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1
/*
2
 * 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.
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 *
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
19

    
20
/**
21
 * @file wmadec.c
22
 * WMA compatible decoder.
23
 * 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
 *
27
 * 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
#define VLCBITS 9
60
#define VLCMAX ((22+VLCBITS-1)/VLCBITS)
61

    
62
#define EXPVLCBITS 8
63
#define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
64

    
65
#define HGAINVLCBITS 9
66
#define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
67

    
68
typedef struct WMADecodeContext {
69
    GetBitContext gb;
70
    int sample_rate;
71
    int nb_channels;
72
    int bit_rate;
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    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
74
    int block_align;
75
    int use_bit_reservoir;
76
    int use_variable_block_len;
77
    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
78
    int use_noise_coding; /* true if perceptual noise is added */
79
    int byte_offset_bits;
80
    VLC exp_vlc;
81
    int exponent_sizes[BLOCK_NB_SIZES];
82
    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
83
    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
84
    int coefs_start;               /* first coded coef */
85
    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
86
    int exponent_high_sizes[BLOCK_NB_SIZES];
87
    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
88
    VLC hgain_vlc;
89

    
90
    /* coded values in high bands */
91
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
92
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
93

    
94
    /* there are two possible tables for spectral coefficients */
95
    VLC coef_vlc[2];
96
    uint16_t *run_table[2];
97
    uint16_t *level_table[2];
98
    /* frame info */
99
    int frame_len;       /* frame length in samples */
100
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
101
    int nb_block_sizes;  /* number of block sizes */
102
    /* block info */
103
    int reset_block_lengths;
104
    int block_len_bits; /* log2 of current block length */
105
    int next_block_len_bits; /* log2 of next block length */
106
    int prev_block_len_bits; /* log2 of prev block length */
107
    int block_len; /* block length in samples */
108
    int block_num; /* block number in current frame */
109
    int block_pos; /* current position in frame */
110
    uint8_t ms_stereo; /* true if mid/side stereo mode */
111
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
112
    DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]);
113
    float max_exponent[MAX_CHANNELS];
114
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
115
    DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);
116
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
117
    float *windows[BLOCK_NB_SIZES];
118
    DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); /* temporary storage for imdct */
119
    /* output buffer for one frame and the last for IMDCT windowing */
120
    DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]);
121
    /* last frame info */
122
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
123
    int last_bitoffset;
124
    int last_superframe_len;
125
    float noise_table[NOISE_TAB_SIZE];
126
    int noise_index;
127
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
128
    /* lsp_to_curve tables */
129
    float lsp_cos_table[BLOCK_MAX_SIZE];
130
    float lsp_pow_e_table[256];
131
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
132
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
133
    /* pow tables */
134
    float pow_005_10[121];
135
    float pow_00625_10[121];
136

    
137
#ifdef TRACE
138
    int frame_count;
139
#endif
140
} WMADecodeContext;
141

    
142
typedef struct CoefVLCTable {
143
    int n; /* total number of codes */
144
    const uint32_t *huffcodes; /* VLC bit values */
145
    const uint8_t *huffbits;   /* VLC bit size */
146
    const uint16_t *levels; /* table to build run/level tables */
147
} CoefVLCTable;
148

    
149
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
150

    
151
#include "wmadata.h"
152

    
153
#ifdef TRACE
154
static void dump_shorts(const char *name, const short *tab, int n)
155
{
156
    int i;
157

    
158
    tprintf("%s[%d]:\n", name, n);
159
    for(i=0;i<n;i++) {
160
        if ((i & 7) == 0)
161
            tprintf("%4d: ", i);
162
        tprintf(" %5d.0", tab[i]);
163
        if ((i & 7) == 7)
164
            tprintf("\n");
165
    }
166
}
167

    
168
static void dump_floats(const char *name, int prec, const float *tab, int n)
169
{
170
    int i;
171

    
172
    tprintf("%s[%d]:\n", name, n);
173
    for(i=0;i<n;i++) {
174
        if ((i & 7) == 0)
175
            tprintf("%4d: ", i);
176
        tprintf(" %8.*f", prec, tab[i]);
177
        if ((i & 7) == 7)
178
            tprintf("\n");
179
    }
180
    if ((i & 7) != 0)
181
        tprintf("\n");
182
}
183
#endif
184

    
185
/* XXX: use same run/length optimization as mpeg decoders */
186
static void init_coef_vlc(VLC *vlc,
187
                          uint16_t **prun_table, uint16_t **plevel_table,
188
                          const CoefVLCTable *vlc_table)
189
{
190
    int n = vlc_table->n;
191
    const uint8_t *table_bits = vlc_table->huffbits;
192
    const uint32_t *table_codes = vlc_table->huffcodes;
193
    const uint16_t *levels_table = vlc_table->levels;
194
    uint16_t *run_table, *level_table;
195
    const uint16_t *p;
196
    int i, l, j, level;
197

    
198
    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
199

    
200
    run_table = av_malloc(n * sizeof(uint16_t));
201
    level_table = av_malloc(n * sizeof(uint16_t));
202
    p = levels_table;
203
    i = 2;
204
    level = 1;
205
    while (i < n) {
206
        l = *p++;
207
        for(j=0;j<l;j++) {
208
            run_table[i] = j;
209
            level_table[i] = level;
210
            i++;
211
        }
212
        level++;
213
    }
214
    *prun_table = run_table;
215
    *plevel_table = level_table;
216
}
217

