Libav
mpegaudiodec_template.c
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1 /*
2  * MPEG Audio decoder
3  * Copyright (c) 2001, 2002 Fabrice Bellard
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "libavutil/attributes.h"
28 #include "libavutil/avassert.h"
30 #include "libavutil/float_dsp.h"
31 #include "avcodec.h"
32 #include "get_bits.h"
33 #include "internal.h"
34 #include "mathops.h"
35 #include "mpegaudiodsp.h"
36 
37 /*
38  * TODO:
39  * - test lsf / mpeg25 extensively.
40  */
41 
42 #include "mpegaudio.h"
43 #include "mpegaudiodecheader.h"
44 
45 #define BACKSTEP_SIZE 512
46 #define EXTRABYTES 24
47 #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES
48 
49 /* layer 3 "granule" */
50 typedef struct GranuleDef {
58  int table_select[3];
59  int subblock_gain[3];
62  int region_size[3]; /* number of huffman codes in each region */
63  int preflag;
64  int short_start, long_end; /* long/short band indexes */
66  DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */
67 } GranuleDef;
68 
69 typedef struct MPADecodeContext {
73  /* next header (used in free format parsing) */
80  INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
81  GranuleDef granules[2][2]; /* Used in Layer 3 */
82  int adu_mode;
90 
91 #define HEADER_SIZE 4
92 
93 #include "mpegaudiodata.h"
94 #include "mpegaudiodectab.h"
95 
96 /* vlc structure for decoding layer 3 huffman tables */
97 static VLC huff_vlc[16];
99  0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +
100  142 + 204 + 190 + 170 + 542 + 460 + 662 + 414
101  ][2];
102 static const int huff_vlc_tables_sizes[16] = {
103  0, 128, 128, 128, 130, 128, 154, 166,
104  142, 204, 190, 170, 542, 460, 662, 414
105 };
106 static VLC huff_quad_vlc[2];
107 static VLC_TYPE huff_quad_vlc_tables[128+16][2];
108 static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };
109 /* computed from band_size_long */
110 static uint16_t band_index_long[9][23];
111 #include "mpegaudio_tablegen.h"
112 /* intensity stereo coef table */
113 static INTFLOAT is_table[2][16];
114 static INTFLOAT is_table_lsf[2][2][16];
115 static INTFLOAT csa_table[8][4];
116 
117 static int16_t division_tab3[1<<6 ];
118 static int16_t division_tab5[1<<8 ];
119 static int16_t division_tab9[1<<11];
120 
121 static int16_t * const division_tabs[4] = {
123 };
124 
125 /* lower 2 bits: modulo 3, higher bits: shift */
126 static uint16_t scale_factor_modshift[64];
127 /* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
129 /* mult table for layer 2 group quantization */
130 
131 #define SCALE_GEN(v) \
132 { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
133 
134 static const int32_t scale_factor_mult2[3][3] = {
135  SCALE_GEN(4.0 / 3.0), /* 3 steps */
136  SCALE_GEN(4.0 / 5.0), /* 5 steps */
137  SCALE_GEN(4.0 / 9.0), /* 9 steps */
138 };
139 
145 {
146  int i, k, j = 0;
147  g->region_size[2] = 576 / 2;
148  for (i = 0; i < 3; i++) {
149  k = FFMIN(g->region_size[i], g->big_values);
150  g->region_size[i] = k - j;
151  j = k;
152  }
153 }
154 
156 {
157  if (g->block_type == 2) {
158  if (s->sample_rate_index != 8)
159  g->region_size[0] = (36 / 2);
160  else
161  g->region_size[0] = (72 / 2);
162  } else {
163  if (s->sample_rate_index <= 2)
164  g->region_size[0] = (36 / 2);
165  else if (s->sample_rate_index != 8)
166  g->region_size[0] = (54 / 2);
167  else
168  g->region_size[0] = (108 / 2);
169  }
170  g->region_size[1] = (576 / 2);
171 }
172 
174  int ra1, int ra2)
175 {
176  int l;
177  g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
178  /* should not overflow */
179  l = FFMIN(ra1 + ra2 + 2, 22);
180  g->region_size[1] = band_index_long[s->sample_rate_index][ l] >> 1;
181 }
182 
184 {
185  if (g->block_type == 2) {
186  if (g->switch_point) {
187  /* if switched mode, we handle the 36 first samples as
188  long blocks. For 8000Hz, we handle the 72 first
189  exponents as long blocks */
190  if (s->sample_rate_index <= 2)
191  g->long_end = 8;
192  else
193  g->long_end = 6;
194 
195  g->short_start = 3;
196  } else {
197  g->long_end = 0;
198  g->short_start = 0;
199  }
200  } else {
201  g->short_start = 13;
202  g->long_end = 22;
203  }
204 }
205 
206 /* layer 1 unscaling */
207 /* n = number of bits of the mantissa minus 1 */
208 static inline int l1_unscale(int n, int mant, int scale_factor)
209 {
210  int shift, mod;
211  int64_t val;
212 
213  shift = scale_factor_modshift[scale_factor];
214  mod = shift & 3;
215  shift >>= 2;
216  val = MUL64(mant + (-1 << n) + 1, scale_factor_mult[n-1][mod]);
217  shift += n;
218  /* NOTE: at this point, 1 <= shift >= 21 + 15 */
219  return (int)((val + (1LL << (shift - 1))) >> shift);
220 }
221 
222 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
223 {
224  int shift, mod, val;
225 
226  shift = scale_factor_modshift[scale_factor];
227  mod = shift & 3;
228  shift >>= 2;
229 
230  val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
231  /* NOTE: at this point, 0 <= shift <= 21 */
232  if (shift > 0)
233  val = (val + (1 << (shift - 1))) >> shift;
234  return val;
235 }
236 
237 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
238 static inline int l3_unscale(int value, int exponent)
239 {
240  unsigned int m;
241  int e;
242 
243  e = table_4_3_exp [4 * value + (exponent & 3)];
244  m = table_4_3_value[4 * value + (exponent & 3)];
245  e -= exponent >> 2;
246  assert(e >= 1);
247  if (e > 31)
248  return 0;
249  m = (m + (1 << (e - 1))) >> e;
250 
251  return m;
252 }
253 
254 static av_cold void decode_init_static(void)
255 {
256  int i, j, k;
257  int offset;
258 
259  /* scale factors table for layer 1/2 */
260  for (i = 0; i < 64; i++) {
261  int shift, mod;
262  /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
263  shift = i / 3;
264  mod = i % 3;
265  scale_factor_modshift[i] = mod | (shift << 2);
266  }
267 
268  /* scale factor multiply for layer 1 */
269  for (i = 0; i < 15; i++) {
270  int n, norm;
271  n = i + 2;
272  norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
273  scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0 * 2.0), FRAC_BITS);
274  scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);
275  scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);
276  av_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,
277  scale_factor_mult[i][0],
278  scale_factor_mult[i][1],
279  scale_factor_mult[i][2]);
280  }
281 
282  RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));
283 
284  /* huffman decode tables */
