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1
/*
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 * MPEG Audio decoder
3
 * Copyright (c) 2001, 2002 Fabrice Bellard.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
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 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
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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 mpegaudiodec.c
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 * MPEG Audio decoder.
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 */ 
24

    
25
//#define DEBUG
26
#include "avcodec.h"
27
#include "mpegaudio.h"
28

    
29
/*
30
 * TODO:
31
 *  - in low precision mode, use more 16 bit multiplies in synth filter
32
 *  - test lsf / mpeg25 extensively.
33
 */
34

    
35
/* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
36
   audio decoder */
37
#ifdef CONFIG_MPEGAUDIO_HP
38
#define USE_HIGHPRECISION
39
#endif
40

    
41
#ifdef USE_HIGHPRECISION
42
#define FRAC_BITS   23   /* fractional bits for sb_samples and dct */
43
#define WFRAC_BITS  16   /* fractional bits for window */
44
#else
45
#define FRAC_BITS   15   /* fractional bits for sb_samples and dct */
46
#define WFRAC_BITS  14   /* fractional bits for window */
47
#endif
48

    
49
#define FRAC_ONE    (1 << FRAC_BITS)
50

    
51
#define MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> FRAC_BITS)
52
#define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
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#define FIX(a)   ((int)((a) * FRAC_ONE))
54
/* WARNING: only correct for posititive numbers */
55
#define FIXR(a)   ((int)((a) * FRAC_ONE + 0.5))
56
#define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
57

    
58
#if FRAC_BITS <= 15
59
typedef int16_t MPA_INT;
60
#else
61
typedef int32_t MPA_INT;
62
#endif
63

    
64
/****************/
65

    
66
#define HEADER_SIZE 4
67
#define BACKSTEP_SIZE 512
68

    
69
typedef struct MPADecodeContext {
70
    uint8_t inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE];        /* input buffer */
71
    int inbuf_index;
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    uint8_t *inbuf_ptr, *inbuf;
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    int frame_size;
74
    int free_format_frame_size; /* frame size in case of free format
75
                                   (zero if currently unknown) */
76
    /* next header (used in free format parsing) */
77
    uint32_t free_format_next_header; 
78
    int error_protection;
79
    int layer;
80
    int sample_rate;
81
    int sample_rate_index; /* between 0 and 8 */
82
    int bit_rate;
83
    int old_frame_size;
84
    GetBitContext gb;
85
    int nb_channels;
86
    int mode;
87
    int mode_ext;
88
    int lsf;
89
    MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2];
90
    int synth_buf_offset[MPA_MAX_CHANNELS];
91
    int32_t sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT];
92
    int32_t mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
93
#ifdef DEBUG
94
    int frame_count;
95
#endif
96
} MPADecodeContext;
97

    
98
/* layer 3 "granule" */
99
typedef struct GranuleDef {
100
    uint8_t scfsi;
101
    int part2_3_length;
102
    int big_values;
103
    int global_gain;
104
    int scalefac_compress;
105
    uint8_t block_type;
106
    uint8_t switch_point;
107
    int table_select[3];
108
    int subblock_gain[3];
109
    uint8_t scalefac_scale;
110
    uint8_t count1table_select;
111
    int region_size[3]; /* number of huffman codes in each region */
112
    int preflag;
113
    int short_start, long_end; /* long/short band indexes */
114
    uint8_t scale_factors[40];
115
    int32_t sb_hybrid[SBLIMIT * 18]; /* 576 samples */
116
} GranuleDef;
117

    
118
#define MODE_EXT_MS_STEREO 2
119
#define MODE_EXT_I_STEREO  1
120

    
121
/* layer 3 huffman tables */
122
typedef struct HuffTable {
123
    int xsize;
124
    const uint8_t *bits;
125
    const uint16_t *codes;
126
} HuffTable;
127

    
128
#include "mpegaudiodectab.h"
129

    
130
/* vlc structure for decoding layer 3 huffman tables */
131
static VLC huff_vlc[16]; 
132
static uint8_t *huff_code_table[16];
133
static VLC huff_quad_vlc[2];
134
/* computed from band_size_long */
135
static uint16_t band_index_long[9][23];
136
/* XXX: free when all decoders are closed */
137
#define TABLE_4_3_SIZE (8191 + 16)
138
static int8_t  *table_4_3_exp;
139
#if FRAC_BITS <= 15
140
static uint16_t *table_4_3_value;
141
#else
142
static uint32_t *table_4_3_value;
143
#endif
144
/* intensity stereo coef table */
145
static int32_t is_table[2][16];
146
static int32_t is_table_lsf[2][2][16];
147
static int32_t csa_table[8][2];
148
static int32_t mdct_win[8][36];
149

    
150
/* lower 2 bits: modulo 3, higher bits: shift */
151
static uint16_t scale_factor_modshift[64];
152
/* [i][j]:  2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
153
static int32_t scale_factor_mult[15][3];
154
/* mult table for layer 2 group quantization */
155

    
156
#define SCALE_GEN(v) \
157
{ FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
158

    
159
static int32_t scale_factor_mult2[3][3] = {
160
    SCALE_GEN(4.0 / 3.0), /* 3 steps */
161
    SCALE_GEN(4.0 / 5.0), /* 5 steps */
162
    SCALE_GEN(4.0 / 9.0), /* 9 steps */
163
};
164

    
165
/* 2^(n/4) */
166
static uint32_t scale_factor_mult3[4] = {
167
    FIXR(1.0),
168
    FIXR(1.18920711500272106671),
169
    FIXR(1.41421356237309504880),
170
    FIXR(1.68179283050742908605),
171
};
172

    
173
static MPA_INT window[512];
174
    
175
/* layer 1 unscaling */
176
/* n = number of bits of the mantissa minus 1 */
177
static inline int l1_unscale(int n, int mant, int scale_factor)
178
{
179
    int shift, mod;
180
    int64_t val;
181

    
182
    shift = scale_factor_modshift[scale_factor];
183
    mod = shift & 3;
184
    shift >>= 2;
185
    val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
186
    shift += n;
187
    /* NOTE: at this point, 1 <= shift >= 21 + 15 */
188
    return (int)((val + (1LL << (shift - 1))) >> shift);
189
}
190

    
191
static inline int l2_unscale_group(int steps, int mant, int scale_factor)
192
{
193
    int shift, mod, val;
194

    
195
    shift = scale_factor_modshift[scale_factor];
196
    mod = shift & 3;
197
    shift >>= 2;
198

    
199
    val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
200
    /* NOTE: at this point, 0 <= shift <= 21 */
201
    if (shift > 0)
202
        val = (val + (1 << (shift - 1))) >> shift;
203
    return val;
204
}
205

    
206
/* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
207
static inline int l3_unscale(int value, int exponent)
208
{
209
#if FRAC_BITS <= 15    
210
    unsigned int m;
211
#else
212
    uint64_t m;
213
#endif
214
    int e;
215

    
216
    e = table_4_3_exp[value];
217
    e += (exponent >> 2);
218
    e = FRAC_BITS - e;
219
#if FRAC_BITS <= 15    
220
    if (e > 31)
221
        e = 31;
222
#endif
223
    m = table_4_3_value[value];
224
#if FRAC_BITS <= 15    
225
    m = (m * scale_factor_mult3[exponent & 3]);
226
    m = (m + (1 << (e-1))) >> e;
227
    return m;
228
#else
229
    m = MUL64(m, scale_factor_mult3[exponent & 3]);
230
    m = (m + (uint64_t_C(1) << (e-1))) >> e;
231
    return m;
232
#endif
233
}
234

    
235
/* all integer n^(4/3) computation code */
236
#define DEV_ORDER 13
237

    
238
#define POW_FRAC_BITS 24
239
#define POW_FRAC_ONE    (1 << POW_FRAC_BITS)
240
#define POW_FIX(a)   ((int)((a) * POW_FRAC_ONE))
241
#define POW_MULL(a,b) (((int64_t)(a) * (int64_t)(b)) >> POW_FRAC_BITS)
242

    
243
static int dev_4_3_coefs[DEV_ORDER];
244

    
245
static int pow_mult3[3] = {
246
    POW_FIX(1.0),
247
    POW_FIX(1.25992104989487316476),
248
    POW_FIX(1.58740105196819947474),
249
};
250

    
251
static void int_pow_init(void)
252
{
253
    int i, a;
254

    
255
    a = POW_FIX(1.0);
256
    for(i=0;i<DEV_ORDER;i++) {
257
        a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
258
        dev_4_3_coefs[i] = a;
259
    }
260
}
261

    
262
/* return the mantissa and the binary exponent */
263
static int int_pow(int i, int *exp_ptr)
264
{
265
    int e, er, eq, j;
266
    int a, a1;
267
    
268
    /* renormalize */
269
    a = i;
270
    e = POW_FRAC_BITS;
271
    while (a < (1 << (POW_FRAC_BITS - 1))) {
272
        a = a << 1;
273
        e--;
274
    }
275
    a -= (1 << POW_FRAC_BITS);
276
    a1 = 0;
277
    for(j = DEV_ORDER - 1; j >= 0; j--)
278
        a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
279
    a = (1 << POW_FRAC_BITS) + a1;
280
    /* exponent compute (exact) */
281
    e = e * 4;
282
    er = e % 3;
283
    eq = e / 3;
284
    a = POW_MULL(a, pow_mult3[er]);
285
    while (a >= 2 * POW_FRAC_ONE) {
286
        a = a >> 1;
287
        eq++;
288
    }
289
    /* convert to float */
290
    while (a < POW_FRAC_ONE) {
291
        a = a << 1;
292
        eq--;
293
    }
294
    /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
295
#if POW_FRAC_BITS > FRAC_BITS
296
    a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
297
    /* correct overflow */
298
    if (a >= 2 * (1 << FRAC_BITS)) {
299
        a = a >> 1;
300
        eq++;
301
    }
302
#endif
303
    *exp_ptr = eq;
304
    return a;
305
}
306

    
307
static int decode_init(AVCodecContext * avctx)
308
{
309
    MPADecodeContext *s = avctx->priv_data;
310
    static int init=0;
311
    int i, j, k;
312

    
313
    if(!init) {
314
        /* scale factors table for layer 1/2 */
315
        for(i=0;i<64;i++) {
316
            int shift, mod;
317
            /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
318
            shift = (i / 3);
319
            mod = i % 3;
320
            scale_factor_modshift[i] = mod | (shift << 2);
321
        }
322

    
323
        /* scale factor multiply for layer 1 */
324
        for(i=0;i<15;i++) {
325
            int n, norm;
326
            n = i + 2;
327
            norm = ((int64_t_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
328
            scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
329
            scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
330
            scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
331
            dprintf("%d: norm=%x s=%x %x %x\n",
332
                    i, norm, 
333
                    scale_factor_mult[i][0],
334
                    scale_factor_mult[i][1],
335
                    scale_factor_mult[i][2]);
336
        }
337
        
338
        /* window */
339
        /* max = 18760, max sum over all 16 coefs : 44736 */
340
        for(i=0;i<257;i++) {
341
            int v;
342
            v = mpa_enwindow[i];
343
#if WFRAC_BITS < 16
344
            v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
345
#endif
346
            window[i] = v;
347
            if ((i & 63) != 0)
348
                v = -v;
349
            if (i != 0)
350
                window[512 - i] = v;
351
        }
352
        
353
        /* huffman decode tables */
354
        huff_code_table[0] = NULL;
355
        for(i=1;i<16;i++) {
356
            const HuffTable *h = &mpa_huff_tables[i];
357
            int xsize, x, y;
358
            unsigned int n;
359
            uint8_t *code_table;
360

    
361
            xsize = h->xsize;
362
            n = xsize * xsize;
363
            /* XXX: fail test */
364
            init_vlc(&huff_vlc[i], 8, n, 
365
                     h->bits, 1, 1, h->codes, 2, 2);
366
            
