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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 FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg 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 FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * MPEG Audio decoder
25  */
26 
27 #include "libavutil/attributes.h"
28 #include "libavutil/avassert.h"
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/float_dsp.h"
31 #include "libavutil/libm.h"
32 #include "avcodec.h"
33 #include "get_bits.h"
34 #include "internal.h"
35 #include "mathops.h"
36 #include "mpegaudiodsp.h"
37 
38 /*
39  * TODO:
40  * - test lsf / mpeg25 extensively.
41  */
42 
43 #include "mpegaudio.h"
44 #include "mpegaudiodecheader.h"
45 
46 #define BACKSTEP_SIZE 512
47 #define EXTRABYTES 24
48 #define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES
49 
50 /* layer 3 "granule" */
51 typedef struct GranuleDef {
52  uint8_t scfsi;
53  int part2_3_length;
54  int big_values;
55  int global_gain;
56  int scalefac_compress;
57  uint8_t block_type;
58  uint8_t switch_point;
59  int table_select[3];
60  int subblock_gain[3];
61  uint8_t scalefac_scale;
62  uint8_t count1table_select;
63  int region_size[3]; /* number of huffman codes in each region */
64  int preflag;
65  int short_start, long_end; /* long/short band indexes */
66  uint8_t scale_factors[40];
67  DECLARE_ALIGNED(16, INTFLOAT, sb_hybrid)[SBLIMIT * 18]; /* 576 samples */
68 } GranuleDef;
69 
70 typedef struct MPADecodeContext {
71  MPA_DECODE_HEADER
72  uint8_t last_buf[LAST_BUF_SIZE];
73  int last_buf_size;
74  /* next header (used in free format parsing) */
75  uint32_t free_format_next_header;
76  GetBitContext gb;
77  GetBitContext in_gb;
78  DECLARE_ALIGNED(32, MPA_INT, synth_buf)[MPA_MAX_CHANNELS][512 * 2];
79  int synth_buf_offset[MPA_MAX_CHANNELS];
80  DECLARE_ALIGNED(32, INTFLOAT, sb_samples)[MPA_MAX_CHANNELS][36][SBLIMIT];
81  INTFLOAT mdct_buf[MPA_MAX_CHANNELS][SBLIMIT * 18]; /* previous samples, for layer 3 MDCT */
82  GranuleDef granules[2][2]; /* Used in Layer 3 */
83  int adu_mode; ///< 0 for standard mp3, 1 for adu formatted mp3
84  int dither_state;
85  int err_recognition;
86  AVCodecContext* avctx;
87  MPADSPContext mpadsp;
88  AVFloatDSPContext *fdsp;
89  AVFrame *frame;
90 } MPADecodeContext;
91 
92 #define HEADER_SIZE 4
93 
94 #include "mpegaudiodata.h"
95 #include "mpegaudiodectab.h"
96 
97 /* vlc structure for decoding layer 3 huffman tables */
98 static VLC huff_vlc[16];
99 static VLC_TYPE huff_vlc_tables[
100  0 + 128 + 128 + 128 + 130 + 128 + 154 + 166 +
101  142 + 204 + 190 + 170 + 542 + 460 + 662 + 414
102  ][2];
103 static const int huff_vlc_tables_sizes[16] = {
104  0, 128, 128, 128, 130, 128, 154, 166,
105  142, 204, 190, 170, 542, 460, 662, 414
106 };
107 static VLC huff_quad_vlc[2];
108 static VLC_TYPE huff_quad_vlc_tables[128+16][2];
109 static const int huff_quad_vlc_tables_sizes[2] = { 128, 16 };
110 /* computed from band_size_long */
111 static uint16_t band_index_long[9][23];
112 #include "mpegaudio_tablegen.h"
113 /* intensity stereo coef table */
114 static INTFLOAT is_table[2][16];
115 static INTFLOAT is_table_lsf[2][2][16];
116 static INTFLOAT csa_table[8][4];
117 
118 static int16_t division_tab3[1<<6 ];
119 static int16_t division_tab5[1<<8 ];
120 static int16_t division_tab9[1<<11];
121 
122 static int16_t * const division_tabs[4] = {
123  division_tab3, division_tab5, NULL, division_tab9
124 };
125 
126 /* lower 2 bits: modulo 3, higher bits: shift */
127 static uint16_t scale_factor_modshift[64];
128 /* [i][j]: 2^(-j/3) * FRAC_ONE * 2^(i+2) / (2^(i+2) - 1) */
129 static int32_t scale_factor_mult[15][3];
130 /* mult table for layer 2 group quantization */
131 
132 #define SCALE_GEN(v) \
133 { FIXR_OLD(1.0 * (v)), FIXR_OLD(0.7937005259 * (v)), FIXR_OLD(0.6299605249 * (v)) }
134 
135 static const int32_t scale_factor_mult2[3][3] = {
136  SCALE_GEN(4.0 / 3.0), /* 3 steps */
137  SCALE_GEN(4.0 / 5.0), /* 5 steps */
138  SCALE_GEN(4.0 / 9.0), /* 9 steps */
139 };
140 
141 /**
142  * Convert region offsets to region sizes and truncate
143  * size to big_values.
