aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/wma.c
blob: c65281711a7f91e7bd57af7ab291568c5c91a260 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
/*
 * WMA compatible codec
 * Copyright (c) 2002-2007 The FFmpeg Project
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avcodec.h"
#include "sinewin.h"
#include "wma.h"
#include "wma_common.h"
#include "wmadata.h"

#undef NDEBUG
#include <assert.h>

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

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

    run_table   = av_malloc(n * sizeof(uint16_t));
    level_table = av_malloc(n * sizeof(uint16_t));
    flevel_table= av_malloc(n * sizeof(*flevel_table));
    int_table   = av_malloc(n * sizeof(uint16_t));
    i = 2;
    level = 1;
    k = 0;
    while (i < n) {
        int_table[k] = i;
        l = levels_table[k++];
        for (j = 0; j < l; j++) {
            run_table[i]   = j;
            level_table[i] = level;
            flevel_table[i]= level;
            i++;
        }
        level++;
    }
    *prun_table   = run_table;
    *plevel_table = flevel_table;
    *pint_table   = int_table;
    av_free(level_table);
}

int ff_wma_init(AVCodecContext *avctx, int flags2)
{
    WMACodecContext *s = avctx->priv_data;
    int i;
    float bps1, high_freq;
    volatile float bps;
    int sample_rate1;
    int coef_vlc_table;

    if (   avctx->sample_rate <= 0 || avctx->sample_rate > 50000
        || avctx->channels    <= 0 || avctx->channels    > 2
        || avctx->bit_rate    <= 0)
        return -1;

    s->sample_rate = avctx->sample_rate;
    s->nb_channels = avctx->channels;
    s->bit_rate    = avctx->bit_rate;
    s->block_align = avctx->block_align;

    ff_dsputil_init(&s->dsp, avctx);
    ff_fmt_convert_init(&s->fmt_conv, avctx);
    avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);

    if (avctx->codec->id == AV_CODEC_ID_WMAV1) {
        s->version = 1;
    } else {
        s->version = 2;
    }

    /* compute MDCT block size */
    s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0);
    s->next_block_len_bits = s->frame_len_bits;
    s->prev_block_len_bits = s->frame_len_bits;
    s->block_len_bits      = s->frame_len_bits;

    s->frame_len = 1 << s->frame_len_bits;
    if (s->use_variable_block_len) {
        int nb_max, nb;
        nb = ((flags2 >> 3) & 3) + 1;
        if ((s->bit_rate / s->nb_channels) >= 32000)
            nb += 2;
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
        if (nb > nb_max)
            nb = nb_max;
        s->nb_block_sizes = nb + 1;
    } else {
        s->nb_block_sizes = 1;
    }

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

    /* if version 2, then the rates are normalized */
    sample_rate1 = s->sample_rate;
    if (s->version == 2) {
        if (sample_rate1 >= 44100) {
            sample_rate1 = 44100;
        } else if (sample_rate1 >= 22050) {
            sample_rate1 = 22050;
        } else if (sample_rate1 >= 16000) {
            sample_rate1 = 16000;
        } else if (sample_rate1 >= 11025) {
            sample_rate1 = 11025;
        } else if (sample_rate1 >= 8000) {
            sample_rate1 = 8000;
        }
    }

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

    /* compute high frequency value and choose if noise coding should
       be activated */
    bps1 = bps;
    if (s->nb_channels == 2)
        bps1 = bps * 1.6;
    if (sample_rate1 == 44100) {
        if (bps1 >= 0.61) {
            s->use_noise_coding = 0;
        } else {
            high_freq = high_freq * 0.4;
        }
    } else if (sample_rate1 == 22050) {
        if (bps1 >= 1.16) {
            s->use_noise_coding = 0;
        } else if (bps1 >= 0.72) {
            high_freq = high_freq * 0.7;
        } else {
            high_freq = high_freq * 0.6;
        }
    } else if (sample_rate1 == 16000) {
        if (bps > 0.5) {
            high_freq = high_freq * 0.5;
        } else {
            high_freq = high_freq * 0.3;
        }
    } else if (sample_rate1 == 11025) {
        high_freq = high_freq * 0.7;
    } else if (sample_rate1 == 8000) {
        if (bps <= 0.625) {
            high_freq = high_freq * 0.5;
        } else if (bps > 0.75) {
            s->use_noise_coding = 0;
        } else {
            high_freq = high_freq * 0.65;
        }
    } else {
        if (bps >= 0.8) {
            high_freq = high_freq * 0.75;
        } else if (bps >= 0.6) {
            high_freq = high_freq * 0.6;
        } else {
            high_freq = high_freq * 0.5;
        }
    }
    av_dlog(s->avctx, "flags2=0x%x\n", flags2);
    av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
            s->version, s->nb_channels, s->sample_rate, s->bit_rate,
            s->block_align);
    av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
            bps, bps1, high_freq, s->byte_offset_bits);
    av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
            s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);