367
            code_table = av_mallocz(n);
368
            j = 0;
369
            for(x=0;x<xsize;x++) {
370
                for(y=0;y<xsize;y++)
371
                    code_table[j++] = (x << 4) | y;
372
            }
373
            huff_code_table[i] = code_table;
374
        }
375
        for(i=0;i<2;i++) {
376
            init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16, 
377
                     mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1);
378
        }
379

    
380
        for(i=0;i<9;i++) {
381
            k = 0;
382
            for(j=0;j<22;j++) {
383
                band_index_long[i][j] = k;
384
                k += band_size_long[i][j];
385
            }
386
            band_index_long[i][22] = k;
387
        }
388

    
389
        /* compute n ^ (4/3) and store it in mantissa/exp format */
390
        if (!av_mallocz_static(&table_4_3_exp,
391
                               TABLE_4_3_SIZE * sizeof(table_4_3_exp[0])))
392
            return -1;
393
        if (!av_mallocz_static(&table_4_3_value,
394
                               TABLE_4_3_SIZE * sizeof(table_4_3_value[0])))
395
            return -1;
396
        
397
        int_pow_init();
398
        for(i=1;i<TABLE_4_3_SIZE;i++) {
399
            int e, m;
400
            m = int_pow(i, &e);
401
#if 0
402
            /* test code */
403
            {
404
                double f, fm;
405
                int e1, m1;
406
                f = pow((double)i, 4.0 / 3.0);
407
                fm = frexp(f, &e1);
408
                m1 = FIXR(2 * fm);
409
#if FRAC_BITS <= 15
410
                if ((unsigned short)m1 != m1) {
411
                    m1 = m1 >> 1;
412
                    e1++;
413
                }
414
#endif
415
                e1--;
416
                if (m != m1 || e != e1) {
417
                    printf("%4d: m=%x m1=%x e=%d e1=%d\n",
418
                           i, m, m1, e, e1);
419
                }
420
            }
421
#endif
422
            /* normalized to FRAC_BITS */
423
            table_4_3_value[i] = m;
424
            table_4_3_exp[i] = e;
425
        }
426
        
427
        for(i=0;i<7;i++) {
428
            float f;
429
            int v;
430
            if (i != 6) {
431
                f = tan((double)i * M_PI / 12.0);
432
                v = FIXR(f / (1.0 + f));
433
            } else {
434
                v = FIXR(1.0);
435
            }
436
            is_table[0][i] = v;
437
            is_table[1][6 - i] = v;
438
        }
439
        /* invalid values */
440
        for(i=7;i<16;i++)
441
            is_table[0][i] = is_table[1][i] = 0.0;
442

    
443
        for(i=0;i<16;i++) {
444
            double f;
445
            int e, k;
446

    
447
            for(j=0;j<2;j++) {
448
                e = -(j + 1) * ((i + 1) >> 1);
449
                f = pow(2.0, e / 4.0);
450
                k = i & 1;
451
                is_table_lsf[j][k ^ 1][i] = FIXR(f);
452
                is_table_lsf[j][k][i] = FIXR(1.0);
453
                dprintf("is_table_lsf %d %d: %x %x\n", 
454
                        i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
455
            }
456
        }
457

    
458
        for(i=0;i<8;i++) {
459
            float ci, cs, ca;
460
            ci = ci_table[i];
461
            cs = 1.0 / sqrt(1.0 + ci * ci);
462
            ca = cs * ci;
463
            csa_table[i][0] = FIX(cs);
464
            csa_table[i][1] = FIX(ca);
465
        }
466

    
467
        /* compute mdct windows */
468
        for(i=0;i<36;i++) {
469
            int v;
470
            v = FIXR(sin(M_PI * (i + 0.5) / 36.0));
471
            mdct_win[0][i] = v;
472
            mdct_win[1][i] = v;
473
            mdct_win[3][i] = v;
474
        }
475
        for(i=0;i<6;i++) {
476
            mdct_win[1][18 + i] = FIXR(1.0);
477
            mdct_win[1][24 + i] = FIXR(sin(M_PI * ((i + 6) + 0.5) / 12.0));
478
            mdct_win[1][30 + i] = FIXR(0.0);
479

    
480
            mdct_win[3][i] = FIXR(0.0);
481
            mdct_win[3][6 + i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
482
            mdct_win[3][12 + i] = FIXR(1.0);
483
        }
484

    
485
        for(i=0;i<12;i++)
486
            mdct_win[2][i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
487
        
488
        /* NOTE: we do frequency inversion adter the MDCT by changing
489
           the sign of the right window coefs */
490
        for(j=0;j<4;j++) {
491
            for(i=0;i<36;i+=2) {
492
                mdct_win[j + 4][i] = mdct_win[j][i];
493
                mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
494
            }
495
        }
496

    
497
#if defined(DEBUG)
498
        for(j=0;j<8;j++) {
499
            printf("win%d=\n", j);
500
            for(i=0;i<36;i++)
501
                printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
502
            printf("\n");
503
        }
504
#endif
505
        init = 1;
506
    }
507

    
508
    s->inbuf_index = 0;
509
    s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
510
    s->inbuf_ptr = s->inbuf;
511
#ifdef DEBUG
512
    s->frame_count = 0;
513
#endif
514
    return 0;
515
}
516

    
517
/* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */
518

    
519
/* cos(i*pi/64) */
520

    
521
#define COS0_0  FIXR(0.50060299823519630134)
522
#define COS0_1  FIXR(0.50547095989754365998)
523
#define COS0_2  FIXR(0.51544730992262454697)
524
#define COS0_3  FIXR(0.53104259108978417447)
525
#define COS0_4  FIXR(0.55310389603444452782)
526
#define COS0_5  FIXR(0.58293496820613387367)
527
#define COS0_6  FIXR(0.62250412303566481615)
528
#define COS0_7  FIXR(0.67480834145500574602)
529
#define COS0_8  FIXR(0.74453627100229844977)
530
#define COS0_9  FIXR(0.83934964541552703873)
531
#define COS0_10 FIXR(0.97256823786196069369)
532
#define COS0_11 FIXR(1.16943993343288495515)
533
#define COS0_12 FIXR(1.48416461631416627724)
534
#define COS0_13 FIXR(2.05778100995341155085)
535
#define COS0_14 FIXR(3.40760841846871878570)
536
#define COS0_15 FIXR(10.19000812354805681150)
537

    
538
#define COS1_0 FIXR(0.50241928618815570551)
539
#define COS1_1 FIXR(0.52249861493968888062)
540
#define COS1_2 FIXR(0.56694403481635770368)
541
#define COS1_3 FIXR(0.64682178335999012954)
542
#define COS1_4 FIXR(0.78815462345125022473)
543
#define COS1_5 FIXR(1.06067768599034747134)
544
#define COS1_6 FIXR(1.72244709823833392782)
545
#define COS1_7 FIXR(5.10114861868916385802)
546

    
547
#define COS2_0 FIXR(0.50979557910415916894)
548
#define COS2_1 FIXR(0.60134488693504528054)
549
#define COS2_2 FIXR(0.89997622313641570463)
550
#define COS2_3 FIXR(2.56291544774150617881)
551

    
552
#define COS3_0 FIXR(0.54119610014619698439)
553
#define COS3_1 FIXR(1.30656296487637652785)
554

    
555
#define COS4_0 FIXR(0.70710678118654752439)
556

    
557
/* butterfly operator */
558
#define BF(a, b, c)\
559
{\
560
    tmp0 = tab[a] + tab[b];\
561
    tmp1 = tab[a] - tab[b];\
562
    tab[a] = tmp0;\
563
    tab[b] = MULL(tmp1, c);\
564
}
565

    
566
#define BF1(a, b, c, d)\
567
{\
568
    BF(a, b, COS4_0);\
569
    BF(c, d, -COS4_0);\
570
    tab[c] += tab[d];\
571
}
572

    
573
#define BF2(a, b, c, d)\
574
{\
575
    BF(a, b, COS4_0);\
576
    BF(c, d, -COS4_0);\
577
    tab[c] += tab[d];\
578
    tab[a] += tab[c];\
579
    tab[c] += tab[b];\
580
    tab[b] += tab[d];\
581
}
582

    
583
#define ADD(a, b) tab[a] += tab[b]
584

    
585
/* DCT32 without 1/sqrt(2) coef zero scaling. */
586
static void dct32(int32_t *out, int32_t *tab)
587
{
588
    int tmp0, tmp1;
589

    
590
    /* pass 1 */
591
    BF(0, 31, COS0_0);
592
    BF(1, 30, COS0_1);
593
    BF(2, 29, COS0_2);
594
    BF(3, 28, COS0_3);
595
    BF(4, 27, COS0_4);
596
    BF(5, 26, COS0_5);
597
    BF(6, 25, COS0_6);
598
    BF(7, 24, COS0_7);
599
    BF(8, 23, COS0_8);
600
    BF(9, 22, COS0_9);
601
    BF(10, 21, COS0_10);
602
    BF(11, 20, COS0_11);
603
    BF(12, 19, COS0_12);
604
    BF(13, 18, COS0_13);
605
    BF(14, 17, COS0_14);
606
    BF(15, 16, COS0_15);
607

    
608
    /* pass 2 */
609
    BF(0, 15, COS1_0);
610
    BF(1, 14, COS1_1);
611
    BF(2, 13, COS1_2);
612
    BF(3, 12, COS1_3);
613
    BF(4, 11, COS1_4);
614
    BF(5, 10, COS1_5);
615
    BF(6,  9, COS1_6);
616
    BF(7,  8, COS1_7);
617
    
618
    BF(16, 31, -COS1_0);
619
    BF(17, 30, -COS1_1);
620
    BF(18, 29, -COS1_2);
621
    BF(19, 28, -COS1_3);
622
    BF(20, 27, -COS1_4);
623
    BF(21, 26, -COS1_5);
624
    BF(22, 25, -COS1_6);
625
    BF(23, 24, -COS1_7);
626
    
627
    /* pass 3 */
628
    BF(0, 7, COS2_0);
629
    BF(1, 6, COS2_1);
630
    BF(2, 5, COS2_2);
631
    BF(3, 4, COS2_3);
632
    
633
    BF(8, 15, -COS2_0);
634
    BF(9, 14, -COS2_1);
635
    BF(10, 13, -COS2_2);
636
    BF(11, 12, -COS2_3);
637
    
638
    BF(16, 23, COS2_0);
639
    BF(17, 22, COS2_1);
640
    BF(18, 21, COS2_2);
641
    BF(19, 20, COS2_3);
642
    
643
    BF(24, 31, -COS2_0);
644
    BF(25, 30, -COS2_1);
645
    BF(26, 29, -COS2_2);
646
    BF(27, 28, -COS2_3);
647

    
648
    /* pass 4 */
649
    BF(0, 3, COS3_0);
650
    BF(1, 2, COS3_1);
651
    
652
    BF(4, 7, -COS3_0);
653
    BF(5, 6, -COS3_1);
654
    
655
    BF(8, 11, COS3_0);
656
    BF(9, 10, COS3_1);
657
    
658
    BF(12, 15, -COS3_0);
659
    BF(13, 14, -COS3_1);
660
    
661
    BF(16, 19, COS3_0);
662
    BF(17, 18, COS3_1);
663
    
664
    BF(20, 23, -COS3_0);
665
    BF(21, 22, -COS3_1);
666
    
667
    BF(24, 27, COS3_0);
668
    BF(25, 26, COS3_1);
669
    
670
    BF(28, 31, -COS3_0);
671
    BF(29, 30, -COS3_1);
672
    
673
    /* pass 5 */
674
    BF1(0, 1, 2, 3);
675
    BF2(4, 5, 6, 7);
676
    BF1(8, 9, 10, 11);
677
    BF2(12, 13, 14, 15);
678
    BF1(16, 17, 18, 19);
679
    BF2(20, 21, 22, 23);
680
    BF1(24, 25, 26, 27);
681
    BF2(28, 29, 30, 31);
682
    