144  */
145 static void region_offset2size(GranuleDef *g)
146 {
147  int i, k, j = 0;
148  g->region_size[2] = 576 / 2;
149  for (i = 0; i < 3; i++) {
150  k = FFMIN(g->region_size[i], g->big_values);
151  g->region_size[i] = k - j;
152  j = k;
153  }
154 }
155 
156 static void init_short_region(MPADecodeContext *s, GranuleDef *g)
157 {
158  if (g->block_type == 2) {
159  if (s->sample_rate_index != 8)
160  g->region_size[0] = (36 / 2);
161  else
162  g->region_size[0] = (72 / 2);
163  } else {
164  if (s->sample_rate_index <= 2)
165  g->region_size[0] = (36 / 2);
166  else if (s->sample_rate_index != 8)
167  g->region_size[0] = (54 / 2);
168  else
169  g->region_size[0] = (108 / 2);
170  }
171  g->region_size[1] = (576 / 2);
172 }
173 
174 static void init_long_region(MPADecodeContext *s, GranuleDef *g,
175  int ra1, int ra2)
176 {
177  int l;
178  g->region_size[0] = band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
179  /* should not overflow */
180  l = FFMIN(ra1 + ra2 + 2, 22);
181  g->region_size[1] = band_index_long[s->sample_rate_index][ l] >> 1;
182 }
183 
184 static void compute_band_indexes(MPADecodeContext *s, GranuleDef *g)
185 {
186  if (g->block_type == 2) {
187  if (g->switch_point) {
188  if(s->sample_rate_index == 8)
189  avpriv_request_sample(s->avctx, "switch point in 8khz");
190  /* if switched mode, we handle the 36 first samples as
191  long blocks. For 8000Hz, we handle the 72 first
192  exponents as long blocks */
193  if (s->sample_rate_index <= 2)
194  g->long_end = 8;
195  else
196  g->long_end = 6;
197 
198  g->short_start = 3;
199  } else {
200  g->long_end = 0;
201  g->short_start = 0;
202  }
203  } else {
204  g->short_start = 13;
205  g->long_end = 22;
206  }
207 }
208 
209 /* layer 1 unscaling */
210 /* n = number of bits of the mantissa minus 1 */
211 static inline int l1_unscale(int n, int mant, int scale_factor)
212 {
213  int shift, mod;
214  int64_t val;
215 
216  shift = scale_factor_modshift[scale_factor];
217  mod = shift & 3;
218  shift >>= 2;
219  val = MUL64((int)(mant + (-1U << n) + 1), scale_factor_mult[n-1][mod]);
220  shift += n;
221  /* NOTE: at this point, 1 <= shift >= 21 + 15 */
222  return (int)((val + (1LL << (shift - 1))) >> shift);
223 }
224 
225 static inline int l2_unscale_group(int steps, int mant, int scale_factor)
226 {
227  int shift, mod, val;
228 
229  shift = scale_factor_modshift[scale_factor];
230  mod = shift & 3;
231  shift >>= 2;
232 
233  val = (mant - (steps >> 1)) * scale_factor_mult2[steps >> 2][mod];
234  /* NOTE: at this point, 0 <= shift <= 21 */
235  if (shift > 0)
236  val = (val + (1 << (shift - 1))) >> shift;
237  return val;
238 }
239 
240 /* compute value^(4/3) * 2^(exponent/4). It normalized to FRAC_BITS */
241 static inline int l3_unscale(int value, int exponent)
242 {
243  unsigned int m;
244  int e;
245 
246  e = table_4_3_exp [4 * value + (exponent & 3)];
247  m = table_4_3_value[4 * value + (exponent & 3)];
248  e -= exponent >> 2;
249 #ifdef DEBUG
250  if(e < 1)
251  av_log(NULL, AV_LOG_WARNING, "l3_unscale: e is %d\n", e);
252 #endif
253  if (e > 31)
254  return 0;
255  m = (m + (1 << (e - 1))) >> e;
256 
257  return m;
258 }
259 
260 static av_cold void decode_init_static(void)
261 {
262  int i, j, k;
263  int offset;
264 
265  /* scale factors table for layer 1/2 */
266  for (i = 0; i < 64; i++) {
267  int shift, mod;
268  /* 1.0 (i = 3) is normalized to 2 ^ FRAC_BITS */
269  shift = i / 3;
270  mod = i % 3;
271  scale_factor_modshift[i] = mod | (shift << 2);
272  }
273 
274  /* scale factor multiply for layer 1 */
275  for (i = 0; i < 15; i++) {
276  int n, norm;
277  n = i + 2;
278  norm = ((INT64_C(1) << n) * FRAC_ONE) / ((1 << n) - 1);
279  scale_factor_mult[i][0] = MULLx(norm, FIXR(1.0 * 2.0), FRAC_BITS);
280  scale_factor_mult[i][1] = MULLx(norm, FIXR(0.7937005259 * 2.0), FRAC_BITS);
281  scale_factor_mult[i][2] = MULLx(norm, FIXR(0.6299605249 * 2.0), FRAC_BITS);
282  av_dlog(NULL, "%d: norm=%x s=%x %x %x\n", i, norm,
283  scale_factor_mult[i][0],
284  scale_factor_mult[i][1],
285  scale_factor_mult[i][2]);
286  }
287 
288  RENAME(ff_mpa_synth_init)(RENAME(ff_mpa_synth_window));
289 
290  /* huffman decode tables */
291  offset = 0;
292  for (i = 1; i < 16; i++) {
293  const HuffTable *h = &mpa_huff_tables[i];
294  int xsize, x, y;
295  uint8_t tmp_bits [512] = { 0 };
296  uint16_t tmp_codes[512] = { 0 };
297 
298  xsize = h->xsize;
299 
300  j = 0;
301  for (x = 0; x < xsize; x++) {
302  for (y = 0; y < xsize; y++) {
303  tmp_bits [(x << 5) | y | ((x&&y)<<4)]= h->bits [j ];
304  tmp_codes[(x << 5) | y | ((x&&y)<<4)]= h->codes[j++];
305  }
306  }
307 
308  /* XXX: fail test */
309  huff_vlc[i].table = huff_vlc_tables+offset;
310  huff_vlc[i].table_allocated = huff_vlc_tables_sizes[i];
311  init_vlc(&huff_vlc[i], 7, 512,
312  tmp_bits, 1, 1, tmp_codes, 2, 2,
313  INIT_VLC_USE_NEW_STATIC);
314  offset += huff_vlc_tables_sizes[i];
315  }
316  av_assert0(offset == FF_ARRAY_ELEMS(huff_vlc_tables));
317 
318  offset = 0;
