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1
/*
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 * WMA compatible decoder
3
 * Copyright (c) 2002 The FFmpeg Project.
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 *
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 * This library is free software; you can redistribute it and/or
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 * 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
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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 this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
19

    
20
/**
21
 * @file wmadec.c
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 * WMA compatible decoder.
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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.
32
 */
33

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

    
37
/* size of blocks */
38
#define BLOCK_MIN_BITS 7
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#define BLOCK_MAX_BITS 11
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#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
41

    
42
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
43

    
44
/* XXX: find exact max size */
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#define HIGH_BAND_MAX_SIZE 16
46

    
47
#define NB_LSP_COEFS 10
48

    
49
/* XXX: is it a suitable value ? */
50
#define MAX_CODED_SUPERFRAME_SIZE 4096
51

    
52
#define MAX_CHANNELS 2
53

    
54
#define NOISE_TAB_SIZE 8192
55

    
56
#define LSP_POW_BITS 7
57

    
58
typedef struct WMADecodeContext {
59
    GetBitContext gb;
60
    int sample_rate;
61
    int nb_channels;
62
    int bit_rate;
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    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
64
    int block_align;
65
    int use_bit_reservoir;
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    int use_variable_block_len;
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    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
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    int use_noise_coding; /* true if perceptual noise is added */
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    int byte_offset_bits;
70
    VLC exp_vlc;
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    int exponent_sizes[BLOCK_NB_SIZES];
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    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
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    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
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    int coefs_start;               /* first coded coef */
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    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
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    int exponent_high_sizes[BLOCK_NB_SIZES];
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    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE]; 
78
    VLC hgain_vlc;
79
    
80
    /* coded values in high bands */
81
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
82
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
83

    
84
    /* there are two possible tables for spectral coefficients */
85
    VLC coef_vlc[2];
86
    uint16_t *run_table[2];
87
    uint16_t *level_table[2];
88
    /* frame info */
89
    int frame_len;       /* frame length in samples */
90
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
91
    int nb_block_sizes;  /* number of block sizes */
92
    /* block info */
93
    int reset_block_lengths;
94
    int block_len_bits; /* log2 of current block length */
95
    int next_block_len_bits; /* log2 of next block length */
96
    int prev_block_len_bits; /* log2 of prev block length */
97
    int block_len; /* block length in samples */
98
    int block_num; /* block number in current frame */
99
    int block_pos; /* current position in frame */
100
    uint8_t ms_stereo; /* true if mid/side stereo mode */
101
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
102
    float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
103
    float max_exponent[MAX_CHANNELS];
104
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
105
    float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
106
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
107
    float *windows[BLOCK_NB_SIZES];
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    FFTSample mdct_tmp[BLOCK_MAX_SIZE] __attribute__((aligned(16))); /* temporary storage for imdct */
109
    /* output buffer for one frame and the last for IMDCT windowing */
110
    float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
111
    /* last frame info */
112
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
113
    int last_bitoffset;
114
    int last_superframe_len;
115
    float noise_table[NOISE_TAB_SIZE];
116
    int noise_index;
117
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
118
    /* lsp_to_curve tables */
119
    float lsp_cos_table[BLOCK_MAX_SIZE];
120
    float lsp_pow_e_table[256];
121
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
122
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
123

    
124
#ifdef TRACE
125
    int frame_count;
126
#endif
127
} WMADecodeContext;
128

    
129
typedef struct CoefVLCTable {
130
    int n; /* total number of codes */
131
    const uint32_t *huffcodes; /* VLC bit values */
132
    const uint8_t *huffbits;   /* VLC bit size */
133
    const uint16_t *levels; /* table to build run/level tables */
134
} CoefVLCTable;
135

    
136
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
137

    
138
#include "wmadata.h"
139

    
140
#ifdef TRACE
141
static void dump_shorts(const char *name, const short *tab, int n)
142
{
143
    int i;
144

    
145
    tprintf("%s[%d]:\n", name, n);
146
    for(i=0;i<n;i++) {
147
        if ((i & 7) == 0)
148
            tprintf("%4d: ", i);
149
        tprintf(" %5d.0", tab[i]);
150
        if ((i & 7) == 7)
151
            tprintf("\n");
152
    }
153
}
154

    
155
static void dump_floats(const char *name, int prec, const float *tab, int n)
156
{
157
    int i;
158

    
159
    tprintf("%s[%d]:\n", name, n);
160
    for(i=0;i<n;i++) {
161
        if ((i & 7) == 0)
162
            tprintf("%4d: ", i);
163
        tprintf(" %8.*f", prec, tab[i]);
164
        if ((i & 7) == 7)
165
            tprintf("\n");
166
    }
167
    if ((i & 7) != 0)
168
        tprintf("\n");
169
}
170
#endif
171

    
172
/* XXX: use same run/length optimization as mpeg decoders */
173
static void init_coef_vlc(VLC *vlc, 
174
                          uint16_t **prun_table, uint16_t **plevel_table,
175
                          const CoefVLCTable *vlc_table)
176
{
177
    int n = vlc_table->n;
178
    const uint8_t *table_bits = vlc_table->huffbits;
179
    const uint32_t *table_codes = vlc_table->huffcodes;
180
    const uint16_t *levels_table = vlc_table->levels;
181
    uint16_t *run_table, *level_table;
182
    const uint16_t *p;
183
    int i, l, j, level;
184

