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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
9
 * 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,
13
 * 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,
32
                          float **plevel_table, uint16_t **pint_table,
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                          const CoefVLCTable *vlc_table)
34
{
35
    int n = vlc_table->n;
36
    const uint8_t  *table_bits   = vlc_table->huffbits;
37
    const uint32_t *table_codes  = vlc_table->huffcodes;
38
    const uint16_t *levels_table = vlc_table->levels;
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    uint16_t *run_table, *level_table, *int_table;
40
    float *flevel_table;
41
    int i, l, j, k, level;
42

    
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    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
44

    
45
    run_table   = av_malloc(n * sizeof(uint16_t));
46
    level_table = av_malloc(n * sizeof(uint16_t));
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    flevel_table= av_malloc(n * sizeof(*flevel_table));
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    int_table   = av_malloc(n * sizeof(uint16_t));
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    i = 2;
50
    level = 1;
51
    k = 0;
52
    while (i < n) {
53
        int_table[k] = i;
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        l = levels_table[k++];
55
        for (j = 0; j < l; j++) {
56
            run_table[i]   = j;
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            level_table[i] = level;
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            flevel_table[i]= level;
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            i++;
60
        }
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        level++;
62
    }
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    *prun_table   = run_table;
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    *plevel_table = flevel_table;
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    *pint_table   = int_table;
66
    av_free(level_table);
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}
68

    
69
/**
70
 *@brief Get the samples per frame for this stream.
71
 *@param sample_rate output sample_rate
72
 *@param version wma version
73
 *@param decode_flags codec compression features
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 *@return log2 of the number of output samples per frame
75
 */
76
int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version,
77
                                      unsigned int decode_flags)
78
{
79

    
80
    int frame_len_bits;
81

    
82
    if (sample_rate <= 16000) {
83
        frame_len_bits = 9;
84
    } else if (sample_rate <= 22050 ||
85
             (sample_rate <= 32000 && version == 1)) {
86
        frame_len_bits = 10;
87
    } else if (sample_rate <= 48000) {
88
        frame_len_bits = 11;
89
    } else if (sample_rate <= 96000) {
90
        frame_len_bits = 12;
91
    } else {
92
        frame_len_bits = 13;
93
    }
94

    
95
    if (version == 3) {
96
        int tmp = decode_flags & 0x6;
97
        if (tmp == 0x2) {
98
            ++frame_len_bits;
99
        } else if (tmp == 0x4) {
100
            --frame_len_bits;
101
        } else if (tmp == 0x6) {
102
            frame_len_bits -= 2;
103
        }
104
    }
105

    
106
    return frame_len_bits;
107
}
108

    
109
int ff_wma_init(AVCodecContext *avctx, int flags2)
110
{
111
    WMACodecContext *s = avctx->priv_data;
112
    int i;
113
    float bps1, high_freq;
114
    volatile float bps;
115
    int sample_rate1;
116
    int coef_vlc_table;
117

    
118
    if (   avctx->sample_rate <= 0 || avctx->sample_rate > 50000
119
        || avctx->channels    <= 0 || avctx->channels    > 8
120
        || avctx->bit_rate    <= 0)
121
        return -1;
122

    
123
    s->sample_rate = avctx->sample_rate;
124
    s->nb_channels = avctx->channels;
125
    s->bit_rate    = avctx->bit_rate;
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    s->block_align = avctx->block_align;
127

    
128
    dsputil_init(&s->dsp, avctx);
129

    
130
    if (avctx->codec->id == CODEC_ID_WMAV1) {
131
        s->version = 1;
132
    } else {
133
        s->version = 2;
134
    }
135

    
136
    /* compute MDCT block size */
137
    s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0);
138

    
139
    s->frame_len = 1 << s->frame_len_bits;
140
    if (s->use_variable_block_len) {
141
        int nb_max, nb;
142
        nb = ((flags2 >> 3) & 3) + 1;
143
        if ((s->bit_rate / s->nb_channels) >= 32000)
144
            nb += 2;
145
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
146
        if (nb > nb_max)
147
            nb = nb_max;
148
        s->nb_block_sizes = nb + 1;
149
    } else {
150
        s->nb_block_sizes = 1;
151
    }
152