285  offset = 0;
286  for (i = 1; i < 16; i++) {
287  const HuffTable *h = &mpa_huff_tables[i];
288  int xsize, x, y;
289  uint8_t tmp_bits [512] = { 0 };
290  uint16_t tmp_codes[512] = { 0 };
291 
292  xsize = h->xsize;
293 
294  j = 0;
295  for (x = 0; x < xsize; x++) {
296  for (y = 0; y < xsize; y++) {
297  tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j ];
298  tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
299  }
300  }
301 
302  /* XXX: fail test */
303  huff_vlc[i].table = huff_vlc_tables+offset;
304  huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
305  init_vlc(&huff_vlc[i], 7, 512,
306  tmp_bits, 1, 1, tmp_codes, 2, 2,
308  offset += huff_vlc_tables_sizes[i];
309  }
310  assert(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
311 
312  offset = 0;
313  for (i = 0; i < 2; i++) {
314  huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
315  huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
316  init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
317  mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
319  offset += huff_quad_vlc_tables_sizes[i];
320  }
321  assert(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
322 
323  for (i = 0; i < 9; i++) {
324  k = 0;
325  for (j = 0; j < 22; j++) {
326  band_index_long[i][j] = k;
327  k += band_size_long[i][j];
328  }
329  band_index_long[i][22] = k;
330  }
331 
332  /* compute n ^ (4/3) and store it in mantissa/exp format */
333 
335 
336  for (i = 0; i < 4; i++) {
337  if (ff_mpa_quant_bits[i] < 0) {
338  for (j = 0; j < (1 << (-ff_mpa_quant_bits[i]+1)); j++) {
339  int val1, val2, val3, steps;
340  int val = j;
341  steps = ff_mpa_quant_steps[i];
342  val1 = val % steps;
343  val /= steps;
344  val2 = val % steps;
345  val3 = val / steps;
346  division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);
347  }
348  }
349  }
350 
351 
352  for (i = 0; i < 7; i++) {
353  float f;
354  INTFLOAT v;
355  if (i != 6) {
356  f = tan((double)i * M_PI / 12.0);
357  v = FIXR(f / (1.0 + f));
358  } else {
359  v = FIXR(1.0);
360  }
361  is_table[0][ i] = v;
362  is_table[1][6 - i] = v;
363  }
364  /* invalid values */
365  for (i = 7; i < 16; i++)
366  is_table[0][i] = is_table[1][i] = 0.0;
367 
368  for (i = 0; i < 16; i++) {
369  double f;
370  int e, k;
371 
372  for (j = 0; j < 2; j++) {
373  e = -(j + 1) * ((i + 1) >> 1);
374  f = pow(2.0, e / 4.0);
375  k = i & 1;
376  is_table_lsf[j][k ^ 1][i] = FIXR(f);
377  is_table_lsf[j][k ][i] = FIXR(1.0);
378  av_dlog(NULL, "is_table_lsf %d %d: %f %f\n",
379  i, j, (float) is_table_lsf[j][0][i],
380  (float) is_table_lsf[j][1][i]);
381  }
382  }
383 
384  for (i = 0; i < 8; i++) {
385  float ci, cs, ca;
386  ci = ci_table[i];
387  cs = 1.0 / sqrt(1.0 + ci * ci);
388  ca = cs * ci;
389 #if !CONFIG_FLOAT
390  csa_table[i][0] = FIXHR(cs/4);
391  csa_table[i][1] = FIXHR(ca/4);
392  csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
393  csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
394 #else
395  csa_table[i][0] = cs;
396  csa_table[i][1] = ca;
397  csa_table[i][2] = ca + cs;
398  csa_table[i][3] = ca - cs;
399 #endif
400  }
401 }
402 
403 static av_cold int decode_init(AVCodecContext * avctx)
404 {
405  static int initialized_tables = 0;
406  MPADecodeContext *s = avctx->priv_data;
407 
408  if (!initialized_tables) {
410  initialized_tables = 1;
411  }
412 
413  s->avctx = avctx;
414 
416  ff_mpadsp_init(&s->mpadsp);
417 
418  if (avctx->request_sample_fmt == OUT_FMT &&
419  avctx->codec_id != AV_CODEC_ID_MP3ON4)
420  avctx->sample_fmt = OUT_FMT;
421  else
422  avctx->sample_fmt = OUT_FMT_P;
423  s->err_recognition = avctx->err_recognition;
424 
425  if (avctx->codec_id == AV_CODEC_ID_MP3ADU)
426  s->adu_mode = 1;
427 
428  return 0;
429 }
430 
431 #define C3 FIXHR(0.86602540378443864676/2)
432 #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
433 #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
434 #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
435 
436 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
437  cases. */
438 static void imdct12(INTFLOAT *out, INTFLOAT *in)
439 {
440  INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
441 
442  in0 = in[0*3];
443  in1 = in[1*3] + in[0*3];
444  in2 = in[2*3] + in[1*3];
445  in3 = in[3*3] + in[2*3];
446  in4 = in[4*3] + in[3*3];
447  in5 = in[5*3] + in[4*3];
448  in5 += in3;
449  in3 += in1;
450 
451  in2 = MULH3(in2, C3, 2);
452  in3 = MULH3(in3, C3, 4);
453 
454  t1 = in0 - in4;
455  t2 = MULH3(in1 - in5, C4, 2);
456 
457  out[ 7] =
458  out[10] = t1 + t2;
459  out[ 1] =
460  out[ 4] = t1 - t2;
461 
462  in0 += SHR(in4, 1);
463  in4 = in0 + in2;
464  in5 += 2*in1;
465  in1 = MULH3(in5 + in3, C5, 1);
466  out[ 8] =
467  out[ 9] = in4 + in1;
468  out[ 2] =
469  out[ 3] = in4 - in1;
470 
471  in0 -= in2;
472  in5 = MULH3(in5 - in3, C6, 2);
473  out[ 0] =
474  out[ 5] = in0 - in5;
475  out[ 6] =
476  out[11] = in0 + in5;
477 }
478 
479 /* return the number of decoded frames */
481 {
482  int bound, i, v, n, ch, j, mant;
483  uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
484  uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
485 
486  if (s->mode == MPA_JSTEREO)
487  bound = (s->mode_ext + 1) * 4;
488  else
489  bound = SBLIMIT;
490 
491  /* allocation bits */
492  for (i = 0; i < bound; i++) {
493  for (ch = 0; ch < s->nb_channels; ch++) {
494  allocation[ch][i] = get_bits(&s->gb, 4);
495  }
496  }
497  for (i = bound; i < SBLIMIT; i++)
498  allocation[0][i] = get_bits(&s->gb, 4);
499 
500  /* scale factors */
501  for (i = 0; i < bound; i++) {
502  for (ch = 0; ch < s->nb_channels; ch++) {
503  if (allocation[ch][i])
504  scale_factors[ch][i] = get_bits(&s->gb, 6);
505  }
506  }
507  for (i = bound; i < SBLIMIT; i++) {
508  if (allocation[0][i]) {
509  scale_factors[0][i] = get_bits(&s->gb, 6);
510  scale_factors[1][i] = get_bits(&s->gb, 6);
511  }
512  }
513 
514  /* compute samples */
515  for (j = 0; j < 12; j++) {
516  for (i = 0; i < bound; i++) {
517  for (ch = 0; ch < s->nb_channels; ch++) {
518  n = allocation[ch][i];
519  if (n) {
520  mant = get_bits(&s->gb, n + 1);
521  v = l1_unscale(n, mant, scale_factors[ch][i]);
522  } else {
523  v = 0;
524  }
525  s->sb_samples[ch][j][i] = v;
526  }
527  }
528  for (i = bound; i < SBLIMIT; i++) {
529  n = allocation[0][i];
530  if (n) {
531  mant = get_bits(&s->gb, n + 1);
532  v = l1_unscale(n, mant, scale_factors[0][i]);
533  s->sb_samples[0][j][i] = v;
