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[libav.git] / libavcodec / mpegaudiodec.c
1 /*
2 * 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 *
10 * 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 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 //#define DEBUG
20 #include "avcodec.h"
21 #include "mpegaudio.h"
22
23 /*
24 * TODO:
25 * - in low precision mode, use more 16 bit multiplies in synth filter
26 * - test lsf / mpeg25 extensively.
27 */
28
29 /* define USE_HIGHPRECISION to have a bit exact (but slower) mpeg
30 audio decoder */
31 #ifdef CONFIG_MPEGAUDIO_HP
32 #define USE_HIGHPRECISION
33 #endif
34
35 #ifdef USE_HIGHPRECISION
36 #define FRAC_BITS 23 /* fractional bits for sb_samples and dct */
37 #define WFRAC_BITS 16 /* fractional bits for window */
38 #else
39 #define FRAC_BITS 15 /* fractional bits for sb_samples and dct */
40 #define WFRAC_BITS 14 /* fractional bits for window */
41 #endif
42
43 #define FRAC_ONE (1 << FRAC_BITS)
44
45 #define MULL(a,b) (((INT64)(a) * (INT64)(b)) >> FRAC_BITS)
46 #define MUL64(a,b) ((INT64)(a) * (INT64)(b))
47 #define FIX(a) ((int)((a) * FRAC_ONE))
48 /* WARNING: only correct for posititive numbers */
49 #define FIXR(a) ((int)((a) * FRAC_ONE + 0.5))
50 #define FRAC_RND(a) (((a) + (FRAC_ONE/2)) >> FRAC_BITS)
51
52 #if FRAC_BITS <= 15
53 typedef INT16 MPA_INT;
54 #else
55 typedef INT32 MPA_INT;
56 #endif
57
58 /****************/
59
60 #define HEADER_SIZE 4
61 #define BACKSTEP_SIZE 512
62
63 typedef struct MPADecodeContext {
64 UINT8 inbuf1[2][MPA_MAX_CODED_FRAME_SIZE + BACKSTEP_SIZE]; /* input buffer */
65 int inbuf_index;
66 UINT8 *inbuf_ptr, *inbuf;
67 int frame_size;
68 int free_format_frame_size; /* frame size in case of free format
69 (zero if currently unknown) */
70 /* next header (used in free format parsing) */
71 UINT32 free_format_next_header;
72 int error_protection;
73 int layer;
74 int sample_rate;
75 int sample_rate_index; /* between 0 and 8 */
76 int bit_rate;
77 int old_frame_size;
78 GetBitContext gb;
79 int nb_channels;
80 int mode;
81 int mode_ext;
82 int lsf;
83 MPA_INT synth_buf[MPA_MAX_CHANNELS][512 * 2];
84 int synth_buf_offset[MPA_MAX_CHANNELS];
85 INT32 sb_samples[MPA_MAX_CHANNELS][36][SBLIMIT];
86 INT32 mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
87 #ifdef DEBUG
88 int frame_count;
89 #endif
90 } MPADecodeContext;
91
92 /* layer 3 "granule" */
93 typedef struct GranuleDef {
94 UINT8 scfsi;
95 int part2_3_length;
96 int big_values;
97 int global_gain;
98 int scalefac_compress;
99 UINT8 block_type;
100 UINT8 switch_point;
101 int table_select[3];
102 int subblock_gain[3];
103 UINT8 scalefac_scale;
104 UINT8 count1table_select;
105 int region_size[3]; /* number of huffman codes in each region */
106 int preflag;
107 int short_start, long_end; /* long/short band indexes */
108 UINT8 scale_factors[40];
109 INT32 sb_hybrid[SBLIMIT * 18]; /* 576 samples */
110 } GranuleDef;
111
112 #define MODE_EXT_MS_STEREO 2
113 #define MODE_EXT_I_STEREO 1
114
115 /* layer 3 huffman tables */
116 typedef struct HuffTable {
117 int xsize;
118 const UINT8 *bits;
119 const UINT16 *codes;
120 } HuffTable;
121
122 #include "mpegaudiodectab.h"
123
124 /* vlc structure for decoding layer 3 huffman tables */
125 static VLC huff_vlc[16];
126 static UINT8 *huff_code_table[16];
127 static VLC huff_quad_vlc[2];
128 /* computed from band_size_long */
129 static UINT16 band_index_long[9][23];
130 /* XXX: free when all decoders are closed */
131 #define TABLE_4_3_SIZE (8191 + 16)
132 static INT8 *table_4_3_exp;
133 #if FRAC_BITS <= 15
134 static UINT16 *table_4_3_value;
135 #else
136 static UINT32 *table_4_3_value;
137 #endif
138 /* intensity stereo coef table */
139 static INT32 is_table[2][16];
140 static INT32 is_table_lsf[2][2][16];
141 static INT32 csa_table[8][2];
142 static INT32 mdct_win[8][36];
143
144 /* lower 2 bits: modulo 3, higher bits: shift */
145 static UINT16 scale_factor_modshift[64];
146 /* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
147 static INT32 scale_factor_mult[15][3];
148 /* mult table for layer 2 group quantization */
149
150 #define SCALE_GEN(v) \
151 { FIXR(1.0 * (v)), FIXR(0.7937005259 * (v)), FIXR(0.6299605249 * (v)) }
152
153 static INT32 scale_factor_mult2[3][3] = {
154 SCALE_GEN(4.0 / 3.0), /* 3 steps */
155 SCALE_GEN(4.0 / 5.0), /* 5 steps */
156 SCALE_GEN(4.0 / 9.0), /* 9 steps */
157 };
158
159 /* 2^(n/4) */
160 static UINT32 scale_factor_mult3[4] = {
161 FIXR(1.0),
162 FIXR(1.18920711500272106671),
163 FIXR(1.41421356237309504880),
164 FIXR(1.68179283050742908605),
165 };
166
167 static MPA_INT window[512];
168
169 /* layer 1 unscaling */
170 /* n = number of bits of the mantissa minus 1 */
171 static inline int l1_unscale(int n, int mant, int scale_factor)
172 {
173 int shift, mod;
174 INT64 val;
175
176 shift = scale_factor_modshift[scale_factor];
177 mod = shift & 3;
178 shift >>= 2;
179 val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
180 shift += n;
181 /* NOTE: at this point, 1 <= shift >= 21 + 15 */
182 return (int)((val + (1LL << (shift - 1))) >> shift);
183 }
184
185 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
186 {
187 int shift, mod, val;
188
189 shift = scale_factor_modshift[scale_factor];
190 mod = shift & 3;
191 shift >>= 2;
192
193 val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
194 /* NOTE: at this point, 0 <= shift <= 21 */
195 if (shift > 0)
196 val = (val + (1 << (shift - 1))) >> shift;
197 return val;
198 }
199
200 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
201 static inline int l3_unscale(int value, int exponent)
202 {
203 #if FRAC_BITS <= 15
204 unsigned int m;
205 #else
206 UINT64 m;
207 #endif
208 int e;
209
210 e = table_4_3_exp[value];
211 e += (exponent >> 2);
212 e = FRAC_BITS - e;
213 #if FRAC_BITS <= 15
214 if (e > 31)
215 e = 31;
216 #endif
217 m = table_4_3_value[value];
218 #if FRAC_BITS <= 15
219 m = (m * scale_factor_mult3[exponent & 3]);
220 m = (m + (1 << (e-1))) >> e;
221 return m;
222 #else
223 m = MUL64(m, scale_factor_mult3[exponent & 3]);
224 m = (m + (UINT64_C(1) << (e-1))) >> e;
225 return m;
226 #endif
227 }
228
229 /* all integer n^(4/3) computation code */
230 #define DEV_ORDER 13
231
232 #define POW_FRAC_BITS 24
233 #define POW_FRAC_ONE (1 << POW_FRAC_BITS)
234 #define POW_FIX(a) ((int)((a) * POW_FRAC_ONE))
235 #define POW_MULL(a,b) (((INT64)(a) * (INT64)(b)) >> POW_FRAC_BITS)
236
237 static int dev_4_3_coefs[DEV_ORDER];
238
239 static int pow_mult3[3] = {
240 POW_FIX(1.0),
241 POW_FIX(1.25992104989487316476),
242 POW_FIX(1.58740105196819947474),
243 };
244
245 static void int_pow_init(void)
246 {
247 int i, a;
248
249 a = POW_FIX(1.0);
250 for(i=0;i<DEV_ORDER;i++) {
251 a = POW_MULL(a, POW_FIX(4.0 / 3.0) - i * POW_FIX(1.0)) / (i + 1);
252 dev_4_3_coefs[i] = a;
253 }
254 }
255
256 /* return the mantissa and the binary exponent */
257 static int int_pow(int i, int *exp_ptr)
258 {
259 int e, er, eq, j;
260 int a, a1;
261
262 /* renormalize */
263 a = i;
264 e = POW_FRAC_BITS;
265 while (a < (1 << (POW_FRAC_BITS - 1))) {
266 a = a << 1;
267 e--;
268 }
269 a -= (1 << POW_FRAC_BITS);
270 a1 = 0;
271 for(j = DEV_ORDER - 1; j >= 0; j--)
272 a1 = POW_MULL(a, dev_4_3_coefs[j] + a1);
273 a = (1 << POW_FRAC_BITS) + a1;
274 /* exponent compute (exact) */
275 e = e * 4;
276 er = e % 3;
277 eq = e / 3;
278 a = POW_MULL(a, pow_mult3[er]);
279 while (a >= 2 * POW_FRAC_ONE) {
280 a = a >> 1;
281 eq++;
282 }
283 /* convert to float */
284 while (a < POW_FRAC_ONE) {
285 a = a << 1;
286 eq--;
287 }
288 /* now POW_FRAC_ONE <= a < 2 * POW_FRAC_ONE */
289 #if POW_FRAC_BITS > FRAC_BITS
290 a = (a + (1 << (POW_FRAC_BITS - FRAC_BITS - 1))) >> (POW_FRAC_BITS - FRAC_BITS);
291 /* correct overflow */
292 if (a >= 2 * (1 << FRAC_BITS)) {
293 a = a >> 1;
294 eq++;
295 }
296 #endif
297 *exp_ptr = eq;
298 return a;
299 }
300
301 static int decode_init(AVCodecContext * avctx)
302 {
303 MPADecodeContext *s = avctx->priv_data;
304 static int init=0;
305 int i, j, k;
306
307 if(!init) {
308 /* scale factors table for layer 1/2 */
309 for(i=0;i<64;i++) {
310 int shift, mod;
311 /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
312 shift = (i / 3);
313 mod = i % 3;