683
    /* pass 6 */
684
    
685
    ADD( 8, 12);
686
    ADD(12, 10);
687
    ADD(10, 14);
688
    ADD(14,  9);
689
    ADD( 9, 13);
690
    ADD(13, 11);
691
    ADD(11, 15);
692

    
693
    out[ 0] = tab[0];
694
    out[16] = tab[1];
695
    out[ 8] = tab[2];
696
    out[24] = tab[3];
697
    out[ 4] = tab[4];
698
    out[20] = tab[5];
699
    out[12] = tab[6];
700
    out[28] = tab[7];
701
    out[ 2] = tab[8];
702
    out[18] = tab[9];
703
    out[10] = tab[10];
704
    out[26] = tab[11];
705
    out[ 6] = tab[12];
706
    out[22] = tab[13];
707
    out[14] = tab[14];
708
    out[30] = tab[15];
709
    
710
    ADD(24, 28);
711
    ADD(28, 26);
712
    ADD(26, 30);
713
    ADD(30, 25);
714
    ADD(25, 29);
715
    ADD(29, 27);
716
    ADD(27, 31);
717

    
718
    out[ 1] = tab[16] + tab[24];
719
    out[17] = tab[17] + tab[25];
720
    out[ 9] = tab[18] + tab[26];
721
    out[25] = tab[19] + tab[27];
722
    out[ 5] = tab[20] + tab[28];
723
    out[21] = tab[21] + tab[29];
724
    out[13] = tab[22] + tab[30];
725
    out[29] = tab[23] + tab[31];
726
    out[ 3] = tab[24] + tab[20];
727
    out[19] = tab[25] + tab[21];
728
    out[11] = tab[26] + tab[22];
729
    out[27] = tab[27] + tab[23];
730
    out[ 7] = tab[28] + tab[18];
731
    out[23] = tab[29] + tab[19];
732
    out[15] = tab[30] + tab[17];
733
    out[31] = tab[31];
734
}
735

    
736
#define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
737

    
738
#if FRAC_BITS <= 15
739

    
740
#define OUT_SAMPLE(sum)\
741
{\
742
    int sum1;\
743
    sum1 = (sum + (1 << (OUT_SHIFT - 1))) >> OUT_SHIFT;\
744
    if (sum1 < -32768)\
745
        sum1 = -32768;\
746
    else if (sum1 > 32767)\
747
        sum1 = 32767;\
748
    *samples = sum1;\
749
    samples += incr;\
750
}
751

    
752
#define SUM8(off, op)                           \
753
{                                               \
754
    sum op w[0 * 64 + off] * p[0 * 64];\
755
    sum op w[1 * 64 + off] * p[1 * 64];\
756
    sum op w[2 * 64 + off] * p[2 * 64];\
757
    sum op w[3 * 64 + off] * p[3 * 64];\
758
    sum op w[4 * 64 + off] * p[4 * 64];\
759
    sum op w[5 * 64 + off] * p[5 * 64];\
760
    sum op w[6 * 64 + off] * p[6 * 64];\
761
    sum op w[7 * 64 + off] * p[7 * 64];\
762
}
763

    
764
#else
765

    
766
#define OUT_SAMPLE(sum)\
767
{\
768
    int sum1;\
769
    sum1 = (int)((sum + (int64_t_C(1) << (OUT_SHIFT - 1))) >> OUT_SHIFT);\
770
    if (sum1 < -32768)\
771
        sum1 = -32768;\
772
    else if (sum1 > 32767)\
773
        sum1 = 32767;\
774
    *samples = sum1;\
775
    samples += incr;\
776
}
777

    
778
#define SUM8(off, op)                           \
779
{                                               \
780
    sum op MUL64(w[0 * 64 + off], p[0 * 64]);\
781
    sum op MUL64(w[1 * 64 + off], p[1 * 64]);\
782
    sum op MUL64(w[2 * 64 + off], p[2 * 64]);\
783
    sum op MUL64(w[3 * 64 + off], p[3 * 64]);\
784
    sum op MUL64(w[4 * 64 + off], p[4 * 64]);\
785
    sum op MUL64(w[5 * 64 + off], p[5 * 64]);\
786
    sum op MUL64(w[6 * 64 + off], p[6 * 64]);\
787
    sum op MUL64(w[7 * 64 + off], p[7 * 64]);\
788
}
789

    
790
#endif
791

    
792
/* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
793
   32 samples. */
794
/* XXX: optimize by avoiding ring buffer usage */
795
static void synth_filter(MPADecodeContext *s1,
796
                         int ch, int16_t *samples, int incr, 
797
                         int32_t sb_samples[SBLIMIT])
798
{
799
    int32_t tmp[32];
800
    register MPA_INT *synth_buf, *p;
801
    register MPA_INT *w;
802
    int j, offset, v;
803
#if FRAC_BITS <= 15
804
    int sum;
805
#else
806
    int64_t sum;
807
#endif
808

    
809
    dct32(tmp, sb_samples);
810
    
811
    offset = s1->synth_buf_offset[ch];
812
    synth_buf = s1->synth_buf[ch] + offset;
813

    
814
    for(j=0;j<32;j++) {
815
        v = tmp[j];
816
#if FRAC_BITS <= 15
817
        /* NOTE: can cause a loss in precision if very high amplitude
818
           sound */
819
        if (v > 32767)
820
            v = 32767;
821
        else if (v < -32768)
822
            v = -32768;
823
#endif
824
        synth_buf[j] = v;
825
    }
826
    /* copy to avoid wrap */
827
    memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
828

    
829
    w = window;
830
    for(j=0;j<16;j++) {
831
        sum = 0;
832
        p = synth_buf + 16 + j;    /* 0-15  */
833
        SUM8(0, +=);
834
        p = synth_buf + 48 - j;    /* 32-47 */
835
        SUM8(32, -=);
836
        OUT_SAMPLE(sum);
837
        w++;
838
    }
839
    
840
    p = synth_buf + 32; /* 48 */
841
    sum = 0;
842
    SUM8(32, -=);
843
    OUT_SAMPLE(sum);
844
    w++;
845

    
846
    for(j=17;j<32;j++) {
847
        sum = 0;
848
        p = synth_buf + 48 - j; /* 17-31 */
849
        SUM8(0, -=);
850
        p = synth_buf + 16 + j; /* 49-63 */
851
        SUM8(32, -=);
852
        OUT_SAMPLE(sum);
853
        w++;
854
    }
855
    offset = (offset - 32) & 511;
856
    s1->synth_buf_offset[ch] = offset;
857
}
858

    
859
/* cos(pi*i/24) */
860
#define C1  FIXR(0.99144486137381041114)
861
#define C3  FIXR(0.92387953251128675612)
862
#define C5  FIXR(0.79335334029123516458)
863
#define C7  FIXR(0.60876142900872063941)
864
#define C9  FIXR(0.38268343236508977173)
865
#define C11 FIXR(0.13052619222005159154)
866

    
867
/* 12 points IMDCT. We compute it "by hand" by factorizing obvious
868
   cases. */
869
static void imdct12(int *out, int *in)
870
{
871
    int tmp;
872
    int64_t in1_3, in1_9, in4_3, in4_9;
873

    
874
    in1_3 = MUL64(in[1], C3);
875
    in1_9 = MUL64(in[1], C9);
876
    in4_3 = MUL64(in[4], C3);
877
    in4_9 = MUL64(in[4], C9);
878
    
879
    tmp = FRAC_RND(MUL64(in[0], C7) - in1_3 - MUL64(in[2], C11) + 
880
                   MUL64(in[3], C1) - in4_9 - MUL64(in[5], C5));
881
    out[0] = tmp;
882
    out[5] = -tmp;
883
    tmp = FRAC_RND(MUL64(in[0] - in[3], C9) - in1_3 + 
884
                   MUL64(in[2] + in[5], C3) - in4_9);
885
    out[1] = tmp;
886
    out[4] = -tmp;
887
    tmp = FRAC_RND(MUL64(in[0], C11) - in1_9 + MUL64(in[2], C7) -
888
                   MUL64(in[3], C5) + in4_3 - MUL64(in[5], C1));
889
    out[2] = tmp;
890
    out[3] = -tmp;
891
    tmp = FRAC_RND(MUL64(-in[0], C5) + in1_9 + MUL64(in[2], C1) + 
892
                   MUL64(in[3], C11) - in4_3 - MUL64(in[5], C7));
893
    out[6] = tmp;
894
    out[11] = tmp;
895
    tmp = FRAC_RND(MUL64(-in[0] + in[3], C3) - in1_9 + 
896
                   MUL64(in[2] + in[5], C9) + in4_3);
897
    out[7] = tmp;
898
    out[10] = tmp;
899
    tmp = FRAC_RND(-MUL64(in[0], C1) - in1_3 - MUL64(in[2], C5) -
900
                   MUL64(in[3], C7) - in4_9 - MUL64(in[5], C11));
901
    out[8] = tmp;
902
    out[9] = tmp;
903
}
904

    
905
#undef C1
906
#undef C3
907
#undef C5
908
#undef C7
909
#undef C9
910
#undef C11
911

    
912
/* cos(pi*i/18) */
913
#define C1 FIXR(0.98480775301220805936)
914
#define C2 FIXR(0.93969262078590838405)
915
#define C3 FIXR(0.86602540378443864676)
916
#define C4 FIXR(0.76604444311897803520)
917
#define C5 FIXR(0.64278760968653932632)
918
#define C6 FIXR(0.5)
919
#define C7 FIXR(0.34202014332566873304)
920
#define C8 FIXR(0.17364817766693034885)
921

    
922
/* 0.5 / cos(pi*(2*i+1)/36) */
923
static const int icos36[9] = {
924
    FIXR(0.50190991877167369479),
925
    FIXR(0.51763809020504152469),
926
    FIXR(0.55168895948124587824),
927
    FIXR(0.61038729438072803416),
928
    FIXR(0.70710678118654752439),
929
    FIXR(0.87172339781054900991),
930
    FIXR(1.18310079157624925896),
931
    FIXR(1.93185165257813657349),
932
    FIXR(5.73685662283492756461),
933
};
934

    
935
static const int icos72[18] = {
936
    /* 0.5 / cos(pi*(2*i+19)/72) */
937
    FIXR(0.74009361646113053152),
938
    FIXR(0.82133981585229078570),
939
    FIXR(0.93057949835178895673),
940
    FIXR(1.08284028510010010928),
941
    FIXR(1.30656296487637652785),
942
    FIXR(1.66275476171152078719),
943
    FIXR(2.31011315767264929558),
944
    FIXR(3.83064878777019433457),
945
    FIXR(11.46279281302667383546),
946

    
947
    /* 0.5 / cos(pi*(2*(i + 18) +19)/72) */
948
    FIXR(-0.67817085245462840086),
949
    FIXR(-0.63023620700513223342),
950
    FIXR(-0.59284452371708034528),
951
    FIXR(-0.56369097343317117734),
952
    FIXR(-0.54119610014619698439),
953
    FIXR(-0.52426456257040533932),
954
    FIXR(-0.51213975715725461845),
955
    FIXR(-0.50431448029007636036),
956
    FIXR(-0.50047634258165998492),
957
};
958

    
959
/* using Lee like decomposition followed by hand coded 9 points DCT */
960
static void imdct36(int *out, int *in)
961
{
962
    int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
963
    int tmp[18], *tmp1, *in1;
964
    int64_t in3_3, in6_6;
965

    
966
    for(i=17;i>=1;i--)
967
        in[i] += in[i-1];
968
    for(i=17;i>=3;i-=2)
969
        in[i] += in[i-2];
970

    
971
    for(j=0;j<2;j++) {
972
        tmp1 = tmp + j;
973
        in1 = in + j;
974