534  v = l1_unscale(n, mant, scale_factors[1][i]);
535  s->sb_samples[1][j][i] = v;
536  } else {
537  s->sb_samples[0][j][i] = 0;
538  s->sb_samples[1][j][i] = 0;
539  }
540  }
541  }
542  return 12;
543 }
544 
546 {
547  int sblimit; /* number of used subbands */
548  const unsigned char *alloc_table;
549  int table, bit_alloc_bits, i, j, ch, bound, v;
550  unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
551  unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
552  unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
553  int scale, qindex, bits, steps, k, l, m, b;
554 
555  /* select decoding table */
556  table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
557  s->sample_rate, s->lsf);
558  sblimit = ff_mpa_sblimit_table[table];
559  alloc_table = ff_mpa_alloc_tables[table];
560 
561  if (s->mode == MPA_JSTEREO)
562  bound = (s->mode_ext + 1) * 4;
563  else
564  bound = sblimit;
565 
566  av_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
567 
568  /* sanity check */
569  if (bound > sblimit)
570  bound = sblimit;
571 
572  /* parse bit allocation */
573  j = 0;
574  for (i = 0; i < bound; i++) {
575  bit_alloc_bits = alloc_table[j];
576  for (ch = 0; ch < s->nb_channels; ch++)
577  bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
578  j += 1 << bit_alloc_bits;
579  }
580  for (i = bound; i < sblimit; i++) {
581  bit_alloc_bits = alloc_table[j];
582  v = get_bits(&s->gb, bit_alloc_bits);
583  bit_alloc[0][i] = v;
584  bit_alloc[1][i] = v;
585  j += 1 << bit_alloc_bits;
586  }
587 
588  /* scale codes */
589  for (i = 0; i < sblimit; i++) {
590  for (ch = 0; ch < s->nb_channels; ch++) {
591  if (bit_alloc[ch][i])
592  scale_code[ch][i] = get_bits(&s->gb, 2);
593  }
594  }
595 
596  /* scale factors */
597  for (i = 0; i < sblimit; i++) {
598  for (ch = 0; ch < s->nb_channels; ch++) {
599  if (bit_alloc[ch][i]) {
600  sf = scale_factors[ch][i];
601  switch (scale_code[ch][i]) {
602  default:
603  case 0:
604  sf[0] = get_bits(&s->gb, 6);
605  sf[1] = get_bits(&s->gb, 6);
606  sf[2] = get_bits(&s->gb, 6);
607  break;
608  case 2:
609  sf[0] = get_bits(&s->gb, 6);
610  sf[1] = sf[0];
611  sf[2] = sf[0];
612  break;
613  case 1:
614  sf[0] = get_bits(&s->gb, 6);
615  sf[2] = get_bits(&s->gb, 6);
616  sf[1] = sf[0];
617  break;
618  case 3:
619  sf[0] = get_bits(&s->gb, 6);
620  sf[2] = get_bits(&s->gb, 6);
621  sf[1] = sf[2];
622  break;
623  }
624  }
625  }
626  }
627 
628  /* samples */
629  for (k = 0; k < 3; k++) {
630  for (l = 0; l < 12; l += 3) {
631  j = 0;
632  for (i = 0; i < bound; i++) {
633  bit_alloc_bits = alloc_table[j];
634  for (ch = 0; ch < s->nb_channels; ch++) {
635  b = bit_alloc[ch][i];
636  if (b) {
637  scale = scale_factors[ch][i][k];
638  qindex = alloc_table[j+b];
639  bits = ff_mpa_quant_bits[qindex];
640  if (bits < 0) {
641  int v2;
642  /* 3 values at the same time */
643  v = get_bits(&s->gb, -bits);
644  v2 = division_tabs[qindex][v];
645  steps = ff_mpa_quant_steps[qindex];
646 
647  s->sb_samples[ch][k * 12 + l + 0][i] =
648  l2_unscale_group(steps, v2 & 15, scale);
649  s->sb_samples[ch][k * 12 + l + 1][i] =
650  l2_unscale_group(steps, (v2 >> 4) & 15, scale);
651  s->sb_samples[ch][k * 12 + l + 2][i] =
652  l2_unscale_group(steps, v2 >> 8 , scale);
653  } else {
654  for (m = 0; m < 3; m++) {
655  v = get_bits(&s->gb, bits);
656  v = l1_unscale(bits - 1, v, scale);
657  s->sb_samples[ch][k * 12 + l + m][i] = v;
658  }
659  }
660  } else {
661  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
662  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
663  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
664  }
665  }
666  /* next subband in alloc table */
667  j += 1 << bit_alloc_bits;
668  }
669  /* XXX: find a way to avoid this duplication of code */
670  for (i = bound; i < sblimit; i++) {
671  bit_alloc_bits = alloc_table[j];
672  b = bit_alloc[0][i];
673  if (b) {
674  int mant, scale0, scale1;
675  scale0 = scale_factors[0][i][k];
676  scale1 = scale_factors[1][i][k];
677  qindex = alloc_table[j+b];
678  bits = ff_mpa_quant_bits[qindex];
679  if (bits < 0) {
680  /* 3 values at the same time */
681  v = get_bits(&s->gb, -bits);
682  steps = ff_mpa_quant_steps[qindex];
683  mant = v % steps;
684  v = v / steps;
685  s->sb_samples[0][k * 12 + l + 0][i] =
686  l2_unscale_group(steps, mant, scale0);
687  s->sb_samples[1][k * 12 + l + 0][i] =
688  l2_unscale_group(steps, mant, scale1);
689  mant = v % steps;
690  v = v / steps;
691  s->sb_samples[0][k * 12 + l + 1][i] =
692  l2_unscale_group(steps, mant, scale0);
693  s->sb_samples[1][k * 12 + l + 1][i] =
694  l2_unscale_group(steps, mant, scale1);
695  s->sb_samples[0][k * 12 + l + 2][i] =
696  l2_unscale_group(steps, v, scale0);
697  s->sb_samples[1][k * 12 + l + 2][i] =
698  l2_unscale_group(steps, v, scale1);
699  } else {
700  for (m = 0; m < 3; m++) {
701  mant = get_bits(&s->gb, bits);
702  s->sb_samples[0][k * 12 + l + m][i] =
703  l1_unscale(bits - 1, mant, scale0);
704  s->sb_samples[1][k * 12 + l + m][i] =
705  l1_unscale(bits - 1, mant, scale1);
706  }
707  }
708  } else {
709  s->sb_samples[0][k * 12 + l + 0][i] = 0;
710  s->sb_samples[0][k * 12 + l + 1][i] = 0;
711  s->sb_samples[0][k * 12 + l + 2][i] = 0;
712  s->sb_samples[1][k * 12 + l + 0][i] = 0;
713  s->sb_samples[1][k * 12 + l + 1][i] = 0;
714  s->sb_samples[1][k * 12 + l + 2][i] = 0;
715  }
716  /* next subband in alloc table */
717  j += 1 << bit_alloc_bits;
718  }
719  /* fill remaining samples to zero */
720  for (i = sblimit; i < SBLIMIT; i++) {
721  for (ch = 0; ch < s->nb_channels; ch++) {
722  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
723  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
724  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
725  }
726  }
727  }
728  }
729  return 3 * 12;
730 }
731 
732 #define SPLIT(dst,sf,n) \
733  if (n == 3) { \
734  int m = (sf * 171) >> 9; \
735  dst = sf - 3 * m; \
736  sf = m; \
737  } else if (n == 4) { \
738  dst = sf & 3; \
739  sf >>= 2; \
740  } else if (n == 5) { \
741  int m = (sf * 205) >> 10; \
742  dst = sf - 5 * m; \
743  sf = m; \
744  } else if (n == 6) { \
745  int m = (sf * 171) >> 10; \
746  dst = sf - 6 * m; \
747  sf = m; \
748  } else { \
749  dst = 0; \
750  }
751 
752 static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
753  int n3)
754 {
755  SPLIT(slen[3], sf, n3)
756  SPLIT(slen[2], sf, n2)
757  SPLIT(slen[1], sf, n1)
758  slen[0] = sf;
759 }
760 
762  int16_t *exponents)