314 scale_factor_modshift[i] = mod | (shift << 2);
315 }
316
317 /* scale factor multiply for layer 1 */
318 for(i=0;i<15;i++) {
319 int n, norm;
320 n = i + 2;
321 norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
322 scale_factor_mult[i][0] = MULL(FIXR(1.0 * 2.0), norm);
323 scale_factor_mult[i][1] = MULL(FIXR(0.7937005259 * 2.0), norm);
324 scale_factor_mult[i][2] = MULL(FIXR(0.6299605249 * 2.0), norm);
325 dprintf("%d: norm=%x s=%x %x %x\n",
326 i, norm,
327 scale_factor_mult[i][0],
328 scale_factor_mult[i][1],
329 scale_factor_mult[i][2]);
330 }
331
332 /* window */
333 /* max = 18760, max sum over all 16 coefs : 44736 */
334 for(i=0;i<257;i++) {
335 int v;
336 v = mpa_enwindow[i];
337 #if WFRAC_BITS < 16
338 v = (v + (1 << (16 - WFRAC_BITS - 1))) >> (16 - WFRAC_BITS);
339 #endif
340 window[i] = v;
341 if ((i & 63) != 0)
342 v = -v;
343 if (i != 0)
344 window[512 - i] = v;
345 }
346
347 /* huffman decode tables */
348 huff_code_table[0] = NULL;
349 for(i=1;i<16;i++) {
350 const HuffTable *h = &mpa_huff_tables[i];
351 int xsize, n, x, y;
352 UINT8 *code_table;
353
354 xsize = h->xsize;
355 n = xsize * xsize;
356 /* XXX: fail test */
357 init_vlc(&huff_vlc[i], 8, n,
358 h->bits, 1, 1, h->codes, 2, 2);
359
360 code_table = av_mallocz(n);
361 j = 0;
362 for(x=0;x<xsize;x++) {
363 for(y=0;y<xsize;y++)
364 code_table[j++] = (x << 4) | y;
365 }
366 huff_code_table[i] = code_table;
367 }
368 for(i=0;i<2;i++) {
369 init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
370 mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1);
371 }
372
373 for(i=0;i<9;i++) {
374 k = 0;
375 for(j=0;j<22;j++) {
376 band_index_long[i][j] = k;
377 k += band_size_long[i][j];
378 }
379 band_index_long[i][22] = k;
380 }
381
382 /* compute n ^ (4/3) and store it in mantissa/exp format */
383 table_4_3_exp = av_mallocz(TABLE_4_3_SIZE *
384 sizeof(table_4_3_exp[0]));
385 if (!table_4_3_exp)
386 return -1;
387 table_4_3_value = av_mallocz(TABLE_4_3_SIZE *
388 sizeof(table_4_3_value[0]));
389 if (!table_4_3_value) {
390 av_free(table_4_3_exp);
391 return -1;
392 }
393
394 int_pow_init();
395 for(i=1;i<TABLE_4_3_SIZE;i++) {
396 int e, m;
397 m = int_pow(i, &e);
398 #if 0
399 /* test code */
400 {
401 double f, fm;
402 int e1, m1;
403 f = pow((double)i, 4.0 / 3.0);
404 fm = frexp(f, &e1);
405 m1 = FIXR(2 * fm);
406 #if FRAC_BITS <= 15
407 if ((unsigned short)m1 != m1) {
408 m1 = m1 >> 1;
409 e1++;
410 }
411 #endif
412 e1--;
413 if (m != m1 || e != e1) {
414 printf("%4d: m=%x m1=%x e=%d e1=%d\n",
415 i, m, m1, e, e1);
416 }
417 }
418 #endif
419 /* normalized to FRAC_BITS */
420 table_4_3_value[i] = m;
421 table_4_3_exp[i] = e;
422 }
423
424 for(i=0;i<7;i++) {
425 float f;
426 int v;
427 if (i != 6) {
428 f = tan((double)i * M_PI / 12.0);
429 v = FIXR(f / (1.0 + f));
430 } else {
431 v = FIXR(1.0);
432 }
433 is_table[0][i] = v;
434 is_table[1][6 - i] = v;
435 }
436 /* invalid values */
437 for(i=7;i<16;i++)
438 is_table[0][i] = is_table[1][i] = 0.0;
439
440 for(i=0;i<16;i++) {
441 double f;
442 int e, k;
443
444 for(j=0;j<2;j++) {
445 e = -(j + 1) * ((i + 1) >> 1);
446 f = pow(2.0, e / 4.0);
447 k = i & 1;
448 is_table_lsf[j][k ^ 1][i] = FIXR(f);
449 is_table_lsf[j][k][i] = FIXR(1.0);
450 dprintf("is_table_lsf %d %d: %x %x\n",
451 i, j, is_table_lsf[j][0][i], is_table_lsf[j][1][i]);
452 }
453 }
454
455 for(i=0;i<8;i++) {
456 float ci, cs, ca;
457 ci = ci_table[i];
458 cs = 1.0 / sqrt(1.0 + ci * ci);
459 ca = cs * ci;
460 csa_table[i][0] = FIX(cs);
461 csa_table[i][1] = FIX(ca);
462 }
463
464 /* compute mdct windows */
465 for(i=0;i<36;i++) {
466 int v;
467 v = FIXR(sin(M_PI * (i + 0.5) / 36.0));
468 mdct_win[0][i] = v;
469 mdct_win[1][i] = v;
470 mdct_win[3][i] = v;
471 }
472 for(i=0;i<6;i++) {
473 mdct_win[1][18 + i] = FIXR(1.0);
474 mdct_win[1][24 + i] = FIXR(sin(M_PI * ((i + 6) + 0.5) / 12.0));
475 mdct_win[1][30 + i] = FIXR(0.0);
476
477 mdct_win[3][i] = FIXR(0.0);
478 mdct_win[3][6 + i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
479 mdct_win[3][12 + i] = FIXR(1.0);
480 }
481
482 for(i=0;i<12;i++)
483 mdct_win[2][i] = FIXR(sin(M_PI * (i + 0.5) / 12.0));
484
485 /* NOTE: we do frequency inversion adter the MDCT by changing
486 the sign of the right window coefs */
487 for(j=0;j<4;j++) {
488 for(i=0;i<36;i+=2) {
489 mdct_win[j + 4][i] = mdct_win[j][i];
490 mdct_win[j + 4][i + 1] = -mdct_win[j][i + 1];
491 }
492 }
493
494 #if defined(DEBUG)
495 for(j=0;j<8;j++) {
496 printf("win%d=\n", j);
497 for(i=0;i<36;i++)
498 printf("%f, ", (double)mdct_win[j][i] / FRAC_ONE);
499 printf("\n");
500 }
501 #endif
502 init = 1;
503 }
504
505 s->inbuf_index = 0;
506 s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
507 s->inbuf_ptr = s->inbuf;
508 #ifdef DEBUG
509 s->frame_count = 0;
510 #endif
511 return 0;
512 }
513
514 /* tab[i][j] = 1.0 / (2.0 * cos(pi*(2*k+1) / 2^(6 - j))) */;
515
516 /* cos(i*pi/64) */
517
518 #define COS0_0 FIXR(0.50060299823519630134)
519 #define COS0_1 FIXR(0.50547095989754365998)
520 #define COS0_2 FIXR(0.51544730992262454697)
521 #define COS0_3 FIXR(0.53104259108978417447)
522 #define COS0_4 FIXR(0.55310389603444452782)
523 #define COS0_5 FIXR(0.58293496820613387367)
524 #define COS0_6 FIXR(0.62250412303566481615)
525 #define COS0_7 FIXR(0.67480834145500574602)
526 #define COS0_8 FIXR(0.74453627100229844977)
527 #define COS0_9 FIXR(0.83934964541552703873)
528 #define COS0_10 FIXR(0.97256823786196069369)
529 #define COS0_11 FIXR(1.16943993343288495515)
530 #define COS0_12 FIXR(1.48416461631416627724)
531 #define COS0_13 FIXR(2.05778100995341155085)
532 #define COS0_14 FIXR(3.40760841846871878570)
533 #define COS0_15 FIXR(10.19000812354805681150)
534
535 #define COS1_0 FIXR(0.50241928618815570551)
536 #define COS1_1 FIXR(0.52249861493968888062)
537 #define COS1_2 FIXR(0.56694403481635770368)
538 #define COS1_3 FIXR(0.64682178335999012954)
539 #define COS1_4 FIXR(0.78815462345125022473)
540 #define COS1_5 FIXR(1.06067768599034747134)
541 #define COS1_6 FIXR(1.72244709823833392782)
542 #define COS1_7 FIXR(5.10114861868916385802)
543
544 #define COS2_0 FIXR(0.50979557910415916894)
545 #define COS2_1 FIXR(0.60134488693504528054)
546 #define COS2_2 FIXR(0.89997622313641570463)
547 #define COS2_3 FIXR(2.56291544774150617881)
548
549 #define COS3_0 FIXR(0.54119610014619698439)
550 #define COS3_1 FIXR(1.30656296487637652785)
551
552 #define COS4_0 FIXR(0.70710678118654752439)
553
554 /* butterfly operator */
555 #define BF(a, b, c)\
556 {\
557 tmp0 = tab[a] + tab[b];\
558 tmp1 = tab[a] - tab[b];\
559 tab[a] = tmp0;\
560 tab[b] = MULL(tmp1, c);\
561 }
562
563 #define BF1(a, b, c, d)\
564 {\
565 BF(a, b, COS4_0);\
566 BF(c, d, -COS4_0);\
567 tab[c] += tab[d];\
568 }
569
570 #define BF2(a, b, c, d)\
571 {\
572 BF(a, b, COS4_0);\
573 BF(c, d, -COS4_0);\
574 tab[c] += tab[d];\
575 tab[a] += tab[c];\
576 tab[c] += tab[b];\
577 tab[b] += tab[d];\
578 }
579
580 #define ADD(a, b) tab[a] += tab[b]
581
582 /* DCT32 without 1/sqrt(2) coef zero scaling. */
583 static void dct32(INT32 *out, INT32 *tab)
584 {
585 int tmp0, tmp1;
586
587 /* pass 1 */
588 BF(0, 31, COS0_0);
589 BF(1, 30, COS0_1);
590 BF(2, 29, COS0_2);
591 BF(3, 28, COS0_3);
592 BF(4, 27, COS0_4);
593 BF(5, 26, COS0_5);
594 BF(6, 25, COS0_6);
595 BF(7, 24, COS0_7);
596 BF(8, 23, COS0_8);
597 BF(9, 22, COS0_9);
598 BF(10, 21, COS0_10);
599 BF(11, 20, COS0_11);
600 BF(12, 19, COS0_12);
601 BF(13, 18, COS0_13);
602 BF(14, 17, COS0_14);
603 BF(15, 16, COS0_15);
604
605 /* pass 2 */
606 BF(0, 15, COS1_0);
607 BF(1, 14, COS1_1);
608 BF(2, 13, COS1_2);
609 BF(3, 12, COS1_3);
610 BF(4, 11, COS1_4);
611 BF(5, 10, COS1_5);
612 BF(6, 9, COS1_6);
613 BF(7, 8, COS1_7);
614
615 BF(16, 31, -COS1_0);
616 BF(17, 30, -COS1_1);
617 BF(18, 29, -COS1_2);
618 BF(19, 28, -COS1_3);
619 BF(20, 27, -COS1_4);
620 BF(21, 26, -COS1_5);
621 BF(22, 25, -COS1_6);
622 BF(23, 24, -COS1_7);
623
624 /* pass 3 */
625 BF(0, 7, COS2_0);
626 BF(1, 6, COS2_1);
627 BF(2, 5, COS2_2);
628 BF(3, 4, COS2_3);
629
630 BF(8, 15, -COS2_0);
631 BF(9, 14, -COS2_1);
632 BF(10, 13, -COS2_2);
633 BF(11, 12, -COS2_3);
634
635 BF(16, 23, COS2_0);
636 BF(17, 22, COS2_1);
637 BF(18, 21, COS2_2);
638 BF(19, 20, COS2_3);
639
640 BF(24, 31, -COS2_0);