    
975
        in3_3 = MUL64(in1[2*3], C3);
976
        in6_6 = MUL64(in1[2*6], C6);
977

    
978
        tmp1[0] = FRAC_RND(MUL64(in1[2*1], C1) + in3_3 + 
979
                           MUL64(in1[2*5], C5) + MUL64(in1[2*7], C7));
980
        tmp1[2] = in1[2*0] + FRAC_RND(MUL64(in1[2*2], C2) + 
981
                                      MUL64(in1[2*4], C4) + in6_6 + 
982
                                      MUL64(in1[2*8], C8));
983
        tmp1[4] = FRAC_RND(MUL64(in1[2*1] - in1[2*5] - in1[2*7], C3));
984
        tmp1[6] = FRAC_RND(MUL64(in1[2*2] - in1[2*4] - in1[2*8], C6)) - 
985
            in1[2*6] + in1[2*0];
986
        tmp1[8] = FRAC_RND(MUL64(in1[2*1], C5) - in3_3 - 
987
                           MUL64(in1[2*5], C7) + MUL64(in1[2*7], C1));
988
        tmp1[10] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C8) - 
989
                                       MUL64(in1[2*4], C2) + in6_6 + 
990
                                       MUL64(in1[2*8], C4));
991
        tmp1[12] = FRAC_RND(MUL64(in1[2*1], C7) - in3_3 + 
992
                            MUL64(in1[2*5], C1) - 
993
                            MUL64(in1[2*7], C5));
994
        tmp1[14] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C4) + 
995
                                       MUL64(in1[2*4], C8) + in6_6 - 
996
                                       MUL64(in1[2*8], C2));
997
        tmp1[16] = in1[2*0] - in1[2*2] + in1[2*4] - in1[2*6] + in1[2*8];
998
    }
999

    
1000
    i = 0;
1001
    for(j=0;j<4;j++) {
1002
        t0 = tmp[i];
1003
        t1 = tmp[i + 2];
1004
        s0 = t1 + t0;
1005
        s2 = t1 - t0;
1006

    
1007
        t2 = tmp[i + 1];
1008
        t3 = tmp[i + 3];
1009
        s1 = MULL(t3 + t2, icos36[j]);
1010
        s3 = MULL(t3 - t2, icos36[8 - j]);
1011
        
1012
        t0 = MULL(s0 + s1, icos72[9 + 8 - j]);
1013
        t1 = MULL(s0 - s1, icos72[8 - j]);
1014
        out[18 + 9 + j] = t0;
1015
        out[18 + 8 - j] = t0;
1016
        out[9 + j] = -t1;
1017
        out[8 - j] = t1;
1018
        
1019
        t0 = MULL(s2 + s3, icos72[9+j]);
1020
        t1 = MULL(s2 - s3, icos72[j]);
1021
        out[18 + 9 + (8 - j)] = t0;
1022
        out[18 + j] = t0;
1023
        out[9 + (8 - j)] = -t1;
1024
        out[j] = t1;
1025
        i += 4;
1026
    }
1027

    
1028
    s0 = tmp[16];
1029
    s1 = MULL(tmp[17], icos36[4]);
1030
    t0 = MULL(s0 + s1, icos72[9 + 4]);
1031
    t1 = MULL(s0 - s1, icos72[4]);
1032
    out[18 + 9 + 4] = t0;
1033
    out[18 + 8 - 4] = t0;
1034
    out[9 + 4] = -t1;
1035
    out[8 - 4] = t1;
1036
}
1037

    
1038
/* fast header check for resync */
1039
static int check_header(uint32_t header)
1040
{
1041
    /* header */
1042
    if ((header & 0xffe00000) != 0xffe00000)
1043
        return -1;
1044
    /* layer check */
1045
    if (((header >> 17) & 3) == 0)
1046
        return -1;
1047
    /* bit rate */
1048
    if (((header >> 12) & 0xf) == 0xf)
1049
        return -1;
1050
    /* frequency */
1051
    if (((header >> 10) & 3) == 3)
1052
        return -1;
1053
    return 0;
1054
}
1055

    
1056
/* header + layer + bitrate + freq + lsf/mpeg25 */
1057
#define SAME_HEADER_MASK \
1058
   (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
1059

    
1060
/* header decoding. MUST check the header before because no
1061
   consistency check is done there. Return 1 if free format found and
1062
   that the frame size must be computed externally */
1063
static int decode_header(MPADecodeContext *s, uint32_t header)
1064
{
1065
    int sample_rate, frame_size, mpeg25, padding;
1066
    int sample_rate_index, bitrate_index;
1067
    if (header & (1<<20)) {
1068
        s->lsf = (header & (1<<19)) ? 0 : 1;
1069
        mpeg25 = 0;
1070
    } else {
1071
        s->lsf = 1;
1072
        mpeg25 = 1;
1073
    }
1074
    
1075
    s->layer = 4 - ((header >> 17) & 3);
1076
    /* extract frequency */
1077
    sample_rate_index = (header >> 10) & 3;
1078
    sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
1079
    sample_rate_index += 3 * (s->lsf + mpeg25);
1080
    s->sample_rate_index = sample_rate_index;
1081
    s->error_protection = ((header >> 16) & 1) ^ 1;
1082
    s->sample_rate = sample_rate;
1083

    
1084
    bitrate_index = (header >> 12) & 0xf;
1085
    padding = (header >> 9) & 1;
1086
    //extension = (header >> 8) & 1;
1087
    s->mode = (header >> 6) & 3;
1088
    s->mode_ext = (header >> 4) & 3;
1089
    //copyright = (header >> 3) & 1;
1090
    //original = (header >> 2) & 1;
1091
    //emphasis = header & 3;
1092

    
1093
    if (s->mode == MPA_MONO)
1094
        s->nb_channels = 1;
1095
    else
1096
        s->nb_channels = 2;
1097
    
1098
    if (bitrate_index != 0) {
1099
        frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
1100
        s->bit_rate = frame_size * 1000;
1101
        switch(s->layer) {
1102
        case 1:
1103
            frame_size = (frame_size * 12000) / sample_rate;
1104
            frame_size = (frame_size + padding) * 4;
1105
            break;
1106
        case 2:
1107
            frame_size = (frame_size * 144000) / sample_rate;
1108
            frame_size += padding;
1109
            break;
1110
        default:
1111
        case 3:
1112
            frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
1113
            frame_size += padding;
1114
            break;
1115
        }
1116
        s->frame_size = frame_size;
1117
    } else {
1118
        /* if no frame size computed, signal it */
1119
        if (!s->free_format_frame_size)
1120
            return 1;
1121
        /* free format: compute bitrate and real frame size from the
1122
           frame size we extracted by reading the bitstream */
1123
        s->frame_size = s->free_format_frame_size;
1124
        switch(s->layer) {
1125
        case 1:
1126
            s->frame_size += padding  * 4;
1127
            s->bit_rate = (s->frame_size * sample_rate) / 48000;
1128
            break;
1129
        case 2:
1130
            s->frame_size += padding;
1131
            s->bit_rate = (s->frame_size * sample_rate) / 144000;
1132
            break;
1133
        default:
1134
        case 3:
1135
            s->frame_size += padding;
1136
            s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
1137
            break;
1138
        }
1139
    }
1140
    
1141
#if defined(DEBUG)
1142
    printf("layer%d, %d Hz, %d kbits/s, ",
1143
           s->layer, s->sample_rate, s->bit_rate);
1144
    if (s->nb_channels == 2) {
1145
        if (s->layer == 3) {
1146
            if (s->mode_ext & MODE_EXT_MS_STEREO)
1147
                printf("ms-");
1148
            if (s->mode_ext & MODE_EXT_I_STEREO)
1149
                printf("i-");
1150
        }
1151
        printf("stereo");
1152
    } else {
1153
        printf("mono");
1154
    }
1155
    printf("\n");
1156
#endif
1157
    return 0;
1158
}
1159

    
1160
/* return the number of decoded frames */
1161
static int mp_decode_layer1(MPADecodeContext *s)
1162
{
1163
    int bound, i, v, n, ch, j, mant;
1164
    uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
1165
    uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
1166

    
1167
    if (s->mode == MPA_JSTEREO) 
1168
        bound = (s->mode_ext + 1) * 4;
1169
    else
1170
        bound = SBLIMIT;
1171

    
1172
    /* allocation bits */
1173
    for(i=0;i<bound;i++) {
1174
        for(ch=0;ch<s->nb_channels;ch++) {
1175
            allocation[ch][i] = get_bits(&s->gb, 4);
1176
        }
1177
    }
1178
    for(i=bound;i<SBLIMIT;i++) {
1179
        allocation[0][i] = get_bits(&s->gb, 4);
1180
    }
1181

    
1182
    /* scale factors */
1183
    for(i=0;i<bound;i++) {
1184
        for(ch=0;ch<s->nb_channels;ch++) {
1185
            if (allocation[ch][i])
1186
                scale_factors[ch][i] = get_bits(&s->gb, 6);
1187
        }
1188
    }
1189
    for(i=bound;i<SBLIMIT;i++) {
1190
        if (allocation[0][i]) {
1191
            scale_factors[0][i] = get_bits(&s->gb, 6);
1192
            scale_factors[1][i] = get_bits(&s->gb, 6);
1193
        }
1194
    }
1195
    
1196
    /* compute samples */
1197
    for(j=0;j<12;j++) {
1198
        for(i=0;i<bound;i++) {
1199
            for(ch=0;ch<s->nb_channels;ch++) {
1200
                n = allocation[ch][i];
1201
                if (n) {
1202
                    mant = get_bits(&s->gb, n + 1);
1203
                    v = l1_unscale(n, mant, scale_factors[ch][i]);
1204
                } else {
1205
                    v = 0;
1206
                }
1207
                s->sb_samples[ch][j][i] = v;
1208
            }
1209
        }
1210
        for(i=bound;i<SBLIMIT;i++) {
1211
            n = allocation[0][i];
1212
            if (n) {
1213
                mant = get_bits(&s->gb, n + 1);
1214
                v = l1_unscale(n, mant, scale_factors[0][i]);
1215
                s->sb_samples[0][j][i] = v;
1216
                v = l1_unscale(n, mant, scale_factors[1][i]);
1217
                s->sb_samples[1][j][i] = v;
1218
            } else {
1219
                s->sb_samples[0][j][i] = 0;
1220
                s->sb_samples[1][j][i] = 0;
1221
            }
1222
        }
1223
    }
1224
    return 12;
1225
}
1226

    
1227
/* bitrate is in kb/s */
1228
int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
1229
{
1230
    int ch_bitrate, table;
1231
    
1232
    ch_bitrate = bitrate / nb_channels;
1233
    if (!lsf) {
1234
        if ((freq == 48000 && ch_bitrate >= 56) ||
1235
            (ch_bitrate >= 56 && ch_bitrate <= 80)) 
1236
            table = 0;
1237
        else if (freq != 48000 && ch_bitrate >= 96) 
1238
            table = 1;
1239
        else if (freq != 32000 && ch_bitrate <= 48) 
1240
            table = 2;
1241
        else 
1242
            table = 3;
1243
    } else {
1244
        table = 4;
1245
    }
1246
    return table;
1247
}
1248

    
1249
static int mp_decode_layer2(MPADecodeContext *s)
1250
{
1251
    int sblimit; /* number of used subbands */
1252
    const unsigned char *alloc_table;
1253
    int table, bit_alloc_bits, i, j, ch, bound, v;
1254
    unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
1255
    unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
1256
    unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
1257
    int scale, qindex, bits, steps, k, l, m, b;
1258

    
1259
    /* select decoding table */
1260
    table = l2_select_table(s->bit_rate / 1000, s->nb_channels, 
1261
                            s->sample_rate, s->lsf);
1262
    sblimit = sblimit_table[table];
1263
    alloc_table = alloc_tables[table];
1264