    
185
    init_vlc(vlc, 9, n, table_bits, 1, 1, table_codes, 4, 4);
186

    
187
    run_table = av_malloc(n * sizeof(uint16_t));
188
    level_table = av_malloc(n * sizeof(uint16_t));
189
    p = levels_table;
190
    i = 2;
191
    level = 1;
192
    while (i < n) {
193
        l = *p++;
194
        for(j=0;j<l;j++) {
195
            run_table[i] = j;
196
            level_table[i] = level;
197
            i++;
198
        }
199
        level++;
200
    }
201
    *prun_table = run_table;
202
    *plevel_table = level_table;
203
}
204

    
205
static int wma_decode_init(AVCodecContext * avctx)
206
{
207
    WMADecodeContext *s = avctx->priv_data;
208
    int i, flags1, flags2;
209
    float *window;
210
    uint8_t *extradata;
211
    float bps1, high_freq, bps;
212
    int sample_rate1;
213
    int coef_vlc_table;
214
    
215
    s->sample_rate = avctx->sample_rate;
216
    s->nb_channels = avctx->channels;
217
    s->bit_rate = avctx->bit_rate;
218
    s->block_align = avctx->block_align;
219

    
220
    if (avctx->codec->id == CODEC_ID_WMAV1) {
221
        s->version = 1;
222
    } else {
223
        s->version = 2;
224
    }
225
    
226
    /* extract flag infos */
227
    flags1 = 0;
228
    flags2 = 0;
229
    extradata = avctx->extradata;
230
    if (s->version == 1 && avctx->extradata_size >= 4) {
231
        flags1 = extradata[0] | (extradata[1] << 8);
232
        flags2 = extradata[2] | (extradata[3] << 8);
233
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
234
        flags1 = extradata[0] | (extradata[1] << 8) | 
235
            (extradata[2] << 16) | (extradata[3] << 24);
236
        flags2 = extradata[4] | (extradata[5] << 8);
237
    }
238
    s->use_exp_vlc = flags2 & 0x0001;
239
    s->use_bit_reservoir = flags2 & 0x0002;
240
    s->use_variable_block_len = flags2 & 0x0004;
241

    
242
    /* compute MDCT block size */
243
    if (s->sample_rate <= 16000) {
244
        s->frame_len_bits = 9;
245
    } else if (s->sample_rate <= 22050 || 
246
               (s->sample_rate <= 32000 && s->version == 1)) {
247
        s->frame_len_bits = 10;
248
    } else {
249
        s->frame_len_bits = 11;
250
    }
251
    s->frame_len = 1 << s->frame_len_bits;
252
    if (s->use_variable_block_len) {
253
        int nb_max, nb;
254
        nb = ((flags2 >> 3) & 3) + 1;
255
        if ((s->bit_rate / s->nb_channels) >= 32000)
256
            nb += 2;
257
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
258
        if (nb > nb_max)
259
            nb = nb_max;
260
        s->nb_block_sizes = nb + 1;
261
    } else {
262
        s->nb_block_sizes = 1;
263
    }
264

    
265
    /* init rate dependant parameters */
266
    s->use_noise_coding = 1;
267
    high_freq = s->sample_rate * 0.5;
268

    
269
    /* if version 2, then the rates are normalized */
270
    sample_rate1 = s->sample_rate;
271
    if (s->version == 2) {
272
        if (sample_rate1 >= 44100) 
273
            sample_rate1 = 44100;
274
        else if (sample_rate1 >= 22050) 
275
            sample_rate1 = 22050;
276
        else if (sample_rate1 >= 16000) 
277
            sample_rate1 = 16000;
278
        else if (sample_rate1 >= 11025) 
279
            sample_rate1 = 11025;
280
        else if (sample_rate1 >= 8000) 
281
            sample_rate1 = 8000;
282
    }
283

    
284
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
285
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0)) + 2;
286

    
287
    /* compute high frequency value and choose if noise coding should
288
       be activated */
289
    bps1 = bps;
290
    if (s->nb_channels == 2)
291
        bps1 = bps * 1.6;
292
    if (sample_rate1 == 44100) {
293
        if (bps1 >= 0.61)
294
            s->use_noise_coding = 0;
295
        else
296
            high_freq = high_freq * 0.4;
297
    } else if (sample_rate1 == 22050) {
298
        if (bps1 >= 1.16)
299
            s->use_noise_coding = 0;
300
        else if (bps1 >= 0.72) 
301
            high_freq = high_freq * 0.7;
302
        else
303
            high_freq = high_freq * 0.6;
304
    } else if (sample_rate1 == 16000) {
305
        if (bps > 0.5)
306
            high_freq = high_freq * 0.5;
307
        else
308
            high_freq = high_freq * 0.3;
309
    } else if (sample_rate1 == 11025) {
310
        high_freq = high_freq * 0.7;
311
    } else if (sample_rate1 == 8000) {
312
        if (bps <= 0.625) {
313
            high_freq = high_freq * 0.5;
314
        } else if (bps > 0.75) {
315
            s->use_noise_coding = 0;
316
        } else {
317
            high_freq = high_freq * 0.65;
318
        }
319
    } else {
320
        if (bps >= 0.8) {
321
            high_freq = high_freq * 0.75;
322
        } else if (bps >= 0.6) {
323
            high_freq = high_freq * 0.6;
324
        } else {
325
            high_freq = high_freq * 0.5;
326
        }
327
    }
328
    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
329
    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
330
           s->version, s->nb_channels, s->sample_rate, s->bit_rate, 
331
           s->block_align);
332
    dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n", 
333
           bps, bps1, high_freq, s->byte_offset_bits);
334
    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
335
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
336

    
337
    /* compute the scale factor band sizes for each MDCT block size */
338
    {
339
        int a, b, pos, lpos, k, block_len, i, j, n;
340
        const uint8_t *table;
341
        