641 BF(25, 30, -COS2_1);
642 BF(26, 29, -COS2_2);
643 BF(27, 28, -COS2_3);
644
645 /* pass 4 */
646 BF(0, 3, COS3_0);
647 BF(1, 2, COS3_1);
648
649 BF(4, 7, -COS3_0);
650 BF(5, 6, -COS3_1);
651
652 BF(8, 11, COS3_0);
653 BF(9, 10, COS3_1);
654
655 BF(12, 15, -COS3_0);
656 BF(13, 14, -COS3_1);
657
658 BF(16, 19, COS3_0);
659 BF(17, 18, COS3_1);
660
661 BF(20, 23, -COS3_0);
662 BF(21, 22, -COS3_1);
663
664 BF(24, 27, COS3_0);
665 BF(25, 26, COS3_1);
666
667 BF(28, 31, -COS3_0);
668 BF(29, 30, -COS3_1);
669
670 /* pass 5 */
671 BF1(0, 1, 2, 3);
672 BF2(4, 5, 6, 7);
673 BF1(8, 9, 10, 11);
674 BF2(12, 13, 14, 15);
675 BF1(16, 17, 18, 19);
676 BF2(20, 21, 22, 23);
677 BF1(24, 25, 26, 27);
678 BF2(28, 29, 30, 31);
679
680 /* pass 6 */
681
682 ADD( 8, 12);
683 ADD(12, 10);
684 ADD(10, 14);
685 ADD(14, 9);
686 ADD( 9, 13);
687 ADD(13, 11);
688 ADD(11, 15);
689
690 out[ 0] = tab[0];
691 out[16] = tab[1];
692 out[ 8] = tab[2];
693 out[24] = tab[3];
694 out[ 4] = tab[4];
695 out[20] = tab[5];
696 out[12] = tab[6];
697 out[28] = tab[7];
698 out[ 2] = tab[8];
699 out[18] = tab[9];
700 out[10] = tab[10];
701 out[26] = tab[11];
702 out[ 6] = tab[12];
703 out[22] = tab[13];
704 out[14] = tab[14];
705 out[30] = tab[15];
706
707 ADD(24, 28);
708 ADD(28, 26);
709 ADD(26, 30);
710 ADD(30, 25);
711 ADD(25, 29);
712 ADD(29, 27);
713 ADD(27, 31);
714
715 out[ 1] = tab[16] + tab[24];
716 out[17] = tab[17] + tab[25];
717 out[ 9] = tab[18] + tab[26];
718 out[25] = tab[19] + tab[27];
719 out[ 5] = tab[20] + tab[28];
720 out[21] = tab[21] + tab[29];
721 out[13] = tab[22] + tab[30];
722 out[29] = tab[23] + tab[31];
723 out[ 3] = tab[24] + tab[20];
724 out[19] = tab[25] + tab[21];
725 out[11] = tab[26] + tab[22];
726 out[27] = tab[27] + tab[23];
727 out[ 7] = tab[28] + tab[18];
728 out[23] = tab[29] + tab[19];
729 out[15] = tab[30] + tab[17];
730 out[31] = tab[31];
731 }
732
733 #define OUT_SHIFT (WFRAC_BITS + FRAC_BITS - 15)
734
735 #if FRAC_BITS <= 15
736
737 #define OUT_SAMPLE(sum)\
738 {\
739 int sum1;\
740 sum1 = (sum + (1 << (OUT_SHIFT - 1))) >> OUT_SHIFT;\
741 if (sum1 < -32768)\
742 sum1 = -32768;\
743 else if (sum1 > 32767)\
744 sum1 = 32767;\
745 *samples = sum1;\
746 samples += incr;\
747 }
748
749 #define SUM8(off, op) \
750 { \
751 sum op w[0 * 64 + off] * p[0 * 64];\
752 sum op w[1 * 64 + off] * p[1 * 64];\
753 sum op w[2 * 64 + off] * p[2 * 64];\
754 sum op w[3 * 64 + off] * p[3 * 64];\
755 sum op w[4 * 64 + off] * p[4 * 64];\
756 sum op w[5 * 64 + off] * p[5 * 64];\
757 sum op w[6 * 64 + off] * p[6 * 64];\
758 sum op w[7 * 64 + off] * p[7 * 64];\
759 }
760
761 #else
762
763 #define OUT_SAMPLE(sum)\
764 {\
765 int sum1;\
766 sum1 = (int)((sum + (INT64_C(1) << (OUT_SHIFT - 1))) >> OUT_SHIFT);\
767 if (sum1 < -32768)\
768 sum1 = -32768;\
769 else if (sum1 > 32767)\
770 sum1 = 32767;\
771 *samples = sum1;\
772 samples += incr;\
773 }
774
775 #define SUM8(off, op) \
776 { \
777 sum op MUL64(w[0 * 64 + off], p[0 * 64]);\
778 sum op MUL64(w[1 * 64 + off], p[1 * 64]);\
779 sum op MUL64(w[2 * 64 + off], p[2 * 64]);\
780 sum op MUL64(w[3 * 64 + off], p[3 * 64]);\
781 sum op MUL64(w[4 * 64 + off], p[4 * 64]);\
782 sum op MUL64(w[5 * 64 + off], p[5 * 64]);\
783 sum op MUL64(w[6 * 64 + off], p[6 * 64]);\
784 sum op MUL64(w[7 * 64 + off], p[7 * 64]);\
785 }
786
787 #endif
788
789 /* 32 sub band synthesis filter. Input: 32 sub band samples, Output:
790 32 samples. */
791 /* XXX: optimize by avoiding ring buffer usage */
792 static void synth_filter(MPADecodeContext *s1,
793 int ch, INT16 *samples, int incr,
794 INT32 sb_samples[SBLIMIT])
795 {
796 INT32 tmp[32];
797 register MPA_INT *synth_buf, *p;
798 register MPA_INT *w;
799 int j, offset, v;
800 #if FRAC_BITS <= 15
801 int sum;
802 #else
803 INT64 sum;
804 #endif
805
806 dct32(tmp, sb_samples);
807
808 offset = s1->synth_buf_offset[ch];
809 synth_buf = s1->synth_buf[ch] + offset;
810
811 for(j=0;j<32;j++) {
812 v = tmp[j];
813 #if FRAC_BITS <= 15
814 /* NOTE: can cause a loss in precision if very high amplitude
815 sound */
816 if (v > 32767)
817 v = 32767;
818 else if (v < -32768)
819 v = -32768;
820 #endif
821 synth_buf[j] = v;
822 }
823 /* copy to avoid wrap */
824 memcpy(synth_buf + 512, synth_buf, 32 * sizeof(MPA_INT));
825
826 w = window;
827 for(j=0;j<16;j++) {
828 sum = 0;
829 p = synth_buf + 16 + j; /* 0-15 */
830 SUM8(0, +=);
831 p = synth_buf + 48 - j; /* 32-47 */
832 SUM8(32, -=);
833 OUT_SAMPLE(sum);
834 w++;
835 }
836
837 p = synth_buf + 32; /* 48 */
838 sum = 0;
839 SUM8(32, -=);
840 OUT_SAMPLE(sum);
841 w++;
842
843 for(j=17;j<32;j++) {
844 sum = 0;
845 p = synth_buf + 48 - j; /* 17-31 */
846 SUM8(0, -=);
847 p = synth_buf + 16 + j; /* 49-63 */
848 SUM8(32, -=);
849 OUT_SAMPLE(sum);
850 w++;
851 }
852 offset = (offset - 32) & 511;
853 s1->synth_buf_offset[ch] = offset;
854 }
855
856 /* cos(pi*i/24) */
857 #define C1 FIXR(0.99144486137381041114)
858 #define C3 FIXR(0.92387953251128675612)
859 #define C5 FIXR(0.79335334029123516458)
860 #define C7 FIXR(0.60876142900872063941)
861 #define C9 FIXR(0.38268343236508977173)
862 #define C11 FIXR(0.13052619222005159154)
863
864 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
865 cases. */
866 static void imdct12(int *out, int *in)
867 {
868 int tmp;
869 INT64 in1_3, in1_9, in4_3, in4_9;
870
871 in1_3 = MUL64(in[1], C3);
872 in1_9 = MUL64(in[1], C9);
873 in4_3 = MUL64(in[4], C3);
874 in4_9 = MUL64(in[4], C9);
875
876 tmp = FRAC_RND(MUL64(in[0], C7) - in1_3 - MUL64(in[2], C11) +
877 MUL64(in[3], C1) - in4_9 - MUL64(in[5], C5));
878 out[0] = tmp;
879 out[5] = -tmp;
880 tmp = FRAC_RND(MUL64(in[0] - in[3], C9) - in1_3 +
881 MUL64(in[2] + in[5], C3) - in4_9);
882 out[1] = tmp;
883 out[4] = -tmp;
884 tmp = FRAC_RND(MUL64(in[0], C11) - in1_9 + MUL64(in[2], C7) -
885 MUL64(in[3], C5) + in4_3 - MUL64(in[5], C1));
886 out[2] = tmp;
887 out[3] = -tmp;
888 tmp = FRAC_RND(MUL64(-in[0], C5) + in1_9 + MUL64(in[2], C1) +
889 MUL64(in[3], C11) - in4_3 - MUL64(in[5], C7));
890 out[6] = tmp;
891 out[11] = tmp;
892 tmp = FRAC_RND(MUL64(-in[0] + in[3], C3) - in1_9 +
893 MUL64(in[2] + in[5], C9) + in4_3);
894 out[7] = tmp;
895 out[10] = tmp;
896 tmp = FRAC_RND(-MUL64(in[0], C1) - in1_3 - MUL64(in[2], C5) -
897 MUL64(in[3], C7) - in4_9 - MUL64(in[5], C11));
898 out[8] = tmp;
899 out[9] = tmp;
900 }
901
902 #undef C1
903 #undef C3
904 #undef C5
905 #undef C7
906 #undef C9
907 #undef C11
908
909 /* cos(pi*i/18) */
910 #define C1 FIXR(0.98480775301220805936)
911 #define C2 FIXR(0.93969262078590838405)
912 #define C3 FIXR(0.86602540378443864676)
913 #define C4 FIXR(0.76604444311897803520)
914 #define C5 FIXR(0.64278760968653932632)
915 #define C6 FIXR(0.5)
916 #define C7 FIXR(0.34202014332566873304)
917 #define C8 FIXR(0.17364817766693034885)
918
919 /* 0.5 / cos(pi*(2*i+1)/36) */
920 static const int icos36[9] = {
921 FIXR(0.50190991877167369479),
922 FIXR(0.51763809020504152469),
923 FIXR(0.55168895948124587824),
924 FIXR(0.61038729438072803416),
925 FIXR(0.70710678118654752439),
926 FIXR(0.87172339781054900991),
927 FIXR(1.18310079157624925896),
928 FIXR(1.93185165257813657349),
929 FIXR(5.73685662283492756461),
930 };
931
932 static const int icos72[18] = {
933 /* 0.5 / cos(pi*(2*i+19)/72) */
934 FIXR(0.74009361646113053152),
935 FIXR(0.82133981585229078570),
936 FIXR(0.93057949835178895673),
937 FIXR(1.08284028510010010928),
938 FIXR(1.30656296487637652785),
939 FIXR(1.66275476171152078719),
940 FIXR(2.31011315767264929558),
941 FIXR(3.83064878777019433457),
942 FIXR(11.46279281302667383546),
943
944 /* 0.5 / cos(pi*(2*(i + 18) +19)/72) */
945 FIXR(-0.67817085245462840086),
946 FIXR(-0.63023620700513223342),
947 FIXR(-0.59284452371708034528),
948 FIXR(-0.56369097343317117734),
949 FIXR(-0.54119610014619698439),
950 FIXR(-0.52426456257040533932),
951 FIXR(-0.51213975715725461845),
952 FIXR(-0.50431448029007636036),
953 FIXR(-0.50047634258165998492),
954 };
955
956 /* using Lee like decomposition followed by hand coded 9 points DCT */
957 static void imdct36(int *out, int *in)
958 {
959 int i, j, t0, t1, t2, t3, s0, s1, s2, s3;
960 int tmp[18], *tmp1, *in1;
961 INT64 in3_3, in6_6;
962
963 for(i=17;i>=1;i--)
964 in[i] += in[i-1];
965 for(i=17;i>=3;i-=2)
966 in[i] += in[i-2];
