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1
/*
2
 * WMA compatible decoder
3
 * Copyright (c) 2002 The FFmpeg Project.
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
8
 * 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 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg 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
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 * 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 FFmpeg; 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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 */
21

    
22
/**
23
 * @file wmadec.c
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 * 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.
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 *
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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.
34
 */
35

    
36
#include "avcodec.h"
37
#include "bitstream.h"
38
#include "dsputil.h"
39

    
40
/* size of blocks */
41
#define BLOCK_MIN_BITS 7
42
#define BLOCK_MAX_BITS 11
43
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
44

    
45
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
46

    
47
/* XXX: find exact max size */
48
#define HIGH_BAND_MAX_SIZE 16
49

    
50
#define NB_LSP_COEFS 10
51

    
52
/* XXX: is it a suitable value ? */
53
#define MAX_CODED_SUPERFRAME_SIZE 16384
54

    
55
#define MAX_CHANNELS 2
56

    
57
#define NOISE_TAB_SIZE 8192
58

    
59
#define LSP_POW_BITS 7
60

    
61
#define VLCBITS 9
62
#define VLCMAX ((22+VLCBITS-1)/VLCBITS)
63

    
64
#define EXPVLCBITS 8
65
#define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
66

    
67
#define HGAINVLCBITS 9
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#define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
69

    
70
typedef struct WMADecodeContext {
71
    GetBitContext gb;
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    int sample_rate;
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    int nb_channels;
74
    int bit_rate;
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    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
76
    int block_align;
77
    int use_bit_reservoir;
78
    int use_variable_block_len;
79
    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
80
    int use_noise_coding; /* true if perceptual noise is added */
81
    int byte_offset_bits;
82
    VLC exp_vlc;
83
    int exponent_sizes[BLOCK_NB_SIZES];
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    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
85
    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
86
    int coefs_start;               /* first coded coef */
87
    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
88
    int exponent_high_sizes[BLOCK_NB_SIZES];
89
    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
90
    VLC hgain_vlc;
91

    
92
    /* coded values in high bands */
93
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
94
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
95

    
96
    /* there are two possible tables for spectral coefficients */
97
    VLC coef_vlc[2];
98
    uint16_t *run_table[2];
99
    uint16_t *level_table[2];
100
    /* frame info */
101
    int frame_len;       /* frame length in samples */
102
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
103
    int nb_block_sizes;  /* number of block sizes */
104
    /* block info */
105
    int reset_block_lengths;
106
    int block_len_bits; /* log2 of current block length */
107
    int next_block_len_bits; /* log2 of next block length */
108
    int prev_block_len_bits; /* log2 of prev block length */
109
    int block_len; /* block length in samples */
110
    int block_num; /* block number in current frame */
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    int block_pos; /* current position in frame */
112
    uint8_t ms_stereo; /* true if mid/side stereo mode */
113
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
114
    DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]);
115
    float max_exponent[MAX_CHANNELS];
116
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
117
    DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);
118
    DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);
119
    DECLARE_ALIGNED_16(float, window[BLOCK_MAX_SIZE * 2]);
120
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
121
    float *windows[BLOCK_NB_SIZES];
122
    DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); /* temporary storage for imdct */
123
    /* output buffer for one frame and the last for IMDCT windowing */
124
    DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]);
125
    /* last frame info */
126
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
127
    int last_bitoffset;
128
    int last_superframe_len;
129
    float noise_table[NOISE_TAB_SIZE];
130
    int noise_index;
131
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
132
    /* lsp_to_curve tables */
133
    float lsp_cos_table[BLOCK_MAX_SIZE];
134
    float lsp_pow_e_table[256];
135
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
136
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
137
    DSPContext dsp;
138

    
139
#ifdef TRACE
140
    int frame_count;
141
#endif
142
} WMADecodeContext;
143

    
144
typedef struct CoefVLCTable {
145
    int n; /* total number of codes */
146
    const uint32_t *huffcodes; /* VLC bit values */
147
    const uint8_t *huffbits;   /* VLC bit size */
148
    const uint16_t *levels; /* table to build run/level tables */
149
} CoefVLCTable;
150

    
151
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
152

    
153
#include "wmadata.h"
154

    
155
#ifdef TRACE
156
static void dump_shorts(const char *name, const short *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(" %5d.0", tab[i]);
165
        if ((i & 7) == 7)
166
            tprintf("\n");
167
    }
168
}
169

    
170
static void dump_floats(const char *name, int prec, const float *tab, int n)
171
{
172
    int i;
173

    
174
    tprintf("%s[%d]:\n", name, n);
175
    for(i=0;i<n;i++) {
176
        if ((i & 7) == 0)
177
            tprintf("%4d: ", i);
178
        tprintf(" %8.*f", prec, tab[i]);
179
        if ((i & 7) == 7)
180
            tprintf("\n");
181
    }
182
    if ((i & 7) != 0)
183
        tprintf("\n");
184
}
185
#endif
186

    
187
/* XXX: use same run/length optimization as mpeg decoders */
188
static void init_coef_vlc(VLC *vlc,
189
                          uint16_t **prun_table, uint16_t **plevel_table,
190
                          const CoefVLCTable *vlc_table)
191
{
192
    int n = vlc_table->n;
193
    const uint8_t *table_bits = vlc_table->huffbits;
194
    const uint32_t *table_codes = vlc_table->huffcodes;
195
    const uint16_t *levels_table = vlc_table->levels;
196
    uint16_t *run_table, *level_table;
197
    const uint16_t *p;
198
    int i, l, j, level;
199