763 {
764  const uint8_t *bstab, *pretab;
765  int len, i, j, k, l, v0, shift, gain, gains[3];
766  int16_t *exp_ptr;
767 
768  exp_ptr = exponents;
769  gain = g->global_gain - 210;
770  shift = g->scalefac_scale + 1;
771 
772  bstab = band_size_long[s->sample_rate_index];
773  pretab = mpa_pretab[g->preflag];
774  for (i = 0; i < g->long_end; i++) {
775  v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
776  len = bstab[i];
777  for (j = len; j > 0; j--)
778  *exp_ptr++ = v0;
779  }
780 
781  if (g->short_start < 13) {
782  bstab = band_size_short[s->sample_rate_index];
783  gains[0] = gain - (g->subblock_gain[0] << 3);
784  gains[1] = gain - (g->subblock_gain[1] << 3);
785  gains[2] = gain - (g->subblock_gain[2] << 3);
786  k = g->long_end;
787  for (i = g->short_start; i < 13; i++) {
788  len = bstab[i];
789  for (l = 0; l < 3; l++) {
790  v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
791  for (j = len; j > 0; j--)
792  *exp_ptr++ = v0;
793  }
794  }
795  }
796 }
797 
798 /* handle n = 0 too */
799 static inline int get_bitsz(GetBitContext *s, int n)
800 {
801  return n ? get_bits(s, n) : 0;
802 }
803 
804 
805 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
806  int *end_pos2)
807 {
808  if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
809  s->gb = s->in_gb;
810  s->in_gb.buffer = NULL;
811  assert((get_bits_count(&s->gb) & 7) == 0);
812  skip_bits_long(&s->gb, *pos - *end_pos);
813  *end_pos2 =
814  *end_pos = *end_pos2 + get_bits_count(&s->gb) - *pos;
815  *pos = get_bits_count(&s->gb);
816  }
817 }
818 
819 /* Following is a optimized code for
820  INTFLOAT v = *src
821  if(get_bits1(&s->gb))
822  v = -v;
823  *dst = v;
824 */
825 #if CONFIG_FLOAT
826 #define READ_FLIP_SIGN(dst,src) \
827  v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31); \
828  AV_WN32A(dst, v);
829 #else
830 #define READ_FLIP_SIGN(dst,src) \
831  v = -get_bits1(&s->gb); \
832  *(dst) = (*(src) ^ v) - v;
833 #endif
834 
836  int16_t *exponents, int end_pos2)
837 {
838  int s_index;
839  int i;
840  int last_pos, bits_left;
841  VLC *vlc;
842  int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
843 
844  /* low frequencies (called big values) */
845  s_index = 0;
846  for (i = 0; i < 3; i++) {
847  int j, k, l, linbits;
848  j = g->region_size[i];
849  if (j == 0)
850  continue;
851  /* select vlc table */
852  k = g->table_select[i];
853  l = mpa_huff_data[k][0];
854  linbits = mpa_huff_data[k][1];
855  vlc = &huff_vlc[l];
856 
857  if (!l) {
858  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
859  s_index += 2 * j;
860  continue;
861  }
862 
863  /* read huffcode and compute each couple */
864  for (; j > 0; j--) {
865  int exponent, x, y;
866  int v;
867  int pos = get_bits_count(&s->gb);
868 
869  if (pos >= end_pos){
870  switch_buffer(s, &pos, &end_pos, &end_pos2);
871  if (pos >= end_pos)
872  break;
873  }
874  y = get_vlc2(&s->gb, vlc->table, 7, 3);
875 
876  if (!y) {
877  g->sb_hybrid[s_index ] =
878  g->sb_hybrid[s_index+1] = 0;
879  s_index += 2;
880  continue;
881  }
882 
883  exponent= exponents[s_index];
884 
885  av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
886  i, g->region_size[i] - j, x, y, exponent);
887  if (y & 16) {
888  x = y >> 5;
889  y = y & 0x0f;
890  if (x < 15) {
891  READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
892  } else {
893  x += get_bitsz(&s->gb, linbits);
894  v = l3_unscale(x, exponent);
895  if (get_bits1(&s->gb))
896  v = -v;
897  g->sb_hybrid[s_index] = v;
898  }
899  if (y < 15) {
900  READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
901  } else {
902  y += get_bitsz(&s->gb, linbits);
903  v = l3_unscale(y, exponent);
904  if (get_bits1(&s->gb))
905  v = -v;
906  g->sb_hybrid[s_index+1] = v;
907  }
908  } else {
909  x = y >> 5;
910  y = y & 0x0f;
911  x += y;
912  if (x < 15) {
913  READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
914  } else {
915  x += get_bitsz(&s->gb, linbits);
916  v = l3_unscale(x, exponent);
917  if (get_bits1(&s->gb))
918  v = -v;
919  g->sb_hybrid[s_index+!!y] = v;
920  }
921  g->sb_hybrid[s_index + !y] = 0;
922  }
923  s_index += 2;
924  }
925  }
926 
927  /* high frequencies */
928  vlc = &huff_quad_vlc[g->count1table_select];
929  last_pos = 0;
930  while (s_index <= 572) {
931  int pos, code;
932  pos = get_bits_count(&s->gb);
933  if (pos >= end_pos) {
934  if (pos > end_pos2 && last_pos) {
935  /* some encoders generate an incorrect size for this
936  part. We must go back into the data */
937  s_index -= 4;
938  skip_bits_long(&s->gb, last_pos - pos);
939  av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
941  s_index=0;
942  break;
943  }
944  switch_buffer(s, &pos, &end_pos, &end_pos2);
945  if (pos >= end_pos)
946  break;
947  }
948  last_pos = pos;
949 
950  code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
951  av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
952  g->sb_hybrid[s_index+0] =
953  g->sb_hybrid[s_index+1] =
954  g->sb_hybrid[s_index+2] =
955  g->sb_hybrid[s_index+3] = 0;
956  while (code) {
957  static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
958  int v;
959  int pos = s_index + idxtab[code];
960  code ^= 8 >> idxtab[code];
961  READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
962  }
963  s_index += 4;
964  }
965  /* skip extension bits */
966  bits_left = end_pos2 - get_bits_count(&s->gb);
967  if (bits_left < 0 && (s->err_recognition & AV_EF_BUFFER)) {
968  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
969  s_index=0;
970  } else if (bits_left > 0 && (s->err_recognition & AV_EF_BUFFER)) {
971  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
972  s_index = 0;
973  }
974  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
975  skip_bits_long(&s->gb, bits_left);
976 
977  i = get_bits_count(&s->gb);
978  switch_buffer(s, &i, &end_pos, &end_pos2);
979 
980  return 0;
981 }
982 
983 /* Reorder short blocks from bitstream order to interleaved order. It
984  would be faster to do it in parsing, but the code would be far more
985  complicated */
987 {
988  int i, j, len;
989  INTFLOAT *ptr, *dst, *ptr1;
990  INTFLOAT tmp[576];
991 
992  if (g->block_type != 2)
993  return;
994 
995  if (g->switch_point) {
996  if (s->sample_rate_index != 8)
997  ptr = g->sb_hybrid + 36;
998  else
999  ptr = g->sb_hybrid + 72;
1000  } else {
1001  ptr = g->sb_hybrid;
1002  }
1003 
1004  for (i = g->short_start; i < 13; i++) {
1005  len = band_size_short[s->sample_rate_index][i];