    
218
static int wma_decode_init(AVCodecContext * avctx)
219
{
220
    WMADecodeContext *s = avctx->priv_data;
221
    int i, flags1, flags2;
222
    float *window;
223
    uint8_t *extradata;
224
    float bps, bps1;
225
    volatile float high_freq_factor;
226
    int sample_rate1;
227
    int coef_vlc_table;
228

    
229
    s->sample_rate = avctx->sample_rate;
230
    s->nb_channels = avctx->channels;
231
    s->bit_rate = avctx->bit_rate;
232
    s->block_align = avctx->block_align;
233

    
234
    if (avctx->codec->id == CODEC_ID_WMAV1) {
235
        s->version = 1;
236
    } else {
237
        s->version = 2;
238
    }
239

    
240
    /* extract flag infos */
241
    flags1 = 0;
242
    flags2 = 0;
243
    extradata = avctx->extradata;
244
    if (s->version == 1 && avctx->extradata_size >= 4) {
245
        flags1 = extradata[0] | (extradata[1] << 8);
246
        flags2 = extradata[2] | (extradata[3] << 8);
247
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
248
        flags1 = extradata[0] | (extradata[1] << 8) |
249
            (extradata[2] << 16) | (extradata[3] << 24);
250
        flags2 = extradata[4] | (extradata[5] << 8);
251
    }
252
    s->use_exp_vlc = flags2 & 0x0001;
253
    s->use_bit_reservoir = flags2 & 0x0002;
254
    s->use_variable_block_len = flags2 & 0x0004;
255

    
256
    /* compute MDCT block size */
257
    if (s->sample_rate <= 16000) {
258
        s->frame_len_bits = 9;
259
    } else if (s->sample_rate <= 22050 ||
260
               (s->sample_rate <= 32000 && s->version == 1)) {
261
        s->frame_len_bits = 10;
262
    } else {
263
        s->frame_len_bits = 11;
264
    }
265
    s->frame_len = 1 << s->frame_len_bits;
266
    if (s->use_variable_block_len) {
267
        int nb_max, nb;
268
        nb = ((flags2 >> 3) & 3) + 1;
269
        if ((s->bit_rate / s->nb_channels) >= 32000)
270
            nb += 2;
271
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
272
        if (nb > nb_max)
273
            nb = nb_max;
274
        s->nb_block_sizes = nb + 1;
275
    } else {
276
        s->nb_block_sizes = 1;
277
    }
278

    
279
    /* init rate dependant parameters */
280
    s->use_noise_coding = 1;
281

    
282
    /* if version 2, then the rates are normalized */
283
    sample_rate1 = s->sample_rate;
284
    if (s->version == 2) {
285
        if (sample_rate1 >= 44100)
286
            sample_rate1 = 44100;
287
        else if (sample_rate1 >= 22050)
288
            sample_rate1 = 22050;
289
        else if (sample_rate1 >= 16000)
290
            sample_rate1 = 16000;
291
        else if (sample_rate1 >= 11025)
292
            sample_rate1 = 11025;
293
        else if (sample_rate1 >= 8000)
294
            sample_rate1 = 8000;
295
    }
296

    
297
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
298
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
299

    
300
    /* compute high frequency value and choose if noise coding should
301
       be activated */
302
    bps1 = bps;
303
    if (s->nb_channels == 2)
304
        bps1 = bps * 1.6;
305
    if (sample_rate1 == 44100) {
306
        if (bps1 >= 0.61)
307
            s->use_noise_coding = 0;
308
        else
309
            high_freq_factor = 0.4;
310
    } else if (sample_rate1 == 22050) {
311
        if (bps1 >= 1.16)
312
            s->use_noise_coding = 0;
313
        else if (bps1 >= 0.72)
314
            high_freq_factor = 0.7;
315
        else
316
            high_freq_factor = 0.6;
317
    } else if (sample_rate1 == 16000) {
318
        if (bps > 0.5)
319
            high_freq_factor = 0.5;
320
        else
321
            high_freq_factor = 0.3;
322
    } else if (sample_rate1 == 11025) {
323
        high_freq_factor = 0.7;
324
    } else if (sample_rate1 == 8000) {
325
        if (bps <= 0.625) {
326
            high_freq_factor = 0.5;
327
        } else if (bps > 0.75) {
328
            s->use_noise_coding = 0;
329
        } else {
330
            high_freq_factor = 0.65;
331
        }
332
    } else {
333
        if (bps >= 0.8) {
334
            high_freq_factor = 0.75;
335
        } else if (bps >= 0.6) {
336
            high_freq_factor = 0.6;
337
        } else {
338
            high_freq_factor = 0.5;
339
        }
340
    }
341
    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
342
    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
343
           s->version, s->nb_channels, s->sample_rate, s->bit_rate,
344
           s->block_align);
345
    dprintf("bps=%f bps1=%f bitoffset=%d\n",
346
           bps, bps1, s->byte_offset_bits);
347
    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
348
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
349

    
350
    /* compute the scale factor band sizes for each MDCT block size */
351
    {
352
        int a, b, pos, lpos, k, block_len, i, j, n;
353
        const uint8_t *table;
354

    
355
        if (s->version == 1) {
356
            s->coefs_start = 3;
357
        } else {
358
            s->coefs_start = 0;
359
        }
360
        for(k = 0; k < s->nb_block_sizes; k++) {
361
            block_len = s->frame_len >> k;
362