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

        if (s->version == 1) {
            s->coefs_start = 3;
        } else {
            s->coefs_start = 0;
        }
        for (k = 0; k < s->nb_block_sizes; k++) {
            block_len = s->frame_len >> k;

            if (s->version == 1) {
                lpos = 0;
                for (i = 0; i < 25; i++) {
                    a = ff_wma_critical_freqs[i];
                    b = s->sample_rate;
                    pos = ((block_len * 2 * a) + (b >> 1)) / b;
                    if (pos > block_len)
                        pos = block_len;
                    s->exponent_bands[0][i] = pos - lpos;
                    if (pos >= block_len) {
                        i++;
                        break;
                    }
                    lpos = pos;
                }
                s->exponent_sizes[0] = i;
            } else {
                /* hardcoded tables */
                table = NULL;
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
                if (a < 3) {
                    if (s->sample_rate >= 44100) {
                        table = exponent_band_44100[a];
                    } else if (s->sample_rate >= 32000) {
                        table = exponent_band_32000[a];
                    } else if (s->sample_rate >= 22050) {
                        table = exponent_band_22050[a];
                    }
                }
                if (table) {
                    n = *table++;
                    for (i = 0; i < n; i++)
                        s->exponent_bands[k][i] = table[i];
                    s->exponent_sizes[k] = n;
                } else {
                    j = 0;
                    lpos = 0;
                    for (i = 0; i < 25; i++) {
                        a = ff_wma_critical_freqs[i];
                        b = s->sample_rate;
                        pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
                        pos <<= 2;
                        if (pos > block_len)
                            pos = block_len;
                        if (pos > lpos)
                            s->exponent_bands[k][j++] = pos - lpos;
                        if (pos >= block_len)
                            break;
                        lpos = pos;
                    }
                    s->exponent_sizes[k] = j;
                }
            }

            /* max number of coefs */
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
            /* high freq computation */
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
                                          s->sample_rate + 0.5);
            n = s->exponent_sizes[k];
            j = 0;
            pos = 0;
            for (i = 0; i < n; i++) {
                int start, end;
                start = pos;
                pos += s->exponent_bands[k][i];
                end = pos;
                if (start < s->high_band_start[k])
                    start = s->high_band_start[k];
                if (end > s->coefs_end[k])
                    end = s->coefs_end[k];
                if (end > start)
                    s->exponent_high_bands[k][j++] = end - start;
            }
            s->exponent_high_sizes[k] = j;
#if 0
            tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
                    s->frame_len >> k,
                    s->coefs_end[k],
                    s->high_band_start[k],
                    s->exponent_high_sizes[k]);
            for (j = 0; j < s->exponent_high_sizes[k]; j++)
                tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
            tprintf(s->avctx, "\n");
#endif
        }
    }

#ifdef TRACE
    {
        int i, j;
        for (i = 0; i < s->nb_block_sizes; i++) {
            tprintf(s->avctx, "%5d: n=%2d:",
                    s->frame_len >> i,
                    s->exponent_sizes[i]);
            for (j = 0; j < s->exponent_sizes[i]; j++)
                tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
            tprintf(s->avctx, "\n");
        }
    }
#endif

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

    s->reset_block_lengths = 1;

    if (s->use_noise_coding) {

        /* init the noise generator */
        if (s->use_exp_vlc) {
            s->noise_mult = 0.02;
        } else {
            s->noise_mult = 0.04;
        }

#ifdef TRACE
        for (i = 0; i < NOISE_TAB_SIZE; i++)
            s->noise_table[i] = 1.0 * s->noise_mult;
#else
        {
            unsigned int seed;
            float norm;
            seed = 1;
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
            for (i = 0; i < NOISE_TAB_SIZE; i++) {
                seed = seed * 314159 + 1;
                s->noise_table[i] = (float)((int)seed) * norm;
            }
        }
#endif
    }