1006  ptr1 = ptr;
1007  dst = tmp;
1008  for (j = len; j > 0; j--) {
1009  *dst++ = ptr[0*len];
1010  *dst++ = ptr[1*len];
1011  *dst++ = ptr[2*len];
1012  ptr++;
1013  }
1014  ptr += 2 * len;
1015  memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
1016  }
1017 }
1018 
1019 #define ISQRT2 FIXR(0.70710678118654752440)
1020 
1022 {
1023  int i, j, k, l;
1024  int sf_max, sf, len, non_zero_found;
1025  INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
1026  int non_zero_found_short[3];
1027 
1028  /* intensity stereo */
1029  if (s->mode_ext & MODE_EXT_I_STEREO) {
1030  if (!s->lsf) {
1031  is_tab = is_table;
1032  sf_max = 7;
1033  } else {
1034  is_tab = is_table_lsf[g1->scalefac_compress & 1];
1035  sf_max = 16;
1036  }
1037 
1038  tab0 = g0->sb_hybrid + 576;
1039  tab1 = g1->sb_hybrid + 576;
1040 
1041  non_zero_found_short[0] = 0;
1042  non_zero_found_short[1] = 0;
1043  non_zero_found_short[2] = 0;
1044  k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1045  for (i = 12; i >= g1->short_start; i--) {
1046  /* for last band, use previous scale factor */
1047  if (i != 11)
1048  k -= 3;
1049  len = band_size_short[s->sample_rate_index][i];
1050  for (l = 2; l >= 0; l--) {
1051  tab0 -= len;
1052  tab1 -= len;
1053  if (!non_zero_found_short[l]) {
1054  /* test if non zero band. if so, stop doing i-stereo */
1055  for (j = 0; j < len; j++) {
1056  if (tab1[j] != 0) {
1057  non_zero_found_short[l] = 1;
1058  goto found1;
1059  }
1060  }
1061  sf = g1->scale_factors[k + l];
1062  if (sf >= sf_max)
1063  goto found1;
1064 
1065  v1 = is_tab[0][sf];
1066  v2 = is_tab[1][sf];
1067  for (j = 0; j < len; j++) {
1068  tmp0 = tab0[j];
1069  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1070  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1071  }
1072  } else {
1073 found1:
1074  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1075  /* lower part of the spectrum : do ms stereo
1076  if enabled */
1077  for (j = 0; j < len; j++) {
1078  tmp0 = tab0[j];
1079  tmp1 = tab1[j];
1080  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1081  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1082  }
1083  }
1084  }
1085  }
1086  }
1087 
1088  non_zero_found = non_zero_found_short[0] |
1089  non_zero_found_short[1] |
1090  non_zero_found_short[2];
1091 
1092  for (i = g1->long_end - 1;i >= 0;i--) {
1093  len = band_size_long[s->sample_rate_index][i];
1094  tab0 -= len;
1095  tab1 -= len;
1096  /* test if non zero band. if so, stop doing i-stereo */
1097  if (!non_zero_found) {
1098  for (j = 0; j < len; j++) {
1099  if (tab1[j] != 0) {
1100  non_zero_found = 1;
1101  goto found2;
1102  }
1103  }
1104  /* for last band, use previous scale factor */
1105  k = (i == 21) ? 20 : i;
1106  sf = g1->scale_factors[k];
1107  if (sf >= sf_max)
1108  goto found2;
1109  v1 = is_tab[0][sf];
1110  v2 = is_tab[1][sf];
1111  for (j = 0; j < len; j++) {
1112  tmp0 = tab0[j];
1113  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1114  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1115  }
1116  } else {
1117 found2:
1118  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1119  /* lower part of the spectrum : do ms stereo
1120  if enabled */
1121  for (j = 0; j < len; j++) {
1122  tmp0 = tab0[j];
1123  tmp1 = tab1[j];
1124  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1125  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1126  }
1127  }
1128  }
1129  }
1130  } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1131  /* ms stereo ONLY */
1132  /* NOTE: the 1/sqrt(2) normalization factor is included in the
1133  global gain */
1134 #if CONFIG_FLOAT
1135  s->fdsp.butterflies_float(g0->sb_hybrid, g1->sb_hybrid, 576);
1136 #else
1137  tab0 = g0->sb_hybrid;
1138  tab1 = g1->sb_hybrid;
1139  for (i = 0; i < 576; i++) {
1140  tmp0 = tab0[i];
1141  tmp1 = tab1[i];
1142  tab0[i] = tmp0 + tmp1;
1143  tab1[i] = tmp0 - tmp1;
1144  }
1145 #endif
1146  }
1147 }
1148 
1149 #if CONFIG_FLOAT
1150 #define AA(j) do { \
1151  float tmp0 = ptr[-1-j]; \
1152  float tmp1 = ptr[ j]; \
1153  ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1]; \
1154  ptr[ j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0]; \
1155  } while (0)
1156 #else
1157 #define AA(j) do { \
1158  int tmp0 = ptr[-1-j]; \
1159  int tmp1 = ptr[ j]; \
1160  int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]); \
1161  ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2])); \
1162  ptr[ j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3])); \
1163  } while (0)
1164 #endif
1165 
1167 {
1168  INTFLOAT *ptr;
1169  int n, i;
1170 
1171  /* we antialias only "long" bands */
1172  if (g->block_type == 2) {
1173  if (!g->switch_point)
1174  return;
1175  /* XXX: check this for 8000Hz case */
1176  n = 1;
1177  } else {
1178  n = SBLIMIT - 1;
1179  }
1180 
1181  ptr = g->sb_hybrid + 18;
1182  for (i = n; i > 0; i--) {
1183  AA(0);
1184  AA(1);
1185  AA(2);
1186  AA(3);
1187  AA(4);
1188  AA(5);
1189  AA(6);
1190  AA(7);
1191 
1192  ptr += 18;
1193  }
1194 }
1195 
1197  INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
1198 {
1199  INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
1200  INTFLOAT out2[12];
1201  int i, j, mdct_long_end, sblimit;
1202 
1203  /* find last non zero block */
1204  ptr = g->sb_hybrid + 576;
1205  ptr1 = g->sb_hybrid + 2 * 18;
1206  while (ptr >= ptr1) {
1207  int32_t *p;
1208  ptr -= 6;
1209  p = (int32_t*)ptr;
1210  if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
1211  break;
1212  }
1213  sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1214 
1215  if (g->block_type == 2) {
1216  /* XXX: check for 8000 Hz */
1217  if (g->switch_point)
1218  mdct_long_end = 2;
1219  else
1220  mdct_long_end = 0;
1221  } else {
1222  mdct_long_end = sblimit;
1223  }
1224 
1225  s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
1226  mdct_long_end, g->switch_point,
1227  g->block_type);
1228 
1229  buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
1230  ptr = g->sb_hybrid + 18 * mdct_long_end;
1231 
1232  for (j = mdct_long_end; j < sblimit; j++) {
1233  /* select frequency inversion */
1234  win = RENAME(ff_mdct_win)[2 + (4 & -(j & 1))];
1235  out_ptr = sb_samples + j;
1236 
1237  for (i = 0; i < 6; i++) {
1238  *out_ptr = buf[4*i];
1239  out_ptr += SBLIMIT;
1240  }
1241  imdct12(out2, ptr + 0);
1242  for (i = 0; i < 6; i++) {
1243  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*1)];