    
200
    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
201

    
202
    run_table = av_malloc(n * sizeof(uint16_t));
203
    level_table = av_malloc(n * sizeof(uint16_t));
204
    p = levels_table;
205
    i = 2;
206
    level = 1;
207
    while (i < n) {
208
        l = *p++;
209
        for(j=0;j<l;j++) {
210
            run_table[i] = j;
211
            level_table[i] = level;
212
            i++;
213
        }
214
        level++;
215
    }
216
    *prun_table = run_table;
217
    *plevel_table = level_table;
218
}
219

    
220
static int wma_decode_init(AVCodecContext * avctx)
221
{
222
    WMADecodeContext *s = avctx->priv_data;
223
    int i, flags1, flags2;
224
    float *window;
225
    uint8_t *extradata;
226
    float bps1, high_freq;
227
    volatile float bps;
228
    int sample_rate1;
229
    int coef_vlc_table;
230

    
231
    s->sample_rate = avctx->sample_rate;
232
    s->nb_channels = avctx->channels;
233
    s->bit_rate = avctx->bit_rate;
234
    s->block_align = avctx->block_align;
235

    
236
    dsputil_init(&s->dsp, avctx);
237

    
238
    if (avctx->codec->id == CODEC_ID_WMAV1) {
239
        s->version = 1;
240
    } else {
241
        s->version = 2;
242
    }
243

    
244
    /* extract flag infos */
245
    flags1 = 0;
246
    flags2 = 0;
247
    extradata = avctx->extradata;
248
    if (s->version == 1 && avctx->extradata_size >= 4) {
249
        flags1 = extradata[0] | (extradata[1] << 8);
250
        flags2 = extradata[2] | (extradata[3] << 8);
251
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
252
        flags1 = extradata[0] | (extradata[1] << 8) |
253
            (extradata[2] << 16) | (extradata[3] << 24);
254
        flags2 = extradata[4] | (extradata[5] << 8);
255
    }
256
    s->use_exp_vlc = flags2 & 0x0001;
257
    s->use_bit_reservoir = flags2 & 0x0002;
258
    s->use_variable_block_len = flags2 & 0x0004;
259

    
260
    /* compute MDCT block size */
261
    if (s->sample_rate <= 16000) {
262
        s->frame_len_bits = 9;
263
    } else if (s->sample_rate <= 22050 ||
264
               (s->sample_rate <= 32000 && s->version == 1)) {
265
        s->frame_len_bits = 10;
266
    } else {
267
        s->frame_len_bits = 11;
268
    }
269
    s->frame_len = 1 << s->frame_len_bits;
270
    if (s->use_variable_block_len) {
271
        int nb_max, nb;
272
        nb = ((flags2 >> 3) & 3) + 1;
273
        if ((s->bit_rate / s->nb_channels) >= 32000)
274
            nb += 2;
275
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
276
        if (nb > nb_max)
277
            nb = nb_max;
278
        s->nb_block_sizes = nb + 1;
279
    } else {
280
        s->nb_block_sizes = 1;
281
    }
282

    
283
    /* init rate dependant parameters */
284
    s->use_noise_coding = 1;
285
    high_freq = s->sample_rate * 0.5;
286

    
287
    /* if version 2, then the rates are normalized */
288
    sample_rate1 = s->sample_rate;
289
    if (s->version == 2) {
290
        if (sample_rate1 >= 44100)
291
            sample_rate1 = 44100;
292
        else if (sample_rate1 >= 22050)
293
            sample_rate1 = 22050;
294
        else if (sample_rate1 >= 16000)
295
            sample_rate1 = 16000;
296
        else if (sample_rate1 >= 11025)
297
            sample_rate1 = 11025;
298
        else if (sample_rate1 >= 8000)
299
            sample_rate1 = 8000;
300
    }
301

    
302
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
303
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
304

    
305
    /* compute high frequency value and choose if noise coding should
306
       be activated */
307
    bps1 = bps;
308
    if (s->nb_channels == 2)
309
        bps1 = bps * 1.6;
310
    if (sample_rate1 == 44100) {
311
        if (bps1 >= 0.61)
312
            s->use_noise_coding = 0;
313
        else
314
            high_freq = high_freq * 0.4;
315
    } else if (sample_rate1 == 22050) {
316
        if (bps1 >= 1.16)
317
            s->use_noise_coding = 0;
318
        else if (bps1 >= 0.72)
319
            high_freq = high_freq * 0.7;
320
        else
321
            high_freq = high_freq * 0.6;
322
    } else if (sample_rate1 == 16000) {
323
        if (bps > 0.5)
324
            high_freq = high_freq * 0.5;
325
        else
326
            high_freq = high_freq * 0.3;
327
    } else if (sample_rate1 == 11025) {
328
        high_freq = high_freq * 0.7;
329
    } else if (sample_rate1 == 8000) {
330
        if (bps <= 0.625) {
331
            high_freq = high_freq * 0.5;
332
        } else if (bps > 0.75) {
333
            s->use_noise_coding = 0;
334
        } else {
335
            high_freq = high_freq * 0.65;
336
        }
337
    } else {
338
        if (bps >= 0.8) {
339
            high_freq = high_freq * 0.75;
340
        } else if (bps >= 0.6) {
341
            high_freq = high_freq * 0.6;
342
        } else {
343
            high_freq = high_freq * 0.5;
344
        }
345
    }
346
    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
347
    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
348
           s->version, s->nb_channels, s->sample_rate, s->bit_rate,
349
           s->block_align);
350
    dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
351
           bps, bps1, high_freq, s->byte_offset_bits);
352
    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
353
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
354