342
        if (s->version == 1) {
343
            s->coefs_start = 3;
344
        } else {
345
            s->coefs_start = 0;
346
        }
347
        for(k = 0; k < s->nb_block_sizes; k++) {
348
            block_len = s->frame_len >> k;
349

    
350
            if (s->version == 1) {
351
                lpos = 0;
352
                for(i=0;i<25;i++) {
353
                    a = wma_critical_freqs[i];
354
                    b = s->sample_rate;
355
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
356
                    if (pos > block_len) 
357
                        pos = block_len;
358
                    s->exponent_bands[0][i] = pos - lpos;
359
                    if (pos >= block_len) {
360
                        i++;
361
                        break;
362
                    }
363
                    lpos = pos;
364
                }
365
                s->exponent_sizes[0] = i;
366
            } else {
367
                /* hardcoded tables */
368
                table = NULL;
369
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
370
                if (a < 3) {
371
                    if (s->sample_rate >= 44100)
372
                        table = exponent_band_44100[a];
373
                    else if (s->sample_rate >= 32000)
374
                        table = exponent_band_32000[a];
375
                    else if (s->sample_rate >= 22050)
376
                        table = exponent_band_22050[a];
377
                }
378
                if (table) {
379
                    n = *table++;
380
                    for(i=0;i<n;i++)
381
                        s->exponent_bands[k][i] = table[i];
382
                    s->exponent_sizes[k] = n;
383
                } else {
384
                    j = 0;
385
                    lpos = 0;
386
                    for(i=0;i<25;i++) {
387
                        a = wma_critical_freqs[i];
388
                        b = s->sample_rate;
389
                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
390
                        pos <<= 2;
391
                        if (pos > block_len) 
392
                            pos = block_len;
393
                        if (pos > lpos)
394
                            s->exponent_bands[k][j++] = pos - lpos;
395
                        if (pos >= block_len)
396
                            break;
397
                        lpos = pos;
398
                    }
399
                    s->exponent_sizes[k] = j;
400
                }
401
            }
402

    
403
            /* max number of coefs */
404
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
405
            /* high freq computation */
406
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) / 
407
                                          s->sample_rate + 0.5);
408
            n = s->exponent_sizes[k];
409
            j = 0;
410
            pos = 0;
411
            for(i=0;i<n;i++) {
412
                int start, end;
413
                start = pos;
414
                pos += s->exponent_bands[k][i];
415
                end = pos;
416
                if (start < s->high_band_start[k])
417
                    start = s->high_band_start[k];
418
                if (end > s->coefs_end[k])
419
                    end = s->coefs_end[k];
420
                if (end > start)
421
                    s->exponent_high_bands[k][j++] = end - start;
422
            }
423
            s->exponent_high_sizes[k] = j;
424
#if 0
425
            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
426
                  s->frame_len >> k, 
427
                  s->coefs_end[k],
428
                  s->high_band_start[k],
429
                  s->exponent_high_sizes[k]);
430
            for(j=0;j<s->exponent_high_sizes[k];j++)
431
                tprintf(" %d", s->exponent_high_bands[k][j]);
432
            tprintf("\n");
433
#endif
434
        }
435
    }
436

    
437
#ifdef TRACE
438
    {
439
        int i, j;
440
        for(i = 0; i < s->nb_block_sizes; i++) {
441
            tprintf("%5d: n=%2d:", 
442
                   s->frame_len >> i, 
443
                   s->exponent_sizes[i]);
444
            for(j=0;j<s->exponent_sizes[i];j++)
445
                tprintf(" %d", s->exponent_bands[i][j]);
446
            tprintf("\n");
447
        }
448
    }
449
#endif
450

    
451
    /* init MDCT */
452
    for(i = 0; i < s->nb_block_sizes; i++)
453
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
454
    
455
    /* init MDCT windows : simple sinus window */
456
    for(i = 0; i < s->nb_block_sizes; i++) {
457
        int n, j;
458
        float alpha;
459
        n = 1 << (s->frame_len_bits - i);
460
        window = av_malloc(sizeof(float) * n);
461
        alpha = M_PI / (2.0 * n);
462
        for(j=0;j<n;j++) {
463
            window[n - j - 1] = sin((j + 0.5) * alpha);
464
        }
465
        s->windows[i] = window;
466
    }
467

    
468
    s->reset_block_lengths = 1;
469
    
470
    if (s->use_noise_coding) {
471

    
472
        /* init the noise generator */
473
        if (s->use_exp_vlc)
474
            s->noise_mult = 0.02;
475
        else
476
            s->noise_mult = 0.04;
477
               
478
#ifdef TRACE
479
        for(i=0;i<NOISE_TAB_SIZE;i++)
480
            s->noise_table[i] = 1.0 * s->noise_mult;
481
#else
482
        {
483
            unsigned int seed;
484
            float norm;
485
            seed = 1;
486
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
487
            for(i=0;i<NOISE_TAB_SIZE;i++) {
488
                seed = seed * 314159 + 1;
489
                s->noise_table[i] = (float)((int)seed) * norm;
490
            }
491
        }
492
#endif
493
        init_vlc(&s->hgain_vlc, 9, sizeof(hgain_huffbits), 
494
                 hgain_huffbits, 1, 1,
495
                 hgain_huffcodes, 2, 2);
496
    }
497

    
498
    if (s->use_exp_vlc) {
499
        init_vlc(&s->exp_vlc, 9, sizeof(scale_huffbits), 
500
                 scale_huffbits, 1, 1,
501
                 scale_huffcodes, 4, 4);
502
    } else {
503
        wma_lsp_to_curve_init(s, s->frame_len);
504
    }
505