967
968 for(j=0;j<2;j++) {
969 tmp1 = tmp + j;
970 in1 = in + j;
971
972 in3_3 = MUL64(in1[2*3], C3);
973 in6_6 = MUL64(in1[2*6], C6);
974
975 tmp1[0] = FRAC_RND(MUL64(in1[2*1], C1) + in3_3 +
976 MUL64(in1[2*5], C5) + MUL64(in1[2*7], C7));
977 tmp1[2] = in1[2*0] + FRAC_RND(MUL64(in1[2*2], C2) +
978 MUL64(in1[2*4], C4) + in6_6 +
979 MUL64(in1[2*8], C8));
980 tmp1[4] = FRAC_RND(MUL64(in1[2*1] - in1[2*5] - in1[2*7], C3));
981 tmp1[6] = FRAC_RND(MUL64(in1[2*2] - in1[2*4] - in1[2*8], C6)) -
982 in1[2*6] + in1[2*0];
983 tmp1[8] = FRAC_RND(MUL64(in1[2*1], C5) - in3_3 -
984 MUL64(in1[2*5], C7) + MUL64(in1[2*7], C1));
985 tmp1[10] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C8) -
986 MUL64(in1[2*4], C2) + in6_6 +
987 MUL64(in1[2*8], C4));
988 tmp1[12] = FRAC_RND(MUL64(in1[2*1], C7) - in3_3 +
989 MUL64(in1[2*5], C1) -
990 MUL64(in1[2*7], C5));
991 tmp1[14] = in1[2*0] + FRAC_RND(MUL64(-in1[2*2], C4) +
992 MUL64(in1[2*4], C8) + in6_6 -
993 MUL64(in1[2*8], C2));
994 tmp1[16] = in1[2*0] - in1[2*2] + in1[2*4] - in1[2*6] + in1[2*8];
995 }
996
997 i = 0;
998 for(j=0;j<4;j++) {
999 t0 = tmp[i];
1000 t1 = tmp[i + 2];
1001 s0 = t1 + t0;
1002 s2 = t1 - t0;
1003
1004 t2 = tmp[i + 1];
1005 t3 = tmp[i + 3];
1006 s1 = MULL(t3 + t2, icos36[j]);
1007 s3 = MULL(t3 - t2, icos36[8 - j]);
1008
1009 t0 = MULL(s0 + s1, icos72[9 + 8 - j]);
1010 t1 = MULL(s0 - s1, icos72[8 - j]);
1011 out[18 + 9 + j] = t0;
1012 out[18 + 8 - j] = t0;
1013 out[9 + j] = -t1;
1014 out[8 - j] = t1;
1015
1016 t0 = MULL(s2 + s3, icos72[9+j]);
1017 t1 = MULL(s2 - s3, icos72[j]);
1018 out[18 + 9 + (8 - j)] = t0;
1019 out[18 + j] = t0;
1020 out[9 + (8 - j)] = -t1;
1021 out[j] = t1;
1022 i += 4;
1023 }
1024
1025 s0 = tmp[16];
1026 s1 = MULL(tmp[17], icos36[4]);
1027 t0 = MULL(s0 + s1, icos72[9 + 4]);
1028 t1 = MULL(s0 - s1, icos72[4]);
1029 out[18 + 9 + 4] = t0;
1030 out[18 + 8 - 4] = t0;
1031 out[9 + 4] = -t1;
1032 out[8 - 4] = t1;
1033 }
1034
1035 /* fast header check for resync */
1036 static int check_header(UINT32 header)
1037 {
1038 /* header */
1039 if ((header & 0xffe00000) != 0xffe00000)
1040 return -1;
1041 /* layer check */
1042 if (((header >> 17) & 3) == 0)
1043 return -1;
1044 /* bit rate */
1045 if (((header >> 12) & 0xf) == 0xf)
1046 return -1;
1047 /* frequency */
1048 if (((header >> 10) & 3) == 3)
1049 return -1;
1050 return 0;
1051 }
1052
1053 /* header + layer + bitrate + freq + lsf/mpeg25 */
1054 #define SAME_HEADER_MASK \
1055 (0xffe00000 | (3 << 17) | (0xf << 12) | (3 << 10) | (3 << 19))
1056
1057 /* header decoding. MUST check the header before because no
1058 consistency check is done there. Return 1 if free format found and
1059 that the frame size must be computed externally */
1060 static int decode_header(MPADecodeContext *s, UINT32 header)
1061 {
1062 int sample_rate, frame_size, mpeg25, padding;
1063 int sample_rate_index, bitrate_index;
1064 if (header & (1<<20)) {
1065 s->lsf = (header & (1<<19)) ? 0 : 1;
1066 mpeg25 = 0;
1067 } else {
1068 s->lsf = 1;
1069 mpeg25 = 1;
1070 }
1071
1072 s->layer = 4 - ((header >> 17) & 3);
1073 /* extract frequency */
1074 sample_rate_index = (header >> 10) & 3;
1075 sample_rate = mpa_freq_tab[sample_rate_index] >> (s->lsf + mpeg25);
1076 sample_rate_index += 3 * (s->lsf + mpeg25);
1077 s->sample_rate_index = sample_rate_index;
1078 s->error_protection = ((header >> 16) & 1) ^ 1;
1079 s->sample_rate = sample_rate;
1080
1081 bitrate_index = (header >> 12) & 0xf;
1082 padding = (header >> 9) & 1;
1083 //extension = (header >> 8) & 1;
1084 s->mode = (header >> 6) & 3;
1085 s->mode_ext = (header >> 4) & 3;
1086 //copyright = (header >> 3) & 1;
1087 //original = (header >> 2) & 1;
1088 //emphasis = header & 3;
1089
1090 if (s->mode == MPA_MONO)
1091 s->nb_channels = 1;
1092 else
1093 s->nb_channels = 2;
1094
1095 if (bitrate_index != 0) {
1096 frame_size = mpa_bitrate_tab[s->lsf][s->layer - 1][bitrate_index];
1097 s->bit_rate = frame_size * 1000;
1098 switch(s->layer) {
1099 case 1:
1100 frame_size = (frame_size * 12000) / sample_rate;
1101 frame_size = (frame_size + padding) * 4;
1102 break;
1103 case 2:
1104 frame_size = (frame_size * 144000) / sample_rate;
1105 frame_size += padding;
1106 break;
1107 default:
1108 case 3:
1109 frame_size = (frame_size * 144000) / (sample_rate << s->lsf);
1110 frame_size += padding;
1111 break;
1112 }
1113 s->frame_size = frame_size;
1114 } else {
1115 /* if no frame size computed, signal it */
1116 if (!s->free_format_frame_size)
1117 return 1;
1118 /* free format: compute bitrate and real frame size from the
1119 frame size we extracted by reading the bitstream */
1120 s->frame_size = s->free_format_frame_size;
1121 switch(s->layer) {
1122 case 1:
1123 s->frame_size += padding * 4;
1124 s->bit_rate = (s->frame_size * sample_rate) / 48000;
1125 break;
1126 case 2:
1127 s->frame_size += padding;
1128 s->bit_rate = (s->frame_size * sample_rate) / 144000;
1129 break;
1130 default:
1131 case 3:
1132 s->frame_size += padding;
1133 s->bit_rate = (s->frame_size * (sample_rate << s->lsf)) / 144000;
1134 break;
1135 }
1136 }
1137
1138 #if defined(DEBUG)
1139 printf("layer%d, %d Hz, %d kbits/s, ",
1140 s->layer, s->sample_rate, s->bit_rate);
1141 if (s->nb_channels == 2) {
1142 if (s->layer == 3) {
1143 if (s->mode_ext & MODE_EXT_MS_STEREO)
1144 printf("ms-");
1145 if (s->mode_ext & MODE_EXT_I_STEREO)
1146 printf("i-");
1147 }
1148 printf("stereo");
1149 } else {
1150 printf("mono");
1151 }
1152 printf("\n");
1153 #endif
1154 return 0;
1155 }
1156
1157 /* return the number of decoded frames */
1158 static int mp_decode_layer1(MPADecodeContext *s)
1159 {
1160 int bound, i, v, n, ch, j, mant;
1161 UINT8 allocation[MPA_MAX_CHANNELS][SBLIMIT];
1162 UINT8 scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
1163
1164 if (s->mode == MPA_JSTEREO)
1165 bound = (s->mode_ext + 1) * 4;
1166 else
1167 bound = SBLIMIT;
1168
1169 /* allocation bits */
1170 for(i=0;i<bound;i++) {
1171 for(ch=0;ch<s->nb_channels;ch++) {
1172 allocation[ch][i] = get_bits(&s->gb, 4);
1173 }
1174 }
1175 for(i=bound;i<SBLIMIT;i++) {
1176 allocation[0][i] = get_bits(&s->gb, 4);
1177 }
1178
1179 /* scale factors */
1180 for(i=0;i<bound;i++) {
1181 for(ch=0;ch<s->nb_channels;ch++) {
1182 if (allocation[ch][i])
1183 scale_factors[ch][i] = get_bits(&s->gb, 6);
1184 }
1185 }
1186 for(i=bound;i<SBLIMIT;i++) {
1187 if (allocation[0][i]) {
1188 scale_factors[0][i] = get_bits(&s->gb, 6);
1189 scale_factors[1][i] = get_bits(&s->gb, 6);
1190 }
1191 }
1192
1193 /* compute samples */
1194 for(j=0;j<12;j++) {
1195 for(i=0;i<bound;i++) {
1196 for(ch=0;ch<s->nb_channels;ch++) {
1197 n = allocation[ch][i];
1198 if (n) {
1199 mant = get_bits(&s->gb, n + 1);
1200 v = l1_unscale(n, mant, scale_factors[ch][i]);
1201 } else {
1202 v = 0;
1203 }
1204 s->sb_samples[ch][j][i] = v;
1205 }
1206 }
1207 for(i=bound;i<SBLIMIT;i++) {
1208 n = allocation[0][i];
1209 if (n) {
1210 mant = get_bits(&s->gb, n + 1);
1211 v = l1_unscale(n, mant, scale_factors[0][i]);
1212 s->sb_samples[0][j][i] = v;
1213 v = l1_unscale(n, mant, scale_factors[1][i]);
1214 s->sb_samples[1][j][i] = v;
1215 } else {
1216 s->sb_samples[0][j][i] = 0;
1217 s->sb_samples[1][j][i] = 0;
1218 }
1219 }
1220 }
1221 return 12;
1222 }
1223
1224 /* bitrate is in kb/s */
1225 int l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
1226 {
1227 int ch_bitrate, table;
1228
1229 ch_bitrate = bitrate / nb_channels;
1230 if (!lsf) {
1231 if ((freq == 48000 && ch_bitrate >= 56) ||
1232 (ch_bitrate >= 56 && ch_bitrate <= 80))
1233 table = 0;
1234 else if (freq != 48000 && ch_bitrate >= 96)
1235 table = 1;
1236 else if (freq != 32000 && ch_bitrate <= 48)
1237 table = 2;
1238 else
1239 table = 3;
1240 } else {
1241 table = 4;
1242 }
1243 return table;
1244 }
1245
1246 static int mp_decode_layer2(MPADecodeContext *s)
1247 {
1248 int sblimit; /* number of used subbands */
1249 const unsigned char *alloc_table;
1250 int table, bit_alloc_bits, i, j, ch, bound, v;
1251 unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
1252 unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
1253 unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
1254 int scale, qindex, bits, steps, k, l, m, b;
1255
1256 /* select decoding table */
