
1134
    /* update block number */
1135
    s->block_num++;
1136
    s->block_pos += s->block_len;
1137
    if (s->block_pos >= s->frame_len)
1138
        return 1;
1139
    else
1140
        return 0;
1141
}
1142

    
1143
/* decode a frame of frame_len samples */
1144
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1145
{
1146
    int ret, i, n, a, ch, incr;
1147
    int16_t *ptr;
1148
    float *iptr;
1149

    
1150
#ifdef TRACE
1151
    tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
1152
#endif
1153

    
1154
    /* read each block */
1155
    s->block_num = 0;
1156
    s->block_pos = 0;
1157
    for(;;) {
1158
        ret = wma_decode_block(s);
1159
        if (ret < 0)
1160
            return -1;
1161
        if (ret)
1162
            break;
1163
    }
1164

    
1165
    /* convert frame to integer */
1166
    n = s->frame_len;
1167
    incr = s->nb_channels;
1168
    for(ch = 0; ch < s->nb_channels; ch++) {
1169
        ptr = samples + ch;
1170
        iptr = s->frame_out[ch];
1171

    
1172
        for(i=0;i<n;i++) {
1173
            a = lrintf(*iptr++);
1174
            if (a > 32767)
1175
                a = 32767;
1176
            else if (a < -32768)
1177
                a = -32768;
1178
            *ptr = a;
1179
            ptr += incr;
1180
        }
1181
        /* prepare for next block */
1182
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1183
                s->frame_len * sizeof(float));
1184
        /* XXX: suppress this */
1185
        memset(&s->frame_out[ch][s->frame_len], 0,
1186
               s->frame_len * sizeof(float));
1187
    }
1188

    
1189
#ifdef TRACE
1190
    dump_shorts("samples", samples, n * s->nb_channels);
1191
#endif
1192
    return 0;
1193
}
1194

    
1195
static int wma_decode_superframe(AVCodecContext *avctx,
1196
                                 void *data, int *data_size,
1197
                                 uint8_t *buf, int buf_size)
1198
{
1199
    WMADecodeContext *s = avctx->priv_data;
1200
    int nb_frames, bit_offset, i, pos, len;
1201
    uint8_t *q;
1202
    int16_t *samples;
1203

    
1204
    tprintf("***decode_superframe:\n");
1205

    
1206
    if(buf_size==0){
1207
        s->last_superframe_len = 0;
1208
        return 0;
1209
    }
1210

    
1211
    samples = data;
1212

    
1213
    init_get_bits(&s->gb, buf, buf_size*8);
1214

    
1215
    if (s->use_bit_reservoir) {
1216
        /* read super frame header */
1217
        get_bits(&s->gb, 4); /* super frame index */
1218
        nb_frames = get_bits(&s->gb, 4) - 1;
1219

    
1220
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1221

    
1222
        if (s->last_superframe_len > 0) {
1223
            //        printf("skip=%d\n", s->last_bitoffset);
1224
            /* add bit_offset bits to last frame */
1225
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1226
                MAX_CODED_SUPERFRAME_SIZE)
1227
                goto fail;
1228
            q = s->last_superframe + s->last_superframe_len;
1229
            len = bit_offset;
1230
            while (len > 0) {
1231
                *q++ = (get_bits)(&s->gb, 8);
1232
                len -= 8;
1233
            }
1234
            if (len > 0) {
1235
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1236
            }
1237

    
1238
            /* XXX: bit_offset bits into last frame */
1239
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1240
            /* skip unused bits */
1241
            if (s->last_bitoffset > 0)
1242
                skip_bits(&s->gb, s->last_bitoffset);
1243
            /* this frame is stored in the last superframe and in the
1244
               current one */
1245
            if (wma_decode_frame(s, samples) < 0)
1246
                goto fail;
1247
            samples += s->nb_channels * s->frame_len;
1248
        }
1249

    
1250
        /* read each frame starting from bit_offset */
1251
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1252
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1253
        len = pos & 7;
1254
        if (len > 0)
1255
            skip_bits(&s->gb, len);
1256

    
1257
        s->reset_block_lengths = 1;
1258
        for(i=0;i<nb_frames;i++) {
1259
            if (wma_decode_frame(s, samples) < 0)
1260
                goto fail;
1261
            samples += s->nb_channels * s->frame_len;
1262
        }
1263

    
1264
        /* we copy the end of the frame in the last frame buffer */
1265
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1266
        s->last_bitoffset = pos & 7;
1267
        pos >>= 3;
1268
        len = buf_size - pos;
1269
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1270
            goto fail;
1271
        }
1272
        s->last_superframe_len = len;
1273
        memcpy(s->last_superframe, buf + pos, len);
1274
    } else {
1275
        /* single frame decode */
1276
        if (wma_decode_frame(s, samples) < 0)
1277
            goto fail;
1278
        samples += s->nb_channels * s->frame_len;
1279
    }
1280
    *data_size = (int8_t *)samples - (int8_t *)data;
1281
    return s->block_align;
1282
 fail:
1283
    /* when error, we reset the bit reservoir */
1284
    s->last_superframe_len = 0;
1285
    return -1;
1286
}
1287

    
1288
static int wma_decode_end(AVCodecContext *avctx)
1289
{
1290
    WMADecodeContext *s = avctx->priv_data;
1291
    int i;
1292

    
1293
    for(i = 0; i < s->nb_block_sizes; i++)
1294
        ff_mdct_end(&s->mdct_ctx[i]);
1295
    for(i = 0; i < s->nb_block_sizes; i++)
1296
        av_free(s->windows[i]);
1297

    
1298
    if (s->use_exp_vlc) {
1299
        free_vlc(&s->exp_vlc);
1300
    }
1301
    if (s->use_noise_coding) {
1302
        free_vlc(&s->hgain_vlc);
1303
    }
1304
    for(i = 0;i < 2; i++) {
1305
        free_vlc(&s->coef_vlc[i]);
1306
        av_free(s->run_table[i]);
1307
        av_free(s->level_table[i]);
1308
    }
1309

    
1310
    return 0;
1311
}
1312

    
1313
AVCodec wmav1_decoder =
1314
{
1315
    "wmav1",
1316
    CODEC_TYPE_AUDIO,
1317
    CODEC_ID_WMAV1,
1318
    sizeof(WMADecodeContext),
1319
    wma_decode_init,
1320
    NULL,
1321
    wma_decode_end,
1322
    wma_decode_superframe,
1323
};
1324

    
1325
AVCodec wmav2_decoder =
1326
{
1327
    "wmav2",
1328
    CODEC_TYPE_AUDIO,
1329
    CODEC_ID_WMAV2,
1330
    sizeof(WMADecodeContext),
1331
    wma_decode_init,
1332
    NULL,
1333
    wma_decode_end,
1334
    wma_decode_superframe,
1335
};