    
506
    /* choose the VLC tables for the coefficients */
507
    coef_vlc_table = 2;
508
    if (s->sample_rate >= 32000) {
509
        if (bps1 < 0.72)
510
            coef_vlc_table = 0;
511
        else if (bps1 < 1.16)
512
            coef_vlc_table = 1;
513
    }
514

    
515
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
516
                  &coef_vlcs[coef_vlc_table * 2]);
517
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
518
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
519
    return 0;
520
}
521

    
522
/* interpolate values for a bigger or smaller block. The block must
523
   have multiple sizes */
524
static void interpolate_array(float *scale, int old_size, int new_size)
525
{
526
    int i, j, jincr, k;
527
    float v;
528

    
529
    if (new_size > old_size) {
530
        jincr = new_size / old_size;
531
        j = new_size;
532
        for(i = old_size - 1; i >=0; i--) {
533
            v = scale[i];
534
            k = jincr;
535
            do {
536
                scale[--j] = v;
537
            } while (--k);
538
        }
539
    } else if (new_size < old_size) {
540
        j = 0;
541
        jincr = old_size / new_size;
542
        for(i = 0; i < new_size; i++) {
543
            scale[i] = scale[j];
544
            j += jincr;
545
        }
546
    }
547
}
548

    
549
/* compute x^-0.25 with an exponent and mantissa table. We use linear
550
   interpolation to reduce the mantissa table size at a small speed
551
   expense (linear interpolation approximately doubles the number of
552
   bits of precision). */
553
static inline float pow_m1_4(WMADecodeContext *s, float x)
554
{
555
    union {
556
        float f;
557
        unsigned int v;
558
    } u, t;
559
    unsigned int e, m;
560
    float a, b;
561

    
562
    u.f = x;
563
    e = u.v >> 23;
564
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
565
    /* build interpolation scale: 1 <= t < 2. */
566
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
567
    a = s->lsp_pow_m_table1[m];
568
    b = s->lsp_pow_m_table2[m];
569
    return s->lsp_pow_e_table[e] * (a + b * t.f);
570
}
571

    
572
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
573
{  
574
    float wdel, a, b;
575
    int i, e, m;
576

    
577
    wdel = M_PI / frame_len;
578
    for(i=0;i<frame_len;i++)
579
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
580

    
581
    /* tables for x^-0.25 computation */
582
    for(i=0;i<256;i++) {
583
        e = i - 126;
584
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
585
    }
586

    
587
    /* NOTE: these two tables are needed to avoid two operations in
588
       pow_m1_4 */
589
    b = 1.0;
590
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
591
        m = (1 << LSP_POW_BITS) + i;
592
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
593
        a = pow(a, -0.25);
594
        s->lsp_pow_m_table1[i] = 2 * a - b;
595
        s->lsp_pow_m_table2[i] = b - a;
596
        b = a;
597
    }
598
#if 0
599
    for(i=1;i<20;i++) {
600
        float v, r1, r2;
601
        v = 5.0 / i;
602
        r1 = pow_m1_4(s, v);
603
        r2 = pow(v,-0.25);
604
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
605
    }
606
#endif
607
}
608

    
609
/* NOTE: We use the same code as Vorbis here */
610
/* XXX: optimize it further with SSE/3Dnow */
611
static void wma_lsp_to_curve(WMADecodeContext *s, 
612
                             float *out, float *val_max_ptr, 
613
                             int n, float *lsp)
614
{
615
    int i, j;
616
    float p, q, w, v, val_max;
617

    
618
    val_max = 0;
619
    for(i=0;i<n;i++) {
620
        p = 0.5f;
621
        q = 0.5f;
622
        w = s->lsp_cos_table[i];
623
        for(j=1;j<NB_LSP_COEFS;j+=2){
624
            q *= w - lsp[j - 1];
625
            p *= w - lsp[j];
626
        }
627
        p *= p * (2.0f - w);
628
        q *= q * (2.0f + w);
629
        v = p + q;
630
        v = pow_m1_4(s, v);
631
        if (v > val_max)
632
            val_max = v;
633
        out[i] = v;
634
    }
635
    *val_max_ptr = val_max;
636
}
637

    
638
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
639
static void decode_exp_lsp(WMADecodeContext *s, int ch)
640
{
641
    float lsp_coefs[NB_LSP_COEFS];
642
    int val, i;
643

    
644
    for(i = 0; i < NB_LSP_COEFS; i++) {
645
        if (i == 0 || i >= 8)
646
            val = get_bits(&s->gb, 3);
647
        else
648
            val = get_bits(&s->gb, 4);
649
        lsp_coefs[i] = lsp_codebook[i][val];
650
    }
651

    
652
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
653
                     s->block_len, lsp_coefs);
654
}
655

    
656
/* decode exponents coded with VLC codes */
657
static int decode_exp_vlc(WMADecodeContext *s, int ch)
658
{
659
    int last_exp, n, code;
660
    const uint16_t *ptr, *band_ptr;
661
    float v, *q, max_scale, *q_end;
662
    
663
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
664
    ptr = band_ptr;
665
    q = s->exponents[ch];
666
    q_end = q + s->block_len;
667
    max_scale = 0;
668
    if (s->version == 1) {
669
        last_exp = get_bits(&s->gb, 5) + 10;
670
        /* XXX: use a table */
671
        v = pow(10, last_exp * (1.0 / 16.0));
672
        max_scale = v;
673
        n = *ptr++;
674
        do {
675
            *q++ = v;
676
        } while (--n);
677
    }
678
    last_exp = 36;
679
    while (q < q_end) {
680
        code = get_vlc(&s->gb, &s->exp_vlc);
681
        if (code < 0)
682
            return -1;
683
        /* NOTE: this offset is the same as MPEG4 AAC ! */
684
        last_exp += code - 60;
685
        /* XXX: use a table */
686
        v = pow(10, last_exp * (1.0 / 16.0));
687
        if (v > max_scale)
688
            max_scale = v;
689
        n = *ptr++;
690
        do {
691
            *q++ = v;
692
        } while (--n);
693
    }
694
    s->max_exponent[ch] = max_scale;
695
    return 0;
696
}
697