319  for (i = 0; i < 2; i++) {
320  huff_quad_vlc[i].table = huff_quad_vlc_tables+offset;
321  huff_quad_vlc[i].table_allocated = huff_quad_vlc_tables_sizes[i];
322  init_vlc(&huff_quad_vlc[i], i == 0 ? 7 : 4, 16,
323  mpa_quad_bits[i], 1, 1, mpa_quad_codes[i], 1, 1,
324  INIT_VLC_USE_NEW_STATIC);
325  offset += huff_quad_vlc_tables_sizes[i];
326  }
327  av_assert0(offset == FF_ARRAY_ELEMS(huff_quad_vlc_tables));
328 
329  for (i = 0; i < 9; i++) {
330  k = 0;
331  for (j = 0; j < 22; j++) {
332  band_index_long[i][j] = k;
333  k += band_size_long[i][j];
334  }
335  band_index_long[i][22] = k;
336  }
337 
338  /* compute n ^ (4/3) and store it in mantissa/exp format */
339 
340  mpegaudio_tableinit();
341 
342  for (i = 0; i < 4; i++) {
343  if (ff_mpa_quant_bits[i] < 0) {
344  for (j = 0; j < (1 << (-ff_mpa_quant_bits[i]+1)); j++) {
345  int val1, val2, val3, steps;
346  int val = j;
347  steps = ff_mpa_quant_steps[i];
348  val1 = val % steps;
349  val /= steps;
350  val2 = val % steps;
351  val3 = val / steps;
352  division_tabs[i][j] = val1 + (val2 << 4) + (val3 << 8);
353  }
354  }
355  }
356 
357 
358  for (i = 0; i < 7; i++) {
359  float f;
360  INTFLOAT v;
361  if (i != 6) {
362  f = tan((double)i * M_PI / 12.0);
363  v = FIXR(f / (1.0 + f));
364  } else {
365  v = FIXR(1.0);
366  }
367  is_table[0][ i] = v;
368  is_table[1][6 - i] = v;
369  }
370  /* invalid values */
371  for (i = 7; i < 16; i++)
372  is_table[0][i] = is_table[1][i] = 0.0;
373 
374  for (i = 0; i < 16; i++) {
375  double f;
376  int e, k;
377 
378  for (j = 0; j < 2; j++) {
379  e = -(j + 1) * ((i + 1) >> 1);
380  f = exp2(e / 4.0);
381  k = i & 1;
382  is_table_lsf[j][k ^ 1][i] = FIXR(f);
383  is_table_lsf[j][k ][i] = FIXR(1.0);
384  av_dlog(NULL, "is_table_lsf %d %d: %f %f\n",
385  i, j, (float) is_table_lsf[j][0][i],
386  (float) is_table_lsf[j][1][i]);
387  }
388  }
389 
390  for (i = 0; i < 8; i++) {
391  float ci, cs, ca;
392  ci = ci_table[i];
393  cs = 1.0 / sqrt(1.0 + ci * ci);
394  ca = cs * ci;
395 #if !USE_FLOATS
396  csa_table[i][0] = FIXHR(cs/4);
397  csa_table[i][1] = FIXHR(ca/4);
398  csa_table[i][2] = FIXHR(ca/4) + FIXHR(cs/4);
399  csa_table[i][3] = FIXHR(ca/4) - FIXHR(cs/4);
400 #else
401  csa_table[i][0] = cs;
402  csa_table[i][1] = ca;
403  csa_table[i][2] = ca + cs;
404  csa_table[i][3] = ca - cs;
405 #endif
406  }
407 }
408 
409 #if USE_FLOATS
410 static av_cold int decode_close(AVCodecContext * avctx)
411 {
412  MPADecodeContext *s = avctx->priv_data;
413  av_freep(&s->fdsp);
414 
415  return 0;
416 }
417 #endif
418 
419 static av_cold int decode_init(AVCodecContext * avctx)
420 {
421  static int initialized_tables = 0;
422  MPADecodeContext *s = avctx->priv_data;
423 
424  if (!initialized_tables) {
425  decode_init_static();
426  initialized_tables = 1;
427  }
428 
429  s->avctx = avctx;
430 
431  s->fdsp = avpriv_float_dsp_alloc(avctx->flags & CODEC_FLAG_BITEXACT);
432  if (!s->fdsp)
433  return AVERROR(ENOMEM);
434 
435  ff_mpadsp_init(&s->mpadsp);
436 
437  if (avctx->request_sample_fmt == OUT_FMT &&
438  avctx->codec_id != AV_CODEC_ID_MP3ON4)
439  avctx->sample_fmt = OUT_FMT;
440  else
441  avctx->sample_fmt = OUT_FMT_P;
442  s->err_recognition = avctx->err_recognition;
443 
444  if (avctx->codec_id == AV_CODEC_ID_MP3ADU)
445  s->adu_mode = 1;
446 
447  return 0;
448 }
449 
450 #define C3 FIXHR(0.86602540378443864676/2)
451 #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
452 #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
453 #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
454 
455 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
456  cases. */
457 static void imdct12(INTFLOAT *out, INTFLOAT *in)
458 {
459  INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
460 
461  in0 = in[0*3];
462  in1 = in[1*3] + in[0*3];
463  in2 = in[2*3] + in[1*3];
464  in3 = in[3*3] + in[2*3];
465  in4 = in[4*3] + in[3*3];
466  in5 = in[5*3] + in[4*3];
467  in5 += in3;
468  in3 += in1;
469 
470  in2 = MULH3(in2, C3, 2);
471  in3 = MULH3(in3, C3, 4);
472 
473  t1 = in0 - in4;
474  t2 = MULH3(in1 - in5, C4, 2);
475 
476  out[ 7] =
477  out[10] = t1 + t2;
478  out[ 1] =
479  out[ 4] = t1 - t2;
480 
481  in0 += SHR(in4, 1);
482  in4 = in0 + in2;
483  in5 += 2*in1;
484  in1 = MULH3(in5 + in3, C5, 1);
485  out[ 8] =
486  out[ 9] = in4 + in1;
487  out[ 2] =
488  out[ 3] = in4 - in1;
489 
490  in0 -= in2;
491  in5 = MULH3(in5 - in3, C6, 2);
492  out[ 0] =
493  out[ 5] = in0 - in5;
494  out[ 6] =
495  out[11] = in0 + in5;
496 }
497 
498 /* return the number of decoded frames */
499 static int mp_decode_layer1(MPADecodeContext *s)
500 {
501  int bound, i, v, n, ch, j, mant;
502  uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
503  uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
504 
505  if (s->mode == MPA_JSTEREO)
506  bound = (s->mode_ext + 1) * 4;
507  else
508  bound = SBLIMIT;
509 
510  /* allocation bits */
511  for (i = 0; i < bound; i++) {
512  for (ch = 0; ch < s->nb_channels; ch++) {
513  allocation[ch][i] = get_bits(&s->gb, 4);