1244  buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
1245  out_ptr += SBLIMIT;
1246  }
1247  imdct12(out2, ptr + 1);
1248  for (i = 0; i < 6; i++) {
1249  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*2)];
1250  buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
1251  out_ptr += SBLIMIT;
1252  }
1253  imdct12(out2, ptr + 2);
1254  for (i = 0; i < 6; i++) {
1255  buf[4*(i + 6*0)] = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*0)];
1256  buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
1257  buf[4*(i + 6*2)] = 0;
1258  }
1259  ptr += 18;
1260  buf += (j&3) != 3 ? 1 : (4*18-3);
1261  }
1262  /* zero bands */
1263  for (j = sblimit; j < SBLIMIT; j++) {
1264  /* overlap */
1265  out_ptr = sb_samples + j;
1266  for (i = 0; i < 18; i++) {
1267  *out_ptr = buf[4*i];
1268  buf[4*i] = 0;
1269  out_ptr += SBLIMIT;
1270  }
1271  buf += (j&3) != 3 ? 1 : (4*18-3);
1272  }
1273 }
1274 
1275 /* main layer3 decoding function */
1277 {
1278  int nb_granules, main_data_begin;
1279  int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
1280  GranuleDef *g;
1281  int16_t exponents[576]; //FIXME try INTFLOAT
1282 
1283  /* read side info */
1284  if (s->lsf) {
1285  main_data_begin = get_bits(&s->gb, 8);
1286  skip_bits(&s->gb, s->nb_channels);
1287  nb_granules = 1;
1288  } else {
1289  main_data_begin = get_bits(&s->gb, 9);
1290  if (s->nb_channels == 2)
1291  skip_bits(&s->gb, 3);
1292  else
1293  skip_bits(&s->gb, 5);
1294  nb_granules = 2;
1295  for (ch = 0; ch < s->nb_channels; ch++) {
1296  s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
1297  s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
1298  }
1299  }
1300 
1301  for (gr = 0; gr < nb_granules; gr++) {
1302  for (ch = 0; ch < s->nb_channels; ch++) {
1303  av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
1304  g = &s->granules[ch][gr];
1305  g->part2_3_length = get_bits(&s->gb, 12);
1306  g->big_values = get_bits(&s->gb, 9);
1307  if (g->big_values > 288) {
1308  av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
1309  return AVERROR_INVALIDDATA;
1310  }
1311 
1312  g->global_gain = get_bits(&s->gb, 8);
1313  /* if MS stereo only is selected, we precompute the
1314  1/sqrt(2) renormalization factor */
1315  if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
1317  g->global_gain -= 2;
1318  if (s->lsf)
1319  g->scalefac_compress = get_bits(&s->gb, 9);
1320  else
1321  g->scalefac_compress = get_bits(&s->gb, 4);
1322  blocksplit_flag = get_bits1(&s->gb);
1323  if (blocksplit_flag) {
1324  g->block_type = get_bits(&s->gb, 2);
1325  if (g->block_type == 0) {
1326  av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
1327  return AVERROR_INVALIDDATA;
1328  }
1329  g->switch_point = get_bits1(&s->gb);
1330  for (i = 0; i < 2; i++)
1331  g->table_select[i] = get_bits(&s->gb, 5);
1332  for (i = 0; i < 3; i++)
1333  g->subblock_gain[i] = get_bits(&s->gb, 3);
1334  init_short_region(s, g);
1335  } else {
1336  int region_address1, region_address2;
1337  g->block_type = 0;
1338  g->switch_point = 0;
1339  for (i = 0; i < 3; i++)
1340  g->table_select[i] = get_bits(&s->gb, 5);
1341  /* compute huffman coded region sizes */
1342  region_address1 = get_bits(&s->gb, 4);
1343  region_address2 = get_bits(&s->gb, 3);
1344  av_dlog(s->avctx, "region1=%d region2=%d\n",
1345  region_address1, region_address2);
1346  init_long_region(s, g, region_address1, region_address2);
1347  }
1348  region_offset2size(g);
1349  compute_band_indexes(s, g);
1350 
1351  g->preflag = 0;
1352  if (!s->lsf)
1353  g->preflag = get_bits1(&s->gb);
1354  g->scalefac_scale = get_bits1(&s->gb);
1355  g->count1table_select = get_bits1(&s->gb);
1356  av_dlog(s->avctx, "block_type=%d switch_point=%d\n",
1357  g->block_type, g->switch_point);
1358  }
1359  }
1360 
1361  if (!s->adu_mode) {
1362  int skip;
1363  const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
1364  int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0,
1365  FFMAX(0, LAST_BUF_SIZE - s->last_buf_size));
1366  assert((get_bits_count(&s->gb) & 7) == 0);
1367  /* now we get bits from the main_data_begin offset */
1368  av_dlog(s->avctx, "seekback:%d, lastbuf:%d\n",
1369  main_data_begin, s->last_buf_size);
1370 
1371  memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
1372  s->in_gb = s->gb;
1373  init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
1374 #if !UNCHECKED_BITSTREAM_READER
1375  s->gb.size_in_bits_plus8 += extrasize * 8;
1376 #endif
1377  s->last_buf_size <<= 3;
1378  for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
1379  for (ch = 0; ch < s->nb_channels; ch++) {
1380  g = &s->granules[ch][gr];
1381  s->last_buf_size += g->part2_3_length;
1382  memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
1383  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1384  }
1385  }
1386  skip = s->last_buf_size - 8 * main_data_begin;
1387  if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
1388  skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
1389  s->gb = s->in_gb;
1390  s->in_gb.buffer = NULL;
1391  } else {
1392  skip_bits_long(&s->gb, skip);
1393  }
1394  } else {
1395  gr = 0;
1396  }
1397 
1398  for (; gr < nb_granules; gr++) {
1399  for (ch = 0; ch < s->nb_channels; ch++) {
1400  g = &s->granules[ch][gr];
1401  bits_pos = get_bits_count(&s->gb);
1402 
1403  if (!s->lsf) {
1404  uint8_t *sc;
1405  int slen, slen1, slen2;
1406 
1407  /* MPEG1 scale factors */
1408  slen1 = slen_table[0][g->scalefac_compress];
1409  slen2 = slen_table[1][g->scalefac_compress];
1410  av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
1411  if (g->block_type == 2) {
1412  n = g->switch_point ? 17 : 18;
1413  j = 0;
1414  if (slen1) {
1415  for (i = 0; i < n; i++)
1416  g->scale_factors[j++] = get_bits(&s->gb, slen1);
1417  } else {
1418  for (i = 0; i < n; i++)
1419  g->scale_factors[j++] = 0;
1420  }
1421  if (slen2) {
1422  for (i = 0; i < 18; i++)
1423  g->scale_factors[j++] = get_bits(&s->gb, slen2);
1424  for (i = 0; i < 3; i++)
1425  g->scale_factors[j++] = 0;
1426  } else {
1427  for (i = 0; i < 21; i++)
1428  g->scale_factors[j++] = 0;
1429  }
1430  } else {
1431  sc = s->granules[ch][0].scale_factors;
1432  j = 0;
1433  for (k = 0; k < 4; k++) {
1434  n = k == 0 ? 6 : 5;
1435  if ((g->scfsi & (0x8 >> k)) == 0) {
1436  slen = (k < 2) ? slen1 : slen2;
1437  if (slen) {
1438  for (i = 0; i < n; i++)
1439  g->scale_factors[j++] = get_bits(&s->gb, slen);
1440  } else {
1441  for (i = 0; i < n; i++)