    
1265
    if (s->mode == MPA_JSTEREO) 
1266
        bound = (s->mode_ext + 1) * 4;
1267
    else
1268
        bound = sblimit;
1269

    
1270
    dprintf("bound=%d sblimit=%d\n", bound, sblimit);
1271
    /* parse bit allocation */
1272
    j = 0;
1273
    for(i=0;i<bound;i++) {
1274
        bit_alloc_bits = alloc_table[j];
1275
        for(ch=0;ch<s->nb_channels;ch++) {
1276
            bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
1277
        }
1278
        j += 1 << bit_alloc_bits;
1279
    }
1280
    for(i=bound;i<sblimit;i++) {
1281
        bit_alloc_bits = alloc_table[j];
1282
        v = get_bits(&s->gb, bit_alloc_bits);
1283
        bit_alloc[0][i] = v;
1284
        bit_alloc[1][i] = v;
1285
        j += 1 << bit_alloc_bits;
1286
    }
1287

    
1288
#ifdef DEBUG
1289
    {
1290
        for(ch=0;ch<s->nb_channels;ch++) {
1291
            for(i=0;i<sblimit;i++)
1292
                printf(" %d", bit_alloc[ch][i]);
1293
            printf("\n");
1294
        }
1295
    }
1296
#endif
1297

    
1298
    /* scale codes */
1299
    for(i=0;i<sblimit;i++) {
1300
        for(ch=0;ch<s->nb_channels;ch++) {
1301
            if (bit_alloc[ch][i]) 
1302
                scale_code[ch][i] = get_bits(&s->gb, 2);
1303
        }
1304
    }
1305
    
1306
    /* scale factors */
1307
    for(i=0;i<sblimit;i++) {
1308
        for(ch=0;ch<s->nb_channels;ch++) {
1309
            if (bit_alloc[ch][i]) {
1310
                sf = scale_factors[ch][i];
1311
                switch(scale_code[ch][i]) {
1312
                default:
1313
                case 0:
1314
                    sf[0] = get_bits(&s->gb, 6);
1315
                    sf[1] = get_bits(&s->gb, 6);
1316
                    sf[2] = get_bits(&s->gb, 6);
1317
                    break;
1318
                case 2:
1319
                    sf[0] = get_bits(&s->gb, 6);
1320
                    sf[1] = sf[0];
1321
                    sf[2] = sf[0];
1322
                    break;
1323
                case 1:
1324
                    sf[0] = get_bits(&s->gb, 6);
1325
                    sf[2] = get_bits(&s->gb, 6);
1326
                    sf[1] = sf[0];
1327
                    break;
1328
                case 3:
1329
                    sf[0] = get_bits(&s->gb, 6);
1330
                    sf[2] = get_bits(&s->gb, 6);
1331
                    sf[1] = sf[2];
1332
                    break;
1333
                }
1334
            }
1335
        }
1336
    }
1337

    
1338
#ifdef DEBUG
1339
    for(ch=0;ch<s->nb_channels;ch++) {
1340
        for(i=0;i<sblimit;i++) {
1341
            if (bit_alloc[ch][i]) {
1342
                sf = scale_factors[ch][i];
1343
                printf(" %d %d %d", sf[0], sf[1], sf[2]);
1344
            } else {
1345
                printf(" -");
1346
            }
1347
        }
1348
        printf("\n");
1349
    }
1350
#endif
1351

    
1352
    /* samples */
1353
    for(k=0;k<3;k++) {
1354
        for(l=0;l<12;l+=3) {
1355
            j = 0;
1356
            for(i=0;i<bound;i++) {
1357
                bit_alloc_bits = alloc_table[j];
1358
                for(ch=0;ch<s->nb_channels;ch++) {
1359
                    b = bit_alloc[ch][i];
1360
                    if (b) {
1361
                        scale = scale_factors[ch][i][k];
1362
                        qindex = alloc_table[j+b];
1363
                        bits = quant_bits[qindex];
1364
                        if (bits < 0) {
1365
                            /* 3 values at the same time */
1366
                            v = get_bits(&s->gb, -bits);
1367
                            steps = quant_steps[qindex];
1368
                            s->sb_samples[ch][k * 12 + l + 0][i] = 
1369
                                l2_unscale_group(steps, v % steps, scale);
1370
                            v = v / steps;
1371
                            s->sb_samples[ch][k * 12 + l + 1][i] = 
1372
                                l2_unscale_group(steps, v % steps, scale);
1373
                            v = v / steps;
1374
                            s->sb_samples[ch][k * 12 + l + 2][i] = 
1375
                                l2_unscale_group(steps, v, scale);
1376
                        } else {
1377
                            for(m=0;m<3;m++) {
1378
                                v = get_bits(&s->gb, bits);
1379
                                v = l1_unscale(bits - 1, v, scale);
1380
                                s->sb_samples[ch][k * 12 + l + m][i] = v;
1381
                            }
1382
                        }
1383
                    } else {
1384
                        s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1385
                        s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1386
                        s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1387
                    }
1388
                }
1389
                /* next subband in alloc table */
1390
                j += 1 << bit_alloc_bits; 
1391
            }
1392
            /* XXX: find a way to avoid this duplication of code */
1393
            for(i=bound;i<sblimit;i++) {
1394
                bit_alloc_bits = alloc_table[j];
1395
                b = bit_alloc[0][i];
1396
                if (b) {
1397
                    int mant, scale0, scale1;
1398
                    scale0 = scale_factors[0][i][k];
1399
                    scale1 = scale_factors[1][i][k];
1400
                    qindex = alloc_table[j+b];
1401
                    bits = quant_bits[qindex];
1402
                    if (bits < 0) {
1403
                        /* 3 values at the same time */
1404
                        v = get_bits(&s->gb, -bits);
1405
                        steps = quant_steps[qindex];
1406
                        mant = v % steps;
1407
                        v = v / steps;
1408
                        s->sb_samples[0][k * 12 + l + 0][i] = 
1409
                            l2_unscale_group(steps, mant, scale0);
1410
                        s->sb_samples[1][k * 12 + l + 0][i] = 
1411
                            l2_unscale_group(steps, mant, scale1);
1412
                        mant = v % steps;
1413
                        v = v / steps;
1414
                        s->sb_samples[0][k * 12 + l + 1][i] = 
1415
                            l2_unscale_group(steps, mant, scale0);
1416
                        s->sb_samples[1][k * 12 + l + 1][i] = 
1417
                            l2_unscale_group(steps, mant, scale1);
1418
                        s->sb_samples[0][k * 12 + l + 2][i] = 
1419
                            l2_unscale_group(steps, v, scale0);
1420
                        s->sb_samples[1][k * 12 + l + 2][i] = 
1421
                            l2_unscale_group(steps, v, scale1);
1422
                    } else {
1423
                        for(m=0;m<3;m++) {
1424
                            mant = get_bits(&s->gb, bits);
1425
                            s->sb_samples[0][k * 12 + l + m][i] = 
1426
                                l1_unscale(bits - 1, mant, scale0);
1427
                            s->sb_samples[1][k * 12 + l + m][i] = 
1428
                                l1_unscale(bits - 1, mant, scale1);
1429
                        }
1430
                    }
1431
                } else {
1432
                    s->sb_samples[0][k * 12 + l + 0][i] = 0;
1433
                    s->sb_samples[0][k * 12 + l + 1][i] = 0;
1434
                    s->sb_samples[0][k * 12 + l + 2][i] = 0;
1435
                    s->sb_samples[1][k * 12 + l + 0][i] = 0;
1436
                    s->sb_samples[1][k * 12 + l + 1][i] = 0;
1437
                    s->sb_samples[1][k * 12 + l + 2][i] = 0;
1438
                }
1439
                /* next subband in alloc table */
1440
                j += 1 << bit_alloc_bits; 
1441
            }
1442
            /* fill remaining samples to zero */
1443
            for(i=sblimit;i<SBLIMIT;i++) {
1444
                for(ch=0;ch<s->nb_channels;ch++) {
1445
                    s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1446
                    s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1447
                    s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1448
                }
1449
            }
1450
        }
1451
    }
1452
    return 3 * 12;
1453
}
1454

    
1455
/*
1456
 * Seek back in the stream for backstep bytes (at most 511 bytes)
1457
 */
1458
static void seek_to_maindata(MPADecodeContext *s, unsigned int backstep)
1459
{
1460
    uint8_t *ptr;
1461

    
1462
    /* compute current position in stream */
1463
    ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
1464

    
1465
    /* copy old data before current one */
1466
    ptr -= backstep;
1467
    memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] + 
1468
           BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
1469
    /* init get bits again */
1470
    init_get_bits(&s->gb, ptr, (s->frame_size + backstep)*8);
1471

    
1472
    /* prepare next buffer */
1473
    s->inbuf_index ^= 1;
1474
    s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
1475
    s->old_frame_size = s->frame_size;
1476
}
1477

    
1478
static inline void lsf_sf_expand(int *slen,
1479
                                 int sf, int n1, int n2, int n3)
1480
{
1481
    if (n3) {
1482
        slen[3] = sf % n3;
1483
        sf /= n3;
1484
    } else {
1485
        slen[3] = 0;
1486
    }
1487
    if (n2) {
1488
        slen[2] = sf % n2;
1489
        sf /= n2;
1490
    } else {
1491
        slen[2] = 0;
1492
    }
1493
    slen[1] = sf % n1;
1494
    sf /= n1;
1495
    slen[0] = sf;
1496
}
1497

    
1498
static void exponents_from_scale_factors(MPADecodeContext *s, 
1499
                                         GranuleDef *g,
1500
                                         int16_t *exponents)
1501
{
1502
    const uint8_t *bstab, *pretab;
1503
    int len, i, j, k, l, v0, shift, gain, gains[3];
1504
    int16_t *exp_ptr;
1505

    
1506
    exp_ptr = exponents;
1507
    gain = g->global_gain - 210;
1508
    shift = g->scalefac_scale + 1;
1509

    
1510
    bstab = band_size_long[s->sample_rate_index];
1511
    pretab = mpa_pretab[g->preflag];
1512
    for(i=0;i<g->long_end;i++) {
1513
        v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
1514
        len = bstab[i];
1515
        for(j=len;j>0;j--)
1516
            *exp_ptr++ = v0;
1517
    }
1518

    
1519
    if (g->short_start < 13) {
1520
        bstab = band_size_short[s->sample_rate_index];
1521
        gains[0] = gain - (g->subblock_gain[0] << 3);
1522
        gains[1] = gain - (g->subblock_gain[1] << 3);
1523
        gains[2] = gain - (g->subblock_gain[2] << 3);
1524
        k = g->long_end;
1525
        for(i=g->short_start;i<13;i++) {
1526
            len = bstab[i];
1527
            for(l=0;l<3;l++) {
1528
                v0 = gains[l] - (g->scale_factors[k++] << shift);
1529
                for(j=len;j>0;j--)
1530
                *exp_ptr++ = v0;
1531
            }
1532
        }
1533
    }
1534
}
1535

    
1536
/* handle n = 0 too */
1537
static inline int get_bitsz(GetBitContext *s, int n)
1538
{
1539
    if (n == 0)
1540
        return 0;
1541
    else
1542
        return get_bits(s, n);
1543
}
1544

    
1545
static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
1546
                          int16_t *exponents, int end_pos)
1547
{
1548
    int s_index;
1549
    int linbits, code, x, y, l, v, i, j, k, pos;
1550
    GetBitContext last_gb;
1551
    VLC *vlc;
1552
    uint8_t *code_table;
1553

    
1554
    /* low frequencies (called big values) */
1555
    s_index = 0;
1556
    for(i=0;i<3;i++) {
1557
        j = g->region_size[i];
1558
        if (j == 0)
1559
            continue;
1560
        /* select vlc table */
1561
        k = g->table_select[i];
1562
        l = mpa_huff_data[k][0];
1563
        linbits = mpa_huff_data[k][1];
1564
        vlc = &huff_vlc[l];
1565
        code_table = huff_code_table[l];
1566