514  }
515  }
516  for (i = bound; i < SBLIMIT; i++)
517  allocation[0][i] = get_bits(&s->gb, 4);
518 
519  /* scale factors */
520  for (i = 0; i < bound; i++) {
521  for (ch = 0; ch < s->nb_channels; ch++) {
522  if (allocation[ch][i])
523  scale_factors[ch][i] = get_bits(&s->gb, 6);
524  }
525  }
526  for (i = bound; i < SBLIMIT; i++) {
527  if (allocation[0][i]) {
528  scale_factors[0][i] = get_bits(&s->gb, 6);
529  scale_factors[1][i] = get_bits(&s->gb, 6);
530  }
531  }
532 
533  /* compute samples */
534  for (j = 0; j < 12; j++) {
535  for (i = 0; i < bound; i++) {
536  for (ch = 0; ch < s->nb_channels; ch++) {
537  n = allocation[ch][i];
538  if (n) {
539  mant = get_bits(&s->gb, n + 1);
540  v = l1_unscale(n, mant, scale_factors[ch][i]);
541  } else {
542  v = 0;
543  }
544  s->sb_samples[ch][j][i] = v;
545  }
546  }
547  for (i = bound; i < SBLIMIT; i++) {
548  n = allocation[0][i];
549  if (n) {
550  mant = get_bits(&s->gb, n + 1);
551  v = l1_unscale(n, mant, scale_factors[0][i]);
552  s->sb_samples[0][j][i] = v;
553  v = l1_unscale(n, mant, scale_factors[1][i]);
554  s->sb_samples[1][j][i] = v;
555  } else {
556  s->sb_samples[0][j][i] = 0;
557  s->sb_samples[1][j][i] = 0;
558  }
559  }
560  }
561  return 12;
562 }
563 
564 static int mp_decode_layer2(MPADecodeContext *s)
565 {
566  int sblimit; /* number of used subbands */
567  const unsigned char *alloc_table;
568  int table, bit_alloc_bits, i, j, ch, bound, v;
569  unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
570  unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
571  unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
572  int scale, qindex, bits, steps, k, l, m, b;
573 
574  /* select decoding table */
575  table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
576  s->sample_rate, s->lsf);
577  sblimit = ff_mpa_sblimit_table[table];
578  alloc_table = ff_mpa_alloc_tables[table];
579 
580  if (s->mode == MPA_JSTEREO)
581  bound = (s->mode_ext + 1) * 4;
582  else
583  bound = sblimit;
584 
585  av_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
586 
587  /* sanity check */
588  if (bound > sblimit)
589  bound = sblimit;
590 
591  /* parse bit allocation */
592  j = 0;
593  for (i = 0; i < bound; i++) {
594  bit_alloc_bits = alloc_table[j];
595  for (ch = 0; ch < s->nb_channels; ch++)
596  bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
597  j += 1 << bit_alloc_bits;
598  }
599  for (i = bound; i < sblimit; i++) {
600  bit_alloc_bits = alloc_table[j];
601  v = get_bits(&s->gb, bit_alloc_bits);
602  bit_alloc[0][i] = v;
603  bit_alloc[1][i] = v;
604  j += 1 << bit_alloc_bits;
605  }
606 
607  /* scale codes */
608  for (i = 0; i < sblimit; i++) {
609  for (ch = 0; ch < s->nb_channels; ch++) {
610  if (bit_alloc[ch][i])
611  scale_code[ch][i] = get_bits(&s->gb, 2);
612  }
613  }
614 
615  /* scale factors */
616  for (i = 0; i < sblimit; i++) {
617  for (ch = 0; ch < s->nb_channels; ch++) {
618  if (bit_alloc[ch][i]) {
619  sf = scale_factors[ch][i];
620  switch (scale_code[ch][i]) {
621  default:
622  case 0:
623  sf[0] = get_bits(&s->gb, 6);
624  sf[1] = get_bits(&s->gb, 6);
625  sf[2] = get_bits(&s->gb, 6);
626  break;
627  case 2:
628  sf[0] = get_bits(&s->gb, 6);
629  sf[1] = sf[0];
630  sf[2] = sf[0];
631  break;
632  case 1:
633  sf[0] = get_bits(&s->gb, 6);
634  sf[2] = get_bits(&s->gb, 6);
635  sf[1] = sf[0];
636  break;
637  case 3:
638  sf[0] = get_bits(&s->gb, 6);
639  sf[2] = get_bits(&s->gb, 6);
640  sf[1] = sf[2];
641  break;
642  }
643  }
644  }
645  }
646 
647  /* samples */
648  for (k = 0; k < 3; k++) {
649  for (l = 0; l < 12; l += 3) {
650  j = 0;
651  for (i = 0; i < bound; i++) {
652  bit_alloc_bits = alloc_table[j];
653  for (ch = 0; ch < s->nb_channels; ch++) {
654  b = bit_alloc[ch][i];
655  if (b) {
656  scale = scale_factors[ch][i][k];
657  qindex = alloc_table[j+b];
658  bits = ff_mpa_quant_bits[qindex];
659  if (bits < 0) {
660  int v2;
661  /* 3 values at the same time */
662  v = get_bits(&s->gb, -bits);
663  v2 = division_tabs[qindex][v];
664  steps = ff_mpa_quant_steps[qindex];
665 
666  s->sb_samples[ch][k * 12 + l + 0][i] =
667  l2_unscale_group(steps, v2 & 15, scale);
668  s->sb_samples[ch][k * 12 + l + 1][i] =
669  l2_unscale_group(steps, (v2 >> 4) & 15, scale);
670  s->sb_samples[ch][k * 12 + l + 2][i] =
671  l2_unscale_group(steps, v2 >> 8 , scale);
672  } else {
673  for (m = 0; m < 3; m++) {
674  v = get_bits(&s->gb, bits);
675  v = l1_unscale(bits - 1, v, scale);
676  s->sb_samples[ch][k * 12 + l + m][i] = v;
677  }
678  }
679  } else {
680  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
681  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
682  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
683  }
684  }
685  /* next subband in alloc table */
686  j += 1 << bit_alloc_bits;
687  }
688  /* XXX: find a way to avoid this duplication of code */
689  for (i = bound; i < sblimit; i++) {
690  bit_alloc_bits = alloc_table[j];
691  b = bit_alloc[0][i];
692  if (b) {