    
363
            if (s->version == 1) {
364
                lpos = 0;
365
                for(i=0;i<25;i++) {
366
                    a = wma_critical_freqs[i];
367
                    b = s->sample_rate;
368
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
369
                    if (pos > block_len)
370
                        pos = block_len;
371
                    s->exponent_bands[0][i] = pos - lpos;
372
                    if (pos >= block_len) {
373
                        i++;
374
                        break;
375
                    }
376
                    lpos = pos;
377
                }
378
                s->exponent_sizes[0] = i;
379
            } else {
380
                /* hardcoded tables */
381
                table = NULL;
382
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
383
                if (a < 3) {
384
                    if (s->sample_rate >= 44100)
385
                        table = exponent_band_44100[a];
386
                    else if (s->sample_rate >= 32000)
387
                        table = exponent_band_32000[a];
388
                    else if (s->sample_rate >= 22050)
389
                        table = exponent_band_22050[a];
390
                }
391
                if (table) {
392
                    n = *table++;
393
                    for(i=0;i<n;i++)
394
                        s->exponent_bands[k][i] = table[i];
395
                    s->exponent_sizes[k] = n;
396
                } else {
397
                    j = 0;
398
                    lpos = 0;
399
                    for(i=0;i<25;i++) {
400
                        a = wma_critical_freqs[i];
401
                        b = s->sample_rate;
402
                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
403
                        pos <<= 2;
404
                        if (pos > block_len)
405
                            pos = block_len;
406
                        if (pos > lpos)
407
                            s->exponent_bands[k][j++] = pos - lpos;
408
                        if (pos >= block_len)
409
                            break;
410
                        lpos = pos;
411
                    }
412
                    s->exponent_sizes[k] = j;
413
                }
414
            }
415

    
416
            /* max number of coefs */
417
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
418
            /* high freq computation */
419
            s->high_band_start[k] = (int)((block_len * high_freq_factor) + 0.5);
420

    
421
            n = s->exponent_sizes[k];
422
            j = 0;
423
            pos = 0;
424
            for(i=0;i<n;i++) {
425
                int start, end;
426
                start = pos;
427
                pos += s->exponent_bands[k][i];
428
                end = pos;
429
                if (start < s->high_band_start[k])
430
                    start = s->high_band_start[k];
431
                if (end > s->coefs_end[k])
432
                    end = s->coefs_end[k];
433
                if (end > start)
434
                    s->exponent_high_bands[k][j++] = end - start;
435
            }
436
            s->exponent_high_sizes[k] = j;
437
#if 0
438
            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
439
                  s->frame_len >> k,
440
                  s->coefs_end[k],
441
                  s->high_band_start[k],
442
                  s->exponent_high_sizes[k]);
443
            for(j=0;j<s->exponent_high_sizes[k];j++)
444
                tprintf(" %d", s->exponent_high_bands[k][j]);
445
            tprintf("\n");
446
#endif
447
        }
448
    }
449

    
450
#ifdef TRACE
451
    {
452
        int i, j;
453
        for(i = 0; i < s->nb_block_sizes; i++) {
454
            tprintf("%5d: n=%2d:",
455
                   s->frame_len >> i,
456
                   s->exponent_sizes[i]);
457
            for(j=0;j<s->exponent_sizes[i];j++)
458
                tprintf(" %d", s->exponent_bands[i][j]);
459
            tprintf("\n");
460
        }
461
    }
462
#endif
463

    
464
    /* init MDCT */
465
    for(i = 0; i < s->nb_block_sizes; i++)
466
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
467

    
468
    /* init MDCT windows : simple sinus window */
469
    for(i = 0; i < s->nb_block_sizes; i++) {
470
        int n, j;
471
        float alpha;
472
        n = 1 << (s->frame_len_bits - i);
473
        window = av_malloc(sizeof(float) * n);
474
        alpha = M_PI / (2.0 * n);
475
        for(j=0;j<n;j++) {
476
            window[n - j - 1] = sin((j + 0.5) * alpha);
477
        }
478
        s->windows[i] = window;
479
    }
480

    
481
    s->reset_block_lengths = 1;
482

    
483
    if (s->use_noise_coding) {
484

    
485
        /* init the noise generator */
486
        if (s->use_exp_vlc)
487
            s->noise_mult = 0.02;
488
        else
489
            s->noise_mult = 0.04;
490

    
491
#ifdef TRACE
492
        for(i=0;i<NOISE_TAB_SIZE;i++)
493
            s->noise_table[i] = 1.0 * s->noise_mult;
494
#else
495
        {
496
            unsigned int seed;
497
            float norm;
498
            seed = 1;
499
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
500
            for(i=0;i<NOISE_TAB_SIZE;i++) {
501
                seed = seed * 314159 + 1;
502
                s->noise_table[i] = (float)((int)seed) * norm;
503
            }
504
        }
505
#endif
506
        init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(hgain_huffbits),
507
                 hgain_huffbits, 1, 1,
508
                 hgain_huffcodes, 2, 2, 0);
509
    }
510

    
511
    if (s->use_exp_vlc) {
512
        init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(scale_huffbits),
513
                 scale_huffbits, 1, 1,
514
                 scale_huffcodes, 4, 4, 0);
515
    } else {
516
        wma_lsp_to_curve_init(s, s->frame_len);
517
    }
518

    
519
    /* choose the VLC tables for the coefficients */
520
    coef_vlc_table = 2;
521
    if (s->sample_rate >= 32000) {
522
        if (bps1 < 0.72)
523
            coef_vlc_table = 0;
524
        else if (bps1 < 1.16)
525
            coef_vlc_table = 1;
526
    }
527

    
528
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
529
                  &coef_vlcs[coef_vlc_table * 2]);
530
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
531
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
532

    
533
    /* init pow tables */
534
    for (i=0 ; i<121 ; i++) {
535
        s->pow_005_10[i] = pow(10, i * 0.05);
536
        s->pow_00625_10[i] = pow(10, i * (1.0 / 16.0));
537
    }
538