    /* choose the VLC tables for the coefficients */
    coef_vlc_table = 2;
    if (s->sample_rate >= 32000) {
        if (bps1 < 0.72) {
            coef_vlc_table = 0;
        } else if (bps1 < 1.16) {
            coef_vlc_table = 1;
        }
    }
    s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
    s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
                  s->coef_vlcs[0]);
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
                  s->coef_vlcs[1]);

    return 0;
}

int ff_wma_total_gain_to_bits(int total_gain)
{
         if (total_gain < 15) return 13;
    else if (total_gain < 32) return 12;
    else if (total_gain < 40) return 11;
    else if (total_gain < 45) return 10;
    else                      return  9;
}

int ff_wma_end(AVCodecContext *avctx)
{
    WMACodecContext *s = avctx->priv_data;
    int i;

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

    if (s->use_exp_vlc) {
        ff_free_vlc(&s->exp_vlc);
    }
    if (s->use_noise_coding) {
        ff_free_vlc(&s->hgain_vlc);
    }
    for (i = 0; i < 2; i++) {
        ff_free_vlc(&s->coef_vlc[i]);
        av_free(s->run_table[i]);
        av_free(s->level_table[i]);
        av_free(s->int_table[i]);
    }

    return 0;
}

/**
 * Decode an uncompressed coefficient.
 * @param gb GetBitContext
 * @return the decoded coefficient
 */
unsigned int ff_wma_get_large_val(GetBitContext* gb)
{
    /** consumes up to 34 bits */
    int n_bits = 8;
    /** decode length */
    if (get_bits1(gb)) {
        n_bits += 8;
        if (get_bits1(gb)) {
            n_bits += 8;
            if (get_bits1(gb)) {
                n_bits += 7;
            }
        }
    }
    return get_bits_long(gb, n_bits);
}

/**
 * Decode run level compressed coefficients.
 * @param avctx codec context
 * @param gb bitstream reader context
 * @param vlc vlc table for get_vlc2
 * @param level_table level codes
 * @param run_table run codes
 * @param version 0 for wma1,2 1 for wmapro
 * @param ptr output buffer
 * @param offset offset in the output buffer
 * @param num_coefs number of input coefficents
 * @param block_len input buffer length (2^n)
 * @param frame_len_bits number of bits for escaped run codes
 * @param coef_nb_bits number of bits for escaped level codes
 * @return 0 on success, -1 otherwise
 */
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
                            VLC *vlc,
                            const float *level_table, const uint16_t *run_table,
                            int version, WMACoef *ptr, int offset,
                            int num_coefs, int block_len, int frame_len_bits,
                            int coef_nb_bits)
{
    int code, level, sign;
    const uint32_t *ilvl = (const uint32_t*)level_table;
    uint32_t *iptr = (uint32_t*)ptr;
    const unsigned int coef_mask = block_len - 1;
    for (; offset < num_coefs; offset++) {
        code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
        if (code > 1) {
            /** normal code */
            offset += run_table[code];
            sign = get_bits1(gb) - 1;
            iptr[offset & coef_mask] = ilvl[code] ^ sign<<31;
        } else if (code == 1) {
            /** EOB */
            break;
        } else {
            /** escape */
            if (!version) {
                level = get_bits(gb, coef_nb_bits);
                /** NOTE: this is rather suboptimal. reading
                    block_len_bits would be better */
                offset += get_bits(gb, frame_len_bits);
            } else {
                level = ff_wma_get_large_val(gb);
                /** escape decode */
                if (get_bits1(gb)) {
                    if (get_bits1(gb)) {
                        if (get_bits1(gb)) {
                            av_log(avctx,AV_LOG_ERROR,
                                "broken escape sequence\n");
                            return -1;
                        } else
                            offset += get_bits(gb, frame_len_bits) + 4;
                    } else
                        offset += get_bits(gb, 2) + 1;
                }
            }
            sign = get_bits1(gb) - 1;
            ptr[offset & coef_mask] = (level^sign) - sign;
        }
    }
    /** NOTE: EOB can be omitted */
    if (offset > num_coefs) {
        av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
        return -1;
    }

    return 0;
}