    
355
    /* compute the scale factor band sizes for each MDCT block size */
356
    {
357
        int a, b, pos, lpos, k, block_len, i, j, n;
358
        const uint8_t *table;
359

    
360
        if (s->version == 1) {
361
            s->coefs_start = 3;
362
        } else {
363
            s->coefs_start = 0;
364
        }
365
        for(k = 0; k < s->nb_block_sizes; k++) {
366
            block_len = s->frame_len >> k;
367

    
368
            if (s->version == 1) {
369
                lpos = 0;
370
                for(i=0;i<25;i++) {
371
                    a = wma_critical_freqs[i];
372
                    b = s->sample_rate;
373
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
374
                    if (pos > block_len)
375
                        pos = block_len;
376
                    s->exponent_bands[0][i] = pos - lpos;
377
                    if (pos >= block_len) {
378
                        i++;
379
                        break;
380
                    }
381
                    lpos = pos;
382
                }
383
                s->exponent_sizes[0] = i;
384
            } else {
385
                /* hardcoded tables */
386
                table = NULL;
387
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
388
                if (a < 3) {
389
                    if (s->sample_rate >= 44100)
390
                        table = exponent_band_44100[a];
391
                    else if (s->sample_rate >= 32000)
392
                        table = exponent_band_32000[a];
393
                    else if (s->sample_rate >= 22050)
394
                        table = exponent_band_22050[a];
395
                }
396
                if (table) {
397
                    n = *table++;
398
                    for(i=0;i<n;i++)
399
                        s->exponent_bands[k][i] = table[i];
400
                    s->exponent_sizes[k] = n;
401
                } else {
402
                    j = 0;
403
                    lpos = 0;
404
                    for(i=0;i<25;i++) {
405
                        a = wma_critical_freqs[i];
406
                        b = s->sample_rate;
407
                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
408
                        pos <<= 2;
409
                        if (pos > block_len)
410
                            pos = block_len;
411
                        if (pos > lpos)
412
                            s->exponent_bands[k][j++] = pos - lpos;
413
                        if (pos >= block_len)
414
                            break;
415
                        lpos = pos;
416
                    }
417
                    s->exponent_sizes[k] = j;
418
                }
419
            }
420

    
421
            /* max number of coefs */
422
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
423
            /* high freq computation */
424
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
425
                                          s->sample_rate + 0.5);
426
            n = s->exponent_sizes[k];
427
            j = 0;
428
            pos = 0;
429
            for(i=0;i<n;i++) {
430
                int start, end;
431
                start = pos;
432
                pos += s->exponent_bands[k][i];
433
                end = pos;
434
                if (start < s->high_band_start[k])
435
                    start = s->high_band_start[k];
436
                if (end > s->coefs_end[k])
437
                    end = s->coefs_end[k];
438
                if (end > start)
439
                    s->exponent_high_bands[k][j++] = end - start;
440
            }
441
            s->exponent_high_sizes[k] = j;
442
#if 0
443
            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
444
                  s->frame_len >> k,
445
                  s->coefs_end[k],
446
                  s->high_band_start[k],
447
                  s->exponent_high_sizes[k]);
448
            for(j=0;j<s->exponent_high_sizes[k];j++)
449
                tprintf(" %d", s->exponent_high_bands[k][j]);
450
            tprintf("\n");
451
#endif
452
        }
453
    }
454

    
455
#ifdef TRACE
456
    {
457
        int i, j;
458
        for(i = 0; i < s->nb_block_sizes; i++) {
459
            tprintf("%5d: n=%2d:",
460
                   s->frame_len >> i,
461
                   s->exponent_sizes[i]);
462
            for(j=0;j<s->exponent_sizes[i];j++)
463
                tprintf(" %d", s->exponent_bands[i][j]);
464
            tprintf("\n");
465
        }
466
    }
467
#endif
468

    
469
    /* init MDCT */
470
    for(i = 0; i < s->nb_block_sizes; i++)
471
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
472

    
473
    /* init MDCT windows : simple sinus window */
474
    for(i = 0; i < s->nb_block_sizes; i++) {
475
        int n, j;
476
        float alpha;
477
        n = 1 << (s->frame_len_bits - i);
478
        window = av_malloc(sizeof(float) * n);
479
        alpha = M_PI / (2.0 * n);
480
        for(j=0;j<n;j++) {
481
            window[n - j - 1] = sin((j + 0.5) * alpha);
482
        }
483
        s->windows[i] = window;
484
    }
485

    
486
    s->reset_block_lengths = 1;
487

    
488
    if (s->use_noise_coding) {
489

    
490
        /* init the noise generator */
491
        if (s->use_exp_vlc)
492
            s->noise_mult = 0.02;
493
        else
494
            s->noise_mult = 0.04;
495

    
496
#ifdef TRACE
497
        for(i=0;i<NOISE_TAB_SIZE;i++)
498
            s->noise_table[i] = 1.0 * s->noise_mult;
499
#else
500
        {
501
            unsigned int seed;
502
            float norm;
503
            seed = 1;
504
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
505
            for(i=0;i<NOISE_TAB_SIZE;i++) {
506
                seed = seed * 314159 + 1;
507
                s->noise_table[i] = (float)((int)seed) * norm;
508
            }
509
        }
510
#endif
511
        init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(hgain_huffbits),
512
                 hgain_huffbits, 1, 1,
513
                 hgain_huffcodes, 2, 2, 0);
514
    }
515