1257 table = l2_select_table(s->bit_rate / 1000, s->nb_channels,
1258 s->sample_rate, s->lsf);
1259 sblimit = sblimit_table[table];
1260 alloc_table = alloc_tables[table];
1261
1262 if (s->mode == MPA_JSTEREO)
1263 bound = (s->mode_ext + 1) * 4;
1264 else
1265 bound = sblimit;
1266
1267 dprintf("bound=%d sblimit=%d\n", bound, sblimit);
1268 /* parse bit allocation */
1269 j = 0;
1270 for(i=0;i<bound;i++) {
1271 bit_alloc_bits = alloc_table[j];
1272 for(ch=0;ch<s->nb_channels;ch++) {
1273 bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
1274 }
1275 j += 1 << bit_alloc_bits;
1276 }
1277 for(i=bound;i<sblimit;i++) {
1278 bit_alloc_bits = alloc_table[j];
1279 v = get_bits(&s->gb, bit_alloc_bits);
1280 bit_alloc[0][i] = v;
1281 bit_alloc[1][i] = v;
1282 j += 1 << bit_alloc_bits;
1283 }
1284
1285 #ifdef DEBUG
1286 {
1287 for(ch=0;ch<s->nb_channels;ch++) {
1288 for(i=0;i<sblimit;i++)
1289 printf(" %d", bit_alloc[ch][i]);
1290 printf("\n");
1291 }
1292 }
1293 #endif
1294
1295 /* scale codes */
1296 for(i=0;i<sblimit;i++) {
1297 for(ch=0;ch<s->nb_channels;ch++) {
1298 if (bit_alloc[ch][i])
1299 scale_code[ch][i] = get_bits(&s->gb, 2);
1300 }
1301 }
1302
1303 /* scale factors */
1304 for(i=0;i<sblimit;i++) {
1305 for(ch=0;ch<s->nb_channels;ch++) {
1306 if (bit_alloc[ch][i]) {
1307 sf = scale_factors[ch][i];
1308 switch(scale_code[ch][i]) {
1309 default:
1310 case 0:
1311 sf[0] = get_bits(&s->gb, 6);
1312 sf[1] = get_bits(&s->gb, 6);
1313 sf[2] = get_bits(&s->gb, 6);
1314 break;
1315 case 2:
1316 sf[0] = get_bits(&s->gb, 6);
1317 sf[1] = sf[0];
1318 sf[2] = sf[0];
1319 break;
1320 case 1:
1321 sf[0] = get_bits(&s->gb, 6);
1322 sf[2] = get_bits(&s->gb, 6);
1323 sf[1] = sf[0];
1324 break;
1325 case 3:
1326 sf[0] = get_bits(&s->gb, 6);
1327 sf[2] = get_bits(&s->gb, 6);
1328 sf[1] = sf[2];
1329 break;
1330 }
1331 }
1332 }
1333 }
1334
1335 #ifdef DEBUG
1336 for(ch=0;ch<s->nb_channels;ch++) {
1337 for(i=0;i<sblimit;i++) {
1338 if (bit_alloc[ch][i]) {
1339 sf = scale_factors[ch][i];
1340 printf(" %d %d %d", sf[0], sf[1], sf[2]);
1341 } else {
1342 printf(" -");
1343 }
1344 }
1345 printf("\n");
1346 }
1347 #endif
1348
1349 /* samples */
1350 for(k=0;k<3;k++) {
1351 for(l=0;l<12;l+=3) {
1352 j = 0;
1353 for(i=0;i<bound;i++) {
1354 bit_alloc_bits = alloc_table[j];
1355 for(ch=0;ch<s->nb_channels;ch++) {
1356 b = bit_alloc[ch][i];
1357 if (b) {
1358 scale = scale_factors[ch][i][k];
1359 qindex = alloc_table[j+b];
1360 bits = quant_bits[qindex];
1361 if (bits < 0) {
1362 /* 3 values at the same time */
1363 v = get_bits(&s->gb, -bits);
1364 steps = quant_steps[qindex];
1365 s->sb_samples[ch][k * 12 + l + 0][i] =
1366 l2_unscale_group(steps, v % steps, scale);
1367 v = v / steps;
1368 s->sb_samples[ch][k * 12 + l + 1][i] =
1369 l2_unscale_group(steps, v % steps, scale);
1370 v = v / steps;
1371 s->sb_samples[ch][k * 12 + l + 2][i] =
1372 l2_unscale_group(steps, v, scale);
1373 } else {
1374 for(m=0;m<3;m++) {
1375 v = get_bits(&s->gb, bits);
1376 v = l1_unscale(bits - 1, v, scale);
1377 s->sb_samples[ch][k * 12 + l + m][i] = v;
1378 }
1379 }
1380 } else {
1381 s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1382 s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1383 s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1384 }
1385 }
1386 /* next subband in alloc table */
1387 j += 1 << bit_alloc_bits;
1388 }
1389 /* XXX: find a way to avoid this duplication of code */
1390 for(i=bound;i<sblimit;i++) {
1391 bit_alloc_bits = alloc_table[j];
1392 b = bit_alloc[0][i];
1393 if (b) {
1394 int mant, scale0, scale1;
1395 scale0 = scale_factors[0][i][k];
1396 scale1 = scale_factors[1][i][k];
1397 qindex = alloc_table[j+b];
1398 bits = quant_bits[qindex];
1399 if (bits < 0) {
1400 /* 3 values at the same time */
1401 v = get_bits(&s->gb, -bits);
1402 steps = quant_steps[qindex];
1403 mant = v % steps;
1404 v = v / steps;
1405 s->sb_samples[0][k * 12 + l + 0][i] =
1406 l2_unscale_group(steps, mant, scale0);
1407 s->sb_samples[1][k * 12 + l + 0][i] =
1408 l2_unscale_group(steps, mant, scale1);
1409 mant = v % steps;
1410 v = v / steps;
1411 s->sb_samples[0][k * 12 + l + 1][i] =
1412 l2_unscale_group(steps, mant, scale0);
1413 s->sb_samples[1][k * 12 + l + 1][i] =
1414 l2_unscale_group(steps, mant, scale1);
1415 s->sb_samples[0][k * 12 + l + 2][i] =
1416 l2_unscale_group(steps, v, scale0);
1417 s->sb_samples[1][k * 12 + l + 2][i] =
1418 l2_unscale_group(steps, v, scale1);
1419 } else {
1420 for(m=0;m<3;m++) {
1421 mant = get_bits(&s->gb, bits);
1422 s->sb_samples[0][k * 12 + l + m][i] =
1423 l1_unscale(bits - 1, mant, scale0);
1424 s->sb_samples[1][k * 12 + l + m][i] =
1425 l1_unscale(bits - 1, mant, scale1);
1426 }
1427 }
1428 } else {
1429 s->sb_samples[0][k * 12 + l + 0][i] = 0;
1430 s->sb_samples[0][k * 12 + l + 1][i] = 0;
1431 s->sb_samples[0][k * 12 + l + 2][i] = 0;
1432 s->sb_samples[1][k * 12 + l + 0][i] = 0;
1433 s->sb_samples[1][k * 12 + l + 1][i] = 0;
1434 s->sb_samples[1][k * 12 + l + 2][i] = 0;
1435 }
1436 /* next subband in alloc table */
1437 j += 1 << bit_alloc_bits;
1438 }
1439 /* fill remaining samples to zero */
1440 for(i=sblimit;i<SBLIMIT;i++) {
1441 for(ch=0;ch<s->nb_channels;ch++) {
1442 s->sb_samples[ch][k * 12 + l + 0][i] = 0;
1443 s->sb_samples[ch][k * 12 + l + 1][i] = 0;
1444 s->sb_samples[ch][k * 12 + l + 2][i] = 0;
1445 }
1446 }
1447 }
1448 }
1449 return 3 * 12;
1450 }
1451
1452 /*
1453 * Seek back in the stream for backstep bytes (at most 511 bytes)
1454 */
1455 static void seek_to_maindata(MPADecodeContext *s, long backstep)
1456 {
1457 UINT8 *ptr;
1458
1459 /* compute current position in stream */
1460 ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
1461
1462 /* copy old data before current one */
1463 ptr -= backstep;
1464 memcpy(ptr, s->inbuf1[s->inbuf_index ^ 1] +
1465 BACKSTEP_SIZE + s->old_frame_size - backstep, backstep);
1466 /* init get bits again */
1467 init_get_bits(&s->gb, ptr, s->frame_size + backstep);
1468
1469 /* prepare next buffer */
1470 s->inbuf_index ^= 1;
1471 s->inbuf = &s->inbuf1[s->inbuf_index][BACKSTEP_SIZE];
1472 s->old_frame_size = s->frame_size;
1473 }
1474
1475 static inline void lsf_sf_expand(int *slen,
1476 int sf, int n1, int n2, int n3)
1477 {
1478 if (n3) {
1479 slen[3] = sf % n3;
1480 sf /= n3;
1481 } else {
1482 slen[3] = 0;
1483 }
1484 if (n2) {
1485 slen[2] = sf % n2;
1486 sf /= n2;
1487 } else {
1488 slen[2] = 0;
1489 }
1490 slen[1] = sf % n1;
1491 sf /= n1;
1492 slen[0] = sf;
1493 }
1494
1495 static void exponents_from_scale_factors(MPADecodeContext *s,
1496 GranuleDef *g,
1497 INT16 *exponents)
1498 {
1499 const UINT8 *bstab, *pretab;
1500 int len, i, j, k, l, v0, shift, gain, gains[3];
1501 INT16 *exp_ptr;
1502
1503 exp_ptr = exponents;
1504 gain = g->global_gain - 210;
1505 shift = g->scalefac_scale + 1;
1506
1507 bstab = band_size_long[s->sample_rate_index];
1508 pretab = mpa_pretab[g->preflag];
1509 for(i=0;i<g->long_end;i++) {
1510 v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift);
1511 len = bstab[i];
1512 for(j=len;j>0;j--)
1513 *exp_ptr++ = v0;
1514 }
1515
1516 if (g->short_start < 13) {
1517 bstab = band_size_short[s->sample_rate_index];
1518 gains[0] = gain - (g->subblock_gain[0] << 3);
1519 gains[1] = gain - (g->subblock_gain[1] << 3);
1520 gains[2] = gain - (g->subblock_gain[2] << 3);
1521 k = g->long_end;
1522 for(i=g->short_start;i<13;i++) {
1523 len = bstab[i];
1524 for(l=0;l<3;l++) {
1525 v0 = gains[l] - (g->scale_factors[k++] << shift);
1526 for(j=len;j>0;j--)
1527 *exp_ptr++ = v0;
1528 }
1529 }
1530 }
1531 }
1532
1533 /* handle n = 0 too */
1534 static inline int get_bitsz(GetBitContext *s, int n)
1535 {
1536 if (n == 0)
1537 return 0;
1538 else
1539 return get_bits(s, n);
1540 }
1541
1542 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
1543 INT16 *exponents, int end_pos)
1544 {
1545 int s_index;
1546 int linbits, code, x, y, l, v, i, j, k, pos;
1547 GetBitContext last_gb;
1548 VLC *vlc;
1549 UINT8 *code_table;
1550
1551 /* low frequencies (called big values) */
1552 s_index = 0;
1553 for(i=0;i<3;i++) {
1554 j = g->region_size[i];
1555 if (j == 0)
1556 continue;
1557 /* select vlc table */
1558 k = g->table_select[i];
1559 l = mpa_huff_data[k][0];