693  int mant, scale0, scale1;
694  scale0 = scale_factors[0][i][k];
695  scale1 = scale_factors[1][i][k];
696  qindex = alloc_table[j+b];
697  bits = ff_mpa_quant_bits[qindex];
698  if (bits < 0) {
699  /* 3 values at the same time */
700  v = get_bits(&s->gb, -bits);
701  steps = ff_mpa_quant_steps[qindex];
702  mant = v % steps;
703  v = v / steps;
704  s->sb_samples[0][k * 12 + l + 0][i] =
705  l2_unscale_group(steps, mant, scale0);
706  s->sb_samples[1][k * 12 + l + 0][i] =
707  l2_unscale_group(steps, mant, scale1);
708  mant = v % steps;
709  v = v / steps;
710  s->sb_samples[0][k * 12 + l + 1][i] =
711  l2_unscale_group(steps, mant, scale0);
712  s->sb_samples[1][k * 12 + l + 1][i] =
713  l2_unscale_group(steps, mant, scale1);
714  s->sb_samples[0][k * 12 + l + 2][i] =
715  l2_unscale_group(steps, v, scale0);
716  s->sb_samples[1][k * 12 + l + 2][i] =
717  l2_unscale_group(steps, v, scale1);
718  } else {
719  for (m = 0; m < 3; m++) {
720  mant = get_bits(&s->gb, bits);
721  s->sb_samples[0][k * 12 + l + m][i] =
722  l1_unscale(bits - 1, mant, scale0);
723  s->sb_samples[1][k * 12 + l + m][i] =
724  l1_unscale(bits - 1, mant, scale1);
725  }
726  }
727  } else {
728  s->sb_samples[0][k * 12 + l + 0][i] = 0;
729  s->sb_samples[0][k * 12 + l + 1][i] = 0;
730  s->sb_samples[0][k * 12 + l + 2][i] = 0;
731  s->sb_samples[1][k * 12 + l + 0][i] = 0;
732  s->sb_samples[1][k * 12 + l + 1][i] = 0;
733  s->sb_samples[1][k * 12 + l + 2][i] = 0;
734  }
735  /* next subband in alloc table */
736  j += 1 << bit_alloc_bits;
737  }
738  /* fill remaining samples to zero */
739  for (i = sblimit; i < SBLIMIT; i++) {
740  for (ch = 0; ch < s->nb_channels; ch++) {
741  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
742  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
743  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
744  }
745  }
746  }
747  }
748  return 3 * 12;
749 }
750 
751 #define SPLIT(dst,sf,n) \
752  if (n == 3) { \
753  int m = (sf * 171) >> 9; \
754  dst = sf - 3 * m; \
755  sf = m; \
756  } else if (n == 4) { \
757  dst = sf & 3; \
758  sf >>= 2; \
759  } else if (n == 5) { \
760  int m = (sf * 205) >> 10; \
761  dst = sf - 5 * m; \
762  sf = m; \
763  } else if (n == 6) { \
764  int m = (sf * 171) >> 10; \
765  dst = sf - 6 * m; \
766  sf = m; \
767  } else { \
768  dst = 0; \
769  }
770 
771 static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
772  int n3)
773 {
774  SPLIT(slen[3], sf, n3)
775  SPLIT(slen[2], sf, n2)
776  SPLIT(slen[1], sf, n1)
777  slen[0] = sf;
778 }
779 
780 static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,
781  int16_t *exponents)
782 {
783  const uint8_t *bstab, *pretab;
784  int len, i, j, k, l, v0, shift, gain, gains[3];
785  int16_t *exp_ptr;
786 
787  exp_ptr = exponents;
788  gain = g->global_gain - 210;
789  shift = g->scalefac_scale + 1;
790 
791  bstab = band_size_long[s->sample_rate_index];
792  pretab = mpa_pretab[g->preflag];
793  for (i = 0; i < g->long_end; i++) {
794  v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
795  len = bstab[i];
796  for (j = len; j > 0; j--)
797  *exp_ptr++ = v0;
798  }
799 
800  if (g->short_start < 13) {
801  bstab = band_size_short[s->sample_rate_index];
802  gains[0] = gain - (g->subblock_gain[0] << 3);
803  gains[1] = gain - (g->subblock_gain[1] << 3);
804  gains[2] = gain - (g->subblock_gain[2] << 3);
805  k = g->long_end;
806  for (i = g->short_start; i < 13; i++) {
807  len = bstab[i];
808  for (l = 0; l < 3; l++) {
809  v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
810  for (j = len; j > 0; j--)
811  *exp_ptr++ = v0;
812  }
813  }
814  }
815 }
816 
817 /* handle n = 0 too */
818 static inline int get_bitsz(GetBitContext *s, int n)
819 {
820  return n ? get_bits(s, n) : 0;
821 }
822 
823 
824 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
825  int *end_pos2)
826 {
827  if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
828  s->gb = s->in_gb;
829  s->in_gb.buffer = NULL;
830  av_assert2((get_bits_count(&s->gb) & 7) == 0);
831  skip_bits_long(&s->gb, *pos - *end_pos);
832  *end_pos2 =
833  *end_pos = *end_pos2 + get_bits_count(&s->gb) - *pos;
834  *pos = get_bits_count(&s->gb);
835  }
836 }
837 
838 /* Following is a optimized code for
839  INTFLOAT v = *src
840  if(get_bits1(&s->gb))
841  v = -v;
842  *dst = v;
843 */
844 #if USE_FLOATS
845 #define READ_FLIP_SIGN(dst,src) \
846  v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31); \
847  AV_WN32A(dst, v);
848 #else
849 #define READ_FLIP_SIGN(dst,src) \
850  v = -get_bits1(&s->gb); \
851  *(dst) = (*(src) ^ v) - v;
852 #endif
853 
854 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
855  int16_t *exponents, int end_pos2)
856 {
857  int s_index;
858  int i;
859  int last_pos, bits_left;
860  VLC *vlc;
861  int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
862 
863  /* low frequencies (called big values) */
864  s_index = 0;
865  for (i = 0; i < 3; i++) {
866  int j, k, l, linbits;
867  j = g->region_size[i];
868  if (j == 0)