    
153
    /* init rate dependent parameters */
154
    s->use_noise_coding = 1;
155
    high_freq = s->sample_rate * 0.5;
156

    
157
    /* if version 2, then the rates are normalized */
158
    sample_rate1 = s->sample_rate;
159
    if (s->version == 2) {
160
        if (sample_rate1 >= 44100) {
161
            sample_rate1 = 44100;
162
        } else if (sample_rate1 >= 22050) {
163
            sample_rate1 = 22050;
164
        } else if (sample_rate1 >= 16000) {
165
            sample_rate1 = 16000;
166
        } else if (sample_rate1 >= 11025) {
167
            sample_rate1 = 11025;
168
        } else if (sample_rate1 >= 8000) {
169
            sample_rate1 = 8000;
170
        }
171
    }
172

    
173
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
174
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
175

    
176
    /* compute high frequency value and choose if noise coding should
177
       be activated */
178
    bps1 = bps;
179
    if (s->nb_channels == 2)
180
        bps1 = bps * 1.6;
181
    if (sample_rate1 == 44100) {
182
        if (bps1 >= 0.61) {
183
            s->use_noise_coding = 0;
184
        } else {
185
            high_freq = high_freq * 0.4;
186
        }
187
    } else if (sample_rate1 == 22050) {
188
        if (bps1 >= 1.16) {
189
            s->use_noise_coding = 0;
190
        } else if (bps1 >= 0.72) {
191
            high_freq = high_freq * 0.7;
192
        } else {
193
            high_freq = high_freq * 0.6;
194
        }
195
    } else if (sample_rate1 == 16000) {
196
        if (bps > 0.5) {
197
            high_freq = high_freq * 0.5;
198
        } else {
199
            high_freq = high_freq * 0.3;
200
        }
201
    } else if (sample_rate1 == 11025) {
202
        high_freq = high_freq * 0.7;
203
    } else if (sample_rate1 == 8000) {
204
        if (bps <= 0.625) {
205
            high_freq = high_freq * 0.5;
206
        } else if (bps > 0.75) {
207
            s->use_noise_coding = 0;
208
        } else {
209
            high_freq = high_freq * 0.65;
210
        }
211
    } else {
212
        if (bps >= 0.8) {
213
            high_freq = high_freq * 0.75;
214
        } else if (bps >= 0.6) {
215
            high_freq = high_freq * 0.6;
216
        } else {
217
            high_freq = high_freq * 0.5;
218
        }
219
    }
220
    av_dlog(s->avctx, "flags2=0x%x\n", flags2);
221
    av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
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            s->version, s->nb_channels, s->sample_rate, s->bit_rate,
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            s->block_align);
224
    av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
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            bps, bps1, high_freq, s->byte_offset_bits);
226
    av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
227
            s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
228

    
229
    /* compute the scale factor band sizes for each MDCT block size */
230
    {
231
        int a, b, pos, lpos, k, block_len, i, j, n;
232
        const uint8_t *table;
233

    
234
        if (s->version == 1) {
235
            s->coefs_start = 3;
236
        } else {
237
            s->coefs_start = 0;
238
        }
239
        for (k = 0; k < s->nb_block_sizes; k++) {
240
            block_len = s->frame_len >> k;
241

    
242
            if (s->version == 1) {
243
                lpos = 0;
244
                for (i = 0; i < 25; i++) {
245
                    a = ff_wma_critical_freqs[i];
246
                    b = s->sample_rate;
247
                    pos = ((block_len * 2 * a) + (b >> 1)) / b;
248
                    if (pos > block_len)
249
                        pos = block_len;
250
                    s->exponent_bands[0][i] = pos - lpos;
251
                    if (pos >= block_len) {
252
                        i++;
253
                        break;
254
                    }
255
                    lpos = pos;
256
                }
257
                s->exponent_sizes[0] = i;
258
            } else {
259
                /* hardcoded tables */
260
                table = NULL;
261
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
262
                if (a < 3) {
263
                    if (s->sample_rate >= 44100) {
264
                        table = exponent_band_44100[a];
265
                    } else if (s->sample_rate >= 32000) {
266
                        table = exponent_band_32000[a];
267
                    } else if (s->sample_rate >= 22050) {
268
                        table = exponent_band_22050[a];
269
                    }
270
                }
271
                if (table) {
272
                    n = *table++;
273
                    for (i = 0; i < n; i++)
274
                        s->exponent_bands[k][i] = table[i];
275
                    s->exponent_sizes[k] = n;
276
                } else {
277
                    j = 0;
278
                    lpos = 0;
279
                    for (i = 0; i < 25; i++) {
280
                        a = ff_wma_critical_freqs[i];
281
                        b = s->sample_rate;
282
                        pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
283
                        pos <<= 2;
284
                        if (pos > block_len)
285
                            pos = block_len;
286
                        if (pos > lpos)
287
                            s->exponent_bands[k][j++] = pos - lpos;
288
                        if (pos >= block_len)
289
                            break;
290
                        lpos = pos;
291
                    }
292
                    s->exponent_sizes[k] = j;
293
                }
294
            }
295