1560 linbits = mpa_huff_data[k][1];
1561 vlc = &huff_vlc[l];
1562 code_table = huff_code_table[l];
1563
1564 /* read huffcode and compute each couple */
1565 for(;j>0;j--) {
1566 if (get_bits_count(&s->gb) >= end_pos)
1567 break;
1568 if (code_table) {
1569 code = get_vlc(&s->gb, vlc);
1570 if (code < 0)
1571 return -1;
1572 y = code_table[code];
1573 x = y >> 4;
1574 y = y & 0x0f;
1575 } else {
1576 x = 0;
1577 y = 0;
1578 }
1579 dprintf("region=%d n=%d x=%d y=%d exp=%d\n",
1580 i, g->region_size[i] - j, x, y, exponents[s_index]);
1581 if (x) {
1582 if (x == 15)
1583 x += get_bitsz(&s->gb, linbits);
1584 v = l3_unscale(x, exponents[s_index]);
1585 if (get_bits1(&s->gb))
1586 v = -v;
1587 } else {
1588 v = 0;
1589 }
1590 g->sb_hybrid[s_index++] = v;
1591 if (y) {
1592 if (y == 15)
1593 y += get_bitsz(&s->gb, linbits);
1594 v = l3_unscale(y, exponents[s_index]);
1595 if (get_bits1(&s->gb))
1596 v = -v;
1597 } else {
1598 v = 0;
1599 }
1600 g->sb_hybrid[s_index++] = v;
1601 }
1602 }
1603
1604 /* high frequencies */
1605 vlc = &huff_quad_vlc[g->count1table_select];
1606 last_gb.buffer = NULL;
1607 while (s_index <= 572) {
1608 pos = get_bits_count(&s->gb);
1609 if (pos >= end_pos) {
1610 if (pos > end_pos && last_gb.buffer != NULL) {
1611 /* some encoders generate an incorrect size for this
1612 part. We must go back into the data */
1613 s_index -= 4;
1614 s->gb = last_gb;
1615 }
1616 break;
1617 }
1618 last_gb= s->gb;
1619
1620 code = get_vlc(&s->gb, vlc);
1621 dprintf("t=%d code=%d\n", g->count1table_select, code);
1622 if (code < 0)
1623 return -1;
1624 for(i=0;i<4;i++) {
1625 if (code & (8 >> i)) {
1626 /* non zero value. Could use a hand coded function for
1627 'one' value */
1628 v = l3_unscale(1, exponents[s_index]);
1629 if(get_bits1(&s->gb))
1630 v = -v;
1631 } else {
1632 v = 0;
1633 }
1634 g->sb_hybrid[s_index++] = v;
1635 }
1636 }
1637 while (s_index < 576)
1638 g->sb_hybrid[s_index++] = 0;
1639 return 0;
1640 }
1641
1642 /* Reorder short blocks from bitstream order to interleaved order. It
1643 would be faster to do it in parsing, but the code would be far more
1644 complicated */
1645 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
1646 {
1647 int i, j, k, len;
1648 INT32 *ptr, *dst, *ptr1;
1649 INT32 tmp[576];
1650
1651 if (g->block_type != 2)
1652 return;
1653
1654 if (g->switch_point) {
1655 if (s->sample_rate_index != 8) {
1656 ptr = g->sb_hybrid + 36;
1657 } else {
1658 ptr = g->sb_hybrid + 48;
1659 }
1660 } else {
1661 ptr = g->sb_hybrid;
1662 }
1663
1664 for(i=g->short_start;i<13;i++) {
1665 len = band_size_short[s->sample_rate_index][i];
1666 ptr1 = ptr;
1667 for(k=0;k<3;k++) {
1668 dst = tmp + k;
1669 for(j=len;j>0;j--) {
1670 *dst = *ptr++;
1671 dst += 3;
1672 }
1673 }
1674 memcpy(ptr1, tmp, len * 3 * sizeof(INT32));
1675 }
1676 }
1677
1678 #define ISQRT2 FIXR(0.70710678118654752440)
1679
1680 static void compute_stereo(MPADecodeContext *s,
1681 GranuleDef *g0, GranuleDef *g1)
1682 {
1683 int i, j, k, l;
1684 INT32 v1, v2;
1685 int sf_max, tmp0, tmp1, sf, len, non_zero_found;
1686 INT32 (*is_tab)[16];
1687 INT32 *tab0, *tab1;
1688 int non_zero_found_short[3];
1689
1690 /* intensity stereo */
1691 if (s->mode_ext & MODE_EXT_I_STEREO) {
1692 if (!s->lsf) {
1693 is_tab = is_table;
1694 sf_max = 7;
1695 } else {
1696 is_tab = is_table_lsf[g1->scalefac_compress & 1];
1697 sf_max = 16;
1698 }
1699
1700 tab0 = g0->sb_hybrid + 576;
1701 tab1 = g1->sb_hybrid + 576;
1702
1703 non_zero_found_short[0] = 0;
1704 non_zero_found_short[1] = 0;
1705 non_zero_found_short[2] = 0;
1706 k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1707 for(i = 12;i >= g1->short_start;i--) {
1708 /* for last band, use previous scale factor */
1709 if (i != 11)
1710 k -= 3;
1711 len = band_size_short[s->sample_rate_index][i];
1712 for(l=2;l>=0;l--) {
1713 tab0 -= len;
1714 tab1 -= len;
1715 if (!non_zero_found_short[l]) {
1716 /* test if non zero band. if so, stop doing i-stereo */
1717 for(j=0;j<len;j++) {
1718 if (tab1[j] != 0) {
1719 non_zero_found_short[l] = 1;
1720 goto found1;
1721 }
1722 }
1723 sf = g1->scale_factors[k + l];
1724 if (sf >= sf_max)
1725 goto found1;
1726
1727 v1 = is_tab[0][sf];
1728 v2 = is_tab[1][sf];
1729 for(j=0;j<len;j++) {
1730 tmp0 = tab0[j];
1731 tab0[j] = MULL(tmp0, v1);
1732 tab1[j] = MULL(tmp0, v2);
1733 }
1734 } else {
1735 found1:
1736 if (s->mode_ext & MODE_EXT_MS_STEREO) {
1737 /* lower part of the spectrum : do ms stereo
1738 if enabled */
1739 for(j=0;j<len;j++) {
1740 tmp0 = tab0[j];
1741 tmp1 = tab1[j];
1742 tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1743 tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1744 }
1745 }
1746 }
1747 }
1748 }
1749
1750 non_zero_found = non_zero_found_short[0] |
1751 non_zero_found_short[1] |
1752 non_zero_found_short[2];
1753
1754 for(i = g1->long_end - 1;i >= 0;i--) {
1755 len = band_size_long[s->sample_rate_index][i];
1756 tab0 -= len;
1757 tab1 -= len;
1758 /* test if non zero band. if so, stop doing i-stereo */
1759 if (!non_zero_found) {
1760 for(j=0;j<len;j++) {
1761 if (tab1[j] != 0) {
1762 non_zero_found = 1;
1763 goto found2;
1764 }
1765 }
1766 /* for last band, use previous scale factor */
1767 k = (i == 21) ? 20 : i;
1768 sf = g1->scale_factors[k];
1769 if (sf >= sf_max)
1770 goto found2;
1771 v1 = is_tab[0][sf];
1772 v2 = is_tab[1][sf];
1773 for(j=0;j<len;j++) {
1774 tmp0 = tab0[j];
1775 tab0[j] = MULL(tmp0, v1);
1776 tab1[j] = MULL(tmp0, v2);
1777 }
1778 } else {
1779 found2:
1780 if (s->mode_ext & MODE_EXT_MS_STEREO) {
1781 /* lower part of the spectrum : do ms stereo
1782 if enabled */
1783 for(j=0;j<len;j++) {
1784 tmp0 = tab0[j];
1785 tmp1 = tab1[j];
1786 tab0[j] = MULL(tmp0 + tmp1, ISQRT2);
1787 tab1[j] = MULL(tmp0 - tmp1, ISQRT2);
1788 }
1789 }
1790 }
1791 }
1792 } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1793 /* ms stereo ONLY */
1794 /* NOTE: the 1/sqrt(2) normalization factor is included in the
1795 global gain */
1796 tab0 = g0->sb_hybrid;
1797 tab1 = g1->sb_hybrid;
1798 for(i=0;i<576;i++) {
1799 tmp0 = tab0[i];
1800 tmp1 = tab1[i];
1801 tab0[i] = tmp0 + tmp1;
1802 tab1[i] = tmp0 - tmp1;
1803 }
1804 }
1805 }
1806
1807 static void compute_antialias(MPADecodeContext *s,
1808 GranuleDef *g)
1809 {
1810 INT32 *ptr, *p0, *p1, *csa;
1811 int n, tmp0, tmp1, i, j;
1812
1813 /* we antialias only "long" bands */
1814 if (g->block_type == 2) {
1815 if (!g->switch_point)
1816 return;
1817 /* XXX: check this for 8000Hz case */
1818 n = 1;
1819 } else {
1820 n = SBLIMIT - 1;
1821 }
1822
1823 ptr = g->sb_hybrid + 18;
1824 for(i = n;i > 0;i--) {
1825 p0 = ptr - 1;
1826 p1 = ptr;
1827 csa = &csa_table[0][0];
1828 for(j=0;j<8;j++) {
1829 tmp0 = *p0;
1830 tmp1 = *p1;
1831 *p0 = FRAC_RND(MUL64(tmp0, csa[0]) - MUL64(tmp1, csa[1]));
1832 *p1 = FRAC_RND(MUL64(tmp0, csa[1]) + MUL64(tmp1, csa[0]));
1833 p0--;
1834 p1++;
1835 csa += 2;
1836 }
1837 ptr += 18;
1838 }
1839 }
1840
1841 static void compute_imdct(MPADecodeContext *s,
1842 GranuleDef *g,
1843 INT32 *sb_samples,
1844 INT32 *mdct_buf)
1845 {
1846 INT32 *ptr, *win, *win1, *buf, *buf2, *out_ptr, *ptr1;
1847 INT32 in[6];
1848 INT32 out[36];
1849 INT32 out2[12];
1850 int i, j, k, mdct_long_end, v, sblimit;
1851
1852 /* find last non zero block */
1853 ptr = g->sb_hybrid + 576;
1854 ptr1 = g->sb_hybrid + 2 * 18;
1855 while (ptr >= ptr1) {
1856 ptr -= 6;
1857 v = ptr[0] | ptr[1] | ptr[2] | ptr[3] | ptr[4] | ptr[5];
1858 if (v != 0)
1859 break;
1860 }
1861 sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1862
1863 if (g->block_type == 2) {
1864 /* XXX: check for 8000 Hz */
1865 if (g->switch_point)
1866 mdct_long_end = 2;
1867 else
1868 mdct_long_end = 0;
1869 } else {
1870 mdct_long_end = sblimit;
1871 }
1872
1873 buf = mdct_buf;
1874 ptr = g->sb_hybrid;
1875 for(j=0;j<mdct_long_end;j++) {
1876 imdct36(out, ptr);
1877 /* apply window & overlap with previous buffer */
1878 out_ptr = sb_samples + j;
1879 /* select window */
1880 if (g->switch_point && j < 2)
1881 win1 = mdct_win[0];
1882 else
1883 win1 = mdct_win[g->block_type];
1884 /* select frequency inversion */
1885 win = win1 + ((4 * 36) & -(j & 1));
1886 for(i=0;i<18;i++) {
1887 *out_ptr = MULL(out[i], win[i]) + buf[i];