869  continue;
870  /* select vlc table */
871  k = g->table_select[i];
872  l = mpa_huff_data[k][0];
873  linbits = mpa_huff_data[k][1];
874  vlc = &huff_vlc[l];
875 
876  if (!l) {
877  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
878  s_index += 2 * j;
879  continue;
880  }
881 
882  /* read huffcode and compute each couple */
883  for (; j > 0; j--) {
884  int exponent, x, y;
885  int v;
886  int pos = get_bits_count(&s->gb);
887 
888  if (pos >= end_pos){
889  switch_buffer(s, &pos, &end_pos, &end_pos2);
890  if (pos >= end_pos)
891  break;
892  }
893  y = get_vlc2(&s->gb, vlc->table, 7, 3);
894 
895  if (!y) {
896  g->sb_hybrid[s_index ] =
897  g->sb_hybrid[s_index+1] = 0;
898  s_index += 2;
899  continue;
900  }
901 
902  exponent= exponents[s_index];
903 
904  av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
905  i, g->region_size[i] - j, x, y, exponent);
906  if (y & 16) {
907  x = y >> 5;
908  y = y & 0x0f;
909  if (x < 15) {
910  READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
911  } else {
912  x += get_bitsz(&s->gb, linbits);
913  v = l3_unscale(x, exponent);
914  if (get_bits1(&s->gb))
915  v = -v;
916  g->sb_hybrid[s_index] = v;
917  }
918  if (y < 15) {
919  READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
920  } else {
921  y += get_bitsz(&s->gb, linbits);
922  v = l3_unscale(y, exponent);
923  if (get_bits1(&s->gb))
924  v = -v;
925  g->sb_hybrid[s_index+1] = v;
926  }
927  } else {
928  x = y >> 5;
929  y = y & 0x0f;
930  x += y;
931  if (x < 15) {
932  READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
933  } else {
934  x += get_bitsz(&s->gb, linbits);
935  v = l3_unscale(x, exponent);
936  if (get_bits1(&s->gb))
937  v = -v;
938  g->sb_hybrid[s_index+!!y] = v;
939  }
940  g->sb_hybrid[s_index + !y] = 0;
941  }
942  s_index += 2;
943  }
944  }
945 
946  /* high frequencies */
947  vlc = &huff_quad_vlc[g->count1table_select];
948  last_pos = 0;
949  while (s_index <= 572) {
950  int pos, code;
951  pos = get_bits_count(&s->gb);
952  if (pos >= end_pos) {
953  if (pos > end_pos2 && last_pos) {
954  /* some encoders generate an incorrect size for this
955  part. We must go back into the data */
956  s_index -= 4;
957  skip_bits_long(&s->gb, last_pos - pos);
958  av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
959  if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
960  s_index=0;
961  break;
962  }
963  switch_buffer(s, &pos, &end_pos, &end_pos2);
964  if (pos >= end_pos)
965  break;
966  }
967  last_pos = pos;
968 
969  code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
970  av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
971  g->sb_hybrid[s_index+0] =
972  g->sb_hybrid[s_index+1] =
973  g->sb_hybrid[s_index+2] =
974  g->sb_hybrid[s_index+3] = 0;
975  while (code) {
976  static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
977  int v;
978  int pos = s_index + idxtab[code];
979  code ^= 8 >> idxtab[code];
980  READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
981  }
982  s_index += 4;
983  }
984  /* skip extension bits */
985  bits_left = end_pos2 - get_bits_count(&s->gb);
986  if (bits_left < 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_COMPLIANT))) {
987  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
988  s_index=0;
989  } else if (bits_left > 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_AGGRESSIVE))) {
990  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
991  s_index = 0;
992  }
993  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
994  skip_bits_long(&s->gb, bits_left);
995 
996  i = get_bits_count(&s->gb);
997  switch_buffer(s, &i, &end_pos, &end_pos2);
998 
999  return 0;
1000 }
1001 
1002 /* Reorder short blocks from bitstream order to interleaved order. It
1003  would be faster to do it in parsing, but the code would be far more
1004  complicated */
1005 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
1006 {
1007  int i, j, len;
1008  INTFLOAT *ptr, *dst, *ptr1;
1009  INTFLOAT tmp[576];
1010 
1011  if (g->block_type != 2)
1012  return;
1013 
1014  if (g->switch_point) {
1015  if (s->sample_rate_index != 8)
1016  ptr = g->sb_hybrid + 36;
1017  else
1018  ptr = g->sb_hybrid + 72;
1019  } else {
1020  ptr = g->sb_hybrid;
1021  }
1022 
1023  for (i = g->short_start; i < 13; i++) {
1024  len = band_size_short[s->sample_rate_index][i];
1025  ptr1 = ptr;
1026  dst = tmp;
1027  for (j = len; j > 0; j--) {
1028  *dst++ = ptr[0*len];
1029  *dst++ = ptr[1*len];
1030  *dst++ = ptr[2*len];
1031  ptr++;
1032  }
1033  ptr += 2 * len;
1034  memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
1035  }
1036 }
1037 
1038 #define ISQRT2 FIXR(0.70710678118654752440)
1039 
1040 static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
1041 {
1042  int i, j, k, l;
1043  int sf_max, sf, len, non_zero_found;
1044  INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
1045  int non_zero_found_short[3];
1046 
1047  /* intensity stereo */
1048  if (s->mode_ext & MODE_EXT_I_STEREO) {
1049  if (!s->lsf) {