1442  g->scale_factors[j++] = 0;
1443  }
1444  } else {
1445  /* simply copy from last granule */
1446  for (i = 0; i < n; i++) {
1447  g->scale_factors[j] = sc[j];
1448  j++;
1449  }
1450  }
1451  }
1452  g->scale_factors[j++] = 0;
1453  }
1454  } else {
1455  int tindex, tindex2, slen[4], sl, sf;
1456 
1457  /* LSF scale factors */
1458  if (g->block_type == 2)
1459  tindex = g->switch_point ? 2 : 1;
1460  else
1461  tindex = 0;
1462 
1463  sf = g->scalefac_compress;
1464  if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
1465  /* intensity stereo case */
1466  sf >>= 1;
1467  if (sf < 180) {
1468  lsf_sf_expand(slen, sf, 6, 6, 0);
1469  tindex2 = 3;
1470  } else if (sf < 244) {
1471  lsf_sf_expand(slen, sf - 180, 4, 4, 0);
1472  tindex2 = 4;
1473  } else {
1474  lsf_sf_expand(slen, sf - 244, 3, 0, 0);
1475  tindex2 = 5;
1476  }
1477  } else {
1478  /* normal case */
1479  if (sf < 400) {
1480  lsf_sf_expand(slen, sf, 5, 4, 4);
1481  tindex2 = 0;
1482  } else if (sf < 500) {
1483  lsf_sf_expand(slen, sf - 400, 5, 4, 0);
1484  tindex2 = 1;
1485  } else {
1486  lsf_sf_expand(slen, sf - 500, 3, 0, 0);
1487  tindex2 = 2;
1488  g->preflag = 1;
1489  }
1490  }
1491 
1492  j = 0;
1493  for (k = 0; k < 4; k++) {
1494  n = lsf_nsf_table[tindex2][tindex][k];
1495  sl = slen[k];
1496  if (sl) {
1497  for (i = 0; i < n; i++)
1498  g->scale_factors[j++] = get_bits(&s->gb, sl);
1499  } else {
1500  for (i = 0; i < n; i++)
1501  g->scale_factors[j++] = 0;
1502  }
1503  }
1504  /* XXX: should compute exact size */
1505  for (; j < 40; j++)
1506  g->scale_factors[j] = 0;
1507  }
1508 
1509  exponents_from_scale_factors(s, g, exponents);
1510 
1511  /* read Huffman coded residue */
1512  huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
1513  } /* ch */
1514 
1515  if (s->mode == MPA_JSTEREO)
1516  compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
1517 
1518  for (ch = 0; ch < s->nb_channels; ch++) {
1519  g = &s->granules[ch][gr];
1520 
1521  reorder_block(s, g);
1522  compute_antialias(s, g);
1523  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1524  }
1525  } /* gr */
1526  if (get_bits_count(&s->gb) < 0)
1527  skip_bits_long(&s->gb, -get_bits_count(&s->gb));
1528  return nb_granules * 18;
1529 }
1530 
1532  const uint8_t *buf, int buf_size)
1533 {
1534  int i, nb_frames, ch, ret;
1535  OUT_INT *samples_ptr;
1536 
1537  init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
1538 
1539  /* skip error protection field */
1540  if (s->error_protection)
1541  skip_bits(&s->gb, 16);
1542 
1543  switch(s->layer) {
1544  case 1:
1545  s->avctx->frame_size = 384;
1546  nb_frames = mp_decode_layer1(s);
1547  break;
1548  case 2:
1549  s->avctx->frame_size = 1152;
1550  nb_frames = mp_decode_layer2(s);
1551  break;
1552  case 3:
1553  s->avctx->frame_size = s->lsf ? 576 : 1152;
1554  default:
1555  nb_frames = mp_decode_layer3(s);
1556 
1557  if (nb_frames < 0)
1558  return nb_frames;
1559 
1560  s->last_buf_size=0;
1561  if (s->in_gb.buffer) {
1562  align_get_bits(&s->gb);
1563  i = get_bits_left(&s->gb)>>3;
1564  if (i >= 0 && i <= BACKSTEP_SIZE) {
1565  memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
1566  s->last_buf_size=i;
1567  } else
1568  av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
1569  s->gb = s->in_gb;
1570  s->in_gb.buffer = NULL;
1571  }
1572 
1573  align_get_bits(&s->gb);
1574  assert((get_bits_count(&s->gb) & 7) == 0);
1575  i = get_bits_left(&s->gb) >> 3;
1576 
1577  if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
1578  if (i < 0)
1579  av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
1580  i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
1581  }
1582  assert(i <= buf_size - HEADER_SIZE && i >= 0);
1583  memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
1584  s->last_buf_size += i;
1585  }
1586 
1587  /* get output buffer */
1588  if (!samples) {
1589  av_assert0(s->frame != NULL);
1590  s->frame->nb_samples = s->avctx->frame_size;
1591  if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0) {
1592  av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
1593  return ret;
1594  }
1595  samples = (OUT_INT **)s->frame->extended_data;
1596  }
1597 
1598  /* apply the synthesis filter */
1599  for (ch = 0; ch < s->nb_channels; ch++) {
1600  int sample_stride;
1601  if (s->avctx->sample_fmt == OUT_FMT_P) {
1602  samples_ptr = samples[ch];
1603  sample_stride = 1;
1604  } else {
1605  samples_ptr = samples[0] + ch;
1606  sample_stride = s->nb_channels;
1607  }
1608  for (i = 0; i < nb_frames; i++) {
1610  &(s->synth_buf_offset[ch]),
1611  RENAME(ff_mpa_synth_window),
1612  &s->dither_state, samples_ptr,
1613  sample_stride, s->sb_samples[ch][i]);
1614  samples_ptr += 32 * sample_stride;
1615  }
1616  }
1617 
1618  return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
1619 }
1620 
1621 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
1622  AVPacket *avpkt)
1623 {
1624  const uint8_t *buf = avpkt->data;
1625  int buf_size = avpkt->size;
1626  MPADecodeContext *s = avctx->priv_data;
1627  uint32_t header;
1628  int ret;
1629 
1630  if (buf_size < HEADER_SIZE)
1631  return AVERROR_INVALIDDATA;
1632 
1633  header = AV_RB32(buf);
1634  if (ff_mpa_check_header(header) < 0) {
1635  av_log(avctx, AV_LOG_ERROR, "Header missing\n");
1636  return AVERROR_INVALIDDATA;
1637  }
1638 
1639  if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
1640  /* free format: prepare to compute frame size */
1641  s->frame_size = -1;
1642  return AVERROR_INVALIDDATA;
1643  }
1644  /* update codec info */
1645  avctx->channels = s->nb_channels;
1646  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1647  if (!avctx->bit_rate)
1648  avctx->bit_rate = s->bit_rate;
1649 
1650  if (s->frame_size <= 0 || s->frame_size > buf_size) {
1651  av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
1652  return AVERROR_INVALIDDATA;
1653  } else if (s->frame_size < buf_size) {
1654  buf_size= s->frame_size;
1655  }
1656 
1657  s->frame = data;
1658 
1659  ret = mp_decode_frame(s, NULL, buf, buf_size);
1660  if (ret >= 0) {
1661  s->frame->nb_samples = avctx->frame_size;
1662  *got_frame_ptr = 1;
1663  avctx->sample_rate = s->sample_rate;
1664  //FIXME maybe move the other codec info stuff from above here too
1665  } else {
1666  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1667  /* Only return an error if the bad frame makes up the whole packet or
1668  * the error is related to buffer management.