    
1567
        /* read huffcode and compute each couple */
1568
        for(;j>0;j--) {
1569
            if (get_bits_count(&s->gb) >= end_pos)
1570
                break;
1571
            if (code_table) {
1572
                code = get_vlc(&s->gb, vlc);
1573
                if (code < 0)
1574
                    return -1;
1575
                y = code_table[code];
1576
                x = y >> 4;
1577
                y = y & 0x0f;
1578
            } else {
1579
                x = 0;
1580
                y = 0;
1581
            }
1582
            dprintf("region=%d n=%d x=%d y=%d exp=%d\n", 
1583
                    i, g->region_size[i] - j, x, y, exponents[s_index]);
1584
            if (x) {
1585
                if (x == 15)
1586
                    x += get_bitsz(&s->gb, linbits);
1587
                v = l3_unscale(x, exponents[s_index]);
1588
                if (get_bits1(&s->gb))
1589
                    v = -v;
1590
            } else {
1591
                v = 0;
1592
            }
1593
            g->sb_hybrid[s_index++] = v;
1594
            if (y) {
1595
                if (y == 15)
1596
                    y += get_bitsz(&s->gb, linbits);
1597
                v = l3_unscale(y, exponents[s_index]);
1598
                if (get_bits1(&s->gb))
1599
                    v = -v;
1600
            } else {
1601
                v = 0;
1602
            }
1603
            g->sb_hybrid[s_index++] = v;
1604
        }
1605
    }
1606
            
1607
    /* high frequencies */
1608
    vlc = &huff_quad_vlc[g->count1table_select];
1609
    last_gb.buffer = NULL;
1610
    while (s_index <= 572) {
1611
        pos = get_bits_count(&s->gb);
1612
        if (pos >= end_pos) {
1613
            if (pos > end_pos && last_gb.buffer != NULL) {
1614
                /* some encoders generate an incorrect size for this
1615
                   part. We must go back into the data */
1616
                s_index -= 4;
1617
                s->gb = last_gb;
1618
            }
1619
            break;
1620
        }
1621
        last_gb= s->gb;
1622

    
1623
        code = get_vlc(&s->gb, vlc);
1624
        dprintf("t=%d code=%d\n", g->count1table_select, code);
1625
        if (code < 0)
1626
            return -1;
1627
        for(i=0;i<4;i++) {
1628
            if (code & (8 >> i)) {
1629
                /* non zero value. Could use a hand coded function for
1630
                   'one' value */
1631
                v = l3_unscale(1, exponents[s_index]);
1632
                if(get_bits1(&s->gb))
1633
                    v = -v;
1634
            } else {
1635
                v = 0;
1636
            }
1637
            g->sb_hybrid[s_index++] = v;
1638
        }
1639
    }
1640
    while (s_index < 576)
1641
        g->sb_hybrid[s_index++] = 0;
1642
    return 0;
1643
}
1644

    
1645
/* Reorder short blocks from bitstream order to interleaved order. It
1646
   would be faster to do it in parsing, but the code would be far more
1647
   complicated */
1648
static void reorder_block(MPADecodeContext *s, GranuleDef *g)
1649
{
1650
    int i, j, k, len;
1651
    int32_t *ptr, *dst, *ptr1;
1652
    int32_t tmp[576];
1653

    
1654
    if (g->block_type != 2)
1655
        return;
1656

    
1657
    if (g->switch_point) {
1658
        if (s->sample_rate_index != 8) {
1659
            ptr = g->sb_hybrid + 36;
1660
        } else {
1661
            ptr = g->sb_hybrid + 48;
1662
        }
1663
    } else {
1664
        ptr = g->sb_hybrid;
1665
    }
1666
    
1667
    for(i=g->short_start;i<13;i++) {
1668
        len = band_size_short[s->sample_rate_index][i];
1669
        ptr1 = ptr;
1670
        for(k=0;k<3;k++) {
1671
            dst = tmp + k;
1672
            for(j=len;j>0;j--) {
1673
                *dst = *ptr++;
1674
                dst += 3;
1675
            }
1676
        }
1677
        memcpy(ptr1, tmp, len * 3 * sizeof(int32_t));
1678
    }
1679
}
1680

    
1681
#define ISQRT2 FIXR(0.70710678118654752440)
1682

    
1683
static void compute_stereo(MPADecodeContext *s,
1684
                           GranuleDef *g0, GranuleDef *g1)
1685
{
1686
    int i, j, k, l;
1687
    int32_t v1, v2;
1688
    int sf_max, tmp0, tmp1, sf, len, non_zero_found;
1689
    int32_t (*is_tab)[16];
1690
    int32_t *tab0, *tab1;
1691
    int non_zero_found_short[3];
1692

    
1693
    /* intensity stereo */
1694
    if (s->mode_ext & MODE_EXT_I_STEREO) {
1695
        if (!s->lsf) {
1696
            is_tab = is_table;
1697
            sf_max = 7;
1698
        } else {
1699
            is_tab = is_table_lsf[g1->scalefac_compress & 1];
1700
            sf_max = 16;
1701
        }
1702
            
1703
        tab0 = g0->sb_hybrid + 576;
1704
        tab1 = g1->sb_hybrid + 576;
1705

    
1706
        non_zero_found_short[0] = 0;
1707
        non_zero_found_short[1] = 0;
1708
        non_zero_found_short[2] = 0;
1709
        k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1710
        for(i = 12;i >= g1->short_start;i--) {
1711
            /* for last band, use previous scale factor */
1712
            if (i != 11)
1713
                k -= 3;
1714
            len = band_size_short[s->sample_rate_index][i];
1715
            for(l=2;l>=0;l--) {
1716
                tab0 -= len;
1717
                tab1 -= len;
1718
                if (!non_zero_found_short[l]) {
1719
                    /* test if non zero band. if so, stop doing i-stereo */
1720
                    for(j=0;j<len;j++) {
1721
                        if (tab1[j] != 0) {
1722
                            non_zero_found_short[l] = 1;
1723
                            goto found1;
1724
                        }
1725
                    }
1726
                    sf = g1->scale_factors[k + l];
1727
                    if (sf >= sf_max)
1728
                        goto found1;
1729

    
1730
                    v1 = is_tab[0][sf];
1731
                    v2 = is_tab[1][sf];
1732
                    for(j=0;j<len;j++) {
1733
                        tmp0 = tab0[j];
1734
                        tab0[j] = MULL(tmp0, v1);
1735
                        tab1[j] = MULL(tmp0, v2);
1736
                    }
1737
                } else {
1738
                found1:
1739
                    if (s->mode_ext & MODE_EXT_MS_STEREO) {
1740
                        /* lower part of the spectrum : do ms stereo
1741
                           if enabled */
1742
                        for(j=0;j<len;j++) {
1743
                            tmp0 = tab0[j];
1744
                            tmp1 = tab1[j];
1745
                            tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1746
                            tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1747
                        }
1748
                    }
1749
                }
1750
            }
1751
        }
1752

    
1753
        non_zero_found = non_zero_found_short[0] | 
1754
            non_zero_found_short[1] | 
1755
            non_zero_found_short[2];
1756

    
1757
        for(i = g1->long_end - 1;i >= 0;i--) {
1758
            len = band_size_long[s->sample_rate_index][i];
1759
            tab0 -= len;
1760
            tab1 -= len;
1761
            /* test if non zero band. if so, stop doing i-stereo */
1762
            if (!non_zero_found) {
1763
                for(j=0;j<len;j++) {
1764
                    if (tab1[j] != 0) {
1765
                        non_zero_found = 1;
1766
                        goto found2;
1767
                    }
1768
                }
1769
                /* for last band, use previous scale factor */
1770
                k = (i == 21) ? 20 : i;
1771
                sf = g1->scale_factors[k];
1772
                if (sf >= sf_max)
1773
                    goto found2;
1774
                v1 = is_tab[0][sf];
1775
                v2 = is_tab[1][sf];
1776
                for(j=0;j<len;j++) {
1777
                    tmp0 = tab0[j];
1778
                    tab0[j] = MULL(tmp0, v1);
1779
                    tab1[j] = MULL(tmp0, v2);
1780
                }
1781
            } else {
1782
            found2:
1783
                if (s->mode_ext & MODE_EXT_MS_STEREO) {
1784
                    /* lower part of the spectrum : do ms stereo
1785
                       if enabled */
1786
                    for(j=0;j<len;j++) {
1787
                        tmp0 = tab0[j];
1788
                        tmp1 = tab1[j];
1789
                        tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1790
                        tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1791
                    }
1792
                }
1793
            }
1794
        }
1795
    } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1796
        /* ms stereo ONLY */
1797
        /* NOTE: the 1/sqrt(2) normalization factor is included in the
1798
           global gain */
1799
        tab0 = g0->sb_hybrid;
1800
        tab1 = g1->sb_hybrid;
1801
        for(i=0;i<576;i++) {
1802
            tmp0 = tab0[i];
1803
            tmp1 = tab1[i];
1804
            tab0[i] = tmp0 + tmp1;
1805
            tab1[i] = tmp0 - tmp1;
1806
        }
1807
    }
1808
}
1809

    
1810
static void compute_antialias(MPADecodeContext *s,
1811
                              GranuleDef *g)
1812
{
1813
    int32_t *ptr, *p0, *p1, *csa;
1814
    int n, tmp0, tmp1, i, j;
1815

    
1816
    /* we antialias only "long" bands */
1817
    if (g->block_type == 2) {
1818
        if (!g->switch_point)
1819
            return;
1820
        /* XXX: check this for 8000Hz case */
1821
        n = 1;
1822
    } else {
1823
        n = SBLIMIT - 1;
1824
    }
1825
    
1826
    ptr = g->sb_hybrid + 18;
1827
    for(i = n;i > 0;i--) {
1828
        p0 = ptr - 1;
1829
        p1 = ptr;
1830
        csa = &csa_table[0][0];
1831
        for(j=0;j<8;j++) {
1832
            tmp0 = *p0;
1833
            tmp1 = *p1;
1834
            *p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
1835
            *p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
1836
            p0--;
1837
            p1++;
1838
            csa += 2;
1839
        }
1840
        ptr += 18;
1841
    }
1842
}
1843

    
1844
static void compute_imdct(MPADecodeContext *s,
1845
                          GranuleDef *g, 
1846
                          int32_t *sb_samples,
1847
                          int32_t *mdct_buf)
1848
{
1849
    int32_t *ptr, *win, *win1, *buf, *buf2, *out_ptr, *ptr1;
1850
    int32_t in[6];
1851
    int32_t out[36];
1852
    int32_t out2[12];
1853
    int i, j, k, mdct_long_end, v, sblimit;
1854

    
1855
    /* find last non zero block */
1856
    ptr = g->sb_hybrid + 576;
1857
    ptr1 = g->sb_hybrid + 2 * 18;
1858
    while (ptr >= ptr1) {
1859
        ptr -= 6;
1860
        v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
1861
        if (v != 0)
1862
            break;
1863
    }
1864
    sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1865

    
1866
    if (g->block_type == 2) {
1867
        /* XXX: check for 8000 Hz */
1868
        if (g->switch_point)
1869
            mdct_long_end = 2;
1870
        else
1871
            mdct_long_end = 0;
1872
    } else {
1873
        mdct_long_end = sblimit;
1874
    }
1875