    
539
    return 0;
540
}
541

    
542
/* interpolate values for a bigger or smaller block. The block must
543
   have multiple sizes */
544
static void interpolate_array(float *scale, int old_size, int new_size)
545
{
546
    int i, j, jincr, k;
547
    float v;
548

    
549
    if (new_size > old_size) {
550
        jincr = new_size / old_size;
551
        j = new_size;
552
        for(i = old_size - 1; i >=0; i--) {
553
            v = scale[i];
554
            k = jincr;
555
            do {
556
                scale[--j] = v;
557
            } while (--k);
558
        }
559
    } else if (new_size < old_size) {
560
        j = 0;
561
        jincr = old_size / new_size;
562
        for(i = 0; i < new_size; i++) {
563
            scale[i] = scale[j];
564
            j += jincr;
565
        }
566
    }
567
}
568

    
569
/* compute x^-0.25 with an exponent and mantissa table. We use linear
570
   interpolation to reduce the mantissa table size at a small speed
571
   expense (linear interpolation approximately doubles the number of
572
   bits of precision). */
573
static inline float pow_m1_4(WMADecodeContext *s, float x)
574
{
575
    union {
576
        float f;
577
        unsigned int v;
578
    } u, t;
579
    unsigned int e, m;
580
    float a, b;
581

    
582
    u.f = x;
583
    e = u.v >> 23;
584
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
585
    /* build interpolation scale: 1 <= t < 2. */
586
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
587
    a = s->lsp_pow_m_table1[m];
588
    b = s->lsp_pow_m_table2[m];
589
    return s->lsp_pow_e_table[e] * (a + b * t.f);
590
}
591

    
592
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
593
{
594
    float wdel, a, b;
595
    int i, e, m;
596

    
597
    wdel = M_PI / frame_len;
598
    for(i=0;i<frame_len;i++)
599
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
600

    
601
    /* tables for x^-0.25 computation */
602
    for(i=0;i<256;i++) {
603
        e = i - 126;
604
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
605
    }
606

    
607
    /* NOTE: these two tables are needed to avoid two operations in
608
       pow_m1_4 */
609
    b = 1.0;
610
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
611
        m = (1 << LSP_POW_BITS) + i;
612
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
613
        a = pow(a, -0.25);
614
        s->lsp_pow_m_table1[i] = 2 * a - b;
615
        s->lsp_pow_m_table2[i] = b - a;
616
        b = a;
617
    }
618
#if 0
619
    for(i=1;i<20;i++) {
620
        float v, r1, r2;
621
        v = 5.0 / i;
622
        r1 = pow_m1_4(s, v);
623
        r2 = pow(v,-0.25);
624
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
625
    }
626
#endif
627
}
628

    
629
/* NOTE: We use the same code as Vorbis here */
630
/* XXX: optimize it further with SSE/3Dnow */
631
static void wma_lsp_to_curve(WMADecodeContext *s,
632
                             float *out, float *val_max_ptr,
633
                             int n, float *lsp)
634
{
635
    int i, j;
636
    float p, q, w, v, val_max;
637

    
638
    val_max = 0;
639
    for(i=0;i<n;i++) {
640
        p = 0.5f;
641
        q = 0.5f;
642
        w = s->lsp_cos_table[i];
643
        for(j=1;j<NB_LSP_COEFS;j+=2){
644
            q *= w - lsp[j - 1];
645
            p *= w - lsp[j];
646
        }
647
        p *= p * (2.0f - w);
648
        q *= q * (2.0f + w);
649
        v = p + q;
650
        v = pow_m1_4(s, v);
651
        if (v > val_max)
652
            val_max = v;
653
        out[i] = v;
654
    }
655
    *val_max_ptr = val_max;
656
}
657

    
658
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
659
static void decode_exp_lsp(WMADecodeContext *s, int ch)
660
{
661
    float lsp_coefs[NB_LSP_COEFS];
662
    int val, i;
663

    
664
    for(i = 0; i < NB_LSP_COEFS; i++) {
665
        if (i == 0 || i >= 8)
666
            val = get_bits(&s->gb, 3);
667
        else
668
            val = get_bits(&s->gb, 4);
669
        lsp_coefs[i] = lsp_codebook[i][val];
670
    }
671

    
672
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
673
                     s->block_len, lsp_coefs);
674
}
675

    
676
/* decode exponents coded with VLC codes */
677
static int decode_exp_vlc(WMADecodeContext *s, int ch)
678
{
679
    int last_exp, n, code;
680
    const uint16_t *ptr, *band_ptr;
681
    float v, *q, max_scale, *q_end;
682

    
683
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
684
    ptr = band_ptr;
685
    q = s->exponents[ch];
686
    q_end = q + s->block_len;
687
    max_scale = 0;
688
    if (s->version == 1) {
689
        last_exp = get_bits(&s->gb, 5) + 10;
690
        v = s->pow_00625_10[last_exp];
691
        max_scale = v;
692
        n = *ptr++;
693
        do {
694
            *q++ = v;
695
        } while (--n);
696
    }
697
    last_exp = 36;
698
    while (q < q_end) {
699
        code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
700
        if (code < 0)
701
            return -1;
702
        /* NOTE: this offset is the same as MPEG4 AAC ! */
703
        last_exp += code - 60;
704
        v = s->pow_00625_10[last_exp];
705
        if (v > max_scale)
706
            max_scale = v;
707
        n = *ptr++;
708
        do {
709
            *q++ = v;
710
        } while (--n);
711
    }
712
    s->max_exponent[ch] = max_scale;
713
    return 0;
714
}
715