    
296
            /* max number of coefs */
297
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
298
            /* high freq computation */
299
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
300
                                          s->sample_rate + 0.5);
301
            n = s->exponent_sizes[k];
302
            j = 0;
303
            pos = 0;
304
            for (i = 0; i < n; i++) {
305
                int start, end;
306
                start = pos;
307
                pos += s->exponent_bands[k][i];
308
                end = pos;
309
                if (start < s->high_band_start[k])
310
                    start = s->high_band_start[k];
311
                if (end > s->coefs_end[k])
312
                    end = s->coefs_end[k];
313
                if (end > start)
314
                    s->exponent_high_bands[k][j++] = end - start;
315
            }
316
            s->exponent_high_sizes[k] = j;
317
#if 0
318
            tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
319
                    s->frame_len >> k,
320
                    s->coefs_end[k],
321
                    s->high_band_start[k],
322
                    s->exponent_high_sizes[k]);
323
            for (j = 0; j < s->exponent_high_sizes[k]; j++)
324
                tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
325
            tprintf(s->avctx, "\n");
326
#endif
327
        }
328
    }
329

    
330
#ifdef TRACE
331
    {
332
        int i, j;
333
        for (i = 0; i < s->nb_block_sizes; i++) {
334
            tprintf(s->avctx, "%5d: n=%2d:",
335
                    s->frame_len >> i,
336
                    s->exponent_sizes[i]);
337
            for (j = 0; j < s->exponent_sizes[i]; j++)
338
                tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
339
            tprintf(s->avctx, "\n");
340
        }
341
    }
342
#endif
343

    
344
    /* init MDCT windows : simple sinus window */
345
    for (i = 0; i < s->nb_block_sizes; i++) {
346
        ff_init_ff_sine_windows(s->frame_len_bits - i);
347
        s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
348
    }
349

    
350
    s->reset_block_lengths = 1;
351

    
352
    if (s->use_noise_coding) {
353

    
354
        /* init the noise generator */
355
        if (s->use_exp_vlc) {
356
            s->noise_mult = 0.02;
357
        } else {
358
            s->noise_mult = 0.04;
359
        }
360

    
361
#ifdef TRACE
362
        for (i = 0; i < NOISE_TAB_SIZE; i++)
363
            s->noise_table[i] = 1.0 * s->noise_mult;
364
#else
365
        {
366
            unsigned int seed;
367
            float norm;
368
            seed = 1;
369
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
370
            for (i = 0; i < NOISE_TAB_SIZE; i++) {
371
                seed = seed * 314159 + 1;
372
                s->noise_table[i] = (float)((int)seed) * norm;
373
            }
374
        }
375
#endif
376
    }
377

    
378
    /* choose the VLC tables for the coefficients */
379
    coef_vlc_table = 2;
380
    if (s->sample_rate >= 32000) {
381
        if (bps1 < 0.72) {
382
            coef_vlc_table = 0;
383
        } else if (bps1 < 1.16) {
384
            coef_vlc_table = 1;
385
        }
386
    }
387
    s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
388
    s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
389
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
390
                  s->coef_vlcs[0]);
391
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
392
                  s->coef_vlcs[1]);
393

    
394
    return 0;
395
}
396

    
397
int ff_wma_total_gain_to_bits(int total_gain)
398
{
399
         if (total_gain < 15) return 13;
400
    else if (total_gain < 32) return 12;
401
    else if (total_gain < 40) return 11;
402
    else if (total_gain < 45) return 10;
403
    else                      return  9;
404
}
405