    
698
/* return 0 if OK. return 1 if last block of frame. return -1 if
699
   unrecorrable error. */
700
static int wma_decode_block(WMADecodeContext *s)
701
{
702
    int n, v, a, ch, code, bsize;
703
    int coef_nb_bits, total_gain, parse_exponents;
704
    float window[BLOCK_MAX_SIZE * 2];
705
    int nb_coefs[MAX_CHANNELS];
706
    float mdct_norm;
707

    
708
#ifdef TRACE
709
    tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
710
#endif
711

    
712
    /* compute current block length */
713
    if (s->use_variable_block_len) {
714
        n = av_log2(s->nb_block_sizes - 1) + 1;
715
    
716
        if (s->reset_block_lengths) {
717
            s->reset_block_lengths = 0;
718
            v = get_bits(&s->gb, n);
719
            if (v >= s->nb_block_sizes)
720
                return -1;
721
            s->prev_block_len_bits = s->frame_len_bits - v;
722
            v = get_bits(&s->gb, n);
723
            if (v >= s->nb_block_sizes)
724
                return -1;
725
            s->block_len_bits = s->frame_len_bits - v;
726
        } else {
727
            /* update block lengths */
728
            s->prev_block_len_bits = s->block_len_bits;
729
            s->block_len_bits = s->next_block_len_bits;
730
        }
731
        v = get_bits(&s->gb, n);
732
        if (v >= s->nb_block_sizes)
733
            return -1;
734
        s->next_block_len_bits = s->frame_len_bits - v;
735
    } else {
736
        /* fixed block len */
737
        s->next_block_len_bits = s->frame_len_bits;
738
        s->prev_block_len_bits = s->frame_len_bits;
739
        s->block_len_bits = s->frame_len_bits;
740
    }
741

    
742
    /* now check if the block length is coherent with the frame length */
743
    s->block_len = 1 << s->block_len_bits;
744
    if ((s->block_pos + s->block_len) > s->frame_len)
745
        return -1;
746

    
747
    if (s->nb_channels == 2) {
748
        s->ms_stereo = get_bits(&s->gb, 1);
749
    }
750
    v = 0;
751
    for(ch = 0; ch < s->nb_channels; ch++) {
752
        a = get_bits(&s->gb, 1);
753
        s->channel_coded[ch] = a;
754
        v |= a;
755
    }
756
    /* if no channel coded, no need to go further */
757
    /* XXX: fix potential framing problems */
758
    if (!v)
759
        goto next;
760

    
761
    bsize = s->frame_len_bits - s->block_len_bits;
762

    
763
    /* read total gain and extract corresponding number of bits for
764
       coef escape coding */
765
    total_gain = 1;
766
    for(;;) {
767
        a = get_bits(&s->gb, 7);
768
        total_gain += a;
769
        if (a != 127)
770
            break;
771
    }
772
    
773
    if (total_gain < 15)
774
        coef_nb_bits = 13;
775
    else if (total_gain < 32)
776
        coef_nb_bits = 12;
777
    else if (total_gain < 40)
778
        coef_nb_bits = 11;
779
    else if (total_gain < 45)
780
        coef_nb_bits = 10;
781
    else
782
        coef_nb_bits = 9;
783

    
784
    /* compute number of coefficients */
785
    n = s->coefs_end[bsize] - s->coefs_start;
786
    for(ch = 0; ch < s->nb_channels; ch++)
787
        nb_coefs[ch] = n;
788

    
789
    /* complex coding */
790
    if (s->use_noise_coding) {
791

    
792
        for(ch = 0; ch < s->nb_channels; ch++) {
793
            if (s->channel_coded[ch]) {
794
                int i, n, a;
795
                n = s->exponent_high_sizes[bsize];
796
                for(i=0;i<n;i++) {
797
                    a = get_bits(&s->gb, 1);
798
                    s->high_band_coded[ch][i] = a;
799
                    /* if noise coding, the coefficients are not transmitted */
800
                    if (a)
801
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
802
                }
803
            }
804
        }
805
        for(ch = 0; ch < s->nb_channels; ch++) {
806
            if (s->channel_coded[ch]) {
807
                int i, n, val, code;
808

    
809
                n = s->exponent_high_sizes[bsize];
810
                val = (int)0x80000000;
811
                for(i=0;i<n;i++) {
812
                    if (s->high_band_coded[ch][i]) {
813
                        if (val == (int)0x80000000) {
814
                            val = get_bits(&s->gb, 7) - 19;
815
                        } else {
816
                            code = get_vlc(&s->gb, &s->hgain_vlc);
817
                            if (code < 0)
818
                                return -1;
819
                            val += code - 18;
820
                        }
821
                        s->high_band_values[ch][i] = val;
822
                    }
823
                }
824
            }
825
        }
826
    }
827
           
828
    /* exposant can be interpolated in short blocks. */
829
    parse_exponents = 1;
830
    if (s->block_len_bits != s->frame_len_bits) {
831
        parse_exponents = get_bits(&s->gb, 1);
832
    }
833
    