1669  * If there is more data in the packet, just consume the bad frame
1670  * instead of returning an error, which would discard the whole
1671  * packet. */
1672  *got_frame_ptr = 0;
1673  if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
1674  return ret;
1675  }
1676  s->frame_size = 0;
1677  return buf_size;
1678 }
1679 
1680 static void mp_flush(MPADecodeContext *ctx)
1681 {
1682  memset(ctx->synth_buf, 0, sizeof(ctx->synth_buf));
1683  ctx->last_buf_size = 0;
1684 }
1685 
1686 static void flush(AVCodecContext *avctx)
1687 {
1688  mp_flush(avctx->priv_data);
1689 }
1690 
1691 #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
1692 static int decode_frame_adu(AVCodecContext *avctx, void *data,
1693  int *got_frame_ptr, AVPacket *avpkt)
1694 {
1695  const uint8_t *buf = avpkt->data;
1696  int buf_size = avpkt->size;
1697  MPADecodeContext *s = avctx->priv_data;
1698  uint32_t header;
1699  int len, ret;
1700 
1701  len = buf_size;
1702 
1703  // Discard too short frames
1704  if (buf_size < HEADER_SIZE) {
1705  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
1706  return AVERROR_INVALIDDATA;
1707  }
1708 
1709 
1710  if (len > MPA_MAX_CODED_FRAME_SIZE)
1712 
1713  // Get header and restore sync word
1714  header = AV_RB32(buf) | 0xffe00000;
1715 
1716  if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
1717  av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
1718  return AVERROR_INVALIDDATA;
1719  }
1720 
1722  /* update codec info */
1723  avctx->sample_rate = s->sample_rate;
1724  avctx->channels = s->nb_channels;
1725  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1726  if (!avctx->bit_rate)
1727  avctx->bit_rate = s->bit_rate;
1728 
1729  s->frame_size = len;
1730 
1731  s->frame = data;
1732 
1733  ret = mp_decode_frame(s, NULL, buf, buf_size);
1734  if (ret < 0) {
1735  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1736  return ret;
1737  }
1738 
1739  *got_frame_ptr = 1;
1740 
1741  return buf_size;
1742 }
1743 #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
1744 
1745 #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
1746 
1750 typedef struct MP3On4DecodeContext {
1751  int frames;
1752  int syncword;
1753  const uint8_t *coff;
1754  MPADecodeContext *mp3decctx[5];
1755 } MP3On4DecodeContext;
1756 
1757 #include "mpeg4audio.h"
1758 
1759 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
1760 
1761 /* number of mp3 decoder instances */
1762 static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
1763 
1764 /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
1765 static const uint8_t chan_offset[8][5] = {
1766  { 0 },
1767  { 0 }, // C
1768  { 0 }, // FLR
1769  { 2, 0 }, // C FLR
1770  { 2, 0, 3 }, // C FLR BS
1771  { 2, 0, 3 }, // C FLR BLRS
1772  { 2, 0, 4, 3 }, // C FLR BLRS LFE
1773  { 2, 0, 6, 4, 3 }, // C FLR BLRS BLR LFE
1774 };
1775 
1776 /* mp3on4 channel layouts */
1777 static const int16_t chan_layout[8] = {
1778  0,
1786 };
1787 
1788 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
1789 {
1790  MP3On4DecodeContext *s = avctx->priv_data;
1791  int i;
1792 
1793  for (i = 0; i < s->frames; i++)
1794  av_free(s->mp3decctx[i]);
1795 
1796  return 0;
1797 }
1798 
1799 
1800 static av_cold int decode_init_mp3on4(AVCodecContext * avctx)
1801 {
1802  MP3On4DecodeContext *s = avctx->priv_data;
1803  MPEG4AudioConfig cfg;
1804  int i;
1805 
1806  if ((avctx->extradata_size < 2) || (avctx->extradata == NULL)) {
1807  av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
1808  return AVERROR_INVALIDDATA;
1809  }
1810 
1812  avctx->extradata_size * 8, 1);
1813  if (!cfg.chan_config || cfg.chan_config > 7) {
1814  av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
1815  return AVERROR_INVALIDDATA;
1816  }
1817  s->frames = mp3Frames[cfg.chan_config];
1818  s->coff = chan_offset[cfg.chan_config];
1820  avctx->channel_layout = chan_layout[cfg.chan_config];
1821 
1822  if (cfg.sample_rate < 16000)
1823  s->syncword = 0xffe00000;
1824  else
1825  s->syncword = 0xfff00000;
1826 
1827  /* Init the first mp3 decoder in standard way, so that all tables get builded
1828  * We replace avctx->priv_data with the context of the first decoder so that
1829  * decode_init() does not have to be changed.
1830  * Other decoders will be initialized here copying data from the first context
1831  */
1832  // Allocate zeroed memory for the first decoder context
1833  s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
1834  if (!s->mp3decctx[0])
1835  goto alloc_fail;
1836  // Put decoder context in place to make init_decode() happy
1837  avctx->priv_data = s->mp3decctx[0];
1838  decode_init(avctx);
1839  // Restore mp3on4 context pointer
1840  avctx->priv_data = s;
1841  s->mp3decctx[0]->adu_mode = 1; // Set adu mode
1842 
1843  /* Create a separate codec/context for each frame (first is already ok).
1844  * Each frame is 1 or 2 channels - up to 5 frames allowed
1845  */
1846  for (i = 1; i < s->frames; i++) {
1847  s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
1848  if (!s->mp3decctx[i])
1849  goto alloc_fail;
1850  s->mp3decctx[i]->adu_mode = 1;
1851  s->mp3decctx[i]->avctx = avctx;
1852  s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
1853  }
1854 
1855  return 0;
1856 alloc_fail:
1857  decode_close_mp3on4(avctx);
1858  return AVERROR(ENOMEM);
1859 }
1860 
1861 
1862 static void flush_mp3on4(AVCodecContext *avctx)
1863 {
1864  int i;
1865  MP3On4DecodeContext *s = avctx->priv_data;
1866 
1867  for (i = 0; i < s->frames; i++)
1868  mp_flush(s->mp3decctx[i]);
1869 }
1870 
1871 
1872 static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
1873  int *got_frame_ptr, AVPacket *avpkt)
1874 {
1875  AVFrame *frame = data;
1876  const uint8_t *buf = avpkt->data;
1877  int buf_size = avpkt->size;
1878  MP3On4DecodeContext *s = avctx->priv_data;
1879  MPADecodeContext *m;
1880  int fsize, len = buf_size, out_size = 0;
1881  uint32_t header;
1882  OUT_INT **out_samples;
1883  OUT_INT *outptr[2];
1884  int fr, ch, ret;
1885 
1886  /* get output buffer */
1887  frame->nb_samples = MPA_FRAME_SIZE;
1888  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
1889  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
1890  return ret;
1891  }
1892  out_samples = (OUT_INT **)frame->extended_data;
1893 
1894  // Discard too short frames
1895  if (buf_size < HEADER_SIZE)
1896  return AVERROR_INVALIDDATA;
1897 
1898  avctx->bit_rate = 0;
1899 
1900  ch = 0;
1901  for (fr = 0; fr < s->frames; fr++) {
1902  fsize = AV_RB16(buf) >> 4;
1903  fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
1904  m = s->mp3decctx[fr];
1905  assert(m != NULL);
1906 
1907  if (fsize < HEADER_SIZE) {
1908  av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
1909  return AVERROR_INVALIDDATA;
1910  }
1911  header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
1912 
1913  if (ff_mpa_check_header(header) < 0) // Bad header, discard block
1914  break;
1915 
1917 
1918  if (ch + m->nb_channels > avctx->channels ||
1919  s->coff[fr] + m->nb_channels > avctx->channels) {
1920  av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
1921  "channel count\n");
1922  return AVERROR_INVALIDDATA;
1923  }
1924  ch += m->nb_channels;
1925 
1926  outptr[0] = out_samples[s->coff[fr]];
1927  if (m->nb_channels > 1)
1928  outptr[1] = out_samples[s->coff[fr] + 1];
1929 
1930  if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0)
1931  return ret;
1932 
1933  out_size += ret;
1934  buf += fsize;
1935  len -= fsize;
1936 
1937  avctx->bit_rate += m->bit_rate;
1938  }
1939 
1940  /* update codec info */
1941  avctx->sample_rate = s->mp3decctx[0]->sample_rate;
1942 
1943  frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
1944  *got_frame_ptr = 1;
1945 
1946  return buf_size;
1947 }
1948 #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */