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1
/*
2
 * WMA compatible codec
3
 * Copyright (c) 2002-2007 The FFmpeg Project
4
 *
5
 * 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
10
 * 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
#include "avcodec.h"
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#include "wma.h"
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#include "wmadata.h"
25

    
26
#undef NDEBUG
27
#include <assert.h>
28

    
29
/* XXX: use same run/length optimization as mpeg decoders */
30
//FIXME maybe split decode / encode or pass flag
31
static void init_coef_vlc(VLC *vlc, uint16_t **prun_table,
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                          uint16_t **plevel_table, uint16_t **pint_table,
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                          const CoefVLCTable *vlc_table)
34
{
35
    int n = vlc_table->n;
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    const uint8_t  *table_bits   = vlc_table->huffbits;
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    const uint32_t *table_codes  = vlc_table->huffcodes;
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    const uint16_t *levels_table = vlc_table->levels;
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    uint16_t *run_table, *level_table, *int_table;
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    int i, l, j, k, level;
41

    
42
    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
43

    
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    run_table   = av_malloc(n * sizeof(uint16_t));
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    level_table = av_malloc(n * sizeof(uint16_t));
46
    int_table   = av_malloc(n * sizeof(uint16_t));
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    i = 2;
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    level = 1;
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    k = 0;
50
    while (i < n) {
51
        int_table[k] = i;
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        l = levels_table[k++];
53
        for (j = 0; j < l; j++) {
54
            run_table[i]   = j;
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            level_table[i] = level;
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            i++;
57
        }
58
        level++;
59
    }
60
    *prun_table   = run_table;
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    *plevel_table = level_table;
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    *pint_table   = int_table;
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}
64

    
65
/**
66
 *@brief Get the samples per frame for this stream.
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 *@param sample_rate output sample_rate
68
 *@param version wma version
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 *@param decode_flags codec compression features
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 *@return log2 of the number of output samples per frame
71
 */
72
int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version,
73
                                      unsigned int decode_flags)
74
{
75

    
76
    int frame_len_bits;
77

    
78
    if (sample_rate <= 16000) {
79
        frame_len_bits = 9;
80
    } else if (sample_rate <= 22050 ||
81
             (sample_rate <= 32000 && version == 1)) {
82
        frame_len_bits = 10;
83
    } else if (sample_rate <= 48000) {
84
        frame_len_bits = 11;
85
    } else if (sample_rate <= 96000) {
86
        frame_len_bits = 12;
87
    } else {
88
        frame_len_bits = 13;
89
    }
90

    
91
    if (version == 3) {
92
        int tmp = decode_flags & 0x6;
93
        if (tmp == 0x2) {
94
            ++frame_len_bits;
95
        } else if (tmp == 0x4) {
96
            --frame_len_bits;
97
        } else if (tmp == 0x6) {
98
            frame_len_bits -= 2;
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        }
100
    }
101

    
102
    return frame_len_bits;
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}
104

    
105
int ff_wma_init(AVCodecContext *avctx, int flags2)
106
{
107
    WMACodecContext *s = avctx->priv_data;
108
    int i;
109
    float bps1, high_freq;
110
    volatile float bps;
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    int sample_rate1;
112
    int coef_vlc_table;
113

    
114
    if (   avctx->sample_rate <= 0 || avctx->sample_rate > 50000
115
        || avctx->channels    <= 0 || avctx->channels    > 8
116
        || avctx->bit_rate    <= 0)
117
        return -1;
118

    
119
    s->sample_rate = avctx->sample_rate;
120
    s->nb_channels = avctx->channels;
121
    s->bit_rate    = avctx->bit_rate;
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    s->block_align = avctx->block_align;
123

    
124
    dsputil_init(&s->dsp, avctx);
125

    
126
    if (avctx->codec->id == CODEC_ID_WMAV1) {
127
        s->version = 1;
128
    } else {
129
        s->version = 2;
130
    }
131

    
132
    /* compute MDCT block size */
133
    s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0);
134

    
135
    s->frame_len = 1 << s->frame_len_bits;
136
    if (s->use_variable_block_len) {
137
        int nb_max, nb;
138
        nb = ((flags2 >> 3) & 3) + 1;
139
        if ((s->bit_rate / s->nb_channels) >= 32000)
140
            nb += 2;
141
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
142
        if (nb > nb_max)
143
            nb = nb_max;
144
        s->nb_block_sizes = nb + 1;
145
    } else {
146
        s->nb_block_sizes = 1;
147
    }
148

    
149
    /* init rate dependent parameters */
150
    s->use_noise_coding = 1;
151
    high_freq = s->sample_rate * 0.5;
152

    
153
    /* if version 2, then the rates are normalized */
154
    sample_rate1 = s->sample_rate;
155
    if (s->version == 2) {
156
        if (sample_rate1 >= 44100) {
157
            sample_rate1 = 44100;
158
        } else if (sample_rate1 >= 22050) {
159
            sample_rate1 = 22050;
160
        } else if (sample_rate1 >= 16000) {
161
            sample_rate1 = 16000;
162
        } else if (sample_rate1 >= 11025) {
163
            sample_rate1 = 11025;
164
        } else if (sample_rate1 >= 8000) {
165
            sample_rate1 = 8000;
166
        }
167
    }
168

    
169
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
170
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
171

    
172
    /* compute high frequency value and choose if noise coding should
173
       be activated */
174
    bps1 = bps;
175
    if (s->nb_channels == 2)
176
        bps1 = bps * 1.6;
177
    if (sample_rate1 == 44100) {
178
        if (bps1 >= 0.61) {
179
            s->use_noise_coding = 0;
180
        } else {
181
            high_freq = high_freq * 0.4;
182
        }
183
    } else if (sample_rate1 == 22050) {
184
        if (bps1 >= 1.16) {
185
            s->use_noise_coding = 0;
186
        } else if (bps1 >= 0.72) {
187
            high_freq = high_freq * 0.7;
188
        } else {
189
            high_freq = high_freq * 0.6;
190
        }
191
    } else if (sample_rate1 == 16000) {
192
        if (bps > 0.5) {
193
            high_freq = high_freq * 0.5;
194
        } else {
195
            high_freq = high_freq * 0.3;
196
        }
197
    } else if (sample_rate1 == 11025) {
198
        high_freq = high_freq * 0.7;
199
    } else if (sample_rate1 == 8000) {
200
        if (bps <= 0.625) {
201
            high_freq = high_freq * 0.5;
202
        } else if (bps > 0.75) {
203
            s->use_noise_coding = 0;
204
        } else {
205
            high_freq = high_freq * 0.65;
206
        }
207
    } else {
208
        if (bps >= 0.8) {
209
            high_freq = high_freq * 0.75;
210
        } else if (bps >= 0.6) {
211
            high_freq = high_freq * 0.6;
212
        } else {
213
            high_freq = high_freq * 0.5;
214
        }
215
    }
216
    dprintf(s->avctx, "flags2=0x%x\n", flags2);
217
    dprintf(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
218
            s->version, s->nb_channels, s->sample_rate, s->bit_rate,
219
            s->block_align);
220
    dprintf(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
221
            bps, bps1, high_freq, s->byte_offset_bits);
222
    dprintf(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
223
            s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
224

    
225
    /* compute the scale factor band sizes for each MDCT block size */
226
    {
227
        int a, b, pos, lpos, k, block_len, i, j, n;
228
        const uint8_t *table;
229

    
230
        if (s->version == 1) {
231
            s->coefs_start = 3;
232
        } else {
233
            s->coefs_start = 0;
234
        }
235
        for (k = 0; k < s->nb_block_sizes; k++) {
236
            block_len = s->frame_len >> k;
237

    
238
            if (s->version == 1) {
239
                lpos = 0;
240
                for (i = 0; i < 25; i++) {
241
                    a = wma_critical_freqs[i];
242
                    b = s->sample_rate;
243
                    pos = ((block_len * 2 * a) + (b >> 1)) / b;
244
                    if (pos > block_len)
245
                        pos = block_len;
246
                    s->exponent_bands[0][i] = pos - lpos;
247
                    if (pos >= block_len) {
248
                        i++;
249
                        break;
250
                    }
251
                    lpos = pos;
252
                }
253
                s->exponent_sizes[0] = i;
254
            } else {
255
                /* hardcoded tables */
256
                table = NULL;
257
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
258
                if (a < 3) {
259
                    if (s->sample_rate >= 44100) {
260
                        table = exponent_band_44100[a];
261
                    } else if (s->sample_rate >= 32000) {
262
                        table = exponent_band_32000[a];
263
                    } else if (s->sample_rate >= 22050) {
264
                        table = exponent_band_22050[a];
265
                    }
266
                }
267
                if (table) {
268
                    n = *table++;
269
                    for (i = 0; i < n; i++)
270
                        s->exponent_bands[k][i] = table[i];
271
                    s->exponent_sizes[k] = n;
272
                } else {
273
                    j = 0;
274
                    lpos = 0;
275
                    for (i = 0; i < 25; i++) {
276
                        a = wma_critical_freqs[i];
277
                        b = s->sample_rate;
278
                        pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
279
                        pos <<= 2;
280
                        if (pos > block_len)
281
                            pos = block_len;
282
                        if (pos > lpos)
283
                            s->exponent_bands[k][j++] = pos - lpos;
284
                        if (pos >= block_len)
285
                            break;
286
                        lpos = pos;
287
                    }
288
                    s->exponent_sizes[k] = j;
289
                }
290
            }
291

    
292
            /* max number of coefs */
293
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
294
            /* high freq computation */
295
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
296
                                          s->sample_rate + 0.5);
297
            n = s->exponent_sizes[k];
298
            j = 0;
299
            pos = 0;
300
            for (i = 0; i < n; i++) {
301
                int start, end;
302
                start = pos;
303
                pos += s->exponent_bands[k][i];
304
                end = pos;
305
                if (start < s->high_band_start[k])
306
                    start = s->high_band_start[k];
307
                if (end > s->coefs_end[k])
308
                    end = s->coefs_end[k];
309
                if (end > start)
310
                    s->exponent_high_bands[k][j++] = end - start;
311
            }
312
            s->exponent_high_sizes[k] = j;
313
#if 0
314
            tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
315
                    s->frame_len >> k,
316
                    s->coefs_end[k],
317
                    s->high_band_start[k],
318
                    s->exponent_high_sizes[k]);
319
            for (j = 0; j < s->exponent_high_sizes[k]; j++)
320
                tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
321
            tprintf(s->avctx, "\n");
322
#endif
323
        }
324
    }
325

    
326
#ifdef TRACE
327
    {
328
        int i, j;
329
        for (i = 0; i < s->nb_block_sizes; i++) {
330
            tprintf(s->avctx, "%5d: n=%2d:",
331
                    s->frame_len >> i,
332
                    s->exponent_sizes[i]);
333
            for (j = 0; j < s->exponent_sizes[i]; j++)
334
                tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
335
            tprintf(s->avctx, "\n");
336
        }
337
    }
338
#endif
339

    
340
    /* init MDCT windows : simple sinus window */
341
    for (i = 0; i < s->nb_block_sizes; i++) {
342
        int n;
343
        n = 1 << (s->frame_len_bits - i);
344
        ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
345
        s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
346
    }
347

    
348
    s->reset_block_lengths = 1;
349

    
350
    if (s->use_noise_coding) {
351

    
352
        /* init the noise generator */
353
        if (s->use_exp_vlc) {
354
            s->noise_mult = 0.02;
355
        } else {
356
            s->noise_mult = 0.04;
357
        }
358

    
359
#ifdef TRACE
360
        for (i = 0; i < NOISE_TAB_SIZE; i++)
361
            s->noise_table[i] = 1.0 * s->noise_mult;
362
#else
363
        {
364
            unsigned int seed;
365
            float norm;
366
            seed = 1;
367
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
368
            for (i = 0; i < NOISE_TAB_SIZE; i++) {
369
                seed = seed * 314159 + 1;
370
                s->noise_table[i] = (float)((int)seed) * norm;
371
            }
372
        }
373
#endif
374
    }
375

    
376
    /* choose the VLC tables for the coefficients */
377
    coef_vlc_table = 2;
378
    if (s->sample_rate >= 32000) {
379
        if (bps1 < 0.72) {
380
            coef_vlc_table = 0;
381
        } else if (bps1 < 1.16) {
382
            coef_vlc_table = 1;
383
        }
384
    }
385
    s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
386
    s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
387
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
388
                  s->coef_vlcs[0]);
389
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
390
                  s->coef_vlcs[1]);
391

    
392
    return 0;
393
}
394

    
395
int ff_wma_total_gain_to_bits(int total_gain)
396
{
397
         if (total_gain < 15) return 13;
398
    else if (total_gain < 32) return 12;
399
    else if (total_gain < 40) return 11;
400
    else if (total_gain < 45) return 10;
401
    else                      return  9;
402
}
403

    
404
int ff_wma_end(AVCodecContext *avctx)
405
{
406
    WMACodecContext *s = avctx->priv_data;
407
    int i;
408

    
409
    for (i = 0; i < s->nb_block_sizes; i++)
410
        ff_mdct_end(&s->mdct_ctx[i]);
411

    
412
    if (s->use_exp_vlc) {
413
        free_vlc(&s->exp_vlc);
414
    }
415
    if (s->use_noise_coding) {
416
        free_vlc(&s->hgain_vlc);
417
    }
418
    for (i = 0; i < 2; i++) {
419
        free_vlc(&s->coef_vlc[i]);
420
        av_free(s->run_table[i]);
421
        av_free(s->level_table[i]);
422
        av_free(s->int_table[i]);
423
    }
424

    
425
    return 0;
426
}
427

    
428
/**
429
 * Decode an uncompressed coefficient.
430
 * @param s codec context
431
 * @return the decoded coefficient
432
 */
433
unsigned int ff_wma_get_large_val(GetBitContext* gb)
434
{
435
    /** consumes up to 34 bits */
436
    int n_bits = 8;
437
    /** decode length */
438
    if (get_bits1(gb)) {
439
        n_bits += 8;
440
        if (get_bits1(gb)) {
441
            n_bits += 8;
442
            if (get_bits1(gb)) {
443
                n_bits += 7;
444
            }
445
        }
446
    }
447
    return get_bits_long(gb, n_bits);
448
}
449

    
450
/**
451
 * Decode run level compressed coefficients.
452
 * @param avctx codec context
453
 * @param gb bitstream reader context
454
 * @param vlc vlc table for get_vlc2
455
 * @param level_table level codes
456
 * @param run_table run codes
457
 * @param version 0 for wma1,2 1 for wmapro
458
 * @param ptr output buffer
459
 * @param offset offset in the output buffer
460
 * @param num_coefs number of input coefficents
461
 * @param block_len input buffer length (2^n)
462
 * @param frame_len_bits number of bits for escaped run codes
463
 * @param coef_nb_bits number of bits for escaped level codes
464
 * @return 0 on success, -1 otherwise
465
 */
466
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
467
                            VLC *vlc,
468
                            const uint16_t *level_table, const uint16_t *run_table,
469
                            int version, WMACoef *ptr, int offset,
470
                            int num_coefs, int block_len, int frame_len_bits,
471
                            int coef_nb_bits)
472
{
473
    int code, run, level, sign;
474
    WMACoef* eptr = ptr + num_coefs;
475
    ptr += offset;
476
    for(;;) {
477
        code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
478
        if (code < 0)
479
            return -1;
480
        if (code == 1) {
481
            /* EOB */
482
            break;
483
        } else if (code == 0) {
484
            /* escape */
485
            if (!version) {
486
            level = get_bits(gb, coef_nb_bits);
487
            /* NOTE: this is rather suboptimal. reading
488
               block_len_bits would be better */
489
            run = get_bits(gb, frame_len_bits);
490
            } else {
491
                level = ff_wma_get_large_val(gb);
492
                /** escape decode */
493
                if (get_bits1(gb)) {
494
                    if (get_bits1(gb)) {
495
                        if (get_bits1(gb)) {
496
                            av_log(avctx,AV_LOG_ERROR,
497
                                "broken escape sequence\n");
498
                            return -1;
499
                        } else
500
                            run = get_bits(gb, frame_len_bits) + 4;
501
                    } else
502
                        run = get_bits(gb, 2) + 1;
503
                } else
504
                     run = 0;
505
            }
506
        } else {
507
            /* normal code */
508
            run = run_table[code];
509
            level = level_table[code];
510
        }
511
        sign = get_bits1(gb);
512
        if (!sign)
513
             level = -level;
514
        ptr += run;
515
        if (ptr >= eptr)
516
        {
517
            av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
518
            break;
519
        }
520
        *ptr++ = level;
521
        /* NOTE: EOB can be omitted */
522
        if (ptr >= eptr)
523
            break;
524
    }
525
    return 0;
526
}
527