    
716
/* return 0 if OK. return 1 if last block of frame. return -1 if
717
   unrecorrable error. */
718
static int wma_decode_block(WMADecodeContext *s)
719
{
720
    int n, v, a, ch, code, bsize;
721
    int coef_nb_bits, total_gain, parse_exponents;
722
    float window[BLOCK_MAX_SIZE * 2];
723
// XXX: FIXME!! there's a bug somewhere which makes this mandatory under altivec
724
#ifdef HAVE_ALTIVEC
725
    volatile int nb_coefs[MAX_CHANNELS] __attribute__((aligned(16)));
726
#else
727
    int nb_coefs[MAX_CHANNELS];
728
#endif
729
    float mdct_norm;
730

    
731
#ifdef TRACE
732
    tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
733
#endif
734

    
735
    /* compute current block length */
736
    if (s->use_variable_block_len) {
737
        n = av_log2(s->nb_block_sizes - 1) + 1;
738

    
739
        if (s->reset_block_lengths) {
740
            s->reset_block_lengths = 0;
741
            v = get_bits(&s->gb, n);
742
            if (v >= s->nb_block_sizes)
743
                return -1;
744
            s->prev_block_len_bits = s->frame_len_bits - v;
745
            v = get_bits(&s->gb, n);
746
            if (v >= s->nb_block_sizes)
747
                return -1;
748
            s->block_len_bits = s->frame_len_bits - v;
749
        } else {
750
            /* update block lengths */
751
            s->prev_block_len_bits = s->block_len_bits;
752
            s->block_len_bits = s->next_block_len_bits;
753
        }
754
        v = get_bits(&s->gb, n);
755
        if (v >= s->nb_block_sizes)
756
            return -1;
757
        s->next_block_len_bits = s->frame_len_bits - v;
758
    } else {
759
        /* fixed block len */
760
        s->next_block_len_bits = s->frame_len_bits;
761
        s->prev_block_len_bits = s->frame_len_bits;
762
        s->block_len_bits = s->frame_len_bits;
763
    }
764

    
765
    /* now check if the block length is coherent with the frame length */
766
    s->block_len = 1 << s->block_len_bits;
767
    if ((s->block_pos + s->block_len) > s->frame_len)
768
        return -1;
769

    
770
    if (s->nb_channels == 2) {
771
        s->ms_stereo = get_bits(&s->gb, 1);
772
    }
773
    v = 0;
774
    for(ch = 0; ch < s->nb_channels; ch++) {
775
        a = get_bits(&s->gb, 1);
776
        s->channel_coded[ch] = a;
777
        v |= a;
778
    }
779
    /* if no channel coded, no need to go further */
780
    /* XXX: fix potential framing problems */
781
    if (!v)
782
        goto next;
783

    
784
    bsize = s->frame_len_bits - s->block_len_bits;
785

    
786
    /* read total gain and extract corresponding number of bits for
787
       coef escape coding */
788
    total_gain = 1;
789
    for(;;) {
790
        a = get_bits(&s->gb, 7);
791
        total_gain += a;
792
        if (a != 127)
793
            break;
794
    }
795

    
796
    if (total_gain < 15)
797
        coef_nb_bits = 13;
798
    else if (total_gain < 32)
799
        coef_nb_bits = 12;
800
    else if (total_gain < 40)
801
        coef_nb_bits = 11;
802
    else if (total_gain < 45)
803
        coef_nb_bits = 10;
804
    else
805
        coef_nb_bits = 9;
806

    
807
    /* compute number of coefficients */
808
    n = s->coefs_end[bsize] - s->coefs_start;
809
    for(ch = 0; ch < s->nb_channels; ch++)
810
        nb_coefs[ch] = n;
811

    
812
    /* complex coding */
813
    if (s->use_noise_coding) {
814

    
815
        for(ch = 0; ch < s->nb_channels; ch++) {
816
            if (s->channel_coded[ch]) {
817
                int i, n, a;
818
                n = s->exponent_high_sizes[bsize];
819
                for(i=0;i<n;i++) {
820
                    a = get_bits(&s->gb, 1);
821
                    s->high_band_coded[ch][i] = a;
822
                    /* if noise coding, the coefficients are not transmitted */
823
                    if (a)
824
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
825
                }
826
            }
827
        }
828
        for(ch = 0; ch < s->nb_channels; ch++) {
829
            if (s->channel_coded[ch]) {
830
                int i, n, val, code;
831

    
832
                n = s->exponent_high_sizes[bsize];
833
                val = (int)0x80000000;
834
                for(i=0;i<n;i++) {
835
                    if (s->high_band_coded[ch][i]) {
836
                        if (val == (int)0x80000000) {
837
                            val = get_bits(&s->gb, 7) - 19;
838
                        } else {
839
                            code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
840
                            if (code < 0)
841
                                return -1;
842
                            val += code - 18;
843
                        }
844
                        s->high_band_values[ch][i] = val;
845
                    }
846
                }
847
            }
848
        }
849
    }
850

    
851
    /* exposant can be interpolated in short blocks. */
852
    parse_exponents = 1;
853
    if (s->block_len_bits != s->frame_len_bits) {
854
        parse_exponents = get_bits(&s->gb, 1);
855
    }
856

    
857
    if (parse_exponents) {
858
        for(ch = 0; ch < s->nb_channels; ch++) {
859
            if (s->channel_coded[ch]) {
860
                if (s->use_exp_vlc) {
861
                    if (decode_exp_vlc(s, ch) < 0)
862
                        return -1;
863
                } else {
864
                    decode_exp_lsp(s, ch);
865
                }
866
            }
867
        }
868
    } else {
869
        for(ch = 0; ch < s->nb_channels; ch++) {
870
            if (s->channel_coded[ch]) {
871
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
872
                                  s->block_len);
873
            }
874
        }
875
    }
876