834
    if (parse_exponents) {
835
        for(ch = 0; ch < s->nb_channels; ch++) {
836
            if (s->channel_coded[ch]) {
837
                if (s->use_exp_vlc) {
838
                    if (decode_exp_vlc(s, ch) < 0)
839
                        return -1;
840
                } else {
841
                    decode_exp_lsp(s, ch);
842
                }
843
            }
844
        }
845
    } else {
846
        for(ch = 0; ch < s->nb_channels; ch++) {
847
            if (s->channel_coded[ch]) {
848
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits, 
849
                                  s->block_len);
850
            }
851
        }
852
    }
853

    
854
    /* parse spectral coefficients : just RLE encoding */
855
    for(ch = 0; ch < s->nb_channels; ch++) {
856
        if (s->channel_coded[ch]) {
857
            VLC *coef_vlc;
858
            int level, run, sign, tindex;
859
            int16_t *ptr, *eptr;
860
            const int16_t *level_table, *run_table;
861

    
862
            /* special VLC tables are used for ms stereo because
863
               there is potentially less energy there */
864
            tindex = (ch == 1 && s->ms_stereo);
865
            coef_vlc = &s->coef_vlc[tindex];
866
            run_table = s->run_table[tindex];
867
            level_table = s->level_table[tindex];
868
            /* XXX: optimize */
869
            ptr = &s->coefs1[ch][0];
870
            eptr = ptr + nb_coefs[ch];
871
            memset(ptr, 0, s->block_len * sizeof(int16_t));
872
            for(;;) {
873
                code = get_vlc(&s->gb, coef_vlc);
874
                if (code < 0)
875
                    return -1;
876
                if (code == 1) {
877
                    /* EOB */
878
                    break;
879
                } else if (code == 0) {
880
                    /* escape */
881
                    level = get_bits(&s->gb, coef_nb_bits);
882
                    /* NOTE: this is rather suboptimal. reading
883
                       block_len_bits would be better */
884
                    run = get_bits(&s->gb, s->frame_len_bits);
885
                } else {
886
                    /* normal code */
887
                    run = run_table[code];
888
                    level = level_table[code];
889
                }
890
                sign = get_bits(&s->gb, 1);
891
                if (!sign)
892
                    level = -level;
893
                ptr += run;
894
                if (ptr >= eptr)
895
                    return -1;
896
                *ptr++ = level;
897
                /* NOTE: EOB can be omitted */
898
                if (ptr >= eptr)
899
                    break;
900
            }
901
        }
902
        if (s->version == 1 && s->nb_channels >= 2) {
903
            align_get_bits(&s->gb);
904
        }
905
    }
906
     
907
    /* normalize */
908
    {
909
        int n4 = s->block_len / 2;
910
        mdct_norm = 1.0 / (float)n4;
911
        if (s->version == 1) {
912
            mdct_norm *= sqrt(n4);
913
        }
914
    }
915

    
916
    /* finally compute the MDCT coefficients */
917
    for(ch = 0; ch < s->nb_channels; ch++) {
918
        if (s->channel_coded[ch]) {
919
            int16_t *coefs1;
920
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
921
            int i, j, n, n1, last_high_band;
922
            float exp_power[HIGH_BAND_MAX_SIZE];
923

    
924
            coefs1 = s->coefs1[ch];
925
            exponents = s->exponents[ch];
926
            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
927
            mult *= mdct_norm;
928
            coefs = s->coefs[ch];
929
            if (s->use_noise_coding) {
930
                mult1 = mult;
931
                /* very low freqs : noise */
932
                for(i = 0;i < s->coefs_start; i++) {
933
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
934
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
935
                }
936
                
937
                n1 = s->exponent_high_sizes[bsize];
938

    
939
                /* compute power of high bands */
940
                exp_ptr = exponents + 
941
                    s->high_band_start[bsize] - 
942
                    s->coefs_start;
943
                last_high_band = 0; /* avoid warning */
944
                for(j=0;j<n1;j++) {
945
                    n = s->exponent_high_bands[s->frame_len_bits - 
946
                                              s->block_len_bits][j];
947
                    if (s->high_band_coded[ch][j]) {
948
                        float e2, v;
949
                        e2 = 0;
950
                        for(i = 0;i < n; i++) {
951
                            v = exp_ptr[i];
952
                            e2 += v * v;
953
                        }
954
                        exp_power[j] = e2 / n;
955
                        last_high_band = j;
956
                        tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
957
                    }
958
                    exp_ptr += n;
959
                }
960

    
961
                /* main freqs and high freqs */
962
                for(j=-1;j<n1;j++) {
963
                    if (j < 0) {
964
                        n = s->high_band_start[bsize] - 
965
                            s->coefs_start;
966
                    } else {
967
                        n = s->exponent_high_bands[s->frame_len_bits - 
968
                                                  s->block_len_bits][j];
969
                    }
970
                    if (j >= 0 && s->high_band_coded[ch][j]) {
971
                        /* use noise with specified power */
972
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
973
                        /* XXX: use a table */
974
                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
975
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
976
                        mult1 *= mdct_norm;
977
                        for(i = 0;i < n; i++) {
978
                            noise = s->noise_table[s->noise_index];
979
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
980
                            *coefs++ = (*exponents++) * noise * mult1;
981
                        }
982
                    } else {
983
                        /* coded values + small noise */
984
                        for(i = 0;i < n; i++) {
985
                            noise = s->noise_table[s->noise_index];
986
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
987
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
988
                        }
989
                    }
990
                }
991

    
992
                /* very high freqs : noise */
993
                n = s->block_len - s->coefs_end[bsize];
994
                mult1 = mult * exponents[-1];
995
                for(i = 0; i < n; i++) {
996
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
997
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
998
                }
999
            } else {
1000
                /* XXX: optimize more */
1001
                for(i = 0;i < s->coefs_start; i++)
1002
                    *coefs++ = 0.0;
1003
                n = nb_coefs[ch];
1004
                for(i = 0;i < n; i++) {
1005
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1006
                }
1007
                n = s->block_len - s->coefs_end[bsize];
1008
                for(i = 0;i < n; i++)
1009
                    *coefs++ = 0.0;
1010
            }
1011
        }
1012
    }
1013