    
516
    if (s->use_exp_vlc) {
517
        init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(scale_huffbits),
518
                 scale_huffbits, 1, 1,
519
                 scale_huffcodes, 4, 4, 0);
520
    } else {
521
        wma_lsp_to_curve_init(s, s->frame_len);
522
    }
523

    
524
    /* choose the VLC tables for the coefficients */
525
    coef_vlc_table = 2;
526
    if (s->sample_rate >= 32000) {
527
        if (bps1 < 0.72)
528
            coef_vlc_table = 0;
529
        else if (bps1 < 1.16)
530
            coef_vlc_table = 1;
531
    }
532

    
533
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
534
                  &coef_vlcs[coef_vlc_table * 2]);
535
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
536
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
537
    return 0;
538
}
539

    
540
/* interpolate values for a bigger or smaller block. The block must
541
   have multiple sizes */
542
static void interpolate_array(float *scale, int old_size, int new_size)
543
{
544
    int i, j, jincr, k;
545
    float v;
546

    
547
    if (new_size > old_size) {
548
        jincr = new_size / old_size;
549
        j = new_size;
550
        for(i = old_size - 1; i >=0; i--) {
551
            v = scale[i];
552
            k = jincr;
553
            do {
554
                scale[--j] = v;
555
            } while (--k);
556
        }
557
    } else if (new_size < old_size) {
558
        j = 0;
559
        jincr = old_size / new_size;
560
        for(i = 0; i < new_size; i++) {
561
            scale[i] = scale[j];
562
            j += jincr;
563
        }
564
    }
565
}
566

    
567
/* compute x^-0.25 with an exponent and mantissa table. We use linear
568
   interpolation to reduce the mantissa table size at a small speed
569
   expense (linear interpolation approximately doubles the number of
570
   bits of precision). */
571
static inline float pow_m1_4(WMADecodeContext *s, float x)
572
{
573
    union {
574
        float f;
575
        unsigned int v;
576
    } u, t;
577
    unsigned int e, m;
578
    float a, b;
579

    
580
    u.f = x;
581
    e = u.v >> 23;
582
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
583
    /* build interpolation scale: 1 <= t < 2. */
584
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
585
    a = s->lsp_pow_m_table1[m];
586
    b = s->lsp_pow_m_table2[m];
587
    return s->lsp_pow_e_table[e] * (a + b * t.f);
588
}
589

    
590
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
591
{
592
    float wdel, a, b;
593
    int i, e, m;
594

    
595
    wdel = M_PI / frame_len;
596
    for(i=0;i<frame_len;i++)
597
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
598

    
599
    /* tables for x^-0.25 computation */
600
    for(i=0;i<256;i++) {
601
        e = i - 126;
602
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
603
    }
604

    
605
    /* NOTE: these two tables are needed to avoid two operations in
606
       pow_m1_4 */
607
    b = 1.0;
608
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
609
        m = (1 << LSP_POW_BITS) + i;
610
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
611
        a = pow(a, -0.25);
612
        s->lsp_pow_m_table1[i] = 2 * a - b;
613
        s->lsp_pow_m_table2[i] = b - a;
614
        b = a;
615
    }
616
#if 0
617
    for(i=1;i<20;i++) {
618
        float v, r1, r2;
619
        v = 5.0 / i;
620
        r1 = pow_m1_4(s, v);
621
        r2 = pow(v,-0.25);
622
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
623
    }
624
#endif
625
}
626

    
627
/* NOTE: We use the same code as Vorbis here */
628
/* XXX: optimize it further with SSE/3Dnow */
629
static void wma_lsp_to_curve(WMADecodeContext *s,
630
                             float *out, float *val_max_ptr,
631
                             int n, float *lsp)
632
{
633
    int i, j;
634
    float p, q, w, v, val_max;
635

    
636
    val_max = 0;
637
    for(i=0;i<n;i++) {
638
        p = 0.5f;
639
        q = 0.5f;
640
        w = s->lsp_cos_table[i];
641
        for(j=1;j<NB_LSP_COEFS;j+=2){
642
            q *= w - lsp[j - 1];
643
            p *= w - lsp[j];
644
        }
645
        p *= p * (2.0f - w);
646
        q *= q * (2.0f + w);
647
        v = p + q;
648
        v = pow_m1_4(s, v);
649
        if (v > val_max)
650
            val_max = v;
651
        out[i] = v;
652
    }
653
    *val_max_ptr = val_max;
654
}
655

    
656
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
657
static void decode_exp_lsp(WMADecodeContext *s, int ch)
658
{
659
    float lsp_coefs[NB_LSP_COEFS];
660
    int val, i;
661

    
662
    for(i = 0; i < NB_LSP_COEFS; i++) {
663
        if (i == 0 || i >= 8)
664
            val = get_bits(&s->gb, 3);
665
        else
666
            val = get_bits(&s->gb, 4);
667
        lsp_coefs[i] = lsp_codebook[i][val];
668
    }
669

    
670
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
671
                     s->block_len, lsp_coefs);
672
}
673

    
674
/* decode exponents coded with VLC codes */
675
static int decode_exp_vlc(WMADecodeContext *s, int ch)
676
{
677
    int last_exp, n, code;
678
    const uint16_t *ptr, *band_ptr;
679
    float v, *q, max_scale, *q_end;
680