1050  is_tab = is_table;
1051  sf_max = 7;
1052  } else {
1053  is_tab = is_table_lsf[g1->scalefac_compress & 1];
1054  sf_max = 16;
1055  }
1056 
1057  tab0 = g0->sb_hybrid + 576;
1058  tab1 = g1->sb_hybrid + 576;
1059 
1060  non_zero_found_short[0] = 0;
1061  non_zero_found_short[1] = 0;
1062  non_zero_found_short[2] = 0;
1063  k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1064  for (i = 12; i >= g1->short_start; i--) {
1065  /* for last band, use previous scale factor */
1066  if (i != 11)
1067  k -= 3;
1068  len = band_size_short[s->sample_rate_index][i];
1069  for (l = 2; l >= 0; l--) {
1070  tab0 -= len;
1071  tab1 -= len;
1072  if (!non_zero_found_short[l]) {
1073  /* test if non zero band. if so, stop doing i-stereo */
1074  for (j = 0; j < len; j++) {
1075  if (tab1[j] != 0) {
1076  non_zero_found_short[l] = 1;
1077  goto found1;
1078  }
1079  }
1080  sf = g1->scale_factors[k + l];
1081  if (sf >= sf_max)
1082  goto found1;
1083 
1084  v1 = is_tab[0][sf];
1085  v2 = is_tab[1][sf];
1086  for (j = 0; j < len; j++) {
1087  tmp0 = tab0[j];
1088  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1089  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1090  }
1091  } else {
1092 found1:
1093  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1094  /* lower part of the spectrum : do ms stereo
1095  if enabled */
1096  for (j = 0; j < len; j++) {
1097  tmp0 = tab0[j];
1098  tmp1 = tab1[j];
1099  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1100  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1101  }
1102  }
1103  }
1104  }
1105  }
1106 
1107  non_zero_found = non_zero_found_short[0] |
1108  non_zero_found_short[1] |
1109  non_zero_found_short[2];
1110 
1111  for (i = g1->long_end - 1;i >= 0;i--) {
1112  len = band_size_long[s->sample_rate_index][i];
1113  tab0 -= len;
1114  tab1 -= len;
1115  /* test if non zero band. if so, stop doing i-stereo */
1116  if (!non_zero_found) {
1117  for (j = 0; j < len; j++) {
1118  if (tab1[j] != 0) {
1119  non_zero_found = 1;
1120  goto found2;
1121  }
1122  }
1123  /* for last band, use previous scale factor */
1124  k = (i == 21) ? 20 : i;
1125  sf = g1->scale_factors[k];
1126  if (sf >= sf_max)
1127  goto found2;
1128  v1 = is_tab[0][sf];
1129  v2 = is_tab[1][sf];
1130  for (j = 0; j < len; j++) {
1131  tmp0 = tab0[j];
1132  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1133  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1134  }
1135  } else {
1136 found2:
1137  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1138  /* lower part of the spectrum : do ms stereo
1139  if enabled */
1140  for (j = 0; j < len; j++) {
1141  tmp0 = tab0[j];
1142  tmp1 = tab1[j];
1143  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1144  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1145  }
1146  }
1147  }
1148  }
1149  } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1150  /* ms stereo ONLY */
1151  /* NOTE: the 1/sqrt(2) normalization factor is included in the
1152  global gain */
1153 #if USE_FLOATS
1154  s->fdsp->butterflies_float(g0->sb_hybrid, g1->sb_hybrid, 576);
1155 #else
1156  tab0 = g0->sb_hybrid;
1157  tab1 = g1->sb_hybrid;
1158  for (i = 0; i < 576; i++) {
1159  tmp0 = tab0[i];
1160  tmp1 = tab1[i];
1161  tab0[i] = tmp0 + tmp1;
1162  tab1[i] = tmp0 - tmp1;
1163  }
1164 #endif
1165  }
1166 }
1167 
1168 #if USE_FLOATS
1169 #if HAVE_MIPSFPU
1170 # include "mips/compute_antialias_float.h"
1171 #endif /* HAVE_MIPSFPU */
1172 #else
1173 #if HAVE_MIPSDSPR1
1174 # include "mips/compute_antialias_fixed.h"
1175 #endif /* HAVE_MIPSDSPR1 */
1176 #endif /* USE_FLOATS */
1177 
1178 #ifndef compute_antialias
1179 #if USE_FLOATS
1180 #define AA(j) do { \
1181  float tmp0 = ptr[-1-j]; \
1182  float tmp1 = ptr[ j]; \
1183  ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1]; \
1184  ptr[ j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0]; \
1185  } while (0)
1186 #else
1187 #define AA(j) do { \
1188  int tmp0 = ptr[-1-j]; \
1189  int tmp1 = ptr[ j]; \
1190  int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]); \
1191  ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2])); \
1192  ptr[ j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3])); \
1193  } while (0)
1194 #endif
1195 
1196 static void compute_antialias(MPADecodeContext *s, GranuleDef *g)
1197 {
1198  INTFLOAT *ptr;
1199  int n, i;
1200 
1201  /* we antialias only "long" bands */
1202  if (g->block_type == 2) {
1203  if (!g->switch_point)
1204  return;
1205  /* XXX: check this for 8000Hz case */
1206  n = 1;
1207  } else {
1208  n = SBLIMIT - 1;
1209  }
1210 
1211  ptr = g->sb_hybrid + 18;
1212  for (i = n; i > 0; i--) {
1213  AA(0);
1214  AA(1);
1215  AA(2);
1216  AA(3);
1217  AA(4);
1218  AA(5);
1219  AA(6);
1220  AA(7);
1221 
1222  ptr += 18;
1223  }
1224 }
1225 #endif /* compute_antialias */
1226 
1227 static void compute_imdct(MPADecodeContext *s, GranuleDef *g,
1228  INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
1229 {
1230  INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