    
1014
#ifdef TRACE
1015
    for(ch = 0; ch < s->nb_channels; ch++) {
1016
        if (s->channel_coded[ch]) {
1017
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1018
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1019
        }
1020
    }
1021
#endif
1022
    
1023
    if (s->ms_stereo && s->channel_coded[1]) {
1024
        float a, b;
1025
        int i;
1026

    
1027
        /* nominal case for ms stereo: we do it before mdct */
1028
        /* no need to optimize this case because it should almost
1029
           never happen */
1030
        if (!s->channel_coded[0]) {
1031
            tprintf("rare ms-stereo case happened\n");
1032
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1033
            s->channel_coded[0] = 1;
1034
        }
1035
        
1036
        for(i = 0; i < s->block_len; i++) {
1037
            a = s->coefs[0][i];
1038
            b = s->coefs[1][i];
1039
            s->coefs[0][i] = a + b;
1040
            s->coefs[1][i] = a - b;
1041
        }
1042
    }
1043

    
1044
    /* build the window : we ensure that when the windows overlap
1045
       their squared sum is always 1 (MDCT reconstruction rule) */
1046
    /* XXX: merge with output */
1047
    {
1048
        int i, next_block_len, block_len, prev_block_len, n;
1049
        float *wptr;
1050

    
1051
        block_len = s->block_len;
1052
        prev_block_len = 1 << s->prev_block_len_bits;
1053
        next_block_len = 1 << s->next_block_len_bits;
1054

    
1055
        /* right part */
1056
        wptr = window + block_len;
1057
        if (block_len <= next_block_len) {
1058
            for(i=0;i<block_len;i++)
1059
                *wptr++ = s->windows[bsize][i];
1060
        } else {
1061
            /* overlap */
1062
            n = (block_len / 2) - (next_block_len / 2);
1063
            for(i=0;i<n;i++)
1064
                *wptr++ = 1.0;
1065
            for(i=0;i<next_block_len;i++)
1066
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1067
            for(i=0;i<n;i++)
1068
                *wptr++ = 0.0;
1069
        }
1070

    
1071
        /* left part */
1072
        wptr = window + block_len;
1073
        if (block_len <= prev_block_len) {
1074
            for(i=0;i<block_len;i++)
1075
                *--wptr = s->windows[bsize][i];
1076
        } else {
1077
            /* overlap */
1078
            n = (block_len / 2) - (prev_block_len / 2);
1079
            for(i=0;i<n;i++)
1080
                *--wptr = 1.0;
1081
            for(i=0;i<prev_block_len;i++)
1082
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1083
            for(i=0;i<n;i++)
1084
                *--wptr = 0.0;
1085
        }
1086
    }
1087

    
1088
    
1089
    for(ch = 0; ch < s->nb_channels; ch++) {
1090
        if (s->channel_coded[ch]) {
1091
            FFTSample output[BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
1092
            float *ptr;
1093
            int i, n4, index, n;
1094

    
1095
            n = s->block_len;
1096
            n4 = s->block_len / 2;
1097
            ff_imdct_calc(&s->mdct_ctx[bsize], 
1098
                          output, s->coefs[ch], s->mdct_tmp);
1099

    
1100
            /* XXX: optimize all that by build the window and
1101
               multipying/adding at the same time */
1102
            /* multiply by the window */
1103
            for(i=0;i<n * 2;i++) {
1104
                output[i] *= window[i];
1105
            }
1106

    
1107
            /* add in the frame */
1108
            index = (s->frame_len / 2) + s->block_pos - n4;
1109
            ptr = &s->frame_out[ch][index];
1110
            for(i=0;i<n * 2;i++) {
1111
                *ptr += output[i];
1112
                ptr++;
1113
            }
1114

    
1115
            /* specific fast case for ms-stereo : add to second
1116
               channel if it is not coded */
1117
            if (s->ms_stereo && !s->channel_coded[1]) {
1118
                ptr = &s->frame_out[1][index];
1119
                for(i=0;i<n * 2;i++) {
1120
                    *ptr += output[i];
1121
                    ptr++;
1122
                }
1123
            }
1124
        }
1125
    }
1126
 next:
1127
    /* update block number */
1128
    s->block_num++;
1129
    s->block_pos += s->block_len;
1130
    if (s->block_pos >= s->frame_len)
1131
        return 1;
1132
    else
1133
        return 0;
1134
}
1135

    
1136
/* decode a frame of frame_len samples */
1137
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1138
{
1139
    int ret, i, n, a, ch, incr;
1140
    int16_t *ptr;
1141
    float *iptr;
1142

    
1143
#ifdef TRACE
1144
    tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
1145
#endif
1146

    
1147
    /* read each block */
1148
    s->block_num = 0;
1149
    s->block_pos = 0;
1150
    for(;;) {
1151
        ret = wma_decode_block(s);
1152
        if (ret < 0) 
1153
            return -1;
1154
        if (ret)
1155
            break;
1156
    }
1157

    
1158
    /* convert frame to integer */
1159
    n = s->frame_len;
1160
    incr = s->nb_channels;
1161
    for(ch = 0; ch < s->nb_channels; ch++) {
1162
        ptr = samples + ch;
1163
        iptr = s->frame_out[ch];
1164

    
1165
        for(i=0;i<n;i++) {
1166
            a = lrintf(*iptr++);
1167
            if (a > 32767)
1168
                a = 32767;
1169
            else if (a < -32768)
1170
                a = -32768;
1171
            *ptr = a;
1172
            ptr += incr;
1173
        }
1174
        /* prepare for next block */
1175
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1176
                s->frame_len * sizeof(float));
1177
        /* XXX: suppress this */
1178
        memset(&s->frame_out[ch][s->frame_len], 0, 
1179
               s->frame_len * sizeof(float));
1180
    }
1181

    
1182
#ifdef TRACE
1183
    dump_shorts("samples", samples, n * s->nb_channels);
1184
#endif
1185
    return 0;
1186
}
1187

    
1188
static int wma_decode_superframe(AVCodecContext *avctx, 
1189
                                 void *data, int *data_size,
1190
                                 uint8_t *buf, int buf_size)
1191
{
1192
    WMADecodeContext *s = avctx->priv_data;
1193
    int nb_frames, bit_offset, i, pos, len;
1194
    uint8_t *q;
1195
    int16_t *samples;
1196
    
1197
    tprintf("***decode_superframe:\n");
1198

    
1199
    if(buf_size==0){
1200
        s->last_superframe_len = 0;
1201
        return 0;
1202
    }
1203
    
1204
    samples = data;
1205

    
1206
    init_get_bits(&s->gb, buf, buf_size*8);
1207
    
1208
    if (s->use_bit_reservoir) {
1209
        /* read super frame header */
1210
        get_bits(&s->gb, 4); /* super frame index */
1211
        nb_frames = get_bits(&s->gb, 4) - 1;
1212

    
1213
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1214

    
1215
        if (s->last_superframe_len > 0) {
1216
            //        printf("skip=%d\n", s->last_bitoffset);
1217
            /* add bit_offset bits to last frame */
1218
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) > 
1219
                MAX_CODED_SUPERFRAME_SIZE)
1220
                goto fail;
1221
            q = s->last_superframe + s->last_superframe_len;
1222
            len = bit_offset;
1223
            while (len > 0) {
1224
                *q++ = (get_bits)(&s->gb, 8);
1225
                len -= 8;
1226
            }
1227
            if (len > 0) {
1228
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1229
            }
1230
            
1231
            /* XXX: bit_offset bits into last frame */
1232
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1233
            /* skip unused bits */
1234
            if (s->last_bitoffset > 0)
1235
                skip_bits(&s->gb, s->last_bitoffset);
1236
            /* this frame is stored in the last superframe and in the
1237
               current one */
1238
            if (wma_decode_frame(s, samples) < 0)
1239
                goto fail;
1240
            samples += s->nb_channels * s->frame_len;
1241
        }
1242

    
1243
        /* read each frame starting from bit_offset */
1244
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1245
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1246
        len = pos & 7;
1247
        if (len > 0)
1248
            skip_bits(&s->gb, len);
1249
    
1250
        s->reset_block_lengths = 1;
1251
        for(i=0;i<nb_frames;i++) {
1252
            if (wma_decode_frame(s, samples) < 0)
1253
                goto fail;
1254
            samples += s->nb_channels * s->frame_len;
1255
        }
1256

    
1257
        /* we copy the end of the frame in the last frame buffer */
1258
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1259
        s->last_bitoffset = pos & 7;
1260
        pos >>= 3;
1261
        len = buf_size - pos;
1262
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1263
            goto fail;
1264
        }
1265
        s->last_superframe_len = len;
1266
        memcpy(s->last_superframe, buf + pos, len);
1267
    } else {
1268
        /* single frame decode */
1269
        if (wma_decode_frame(s, samples) < 0)
1270
            goto fail;
1271
        samples += s->nb_channels * s->frame_len;
1272
    }
1273
    *data_size = (int8_t *)samples - (int8_t *)data;
1274
    return s->block_align;
1275
 fail:
1276
    /* when error, we reset the bit reservoir */
1277
    s->last_superframe_len = 0;
1278
    return -1;
1279
}
1280

    
1281
static int wma_decode_end(AVCodecContext *avctx)
1282
{
1283
    WMADecodeContext *s = avctx->priv_data;
1284
    int i;
1285

    
1286
    for(i = 0; i < s->nb_block_sizes; i++)
1287
        ff_mdct_end(&s->mdct_ctx[i]);
1288
    for(i = 0; i < s->nb_block_sizes; i++)
1289
        av_free(s->windows[i]);
1290

    
1291
    if (s->use_exp_vlc) {
1292
        free_vlc(&s->exp_vlc);
1293
    }
1294
    if (s->use_noise_coding) {
1295
        free_vlc(&s->hgain_vlc);
1296
    }
1297
    for(i = 0;i < 2; i++) {
1298
        free_vlc(&s->coef_vlc[i]);
1299
        av_free(s->run_table[i]);
1300
        av_free(s->level_table[i]);
1301
    }
1302
    
1303
    return 0;
1304
}
1305

    
1306
AVCodec wmav1_decoder =
1307
{
1308
    "wmav1",
1309
    CODEC_TYPE_AUDIO,
1310
    CODEC_ID_WMAV1,
1311
    sizeof(WMADecodeContext),
1312
    wma_decode_init,
1313
    NULL,
1314
    wma_decode_end,
1315
    wma_decode_superframe,
1316
};
1317

    
1318
AVCodec wmav2_decoder =
1319
{
1320
    "wmav2",
1321
    CODEC_TYPE_AUDIO,
1322
    CODEC_ID_WMAV2,
1323
    sizeof(WMADecodeContext),
1324
    wma_decode_init,
1325
    NULL,
1326
    wma_decode_end,
1327
    wma_decode_superframe,
1328
};