    
877
    /* parse spectral coefficients : just RLE encoding */
878
    for(ch = 0; ch < s->nb_channels; ch++) {
879
        if (s->channel_coded[ch]) {
880
            VLC *coef_vlc;
881
            int level, run, sign, tindex;
882
            int16_t *ptr, *eptr;
883
            const int16_t *level_table, *run_table;
884

    
885
            /* special VLC tables are used for ms stereo because
886
               there is potentially less energy there */
887
            tindex = (ch == 1 && s->ms_stereo);
888
            coef_vlc = &s->coef_vlc[tindex];
889
            run_table = s->run_table[tindex];
890
            level_table = s->level_table[tindex];
891
            /* XXX: optimize */
892
            ptr = &s->coefs1[ch][0];
893
            eptr = ptr + nb_coefs[ch];
894
            memset(ptr, 0, s->block_len * sizeof(int16_t));
895
            for(;;) {
896
                code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
897
                if (code < 0)
898
                    return -1;
899
                if (code == 1) {
900
                    /* EOB */
901
                    break;
902
                } else if (code == 0) {
903
                    /* escape */
904
                    level = get_bits(&s->gb, coef_nb_bits);
905
                    /* NOTE: this is rather suboptimal. reading
906
                       block_len_bits would be better */
907
                    run = get_bits(&s->gb, s->frame_len_bits);
908
                } else {
909
                    /* normal code */
910
                    run = run_table[code];
911
                    level = level_table[code];
912
                }
913
                sign = get_bits(&s->gb, 1);
914
                if (!sign)
915
                    level = -level;
916
                ptr += run;
917
                if (ptr >= eptr)
918
                    return -1;
919
                *ptr++ = level;
920
                /* NOTE: EOB can be omitted */
921
                if (ptr >= eptr)
922
                    break;
923
            }
924
        }
925
        if (s->version == 1 && s->nb_channels >= 2) {
926
            align_get_bits(&s->gb);
927
        }
928
    }
929

    
930
    /* normalize */
931
    {
932
        int n4 = s->block_len / 2;
933
        mdct_norm = 1.0 / (float)n4;
934
        if (s->version == 1) {
935
            mdct_norm *= sqrt(n4);
936
        }
937
    }
938

    
939
    /* finally compute the MDCT coefficients */
940
    for(ch = 0; ch < s->nb_channels; ch++) {
941
        if (s->channel_coded[ch]) {
942
            int16_t *coefs1;
943
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
944
            int i, j, n, n1, last_high_band;
945
            float exp_power[HIGH_BAND_MAX_SIZE];
946

    
947
            coefs1 = s->coefs1[ch];
948
            exponents = s->exponents[ch];
949
            mult = s->pow_005_10[total_gain] / s->max_exponent[ch];
950
            mult *= mdct_norm;
951
            coefs = s->coefs[ch];
952
            if (s->use_noise_coding) {
953
                mult1 = mult;
954
                /* very low freqs : noise */
955
                for(i = 0;i < s->coefs_start; i++) {
956
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
957
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
958
                }
959

    
960
                n1 = s->exponent_high_sizes[bsize];
961

    
962
                /* compute power of high bands */
963
                exp_ptr = exponents +
964
                    s->high_band_start[bsize] -
965
                    s->coefs_start;
966
                last_high_band = 0; /* avoid warning */
967
                for(j=0;j<n1;j++) {
968
                    n = s->exponent_high_bands[s->frame_len_bits -
969
                                              s->block_len_bits][j];
970
                    if (s->high_band_coded[ch][j]) {
971
                        float e2, v;
972
                        e2 = 0;
973
                        for(i = 0;i < n; i++) {
974
                            v = exp_ptr[i];
975
                            e2 += v * v;
976
                        }
977
                        exp_power[j] = e2 / n;
978
                        last_high_band = j;
979
                        tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
980
                    }
981
                    exp_ptr += n;
982
                }
983

    
984
                /* main freqs and high freqs */
985
                for(j=-1;j<n1;j++) {
986
                    if (j < 0) {
987
                        n = s->high_band_start[bsize] -
988
                            s->coefs_start;
989
                    } else {
990
                        n = s->exponent_high_bands[s->frame_len_bits -
991
                                                  s->block_len_bits][j];
992
                    }
993
                    if (j >= 0 && s->high_band_coded[ch][j]) {
994
                        /* use noise with specified power */
995
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
996
                        mult1 = mult1 * s->pow_005_10[s->high_band_values[ch][j]];
997
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
998
                        mult1 *= mdct_norm;
999
                        for(i = 0;i < n; i++) {
1000
                            noise = s->noise_table[s->noise_index];
1001
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1002
                            *coefs++ = (*exponents++) * noise * mult1;
1003
                        }
1004
                    } else {
1005
                        /* coded values + small noise */
1006
                        for(i = 0;i < n; i++) {
1007
                            noise = s->noise_table[s->noise_index];
1008
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1009
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
1010
                        }
1011
                    }
1012
                }
1013

    
1014
                /* very high freqs : noise */
1015
                n = s->block_len - s->coefs_end[bsize];
1016
                mult1 = mult * exponents[-1];
1017
                for(i = 0; i < n; i++) {
1018
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
1019
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1020
                }
1021
            } else {
1022
                /* XXX: optimize more */
1023
                for(i = 0;i < s->coefs_start; i++)
1024
                    *coefs++ = 0.0;
1025
                n = nb_coefs[ch];
1026
                for(i = 0;i < n; i++) {
1027
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1028
                }
1029
                n = s->block_len - s->coefs_end[bsize];
1030
                for(i = 0;i < n; i++)
1031
                    *coefs++ = 0.0;
1032
            }
1033
        }
1034
    }
1035

    
1036
#ifdef TRACE
1037
    for(ch = 0; ch < s->nb_channels; ch++) {
1038
        if (s->channel_coded[ch]) {
1039
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1040
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1041
        }
1042
    }
1043
#endif
1044

    
1045
    if (s->ms_stereo && s->channel_coded[1]) {
1046
        float a, b;
1047
        int i;
1048

    
1049
        /* nominal case for ms stereo: we do it before mdct */
1050
        /* no need to optimize this case because it should almost
1051
           never happen */
1052
        if (!s->channel_coded[0]) {
1053
            tprintf("rare ms-stereo case happened\n");
1054
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1055
            s->channel_coded[0] = 1;
1056
        }
1057

    
1058
        for(i = 0; i < s->block_len; i++) {
1059
            a = s->coefs[0][i];
1060
            b = s->coefs[1][i];
1061
            s->coefs[0][i] = a + b;
1062
            s->coefs[1][i] = a - b;
1063
        }
1064
    }
1065

    
1066
    /* build the window : we ensure that when the windows overlap
1067
       their squared sum is always 1 (MDCT reconstruction rule) */
1068
    /* XXX: merge with output */
1069
    {
1070
        int i, next_block_len, block_len, prev_block_len, n;
1071
        float *wptr;
1072

    
1073
        block_len = s->block_len;
1074
        prev_block_len = 1 << s->prev_block_len_bits;
1075
        next_block_len = 1 << s->next_block_len_bits;
1076

    
1077
        /* right part */
1078
        wptr = window + block_len;
1079
        if (block_len <= next_block_len) {
1080
            for(i=0;i<block_len;i++)
1081
                *wptr++ = s->windows[bsize][i];
1082
        } else {
1083
            /* overlap */
1084
            n = (block_len / 2) - (next_block_len / 2);
1085
            for(i=0;i<n;i++)
1086
                *wptr++ = 1.0;
1087
            for(i=0;i<next_block_len;i++)
1088
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1089
            for(i=0;i<n;i++)
1090
                *wptr++ = 0.0;
1091
        }
1092

    
1093
        /* left part */
1094
        wptr = window + block_len;
1095
        if (block_len <= prev_block_len) {
1096
            for(i=0;i<block_len;i++)
1097
                *--wptr = s->windows[bsize][i];
1098
        } else {
1099
            /* overlap */
1100
            n = (block_len / 2) - (prev_block_len / 2);
1101
            for(i=0;i<n;i++)
1102
                *--wptr = 1.0;
1103
            for(i=0;i<prev_block_len;i++)
1104
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1105
            for(i=0;i<n;i++)
1106
                *--wptr = 0.0;
1107
        }
1108
    }
1109

    
1110

    
1111
    for(ch = 0; ch < s->nb_channels; ch++) {
1112
        if (s->channel_coded[ch]) {
1113
            DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);
1114
            float *ptr;
1115
            int i, n4, index, n;
1116

    
1117
            n = s->block_len;
1118
            n4 = s->block_len / 2;
1119
            ff_imdct_calc(&s->mdct_ctx[bsize],
1120
                          output, s->coefs[ch], s->mdct_tmp);
1121

    
1122
            /* XXX: optimize all that by build the window and
1123
               multipying/adding at the same time */
1124
            /* multiply by the window */
1125
            for(i=0;i<n * 2;i++) {
1126
                output[i] *= window[i];
1127
            }
1128

    
1129
            /* add in the frame */
1130
            index = (s->frame_len / 2) + s->block_pos - n4;
1131
            ptr = &s->frame_out[ch][index];
1132
            for(i=0;i<n * 2;i++) {
1133
                *ptr += output[i];
1134
                ptr++;
1135
            }
1136

    
1137
            /* specific fast case for ms-stereo : add to second
1138
               channel if it is not coded */
1139
            if (s->ms_stereo && !s->channel_coded[1]) {
1140
                ptr = &s->frame_out[1][index];
1141
                for(i=0;i<n * 2;i++) {
1142
                    *ptr += output[i];
1143
                    ptr++;
1144
                }
1145
            }
1146
        }
1147
    }
1148
 next:
1149
    /* update block number */
1150
    s->block_num++;
1151
    s->block_pos += s->block_len;
1152
    if (s->block_pos >= s->frame_len)
1153
        return 1;
1154
    else
1155
        return 0;
1156
}
1157

    
1158
/* decode a frame of frame_len samples */
1159
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1160
{
1161
    int ret, i, n, a, ch, incr;
1162
    int16_t *ptr;
1163
    float *iptr;
1164

    
1165
#ifdef TRACE
1166
    tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
1167
#endif
1168

    
1169
    /* read each block */
1170
    s->block_num = 0;
1171
    s->block_pos = 0;
1172
    for(;;) {
1173
        ret = wma_decode_block(s);
1174
        if (ret < 0)
1175
            return -1;
1176
        if (ret)
1177
            break;
1178
    }
1179

    
1180
    /* convert frame to integer */
1181
    n = s->frame_len;
1182
    incr = s->nb_channels;
1183
    for(ch = 0; ch < s->nb_channels; ch++) {
1184
        ptr = samples + ch;
1185
        iptr = s->frame_out[ch];
1186