    
681
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
682
    ptr = band_ptr;
683
    q = s->exponents[ch];
684
    q_end = q + s->block_len;
685
    max_scale = 0;
686
    if (s->version == 1) {
687
        last_exp = get_bits(&s->gb, 5) + 10;
688
        /* XXX: use a table */
689
        v = pow(10, last_exp * (1.0 / 16.0));
690
        max_scale = v;
691
        n = *ptr++;
692
        do {
693
            *q++ = v;
694
        } while (--n);
695
    }
696
    last_exp = 36;
697
    while (q < q_end) {
698
        code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
699
        if (code < 0)
700
            return -1;
701
        /* NOTE: this offset is the same as MPEG4 AAC ! */
702
        last_exp += code - 60;
703
        /* XXX: use a table */
704
        v = pow(10, last_exp * (1.0 / 16.0));
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
    int nb_coefs[MAX_CHANNELS];
723
    float mdct_norm;
724

    
725
#ifdef TRACE
726
    tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
727
#endif
728

    
729
    /* compute current block length */
730
    if (s->use_variable_block_len) {
731
        n = av_log2(s->nb_block_sizes - 1) + 1;
732

    
733
        if (s->reset_block_lengths) {
734
            s->reset_block_lengths = 0;
735
            v = get_bits(&s->gb, n);
736
            if (v >= s->nb_block_sizes)
737
                return -1;
738
            s->prev_block_len_bits = s->frame_len_bits - v;
739
            v = get_bits(&s->gb, n);
740
            if (v >= s->nb_block_sizes)
741
                return -1;
742
            s->block_len_bits = s->frame_len_bits - v;
743
        } else {
744
            /* update block lengths */
745
            s->prev_block_len_bits = s->block_len_bits;
746
            s->block_len_bits = s->next_block_len_bits;
747
        }
748
        v = get_bits(&s->gb, n);
749
        if (v >= s->nb_block_sizes)
750
            return -1;
751
        s->next_block_len_bits = s->frame_len_bits - v;
752
    } else {
753
        /* fixed block len */
754
        s->next_block_len_bits = s->frame_len_bits;
755
        s->prev_block_len_bits = s->frame_len_bits;
756
        s->block_len_bits = s->frame_len_bits;
757
    }
758

    
759
    /* now check if the block length is coherent with the frame length */
760
    s->block_len = 1 << s->block_len_bits;
761
    if ((s->block_pos + s->block_len) > s->frame_len)
762
        return -1;
763

    
764
    if (s->nb_channels == 2) {
765
        s->ms_stereo = get_bits(&s->gb, 1);
766
    }
767
    v = 0;
768
    for(ch = 0; ch < s->nb_channels; ch++) {
769
        a = get_bits(&s->gb, 1);
770
        s->channel_coded[ch] = a;
771
        v |= a;
772
    }
773
    /* if no channel coded, no need to go further */
774
    /* XXX: fix potential framing problems */
775
    if (!v)
776
        goto next;
777

    
778
    bsize = s->frame_len_bits - s->block_len_bits;
779

    
780
    /* read total gain and extract corresponding number of bits for
781
       coef escape coding */
782
    total_gain = 1;
783
    for(;;) {
784
        a = get_bits(&s->gb, 7);
785
        total_gain += a;
786
        if (a != 127)
787
            break;
788
    }
789

    
790
    if (total_gain < 15)
791
        coef_nb_bits = 13;
792
    else if (total_gain < 32)
793
        coef_nb_bits = 12;
794
    else if (total_gain < 40)
795
        coef_nb_bits = 11;
796
    else if (total_gain < 45)
797
        coef_nb_bits = 10;
798
    else
799
        coef_nb_bits = 9;
800

    
801
    /* compute number of coefficients */
802
    n = s->coefs_end[bsize] - s->coefs_start;
803
    for(ch = 0; ch < s->nb_channels; ch++)
804
        nb_coefs[ch] = n;
805

    
806
    /* complex coding */
807
    if (s->use_noise_coding) {
808

    
809
        for(ch = 0; ch < s->nb_channels; ch++) {
810
            if (s->channel_coded[ch]) {
811
                int i, n, a;
812
                n = s->exponent_high_sizes[bsize];
813
                for(i=0;i<n;i++) {
814
                    a = get_bits(&s->gb, 1);
815
                    s->high_band_coded[ch][i] = a;
816
                    /* if noise coding, the coefficients are not transmitted */
817
                    if (a)
818
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
819
                }
820
            }
821
        }
822
        for(ch = 0; ch < s->nb_channels; ch++) {
823
            if (s->channel_coded[ch]) {
824
                int i, n, val, code;
825

    
826
                n = s->exponent_high_sizes[bsize];
827
                val = (int)0x80000000;
828
                for(i=0;i<n;i++) {
829
                    if (s->high_band_coded[ch][i]) {
830
                        if (val == (int)0x80000000) {
831
                            val = get_bits(&s->gb, 7) - 19;
832
                        } else {
833
                            code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
834
                            if (code < 0)
835
                                return -1;
836
                            val += code - 18;
837
                        }
838
                        s->high_band_values[ch][i] = val;
839
                    }
840
                }
841
            }
842
        }
843
    }
844

    
845
    /* exposant can be interpolated in short blocks. */
846
    parse_exponents = 1;
847
    if (s->block_len_bits != s->frame_len_bits) {
848
        parse_exponents = get_bits(&s->gb, 1);
849
    }
850

    
851
    if (parse_exponents) {
852
        for(ch = 0; ch < s->nb_channels; ch++) {
853
            if (s->channel_coded[ch]) {
854
                if (s->use_exp_vlc) {
855
                    if (decode_exp_vlc(s, ch) < 0)
856
                        return -1;
857
                } else {
858
                    decode_exp_lsp(s, ch);
859
                }
860
            }
861
        }
862
    } else {
863
        for(ch = 0; ch < s->nb_channels; ch++) {
864
            if (s->channel_coded[ch]) {
865
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
866
                                  s->block_len);
867
            }
868
        }
869
    }
870