1888 buf[i] = MULL(out[i + 18], win[i + 18]);
1889 out_ptr += SBLIMIT;
1890 }
1891 ptr += 18;
1892 buf += 18;
1893 }
1894 for(j=mdct_long_end;j<sblimit;j++) {
1895 for(i=0;i<6;i++) {
1896 out[i] = 0;
1897 out[6 + i] = 0;
1898 out[30+i] = 0;
1899 }
1900 /* select frequency inversion */
1901 win = mdct_win[2] + ((4 * 36) & -(j & 1));
1902 buf2 = out + 6;
1903 for(k=0;k<3;k++) {
1904 /* reorder input for short mdct */
1905 ptr1 = ptr + k;
1906 for(i=0;i<6;i++) {
1907 in[i] = *ptr1;
1908 ptr1 += 3;
1909 }
1910 imdct12(out2, in);
1911 /* apply 12 point window and do small overlap */
1912 for(i=0;i<6;i++) {
1913 buf2[i] = MULL(out2[i], win[i]) + buf2[i];
1914 buf2[i + 6] = MULL(out2[i + 6], win[i + 6]);
1915 }
1916 buf2 += 6;
1917 }
1918 /* overlap */
1919 out_ptr = sb_samples + j;
1920 for(i=0;i<18;i++) {
1921 *out_ptr = out[i] + buf[i];
1922 buf[i] = out[i + 18];
1923 out_ptr += SBLIMIT;
1924 }
1925 ptr += 18;
1926 buf += 18;
1927 }
1928 /* zero bands */
1929 for(j=sblimit;j<SBLIMIT;j++) {
1930 /* overlap */
1931 out_ptr = sb_samples + j;
1932 for(i=0;i<18;i++) {
1933 *out_ptr = buf[i];
1934 buf[i] = 0;
1935 out_ptr += SBLIMIT;
1936 }
1937 buf += 18;
1938 }
1939 }
1940
1941 #if defined(DEBUG)
1942 void sample_dump(int fnum, INT32 *tab, int n)
1943 {
1944 static FILE *files[16], *f;
1945 char buf[512];
1946 int i;
1947 INT32 v;
1948
1949 f = files[fnum];
1950 if (!f) {
1951 sprintf(buf, "/tmp/out%d.%s.pcm",
1952 fnum,
1953 #ifdef USE_HIGHPRECISION
1954 "hp"
1955 #else
1956 "lp"
1957 #endif
1958 );
1959 f = fopen(buf, "w");
1960 if (!f)
1961 return;
1962 files[fnum] = f;
1963 }
1964
1965 if (fnum == 0) {
1966 static int pos = 0;
1967 printf("pos=%d\n", pos);
1968 for(i=0;i<n;i++) {
1969 printf(" %0.4f", (double)tab[i] / FRAC_ONE);
1970 if ((i % 18) == 17)
1971 printf("\n");
1972 }
1973 pos += n;
1974 }
1975 for(i=0;i<n;i++) {
1976 /* normalize to 23 frac bits */
1977 v = tab[i] << (23 - FRAC_BITS);
1978 fwrite(&v, 1, sizeof(INT32), f);
1979 }
1980 }
1981 #endif
1982
1983
1984 /* main layer3 decoding function */
1985 static int mp_decode_layer3(MPADecodeContext *s)
1986 {
1987 int nb_granules, main_data_begin, private_bits;
1988 int gr, ch, blocksplit_flag, i, j, k, n, bits_pos, bits_left;
1989 GranuleDef granules[2][2], *g;
1990 INT16 exponents[576];
1991
1992 /* read side info */
1993 if (s->lsf) {
1994 main_data_begin = get_bits(&s->gb, 8);
1995 if (s->nb_channels == 2)
1996 private_bits = get_bits(&s->gb, 2);
1997 else
1998 private_bits = get_bits(&s->gb, 1);
1999 nb_granules = 1;
2000 } else {
2001 main_data_begin = get_bits(&s->gb, 9);
2002 if (s->nb_channels == 2)
2003 private_bits = get_bits(&s->gb, 3);
2004 else
2005 private_bits = get_bits(&s->gb, 5);
2006 nb_granules = 2;
2007 for(ch=0;ch<s->nb_channels;ch++) {
2008 granules[ch][0].scfsi = 0; /* all scale factors are transmitted */
2009 granules[ch][1].scfsi = get_bits(&s->gb, 4);
2010 }
2011 }
2012
2013 for(gr=0;gr<nb_granules;gr++) {
2014 for(ch=0;ch<s->nb_channels;ch++) {
2015 dprintf("gr=%d ch=%d: side_info\n", gr, ch);
2016 g = &granules[ch][gr];
2017 g->part2_3_length = get_bits(&s->gb, 12);
2018 g->big_values = get_bits(&s->gb, 9);
2019 g->global_gain = get_bits(&s->gb, 8);
2020 /* if MS stereo only is selected, we precompute the
2021 1/sqrt(2) renormalization factor */
2022 if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
2023 MODE_EXT_MS_STEREO)
2024 g->global_gain -= 2;
2025 if (s->lsf)
2026 g->scalefac_compress = get_bits(&s->gb, 9);
2027 else
2028 g->scalefac_compress = get_bits(&s->gb, 4);
2029 blocksplit_flag = get_bits(&s->gb, 1);
2030 if (blocksplit_flag) {
2031 g->block_type = get_bits(&s->gb, 2);
2032 if (g->block_type == 0)
2033 return -1;
2034 g->switch_point = get_bits(&s->gb, 1);
2035 for(i=0;i<2;i++)
2036 g->table_select[i] = get_bits(&s->gb, 5);
2037 for(i=0;i<3;i++)
2038 g->subblock_gain[i] = get_bits(&s->gb, 3);
2039 /* compute huffman coded region sizes */
2040 if (g->block_type == 2)
2041 g->region_size[0] = (36 / 2);
2042 else {
2043 if (s->sample_rate_index <= 2)
2044 g->region_size[0] = (36 / 2);
2045 else if (s->sample_rate_index != 8)
2046 g->region_size[0] = (54 / 2);
2047 else
2048 g->region_size[0] = (108 / 2);
2049 }
2050 g->region_size[1] = (576 / 2);
2051 } else {
2052 int region_address1, region_address2, l;
2053 g->block_type = 0;
2054 g->switch_point = 0;
2055 for(i=0;i<3;i++)
2056 g->table_select[i] = get_bits(&s->gb, 5);
2057 /* compute huffman coded region sizes */
2058 region_address1 = get_bits(&s->gb, 4);
2059 region_address2 = get_bits(&s->gb, 3);
2060 dprintf("region1=%d region2=%d\n",
2061 region_address1, region_address2);
2062 g->region_size[0] =
2063 band_index_long[s->sample_rate_index][region_address1 + 1] >> 1;
2064 l = region_address1 + region_address2 + 2;
2065 /* should not overflow */
2066 if (l > 22)
2067 l = 22;
2068 g->region_size[1] =
2069 band_index_long[s->sample_rate_index][l] >> 1;
2070 }
2071 /* convert region offsets to region sizes and truncate
2072 size to big_values */
2073 g->region_size[2] = (576 / 2);
2074 j = 0;
2075 for(i=0;i<3;i++) {
2076 k = g->region_size[i];
2077 if (k > g->big_values)
2078 k = g->big_values;
2079 g->region_size[i] = k - j;
2080 j = k;
2081 }
2082
2083 /* compute band indexes */
2084 if (g->block_type == 2) {
2085 if (g->switch_point) {
2086 /* if switched mode, we handle the 36 first samples as
2087 long blocks. For 8000Hz, we handle the 48 first
2088 exponents as long blocks (XXX: check this!) */
2089 if (s->sample_rate_index <= 2)
2090 g->long_end = 8;
2091 else if (s->sample_rate_index != 8)
2092 g->long_end = 6;
2093 else
2094 g->long_end = 4; /* 8000 Hz */
2095
2096 if (s->sample_rate_index != 8)
2097 g->short_start = 3;
2098 else
2099 g->short_start = 2;
2100 } else {
2101 g->long_end = 0;
2102 g->short_start = 0;
2103 }
2104 } else {
2105 g->short_start = 13;
2106 g->long_end = 22;
2107 }
2108
2109 g->preflag = 0;
2110 if (!s->lsf)
2111 g->preflag = get_bits(&s->gb, 1);
2112 g->scalefac_scale = get_bits(&s->gb, 1);
2113 g->count1table_select = get_bits(&s->gb, 1);
2114 dprintf("block_type=%d switch_point=%d\n",
2115 g->block_type, g->switch_point);
2116 }
2117 }
2118
2119 /* now we get bits from the main_data_begin offset */
2120 dprintf("seekback: %d\n", main_data_begin);
2121 seek_to_maindata(s, main_data_begin);
2122
2123 for(gr=0;gr<nb_granules;gr++) {
2124 for(ch=0;ch<s->nb_channels;ch++) {
2125 g = &granules[ch][gr];
2126
2127 bits_pos = get_bits_count(&s->gb);
2128
2129 if (!s->lsf) {
2130 UINT8 *sc;
2131 int slen, slen1, slen2;
2132
2133 /* MPEG1 scale factors */
2134 slen1 = slen_table[0][g->scalefac_compress];
2135 slen2 = slen_table[1][g->scalefac_compress];
2136 dprintf("slen1=%d slen2=%d\n", slen1, slen2);
2137 if (g->block_type == 2) {
2138 n = g->switch_point ? 17 : 18;
2139 j = 0;
2140 for(i=0;i<n;i++)
2141 g->scale_factors[j++] = get_bitsz(&s->gb, slen1);
2142 for(i=0;i<18;i++)
2143 g->scale_factors[j++] = get_bitsz(&s->gb, slen2);
2144 for(i=0;i<3;i++)
2145 g->scale_factors[j++] = 0;
2146 } else {
2147 sc = granules[ch][0].scale_factors;
2148 j = 0;
2149 for(k=0;k<4;k++) {
2150 n = (k == 0 ? 6 : 5);
2151 if ((g->scfsi & (0x8 >> k)) == 0) {
2152 slen = (k < 2) ? slen1 : slen2;
2153 for(i=0;i<n;i++)
2154 g->scale_factors[j++] = get_bitsz(&s->gb, slen);
2155 } else {
2156 /* simply copy from last granule */
2157 for(i=0;i<n;i++) {
2158 g->scale_factors[j] = sc[j];
2159 j++;
2160 }
2161 }
2162 }
2163 g->scale_factors[j++] = 0;
2164 }
2165 #if defined(DEBUG)
2166 {
2167 printf("scfsi=%x gr=%d ch=%d scale_factors:\n",
2168 g->scfsi, gr, ch);
2169 for(i=0;i<j;i++)
2170 printf(" %d", g->scale_factors[i]);
2171 printf("\n");
2172 }
2173 #endif
2174 } else {
2175 int tindex, tindex2, slen[4], sl, sf;
2176
2177 /* LSF scale factors */
2178 if (g->block_type == 2) {
2179 tindex = g->switch_point ? 2 : 1;
2180 } else {
2181 tindex = 0;
2182 }
2183 sf = g->scalefac_compress;
2184 if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
2185 /* intensity stereo case */
2186 sf >>= 1;
2187 if (sf < 180) {
2188 lsf_sf_expand(slen, sf, 6, 6, 0);
2189 tindex2 = 3;
2190 } else if (sf < 244) {
2191 lsf_sf_expand(slen, sf - 180, 4, 4, 0);
2192 tindex2 = 4;
2193 } else {