    
406
int ff_wma_end(AVCodecContext *avctx)
407
{
408
    WMACodecContext *s = avctx->priv_data;
409
    int i;
410

    
411
    for (i = 0; i < s->nb_block_sizes; i++)
412
        ff_mdct_end(&s->mdct_ctx[i]);
413

    
414
    if (s->use_exp_vlc) {
415
        free_vlc(&s->exp_vlc);
416
    }
417
    if (s->use_noise_coding) {
418
        free_vlc(&s->hgain_vlc);
419
    }
420
    for (i = 0; i < 2; i++) {
421
        free_vlc(&s->coef_vlc[i]);
422
        av_free(s->run_table[i]);
423
        av_free(s->level_table[i]);
424
        av_free(s->int_table[i]);
425
    }
426

    
427
    return 0;
428
}
429

    
430
/**
431
 * Decode an uncompressed coefficient.
432
 * @param gb GetBitContext
433
 * @return the decoded coefficient
434
 */
435
unsigned int ff_wma_get_large_val(GetBitContext* gb)
436
{
437
    /** consumes up to 34 bits */
438
    int n_bits = 8;
439
    /** decode length */
440
    if (get_bits1(gb)) {
441
        n_bits += 8;
442
        if (get_bits1(gb)) {
443
            n_bits += 8;
444
            if (get_bits1(gb)) {
445
                n_bits += 7;
446
            }
447
        }
448
    }
449
    return get_bits_long(gb, n_bits);
450
}
451

    
452
/**
453
 * Decode run level compressed coefficients.
454
 * @param avctx codec context
455
 * @param gb bitstream reader context
456
 * @param vlc vlc table for get_vlc2
457
 * @param level_table level codes
458
 * @param run_table run codes
459
 * @param version 0 for wma1,2 1 for wmapro
460
 * @param ptr output buffer
461
 * @param offset offset in the output buffer
462
 * @param num_coefs number of input coefficents
463
 * @param block_len input buffer length (2^n)
464
 * @param frame_len_bits number of bits for escaped run codes
465
 * @param coef_nb_bits number of bits for escaped level codes
466
 * @return 0 on success, -1 otherwise
467
 */
468
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
469
                            VLC *vlc,
470
                            const float *level_table, const uint16_t *run_table,
471
                            int version, WMACoef *ptr, int offset,
472
                            int num_coefs, int block_len, int frame_len_bits,
473
                            int coef_nb_bits)
474
{
475
    int code, level, sign;
476
    const uint32_t *ilvl = (const uint32_t*)level_table;
477
    uint32_t *iptr = (uint32_t*)ptr;
478
    const unsigned int coef_mask = block_len - 1;
479
    for (; offset < num_coefs; offset++) {
480
        code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
481
        if (code > 1) {
482
            /** normal code */
483
            offset += run_table[code];
484
            sign = get_bits1(gb) - 1;
485
            iptr[offset & coef_mask] = ilvl[code] ^ sign<<31;
486
        } else if (code == 1) {
487
            /** EOB */
488
            break;
489
        } else {
490
            /** escape */
491
            if (!version) {
492
                level = get_bits(gb, coef_nb_bits);
493
                /** NOTE: this is rather suboptimal. reading
494
                    block_len_bits would be better */
495
                offset += get_bits(gb, frame_len_bits);
496
            } else {
497
                level = ff_wma_get_large_val(gb);
498
                /** escape decode */
499
                if (get_bits1(gb)) {
500
                    if (get_bits1(gb)) {
501
                        if (get_bits1(gb)) {
502
                            av_log(avctx,AV_LOG_ERROR,
503
                                "broken escape sequence\n");
504
                            return -1;
505
                        } else
506
                            offset += get_bits(gb, frame_len_bits) + 4;
507
                    } else
508
                        offset += get_bits(gb, 2) + 1;
509
                }
510
            }
511
            sign = get_bits1(gb) - 1;
512
            ptr[offset & coef_mask] = (level^sign) - sign;
513
        }
514
    }
515
    /** NOTE: EOB can be omitted */
516
    if (offset > num_coefs) {
517
        av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
518
        return -1;
519
    }
520

    
521
    return 0;
522
}
523