    
871
    /* parse spectral coefficients : just RLE encoding */
872
    for(ch = 0; ch < s->nb_channels; ch++) {
873
        if (s->channel_coded[ch]) {
874
            VLC *coef_vlc;
875
            int level, run, sign, tindex;
876
            int16_t *ptr, *eptr;
877
            const uint16_t *level_table, *run_table;
878

    
879
            /* special VLC tables are used for ms stereo because
880
               there is potentially less energy there */
881
            tindex = (ch == 1 && s->ms_stereo);
882
            coef_vlc = &s->coef_vlc[tindex];
883
            run_table = s->run_table[tindex];
884
            level_table = s->level_table[tindex];
885
            /* XXX: optimize */
886
            ptr = &s->coefs1[ch][0];
887
            eptr = ptr + nb_coefs[ch];
888
            memset(ptr, 0, s->block_len * sizeof(int16_t));
889
            for(;;) {
890
                code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
891
                if (code < 0)
892
                    return -1;
893
                if (code == 1) {
894
                    /* EOB */
895
                    break;
896
                } else if (code == 0) {
897
                    /* escape */
898
                    level = get_bits(&s->gb, coef_nb_bits);
899
                    /* NOTE: this is rather suboptimal. reading
900
                       block_len_bits would be better */
901
                    run = get_bits(&s->gb, s->frame_len_bits);
902
                } else {
903
                    /* normal code */
904
                    run = run_table[code];
905
                    level = level_table[code];
906
                }
907
                sign = get_bits(&s->gb, 1);
908
                if (!sign)
909
                    level = -level;
910
                ptr += run;
911
                if (ptr >= eptr)
912
                {
913
                    av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
914
                    break;
915
                }
916
                *ptr++ = level;
917
                /* NOTE: EOB can be omitted */
918
                if (ptr >= eptr)
919
                    break;
920
            }
921
        }
922
        if (s->version == 1 && s->nb_channels >= 2) {
923
            align_get_bits(&s->gb);
924
        }
925
    }
926

    
927
    /* normalize */
928
    {
929
        int n4 = s->block_len / 2;
930
        mdct_norm = 1.0 / (float)n4;
931
        if (s->version == 1) {
932
            mdct_norm *= sqrt(n4);
933
        }
934
    }
935

    
936
    /* finally compute the MDCT coefficients */
937
    for(ch = 0; ch < s->nb_channels; ch++) {
938
        if (s->channel_coded[ch]) {
939
            int16_t *coefs1;
940
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
941
            int i, j, n, n1, last_high_band;
942
            float exp_power[HIGH_BAND_MAX_SIZE];
943

    
944
            coefs1 = s->coefs1[ch];
945
            exponents = s->exponents[ch];
946
            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
947
            mult *= mdct_norm;
948
            coefs = s->coefs[ch];
949
            if (s->use_noise_coding) {
950
                mult1 = mult;
951
                /* very low freqs : noise */
952
                for(i = 0;i < s->coefs_start; i++) {
953
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
954
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
955
                }
956

    
957
                n1 = s->exponent_high_sizes[bsize];
958

    
959
                /* compute power of high bands */
960
                exp_ptr = exponents +
961
                    s->high_band_start[bsize] -
962
                    s->coefs_start;
963
                last_high_band = 0; /* avoid warning */
964
                for(j=0;j<n1;j++) {
965
                    n = s->exponent_high_bands[s->frame_len_bits -
966
                                              s->block_len_bits][j];
967
                    if (s->high_band_coded[ch][j]) {
968
                        float e2, v;
969
                        e2 = 0;
970
                        for(i = 0;i < n; i++) {
971
                            v = exp_ptr[i];
972
                            e2 += v * v;
973
                        }
974
                        exp_power[j] = e2 / n;
975
                        last_high_band = j;
976
                        tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
977
                    }
978
                    exp_ptr += n;
979
                }
980

    
981
                /* main freqs and high freqs */
982
                for(j=-1;j<n1;j++) {
983
                    if (j < 0) {
984
                        n = s->high_band_start[bsize] -
985
                            s->coefs_start;
986
                    } else {
987
                        n = s->exponent_high_bands[s->frame_len_bits -
988
                                                  s->block_len_bits][j];
989
                    }
990
                    if (j >= 0 && s->high_band_coded[ch][j]) {
991
                        /* use noise with specified power */
992
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
993
                        /* XXX: use a table */
994
                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
995
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
996
                        mult1 *= mdct_norm;
997
                        for(i = 0;i < n; i++) {
998
                            noise = s->noise_table[s->noise_index];
999
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1000
                            *coefs++ = (*exponents++) * noise * mult1;
1001
                        }
1002
                    } else {
1003
                        /* coded values + small noise */
1004
                        for(i = 0;i < n; i++) {
1005
                            noise = s->noise_table[s->noise_index];
1006
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1007
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
1008
                        }
1009
                    }
1010
                }
1011

    
1012
                /* very high freqs : noise */
1013
                n = s->block_len - s->coefs_end[bsize];
1014
                mult1 = mult * exponents[-1];
1015
                for(i = 0; i < n; i++) {
1016
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
1017
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1018
                }
1019
            } else {
1020
                /* XXX: optimize more */
1021
                for(i = 0;i < s->coefs_start; i++)
1022
                    *coefs++ = 0.0;
1023
                n = nb_coefs[ch];
1024
                for(i = 0;i < n; i++) {
1025
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1026
                }
1027
                n = s->block_len - s->coefs_end[bsize];
1028
                for(i = 0;i < n; i++)
1029
                    *coefs++ = 0.0;
1030
            }
1031
        }
1032
    }
1033

    
1034
#ifdef TRACE
1035
    for(ch = 0; ch < s->nb_channels; ch++) {
1036
        if (s->channel_coded[ch]) {
1037
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1038
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1039
        }
1040
    }
1041
#endif
1042

    
1043
    if (s->ms_stereo && s->channel_coded[1]) {
1044
        float a, b;
1045
        int i;
1046

    
1047
        /* nominal case for ms stereo: we do it before mdct */
1048
        /* no need to optimize this case because it should almost
1049
           never happen */
1050
        if (!s->channel_coded[0]) {
1051
            tprintf("rare ms-stereo case happened\n");
1052
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1053
            s->channel_coded[0] = 1;
1054
        }
1055

    
1056
        for(i = 0; i < s->block_len; i++) {
1057
            a = s->coefs[0][i];
1058
            b = s->coefs[1][i];
1059
            s->coefs[0][i] = a + b;
1060
            s->coefs[1][i] = a - b;
1061
        }
1062
    }
1063

    
1064
    /* build the window : we ensure that when the windows overlap
1065
       their squared sum is always 1 (MDCT reconstruction rule) */
1066
    /* XXX: merge with output */
1067
    {
1068
        int i, next_block_len, block_len, prev_block_len, n;
1069
        float *wptr;
1070

    
1071
        block_len = s->block_len;
1072
        prev_block_len = 1 << s->prev_block_len_bits;
1073
        next_block_len = 1 << s->next_block_len_bits;
1074

    
1075
        /* right part */
1076
        wptr = s->window + block_len;
1077
        if (block_len <= next_block_len) {
1078
            for(i=0;i<block_len;i++)
1079
                *wptr++ = s->windows[bsize][i];
1080
        } else {
1081
            /* overlap */
1082
            n = (block_len / 2) - (next_block_len / 2);
1083
            for(i=0;i<n;i++)
1084
                *wptr++ = 1.0;
1085
            for(i=0;i<next_block_len;i++)
1086
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1087
            for(i=0;i<n;i++)
1088
                *wptr++ = 0.0;
1089
        }
1090

    
1091
        /* left part */
1092
        wptr = s->window + block_len;
1093
        if (block_len <= prev_block_len) {
1094
            for(i=0;i<block_len;i++)
1095
                *--wptr = s->windows[bsize][i];
1096
        } else {
1097
            /* overlap */
1098
            n = (block_len / 2) - (prev_block_len / 2);
1099
            for(i=0;i<n;i++)
1100
                *--wptr = 1.0;
1101
            for(i=0;i<prev_block_len;i++)
1102
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1103
            for(i=0;i<n;i++)
1104
                *--wptr = 0.0;
1105
        }
1106
    }
1107

    
1108

    
1109
    for(ch = 0; ch < s->nb_channels; ch++) {
1110
        if (s->channel_coded[ch]) {
1111
            float *ptr;
1112
            int n4, index, n;
1113

    
1114
            n = s->block_len;
1115
            n4 = s->block_len / 2;
1116
            s->mdct_ctx[bsize].fft.imdct_calc(&s->mdct_ctx[bsize],
1117
                          s->output, s->coefs[ch], s->mdct_tmp);
1118

    
1119
            /* XXX: optimize all that by build the window and
1120
               multipying/adding at the same time */
1121

    
1122
            /* multiply by the window and add in the frame */
1123
            index = (s->frame_len / 2) + s->block_pos - n4;
1124
            ptr = &s->frame_out[ch][index];
1125
            s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
1126

    
1127
            /* specific fast case for ms-stereo : add to second
1128
               channel if it is not coded */
1129
            if (s->ms_stereo && !s->channel_coded[1]) {
1130
                ptr = &s->frame_out[1][index];
1131
                s->dsp.vector_fmul_add_add(ptr,s->window,s->output,ptr,0,2*n,1);
1132
            }
1133
        }
1134
    }
1135
 next:
1136
    /* update block number */
1137
    s->block_num++;
1138
    s->block_pos += s->block_len;
1139
    if (s->block_pos >= s->frame_len)
1140
        return 1;
1141
    else
1142
        return 0;
1143
}
1144

    
1145
/* decode a frame of frame_len samples */
1146
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1147
{
1148
    int ret, i, n, a, ch, incr;
1149
    int16_t *ptr;
1150
    float *iptr;
1151

    
1152
#ifdef TRACE
1153
    tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
1154
#endif
1155

    
1156
    /* read each block */
1157
    s->block_num = 0;
1158
    s->block_pos = 0;
1159
    for(;;) {
1160
        ret = wma_decode_block(s);
1161
        if (ret < 0)
1162
            return -1;
1163
        if (ret)
1164
            break;
1165
    }
1166

    
1167
    /* convert frame to integer */
1168
    n = s->frame_len;
1169
    incr = s->nb_channels;
1170
    for(ch = 0; ch < s->nb_channels; ch++) {
1171
        ptr = samples + ch;
1172
        iptr = s->frame_out[ch];
1173

    
1174
        for(i=0;i<n;i++) {
1175
            a = lrintf(*iptr++);
1176
            if (a > 32767)
1177
                a = 32767;
1178
            else if (a < -32768)
1179
                a = -32768;
1180
            *ptr = a;
1181
            ptr += incr;
1182
        }
1183
        /* prepare for next block */
1184
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1185
                s->frame_len * sizeof(float));
1186
        /* XXX: suppress this */
1187
        memset(&s->frame_out[ch][s->frame_len], 0,
1188
               s->frame_len * sizeof(float));
1189
    }
1190

    
1191
#ifdef TRACE
1192
    dump_shorts("samples", samples, n * s->nb_channels);
1193
#endif
1194
    return 0;
1195
}
1196

    
1197
static int wma_decode_superframe(AVCodecContext *avctx,
1198
                                 void *data, int *data_size,
1199
                                 uint8_t *buf, int buf_size)
1200
{
1201
    WMADecodeContext *s = avctx->priv_data;
1202
    int nb_frames, bit_offset, i, pos, len;
1203
    uint8_t *q;
1204
    int16_t *samples;
1205

    
1206
    tprintf("***decode_superframe:\n");
1207

    
1208
    if(buf_size==0){
1209
        s->last_superframe_len = 0;
1210
        return 0;
1211
    }
1212

    
1213
    samples = data;
1214

    
1215
    init_get_bits(&s->gb, buf, buf_size*8);
1216

    
1217
    if (s->use_bit_reservoir) {
1218
        /* read super frame header */
1219
        get_bits(&s->gb, 4); /* super frame index */
1220
        nb_frames = get_bits(&s->gb, 4) - 1;
1221

    
1222
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1223

    
1224
        if (s->last_superframe_len > 0) {
1225
            //        printf("skip=%d\n", s->last_bitoffset);
1226
            /* add bit_offset bits to last frame */
1227
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1228
                MAX_CODED_SUPERFRAME_SIZE)
1229
                goto fail;
1230
            q = s->last_superframe + s->last_superframe_len;
1231
            len = bit_offset;
1232
            while (len > 7) {
1233
                *q++ = (get_bits)(&s->gb, 8);
1234
                len -= 8;
1235
            }
1236
            if (len > 0) {
1237
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1238
            }
1239

    
1240
            /* XXX: bit_offset bits into last frame */
1241
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1242
            /* skip unused bits */
1243
            if (s->last_bitoffset > 0)
1244
                skip_bits(&s->gb, s->last_bitoffset);
1245
            /* this frame is stored in the last superframe and in the
1246
               current one */
1247
            if (wma_decode_frame(s, samples) < 0)
1248
                goto fail;
1249
            samples += s->nb_channels * s->frame_len;
1250
        }
1251

    
1252
        /* read each frame starting from bit_offset */
1253
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1254
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1255
        len = pos & 7;
1256
        if (len > 0)
1257
            skip_bits(&s->gb, len);
1258

    
1259
        s->reset_block_lengths = 1;
1260
        for(i=0;i<nb_frames;i++) {
1261
            if (wma_decode_frame(s, samples) < 0)
1262
                goto fail;
1263
            samples += s->nb_channels * s->frame_len;
1264
        }
1265

    
1266
        /* we copy the end of the frame in the last frame buffer */
1267
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1268
        s->last_bitoffset = pos & 7;
1269
        pos >>= 3;
1270
        len = buf_size - pos;
1271
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1272
            goto fail;
1273
        }
1274
        s->last_superframe_len = len;
1275
        memcpy(s->last_superframe, buf + pos, len);
1276
    } else {
1277
        /* single frame decode */
1278
        if (wma_decode_frame(s, samples) < 0)
1279
            goto fail;
1280
        samples += s->nb_channels * s->frame_len;
1281
    }
1282
    *data_size = (int8_t *)samples - (int8_t *)data;
1283
    return s->block_align;
1284
 fail:
1285
    /* when error, we reset the bit reservoir */
1286
    s->last_superframe_len = 0;
1287
    return -1;
1288
}
1289

    
1290
static int wma_decode_end(AVCodecContext *avctx)
1291
{
1292
    WMADecodeContext *s = avctx->priv_data;
1293
    int i;
1294

    
1295
    for(i = 0; i < s->nb_block_sizes; i++)
1296
        ff_mdct_end(&s->mdct_ctx[i]);
1297
    for(i = 0; i < s->nb_block_sizes; i++)
1298
        av_free(s->windows[i]);
1299

    
1300
    if (s->use_exp_vlc) {
1301
        free_vlc(&s->exp_vlc);
1302
    }
1303
    if (s->use_noise_coding) {
1304
        free_vlc(&s->hgain_vlc);
1305
    }
1306
    for(i = 0;i < 2; i++) {
1307
        free_vlc(&s->coef_vlc[i]);
1308
        av_free(s->run_table[i]);
1309
        av_free(s->level_table[i]);
1310
    }
1311

    
1312
    return 0;
1313
}
1314

    
1315
AVCodec wmav1_decoder =
1316
{
1317
    "wmav1",
1318
    CODEC_TYPE_AUDIO,
1319
    CODEC_ID_WMAV1,
1320
    sizeof(WMADecodeContext),
1321
    wma_decode_init,
1322
    NULL,
1323
    wma_decode_end,
1324
    wma_decode_superframe,
1325
};
1326

    
1327
AVCodec wmav2_decoder =
1328
{
1329
    "wmav2",
1330
    CODEC_TYPE_AUDIO,
1331
    CODEC_ID_WMAV2,
1332
    sizeof(WMADecodeContext),
1333
    wma_decode_init,
1334
    NULL,
1335
    wma_decode_end,
1336
    wma_decode_superframe,
1337
};