2194 lsf_sf_expand(slen, sf - 244, 3, 0, 0);
2195 tindex2 = 5;
2196 }
2197 } else {
2198 /* normal case */
2199 if (sf < 400) {
2200 lsf_sf_expand(slen, sf, 5, 4, 4);
2201 tindex2 = 0;
2202 } else if (sf < 500) {
2203 lsf_sf_expand(slen, sf - 400, 5, 4, 0);
2204 tindex2 = 1;
2205 } else {
2206 lsf_sf_expand(slen, sf - 500, 3, 0, 0);
2207 tindex2 = 2;
2208 g->preflag = 1;
2209 }
2210 }
2211
2212 j = 0;
2213 for(k=0;k<4;k++) {
2214 n = lsf_nsf_table[tindex2][tindex][k];
2215 sl = slen[k];
2216 for(i=0;i<n;i++)
2217 g->scale_factors[j++] = get_bitsz(&s->gb, sl);
2218 }
2219 /* XXX: should compute exact size */
2220 for(;j<40;j++)
2221 g->scale_factors[j] = 0;
2222 #if defined(DEBUG)
2223 {
2224 printf("gr=%d ch=%d scale_factors:\n",
2225 gr, ch);
2226 for(i=0;i<40;i++)
2227 printf(" %d", g->scale_factors[i]);
2228 printf("\n");
2229 }
2230 #endif
2231 }
2232
2233 exponents_from_scale_factors(s, g, exponents);
2234
2235 /* read Huffman coded residue */
2236 if (huffman_decode(s, g, exponents,
2237 bits_pos + g->part2_3_length) < 0)
2238 return -1;
2239 #if defined(DEBUG)
2240 sample_dump(0, g->sb_hybrid, 576);
2241 #endif
2242
2243 /* skip extension bits */
2244 bits_left = g->part2_3_length - (get_bits_count(&s->gb) - bits_pos);
2245 if (bits_left < 0) {
2246 dprintf("bits_left=%d\n", bits_left);
2247 return -1;
2248 }
2249 while (bits_left >= 16) {
2250 skip_bits(&s->gb, 16);
2251 bits_left -= 16;
2252 }
2253 if (bits_left > 0)
2254 skip_bits(&s->gb, bits_left);
2255 } /* ch */
2256
2257 if (s->nb_channels == 2)
2258 compute_stereo(s, &granules[0][gr], &granules[1][gr]);
2259
2260 for(ch=0;ch<s->nb_channels;ch++) {
2261 g = &granules[ch][gr];
2262
2263 reorder_block(s, g);
2264 #if defined(DEBUG)
2265 sample_dump(0, g->sb_hybrid, 576);
2266 #endif
2267 compute_antialias(s, g);
2268 #if defined(DEBUG)
2269 sample_dump(1, g->sb_hybrid, 576);
2270 #endif
2271 compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
2272 #if defined(DEBUG)
2273 sample_dump(2, &s->sb_samples[ch][18 * gr][0], 576);
2274 #endif
2275 }
2276 } /* gr */
2277 return nb_granules * 18;
2278 }
2279
2280 static int mp_decode_frame(MPADecodeContext *s,
2281 short *samples)
2282 {
2283 int i, nb_frames, ch;
2284 short *samples_ptr;
2285
2286 init_get_bits(&s->gb, s->inbuf + HEADER_SIZE,
2287 s->inbuf_ptr - s->inbuf - HEADER_SIZE);
2288
2289 /* skip error protection field */
2290 if (s->error_protection)
2291 get_bits(&s->gb, 16);
2292
2293 dprintf("frame %d:\n", s->frame_count);
2294 switch(s->layer) {
2295 case 1:
2296 nb_frames = mp_decode_layer1(s);
2297 break;
2298 case 2:
2299 nb_frames = mp_decode_layer2(s);
2300 break;
2301 case 3:
2302 default:
2303 nb_frames = mp_decode_layer3(s);
2304 break;
2305 }
2306 #if defined(DEBUG)
2307 for(i=0;i<nb_frames;i++) {
2308 for(ch=0;ch<s->nb_channels;ch++) {
2309 int j;
2310 printf("%d-%d:", i, ch);
2311 for(j=0;j<SBLIMIT;j++)
2312 printf(" %0.6f", (double)s->sb_samples[ch][i][j] / FRAC_ONE);
2313 printf("\n");
2314 }
2315 }
2316 #endif
2317 /* apply the synthesis filter */
2318 for(ch=0;ch<s->nb_channels;ch++) {
2319 samples_ptr = samples + ch;
2320 for(i=0;i<nb_frames;i++) {
2321 synth_filter(s, ch, samples_ptr, s->nb_channels,
2322 s->sb_samples[ch][i]);
2323 samples_ptr += 32 * s->nb_channels;
2324 }
2325 }
2326 #ifdef DEBUG
2327 s->frame_count++;
2328 #endif
2329 return nb_frames * 32 * sizeof(short) * s->nb_channels;
2330 }
2331
2332 static int decode_frame(AVCodecContext * avctx,
2333 void *data, int *data_size,
2334 UINT8 * buf, int buf_size)
2335 {
2336 MPADecodeContext *s = avctx->priv_data;
2337 UINT32 header;
2338 UINT8 *buf_ptr;
2339 int len, out_size;
2340 short *out_samples = data;
2341
2342 *data_size = 0;
2343 buf_ptr = buf;
2344 while (buf_size > 0) {
2345 len = s->inbuf_ptr - s->inbuf;
2346 if (s->frame_size == 0) {
2347 /* special case for next header for first frame in free
2348 format case (XXX: find a simpler method) */
2349 if (s->free_format_next_header != 0) {
2350 s->inbuf[0] = s->free_format_next_header >> 24;
2351 s->inbuf[1] = s->free_format_next_header >> 16;
2352 s->inbuf[2] = s->free_format_next_header >> 8;
2353 s->inbuf[3] = s->free_format_next_header;
2354 s->inbuf_ptr = s->inbuf + 4;
2355 s->free_format_next_header = 0;
2356 goto got_header;
2357 }
2358 /* no header seen : find one. We need at least HEADER_SIZE
2359 bytes to parse it */
2360 len = HEADER_SIZE - len;
2361 if (len > buf_size)
2362 len = buf_size;
2363 if (len > 0) {
2364 memcpy(s->inbuf_ptr, buf_ptr, len);
2365 buf_ptr += len;
2366 buf_size -= len;
2367 s->inbuf_ptr += len;
2368 }
2369 if ((s->inbuf_ptr - s->inbuf) >= HEADER_SIZE) {
2370 got_header:
2371 header = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2372 (s->inbuf[2] << 8) | s->inbuf[3];
2373
2374 if (check_header(header) < 0) {
2375 /* no sync found : move by one byte (inefficient, but simple!) */
2376 memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2377 s->inbuf_ptr--;
2378 dprintf("skip %x\n", header);
2379 /* reset free format frame size to give a chance
2380 to get a new bitrate */
2381 s->free_format_frame_size = 0;
2382 } else {
2383 if (decode_header(s, header) == 1) {
2384 /* free format: prepare to compute frame size */
2385 s->frame_size = -1;
2386 }
2387 /* update codec info */
2388 avctx->sample_rate = s->sample_rate;
2389 avctx->channels = s->nb_channels;
2390 avctx->bit_rate = s->bit_rate;
2391 avctx->frame_size = s->frame_size;
2392 }
2393 }
2394 } else if (s->frame_size == -1) {
2395 /* free format : find next sync to compute frame size */
2396 len = MPA_MAX_CODED_FRAME_SIZE - len;
2397 if (len > buf_size)
2398 len = buf_size;
2399 if (len == 0) {
2400 /* frame too long: resync */
2401 s->frame_size = 0;
2402 memcpy(s->inbuf, s->inbuf + 1, s->inbuf_ptr - s->inbuf - 1);
2403 s->inbuf_ptr--;
2404 } else {
2405 UINT8 *p, *pend;
2406 UINT32 header1;
2407 int padding;
2408
2409 memcpy(s->inbuf_ptr, buf_ptr, len);
2410 /* check for header */
2411 p = s->inbuf_ptr - 3;
2412 pend = s->inbuf_ptr + len - 4;
2413 while (p <= pend) {
2414 header = (p[0] << 24) | (p[1] << 16) |
2415 (p[2] << 8) | p[3];
2416 header1 = (s->inbuf[0] << 24) | (s->inbuf[1] << 16) |
2417 (s->inbuf[2] << 8) | s->inbuf[3];
2418 /* check with high probability that we have a
2419 valid header */
2420 if ((header & SAME_HEADER_MASK) ==
2421 (header1 & SAME_HEADER_MASK)) {
2422 /* header found: update pointers */
2423 len = (p + 4) - s->inbuf_ptr;
2424 buf_ptr += len;
2425 buf_size -= len;
2426 s->inbuf_ptr = p;
2427 /* compute frame size */
2428 s->free_format_next_header = header;
2429 s->free_format_frame_size = s->inbuf_ptr - s->inbuf;
2430 padding = (header1 >> 9) & 1;
2431 if (s->layer == 1)
2432 s->free_format_frame_size -= padding * 4;
2433 else
2434 s->free_format_frame_size -= padding;
2435 dprintf("free frame size=%d padding=%d\n",
2436 s->free_format_frame_size, padding);
2437 decode_header(s, header1);
2438 goto next_data;
2439 }
2440 p++;
2441 }
2442 /* not found: simply increase pointers */
2443 buf_ptr += len;
2444 s->inbuf_ptr += len;
2445 buf_size -= len;
2446 }
2447 } else if (len < s->frame_size) {
2448 if (s->frame_size > MPA_MAX_CODED_FRAME_SIZE)
2449 s->frame_size = MPA_MAX_CODED_FRAME_SIZE;
2450 len = s->frame_size - len;
2451 if (len > buf_size)
2452 len = buf_size;
2453 memcpy(s->inbuf_ptr, buf_ptr, len);
2454 buf_ptr += len;
2455 s->inbuf_ptr += len;
2456 buf_size -= len;
2457 } else {
2458 out_size = mp_decode_frame(s, out_samples);
2459 s->inbuf_ptr = s->inbuf;
2460 s->frame_size = 0;
2461 *data_size = out_size;
2462 break;
2463 }
2464 next_data:
2465 ;
2466 }
2467 return buf_ptr - buf;
2468 }
2469
2470 AVCodec mp2_decoder =
2471 {
2472 "mp2",
2473 CODEC_TYPE_AUDIO,
2474 CODEC_ID_MP2,
2475 sizeof(MPADecodeContext),
2476 decode_init,
2477 NULL,
2478 NULL,
2479 decode_frame,
2480 };
2481
2482 AVCodec mp3_decoder =
2483 {
2484 "mp3",
2485 CODEC_TYPE_AUDIO,
2486 CODEC_ID_MP3LAME,
2487 sizeof(MPADecodeContext),
2488 decode_init,
2489 NULL,
2490 NULL,
2491 decode_frame,
2492 };
2493
2494 #undef C1
2495 #undef C2
2496 #undef C3
2497 #undef C4
2498 #undef C5
2499 #undef C6
2500 #undef C7
2501 #undef C8
2502 #undef FRAC_BITS
2503 #undef HEADER_SIZE
Libav master