    
1876
    buf = mdct_buf;
1877
    ptr = g->sb_hybrid;
1878
    for(j=0;j<mdct_long_end;j++) {
1879
        imdct36(out, ptr);
1880
        /* apply window & overlap with previous buffer */
1881
        out_ptr = sb_samples + j;
1882
        /* select window */
1883
        if (g->switch_point && j < 2)
1884
            win1 = mdct_win[0];
1885
        else
1886
            win1 = mdct_win[g->block_type];
1887
        /* select frequency inversion */
1888
        win = win1 + ((4 * 36) & -(j & 1));
1889
        for(i=0;i<18;i++) {
1890
            *out_ptr = MULL(out[i], win[i]) + buf[i];
1891
            buf[i] = MULL(out[i + 18], win[i + 18]);
1892
            out_ptr += SBLIMIT;
1893
        }
1894
        ptr += 18;
1895
        buf += 18;
1896
    }
1897
    for(j=mdct_long_end;j<sblimit;j++) {
1898
        for(i=0;i<6;i++) {
1899
            out[i] = 0;
1900
            out[6 + i] = 0;
1901
            out[30+i] = 0;
1902
        }
1903
        /* select frequency inversion */
1904
        win = mdct_win[2] + ((4 * 36) & -(j & 1));
1905
        buf2 = out + 6;
1906
        for(k=0;k<3;k++) {
1907
            /* reorder input for short mdct */
1908
            ptr1 = ptr + k;
1909
            for(i=0;i<6;i++) {
1910
                in[i] = *ptr1;
1911
                ptr1 += 3;
1912
            }
1913
            imdct12(out2, in);
1914
            /* apply 12 point window and do small overlap */
1915
            for(i=0;i<6;i++) {
1916
                buf2[i] = MULL(out2[i], win[i]) + buf2[i];
1917
                buf2[i + 6] = MULL(out2[i + 6], win[i + 6]);
1918
            }
1919
            buf2 += 6;
1920
        }
1921
        /* overlap */
1922
        out_ptr = sb_samples + j;
1923
        for(i=0;i<18;i++) {
1924
            *out_ptr = out[i] + buf[i];
1925
            buf[i] = out[i + 18];
1926
            out_ptr += SBLIMIT;
1927
        }
1928
        ptr += 18;
1929
        buf += 18;
1930
    }
1931
    /* zero bands */
1932
    for(j=sblimit;j<SBLIMIT;j++) {
1933
        /* overlap */
1934
        out_ptr = sb_samples + j;
1935
        for(i=0;i<18;i++) {
1936
            *out_ptr = buf[i];
1937
            buf[i] = 0;
1938
            out_ptr += SBLIMIT;
1939
        }
1940
        buf += 18;
1941
    }
1942
}
1943

    
1944
#if defined(DEBUG)
1945
void sample_dump(int fnum, int32_t *tab, int n)
1946
{
1947
    static FILE *files[16], *f;
1948
    char buf[512];
1949
    int i;
1950
    int32_t v;
1951
    
1952
    f = files[fnum];
1953
    if (!f) {
1954
        sprintf(buf, "/tmp/out%d.%s.pcm", 
1955
                fnum, 
1956
#ifdef USE_HIGHPRECISION
1957
                "hp"
1958
#else
1959
                "lp"
1960
#endif
1961
                );
1962
        f = fopen(buf, "w");
1963
        if (!f)
1964
            return;
1965
        files[fnum] = f;
1966
    }
1967
    
1968
    if (fnum == 0) {
1969
        static int pos = 0;
1970
        printf("pos=%d\n", pos);
1971
        for(i=0;i<n;i++) {
1972
            printf(" %0.4f", (double)tab[i] / FRAC_ONE);
1973
            if ((i % 18) == 17)
1974
                printf("\n");
1975
        }
1976
        pos += n;
1977
    }
1978
    for(i=0;i<n;i++) {
1979
        /* normalize to 23 frac bits */
1980
        v = tab[i] << (23 - FRAC_BITS);
1981
        fwrite(&v, 1, sizeof(int32_t), f);
1982
    }
1983
}
1984
#endif
1985

    
1986

    
1987
/* main layer3 decoding function */
1988
static int mp_decode_layer3(MPADecodeContext *s)
1989
{
1990
    int nb_granules, main_data_begin, private_bits;
1991
    int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
1992
    GranuleDef granules[2][2], *g;
1993
    int16_t exponents[576];
1994

    
1995
    /* read side info */
1996
    if (s->lsf) {
1997
        main_data_begin = get_bits(&s->gb, 8);
1998
        if (s->nb_channels == 2)
1999
            private_bits = get_bits(&s->gb, 2);
2000
        else
2001
            private_bits = get_bits(&s->gb, 1);
2002
        nb_granules = 1;
2003
    } else {
2004
        main_data_begin = get_bits(&s->gb, 9);
2005
        if (s->nb_channels == 2)
2006
            private_bits = get_bits(&s->gb, 3);
2007
        else
2008
            private_bits = get_bits(&s->gb, 5);
2009
        nb_granules = 2;
2010
        for(ch=0;ch<s->nb_channels;ch++) {
2011
            granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
2012
            granules[ch][1].scfsi = get_bits(&s->gb, 4);
2013
        }
2014
    }
2015
    
2016
    for(gr=0;gr<nb_granules;gr++) {
2017
        for(ch=0;ch<s->nb_channels;ch++) {
2018
            dprintf("gr=%d ch=%d: side_info\n", gr, ch);
2019
            g = &granules[ch][gr];
2020
            g->part2_3_length = get_bits(&s->gb, 12);
2021
            g->big_values = get_bits(&s->gb, 9);
2022
            g->global_gain = get_bits(&s->gb, 8);
2023
            /* if MS stereo only is selected, we precompute the
2024
               1/sqrt(2) renormalization factor */
2025
            if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) == 
2026
                MODE_EXT_MS_STEREO)
2027
                g->global_gain -= 2;
2028
            if (s->lsf)
2029
                g->scalefac_compress = get_bits(&s->gb, 9);
2030
            else
2031
                g->scalefac_compress = get_bits(&s->gb, 4);
2032
            blocksplit_flag = get_bits(&s->gb, 1);
2033
            if (blocksplit_flag) {
2034
                g->block_type = get_bits(&s->gb, 2);
2035
                if (g->block_type == 0)
2036
                    return -1;
2037
                g->switch_point = get_bits(&s->gb, 1);
2038
                for(i=0;i<2;i++)
2039
                    g->table_select[i] = get_bits(&s->gb, 5);
2040
                for(i=0;i<3;i++) 
2041
                    g->subblock_gain[i] = get_bits(&s->gb, 3);
2042
                /* compute huffman coded region sizes */
2043
                if (g->block_type == 2)
2044
                    g->region_size[0] = (36 / 2);
2045
                else {
2046
                    if (s->sample_rate_index <= 2) 
2047
                        g->region_size[0] = (36 / 2);
2048
                    else if (s->sample_rate_index != 8) 
2049
                        g->region_size[0] = (54 / 2);
2050
                    else
2051
                        g->region_size[0] = (108 / 2);
2052
                }
2053
                g->region_size[1] = (576 / 2);
2054
            } else {
2055
                int region_address1, region_address2, l;
2056
                g->block_type = 0;
2057
                g->switch_point = 0;
2058
                for(i=0;i<3;i++)
2059
                    g->table_select[i] = get_bits(&s->gb, 5);
2060
                /* compute huffman coded region sizes */
2061
                region_address1 = get_bits(&s->gb, 4);
2062
                region_address2 = get_bits(&s->gb, 3);
2063
                dprintf("region1=%d region2=%d\n", 
2064
                        region_address1, region_address2);
2065
                g->region_size[0] = 
2066
                    band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
2067
                l = region_address1 + region_address2 + 2;
2068
                /* should not overflow */
2069
                if (l > 22)
2070
                    l = 22;
2071
                g->region_size[1] = 
2072
                    band_index_long[s->sample_rate_index][l] >> 1;
2073
            }
2074
            /* convert region offsets to region sizes and truncate
2075
               size to big_values */
2076
            g->region_size[2] = (576 / 2);
2077
            j = 0;
2078
            for(i=0;i<3;i++) {
2079
                k = g->region_size[i];
2080
                if (k > g->big_values)
2081
                    k = g->big_values;
2082
                g->region_size[i] = k - j;
2083
                j = k;
2084
            }
2085

    
2086
            /* compute band indexes */
2087
            if (g->block_type == 2) {
2088
                if (g->switch_point) {
2089
                    /* if switched mode, we handle the 36 first samples as
2090
                       long blocks.  For 8000Hz, we handle the 48 first
2091
                       exponents as long blocks (XXX: check this!) */
2092
                    if (s->sample_rate_index <= 2)
2093
                        g->long_end = 8;
2094
                    else if (s->sample_rate_index != 8)
2095
                        g->long_end = 6;
2096
                    else
2097
                        g->long_end = 4; /* 8000 Hz */
2098
                    
2099
                    if (s->sample_rate_index != 8)
2100
                        g->short_start = 3;
2101
                    else
2102
                        g->short_start = 2; 
2103
                } else {
2104
                    g->long_end = 0;
2105
                    g->short_start = 0;
2106
                }
2107
            } else {
2108
                g->short_start = 13;
2109
                g->long_end = 22;
2110
            }
2111
            
2112
            g->preflag = 0;
2113
            if (!s->lsf)
2114
                g->preflag = get_bits(&s->gb, 1);
2115
            g->scalefac_scale = get_bits(&s->gb, 1);
2116
            g->count1table_select = get_bits(&s->gb, 1);
2117
            dprintf("block_type=%d switch_point=%d\n",
2118
                    g->block_type, g->switch_point);
2119
        }
2120
    }
2121

    
2122
    /* now we get bits from the main_data_begin offset */
2123
    dprintf("seekback: %d\n", main_data_begin);
2124
    seek_to_maindata(s, main_data_begin);
2125

    
2126
    for(gr=0;gr<nb_granules;gr++) {
2127
        for(ch=0;ch<s->nb_channels;ch++) {
2128
            g = &granules[ch][gr];
2129
            
2130
            bits_pos = get_bits_count(&s->gb);
2131
            
2132
            if (!s->lsf) {
2133
                uint8_t *sc;
2134
                int slen, slen1, slen2;
2135

    
2136
                /* MPEG1 scale factors */
2137
                slen1 = slen_table[0][g->scalefac_compress];
2138
                slen2 = slen_table[1][g->scalefac_compress];
2139
                dprintf("slen1=%d slen2=%d\n", slen1, slen2);
2140
                if (g->block_type == 2) {
2141
                    n = g->switch_point ? 17 : 18;
2142
                    j = 0;
2143
                    for(i=0;i<n;i++)
2144
                        g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
2145
                    for(i=0;i<18;i++)
2146
                        g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
2147
                    for(i=0;i<3;i++)
2148
                        g->scale_factors[j++] = 0;
2149
                } else {
2150
                    sc = granules[ch][0].scale_factors;
2151
                    j = 0;
2152
                    for(k=0;k<4;k++) {
2153
                        n = (k == 0 ? 6 : 5);
2154
                        if ((g->scfsi & (0x8 >> k)) == 0) {
2155
                            slen = (k < 2) ? slen1 : slen2;
2156
                            for(i=0;i<n;i++)
2157
                                g->scale_factors[j++] = get_bitsz(&s->gb, slen);
2158
                        } else {
2159
                            /* simply copy from last granule */
2160
                            for(i=0;i<n;i++) {
2161
                                g->scale_factors[j] = sc[j];
2162
                                j++;
2163
                            }
2164
                        }
2165
                    }
2166
                    g->scale_factors[j++] = 0;
2167
                }
2168
#if defined(DEBUG)
2169
                {
2170
                    printf("scfsi=%x gr=%d ch=%d scale_factors:\n", 
2171
                           g->scfsi, gr, ch);
2172
                    for(i=0;i<j;i++)
2173
                        printf(" %d", g->scale_factors[i]);
2174
                    printf("\n");
2175
                }
2176
#endif
2177
            } else {
2178
                int tindex, tindex2, slen[4], sl, sf;
2179

    
2180
                /* LSF scale factors */
2181
                if (g->block_type == 2) {
2182
                    tindex = g->switch_point ? 2 : 1;
2183
                } else {
2184
                    tindex = 0;
2185
                }
2186
                sf = g->scalefac_compress;
2187
                if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
2188
                    /* intensity stereo case */
2189
                    sf >>= 1;
2190
                    if (sf < 180) {
2191
                        lsf_sf_expand(slen, sf, 6, 6, 0);
2192
                        tindex2 = 3;
2193
                    } else if (sf < 244) {
2194
                        lsf_sf_expand(slen, sf - 180, 4, 4, 0);
2195
                        tindex2 = 4;
2196
                    } else {
2197
                        lsf_sf_expand(slen, sf - 244, 3, 0, 0);
2198
                        tindex2 = 5;
2199
                    }
2200
                } else {
2201
                    /* normal case */
2202
                    if (sf < 400) {
2203
                        lsf_sf_expand(slen, sf, 5, 4, 4);
2204
                        tindex2 = 0;
2205
                    } else if (sf < 500) {
2206
                        lsf_sf_expand(slen, sf - 400, 5, 4, 0);
2207
                        tindex2 = 1;
2208
                    } else {
2209
                        lsf_sf_expand(slen, sf - 500, 3, 0, 0);
2210
                        tindex2 = 2;
2211
                        g->preflag = 1;
2212
                    }
2213
                }
2214

    
2215
                j = 0;
2216
                for(k=0;k<4;k++) {
2217
                    n = lsf_nsf_table[tindex2][tindex][k];
2218
                    sl = slen[k];
2219
                    for(i=0;i<n;i++)
2220
                        g->scale_factors[j++] = get_bitsz(&s->gb, sl);
2221
                }
2222
                /* XXX: should compute exact size */
2223
                for(;j<40;j++)
2224
                    g->scale_factors[j] = 0;
2225
#if defined(DEBUG)
2226
                {
2227
                    printf("gr=%d ch=%d scale_factors:\n", 
2228
                           gr, ch);
2229
                    for(i=0;i<40;i++)
2230
                        printf(" %d", g->scale_factors[i]);
2231
                    printf("\n");
2232
                }
2233
#endif
2234
            }
2235

    
2236
            exponents_from_scale_factors(s, g, exponents);
2237

    
2238
            /* read Huffman coded residue */
2239
            if (huffman_decode(s, g, exponents,
2240
                               bits_pos + g->part2_3_length) < 0)
2241
                return -1;
2242
#if defined(DEBUG)
2243
            sample_dump(0, g->sb_hybrid, 576);
2244
#endif
2245

    
2246
            /* skip extension bits */
2247
            bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
2248
            if (bits_left < 0) {
2249
                dprintf("bits_left=%d\n", bits_left);
2250
                return -1;
2251
            }
2252
            while (bits_left >= 16) {
2253
                skip_bits(&s->gb, 16);
2254
                bits_left -= 16;
2255
            }
2256
            if (bits_left > 0)
2257
                skip_bits(&s->gb, bits_left);
2258
        } /* ch */
2259

    
2260
        if (s->nb_channels == 2)
2261
            compute_stereo(s, &granules[0][gr], &granules[1][gr]);
2262

    
2263
        for(ch=0;ch<s->nb_channels;ch++) {
2264
            g = &granules[ch][gr];
2265

    
2266
            reorder_block(s, g);
2267
#if defined(DEBUG)
2268
            sample_dump(0, g->sb_hybrid, 576);
2269
#endif
2270
            compute_antialias(s, g);
2271
#if defined(DEBUG)
2272
            sample_dump(1, g->sb_hybrid, 576);
2273
#endif
2274
            compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]); 
2275
#if defined(DEBUG)
2276
            sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
2277
#endif
2278
        }
2279
    } /* gr */
2280
    return nb_granules * 18;
2281
}
2282

    
2283
static int mp_decode_frame(MPADecodeContext *s, 
2284
                           short *samples)
2285
{
2286
    int i, nb_frames, ch;
2287
    short *samples_ptr;
2288

    
2289
    init_get_bits(&s->gb, s->inbuf + HEADER_SIZE, 
2290
                  (s->inbuf_ptr - s->inbuf - HEADER_SIZE)*8);
2291
    
2292
    /* skip error protection field */
2293
    if (s->error_protection)
2294
        get_bits(&s->gb, 16);
2295

    
2296
    dprintf("frame %d:\n", s->frame_count);
2297
    switch(s->layer) {
2298
    case 1:
2299
        nb_frames = mp_decode_layer1(s);
2300
        break;
2301
    case 2:
2302
        nb_frames = mp_decode_layer2(s);
2303
        break;
2304
    case 3:
2305
    default:
2306
        nb_frames = mp_decode_layer3(s);
2307
        break;
2308
    }
2309
#if defined(DEBUG)
2310
    for(i=0;i<nb_frames;i++) {
2311
        for(ch=0;ch<s->nb_channels;ch++) {
2312
            int j;
2313
            printf("%d-%d:", i, ch);
2314
            for(j=0;j<SBLIMIT;j++)
2315
                printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
2316
            printf("\n");
2317
        }
2318
    }
2319
#endif
2320
    /* apply the synthesis filter */
2321
    for(ch=0;ch<s->nb_channels;ch++) {
2322
        samples_ptr = samples + ch;
2323
        for(i=0;i<nb_frames;i++) {
2324
            synth_filter(s, ch, samples_ptr, s->nb_channels,
2325
                         s->sb_samples[ch][i]);
2326
            samples_ptr += 32 * s->nb_channels;
2327
        }
2328
    }
2329
#ifdef DEBUG
2330
    s->frame_count++;        
2331
#endif
2332
    return nb_frames * 32 * sizeof(short) * s->nb_channels;
2333
}
2334

    
2335
static int decode_frame(AVCodecContext * avctx,
2336
                        void *data, int *data_size,
2337
                        uint8_t * buf, int buf_size)
2338
{
2339
    MPADecodeContext *s = avctx->priv_data;
2340
    uint32_t header;
2341
    uint8_t *buf_ptr;
2342
    int len, out_size;
2343
    short *out_samples = data;
2344

    
2345
    *data_size = 0;
2346
    buf_ptr = buf;
2347
    while (buf_size > 0) {
2348
        len = s->inbuf_ptr - s->inbuf;
2349
        if (s->frame_size == 0) {
2350
            /* special case for next header for first frame in free
2351
               format case (XXX: find a simpler method) */
2352
            if (s->free_format_next_header != 0) {
2353
                s->inbuf[0] = s->free_format_next_header >> 24;
2354
                s->inbuf[1] = s->free_format_next_header >> 16;
2355
                s->inbuf[2] = s->free_format_next_header >> 8;
2356
                s->inbuf[3] = s->free_format_next_header;
2357
                s->inbuf_ptr = s->inbuf + 4;
2358
                s->free_format_next_header = 0;
2359
                goto got_header;
2360
            }
2361
            /* no header seen : find one. We need at least HEADER_SIZE
2362
               bytes to parse it */
2363
            len = HEADER_SIZE - len;
2364
            if (len > buf_size)
2365
                len = buf_size;
2366
            if (len > 0) {
2367
                memcpy(s->inbuf_ptr, buf_ptr, len);
2368
                buf_ptr += len;
2369
                buf_size -= len;
2370
                s->inbuf_ptr += len;
2371
            }
2372
            if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {
2373
            got_header:
2374
                header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2375
                    (s->inbuf[2] << 8) | s->inbuf[3];
2376

    
2377
                if (check_header(header) < 0) {
2378
                    /* no sync found : move by one byte (inefficient, but simple!) */
2379
                    memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2380
                    s->inbuf_ptr--;
2381
                    dprintf("skip %x\n", header);
2382
                    /* reset free format frame size to give a chance
2383
                       to get a new bitrate */
2384
                    s->free_format_frame_size = 0;
2385
                } else {
2386
                    if (decode_header(s, header) == 1) {
2387
                        /* free format: prepare to compute frame size */
2388
                        s->frame_size = -1;
2389
                    }
2390
                    /* update codec info */
2391
                    avctx->sample_rate = s->sample_rate;
2392
                    avctx->channels = s->nb_channels;
2393
                    avctx->bit_rate = s->bit_rate;
2394
                    avctx->frame_size = s->frame_size;
2395
                }
2396
            }
2397
        } else if (s->frame_size == -1) {
2398
            /* free format : find next sync to compute frame size */
2399
            len = MPA_MAX_CODED_FRAME_SIZE - len;
2400
            if (len > buf_size)
2401
                len = buf_size;
2402
            if (len == 0) {
2403
                /* frame too long: resync */
2404
                s->frame_size = 0;
2405
                memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2406
                s->inbuf_ptr--;
2407
            } else {
2408
                uint8_t *p, *pend;
2409
                uint32_t header1;
2410
                int padding;
2411

    
2412
                memcpy(s->inbuf_ptr, buf_ptr, len);
2413
                /* check for header */
2414
                p = s->inbuf_ptr - 3;
2415
                pend = s->inbuf_ptr + len - 4;
2416
                while (p <= pend) {
2417
                    header = (p[0] << 24) | (p[1] << 16) |
2418
                        (p[2] << 8) | p[3];
2419
                    header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2420
                        (s->inbuf[2] << 8) | s->inbuf[3];
2421
                    /* check with high probability that we have a
2422
                       valid header */
2423
                    if ((header & SAME_HEADER_MASK) ==
2424
                        (header1 & SAME_HEADER_MASK)) {
2425
                        /* header found: update pointers */
2426
                        len = (p + 4) - s->inbuf_ptr;
2427
                        buf_ptr += len;
2428
                        buf_size -= len;
2429
                        s->inbuf_ptr = p;
2430
                        /* compute frame size */
2431
                        s->free_format_next_header = header;
2432
                        s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
2433
                        padding = (header1 >> 9) & 1;
2434
                        if (s->layer == 1)
2435
                            s->free_format_frame_size -= padding * 4;
2436
                        else
2437
                            s->free_format_frame_size -= padding;
2438
                        dprintf("free frame size=%d padding=%d\n", 
2439
                                s->free_format_frame_size, padding);
2440
                        decode_header(s, header1);
2441
                        goto next_data;
2442
                    }
2443
                    p++;
2444
                }
2445
                /* not found: simply increase pointers */
2446
                buf_ptr += len;
2447
                s->inbuf_ptr += len;
2448
                buf_size -= len;
2449
            }
2450
        } else if (len < s->frame_size) {
2451
            if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
2452
                s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
2453
            len = s->frame_size - len;
2454
            if (len > buf_size)
2455
                len = buf_size;
2456
            memcpy(s->inbuf_ptr, buf_ptr, len);
2457
            buf_ptr += len;
2458
            s->inbuf_ptr += len;
2459
            buf_size -= len;
2460
        } else {
2461
            out_size = mp_decode_frame(s, out_samples);
2462
            s->inbuf_ptr = s->inbuf;
2463
            s->frame_size = 0;
2464
            *data_size = out_size;
2465
            break;
2466
        }
2467
    next_data:
2468
        ;
2469
    }
2470
    return buf_ptr - buf;
2471
}
2472

    
2473
AVCodec mp2_decoder =
2474
{
2475
    "mp2",
2476
    CODEC_TYPE_AUDIO,
2477
    CODEC_ID_MP2,
2478
    sizeof(MPADecodeContext),
2479
    decode_init,
2480
    NULL,
2481
    NULL,
2482
    decode_frame,
2483
};
2484

    
2485
AVCodec mp3_decoder =
2486
{
2487
    "mp3",
2488
    CODEC_TYPE_AUDIO,
2489
    CODEC_ID_MP3LAME,
2490
    sizeof(MPADecodeContext),
2491
    decode_init,
2492
    NULL,
2493
    NULL,
2494
    decode_frame,
2495
};
2496

    
2497
#undef C1
2498
#undef C2
2499
#undef C3
2500
#undef C4
2501
#undef C5
2502
#undef C6
2503
#undef C7
2504
#undef C8
2505
#undef FRAC_BITS
2506
#undef HEADER_SIZE