    
1187
        for(i=0;i<n;i++) {
1188
            a = lrintf(*iptr++);
1189
            if (a > 32767)
1190
                a = 32767;
1191
            else if (a < -32768)
1192
                a = -32768;
1193
            *ptr = a;
1194
            ptr += incr;
1195
        }
1196
        /* prepare for next block */
1197
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1198
                s->frame_len * sizeof(float));
1199
        /* XXX: suppress this */
1200
        memset(&s->frame_out[ch][s->frame_len], 0,
1201
               s->frame_len * sizeof(float));
1202
    }
1203

    
1204
#ifdef TRACE
1205
    dump_shorts("samples", samples, n * s->nb_channels);
1206
#endif
1207
    return 0;
1208
}
1209

    
1210
static int wma_decode_superframe(AVCodecContext *avctx,
1211
                                 void *data, int *data_size,
1212
                                 uint8_t *buf, int buf_size)
1213
{
1214
    WMADecodeContext *s = avctx->priv_data;
1215
    int nb_frames, bit_offset, i, pos, len;
1216
    uint8_t *q;
1217
    int16_t *samples;
1218

    
1219
    tprintf("***decode_superframe:\n");
1220

    
1221
    if(buf_size==0){
1222
        s->last_superframe_len = 0;
1223
        return 0;
1224
    }
1225

    
1226
    samples = data;
1227

    
1228
    init_get_bits(&s->gb, buf, buf_size*8);
1229

    
1230
    if (s->use_bit_reservoir) {
1231
        /* read super frame header */
1232
        get_bits(&s->gb, 4); /* super frame index */
1233
        nb_frames = get_bits(&s->gb, 4) - 1;
1234

    
1235
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1236

    
1237
        if (s->last_superframe_len > 0) {
1238
            //        printf("skip=%d\n", s->last_bitoffset);
1239
            /* add bit_offset bits to last frame */
1240
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1241
                MAX_CODED_SUPERFRAME_SIZE)
1242
                goto fail;
1243
            q = s->last_superframe + s->last_superframe_len;
1244
            len = bit_offset;
1245
            while (len > 0) {
1246
                *q++ = (get_bits)(&s->gb, 8);
1247
                len -= 8;
1248
            }
1249
            if (len > 0) {
1250
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1251
            }
1252

    
1253
            /* XXX: bit_offset bits into last frame */
1254
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1255
            /* skip unused bits */
1256
            if (s->last_bitoffset > 0)
1257
                skip_bits(&s->gb, s->last_bitoffset);
1258
            /* this frame is stored in the last superframe and in the
1259
               current one */
1260
            if (wma_decode_frame(s, samples) < 0)
1261
                goto fail;
1262
            samples += s->nb_channels * s->frame_len;
1263
        }
1264

    
1265
        /* read each frame starting from bit_offset */
1266
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1267
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1268
        len = pos & 7;
1269
        if (len > 0)
1270
            skip_bits(&s->gb, len);
1271

    
1272
        s->reset_block_lengths = 1;
1273
        for(i=0;i<nb_frames;i++) {
1274
            if (wma_decode_frame(s, samples) < 0)
1275
                goto fail;
1276
            samples += s->nb_channels * s->frame_len;
1277
        }
1278

    
1279
        /* we copy the end of the frame in the last frame buffer */
1280
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1281
        s->last_bitoffset = pos & 7;
1282
        pos >>= 3;
1283
        len = buf_size - pos;
1284
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1285
            goto fail;
1286
        }
1287
        s->last_superframe_len = len;
1288
        memcpy(s->last_superframe, buf + pos, len);
1289
    } else {
1290
        /* single frame decode */
1291
        if (wma_decode_frame(s, samples) < 0)
1292
            goto fail;
1293
        samples += s->nb_channels * s->frame_len;
1294
    }
1295
    *data_size = (int8_t *)samples - (int8_t *)data;
1296
    return s->block_align;
1297
 fail:
1298
    /* when error, we reset the bit reservoir */
1299
    s->last_superframe_len = 0;
1300
    return -1;
1301
}
1302

    
1303
static int wma_decode_end(AVCodecContext *avctx)
1304
{
1305
    WMADecodeContext *s = avctx->priv_data;
1306
    int i;
1307

    
1308
    for(i = 0; i < s->nb_block_sizes; i++)
1309
        ff_mdct_end(&s->mdct_ctx[i]);
1310
    for(i = 0; i < s->nb_block_sizes; i++)
1311
        av_free(s->windows[i]);
1312

    
1313
    if (s->use_exp_vlc) {
1314
        free_vlc(&s->exp_vlc);
1315
    }
1316
    if (s->use_noise_coding) {
1317
        free_vlc(&s->hgain_vlc);
1318
    }
1319
    for(i = 0;i < 2; i++) {
1320
        free_vlc(&s->coef_vlc[i]);
1321
        av_free(s->run_table[i]);
1322
        av_free(s->level_table[i]);
1323
    }
1324

    
1325
    return 0;
1326
}
1327

    
1328
AVCodec wmav1_decoder =
1329
{
1330
    "wmav1",
1331
    CODEC_TYPE_AUDIO,
1332
    CODEC_ID_WMAV1,
1333
    sizeof(WMADecodeContext),
1334
    wma_decode_init,
1335
    NULL,
1336
    wma_decode_end,
1337
    wma_decode_superframe,
1338
};
1339

    
1340
AVCodec wmav2_decoder =
1341
{
1342
    "wmav2",
1343
    CODEC_TYPE_AUDIO,
1344
    CODEC_ID_WMAV2,
1345
    sizeof(WMADecodeContext),
1346
    wma_decode_init,
1347
    NULL,
1348
    wma_decode_end,
1349
    wma_decode_superframe,
1350
};