1231  INTFLOAT out2[12];
1232  int i, j, mdct_long_end, sblimit;
1233 
1234  /* find last non zero block */
1235  ptr = g->sb_hybrid + 576;
1236  ptr1 = g->sb_hybrid + 2 * 18;
1237  while (ptr >= ptr1) {
1238  int32_t *p;
1239  ptr -= 6;
1240  p = (int32_t*)ptr;
1241  if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
1242  break;
1243  }
1244  sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1245 
1246  if (g->block_type == 2) {
1247  /* XXX: check for 8000 Hz */
1248  if (g->switch_point)
1249  mdct_long_end = 2;
1250  else
1251  mdct_long_end = 0;
1252  } else {
1253  mdct_long_end = sblimit;
1254  }
1255 
1256  s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
1257  mdct_long_end, g->switch_point,
1258  g->block_type);
1259 
1260  buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
1261  ptr = g->sb_hybrid + 18 * mdct_long_end;
1262 
1263  for (j = mdct_long_end; j < sblimit; j++) {
1264  /* select frequency inversion */
1265  win = RENAME(ff_mdct_win)[2 + (4 & -(j & 1))];
1266  out_ptr = sb_samples + j;
1267 
1268  for (i = 0; i < 6; i++) {
1269  *out_ptr = buf[4*i];
1270  out_ptr += SBLIMIT;
1271  }
1272  imdct12(out2, ptr + 0);
1273  for (i = 0; i < 6; i++) {
1274  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*1)];
1275  buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
1276  out_ptr += SBLIMIT;
1277  }
1278  imdct12(out2, ptr + 1);
1279  for (i = 0; i < 6; i++) {
1280  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*2)];
1281  buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
1282  out_ptr += SBLIMIT;
1283  }
1284  imdct12(out2, ptr + 2);
1285  for (i = 0; i < 6; i++) {
1286  buf[4*(i + 6*0)] = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*0)];
1287  buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
1288  buf[4*(i + 6*2)] = 0;
1289  }
1290  ptr += 18;
1291  buf += (j&3) != 3 ? 1 : (4*18-3);
1292  }
1293  /* zero bands */
1294  for (j = sblimit; j < SBLIMIT; j++) {
1295  /* overlap */
1296  out_ptr = sb_samples + j;
1297  for (i = 0; i < 18; i++) {
1298  *out_ptr = buf[4*i];
1299  buf[4*i] = 0;
1300  out_ptr += SBLIMIT;
1301  }
1302  buf += (j&3) != 3 ? 1 : (4*18-3);
1303  }
1304 }
1305 
1306 /* main layer3 decoding function */
1307 static int mp_decode_layer3(MPADecodeContext *s)
1308 {
1309  int nb_granules, main_data_begin;
1310  int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
1311  GranuleDef *g;
1312  int16_t exponents[576]; //FIXME try INTFLOAT
1313 
1314  /* read side info */
1315  if (s->lsf) {
1316  main_data_begin = get_bits(&s->gb, 8);
1317  skip_bits(&s->gb, s->nb_channels);
1318  nb_granules = 1;
1319  } else {
1320  main_data_begin = get_bits(&s->gb, 9);
1321  if (s->nb_channels == 2)
1322  skip_bits(&s->gb, 3);
1323  else
1324  skip_bits(&s->gb, 5);
1325  nb_granules = 2;
1326  for (ch = 0; ch < s->nb_channels; ch++) {
1327  s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
1328  s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
1329  }
1330  }
1331 
1332  for (gr = 0; gr < nb_granules; gr++) {
1333  for (ch = 0; ch < s->nb_channels; ch++) {
1334  av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
1335  g = &s->granules[ch][gr];
1336  g->part2_3_length = get_bits(&s->gb, 12);
1337  g->big_values = get_bits(&s->gb, 9);
1338  if (g->big_values > 288) {
1339  av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
1340  return AVERROR_INVALIDDATA;
1341  }
1342 
1343  g->global_gain = get_bits(&s->gb, 8);
1344  /* if MS stereo only is selected, we precompute the
1345  1/sqrt(2) renormalization factor */
1346  if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
1347  MODE_EXT_MS_STEREO)
1348  g->global_gain -= 2;
1349  if (s->lsf)
1350  g->scalefac_compress = get_bits(&s->gb, 9);
1351  else
1352  g->scalefac_compress = get_bits(&s->gb, 4);
1353  blocksplit_flag = get_bits1(&s->gb);
1354  if (blocksplit_flag) {
1355  g->block_type = get_bits(&s->gb, 2);
1356  if (g->block_type == 0) {
1357  av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
1358  return AVERROR_INVALIDDATA;
1359  }
1360  g->switch_point = get_bits1(&s->gb);
1361  for (i = 0; i < 2; i++)
1362  g->table_select[i] = get_bits(&s->gb, 5);
1363  for (i = 0; i < 3; i++)
1364  g->subblock_gain[i] = get_bits(&s->gb, 3);
1365  init_short_region(s, g);
1366  } else {
1367  int region_address1, region_address2;
1368  g->block_type = 0;
1369  g->switch_point = 0;
1370  for (i = 0; i < 3; i++)
1371  g->table_select[i] = get_bits(&s->gb, 5);
1372  /* compute huffman coded region sizes */
1373  region_address1 = get_bits(&s->gb, 4);
1374  region_address2 = get_bits(&s->gb, 3);
1375  av_dlog(s->avctx, "region1=%d region2=%d\n",
1376  region_address1, region_address2);
1377  init_long_region(s, g, region_address1, region_address2);
1378  }
1379  region_offset2size(g);
1380  compute_band_indexes(s, g);
1381 
1382  g->preflag = 0;
1383  if (!s->lsf)
1384  g->preflag = get_bits1(&s->gb);
1385  g->scalefac_scale = get_bits1(&s->gb);
1386  g->count1table_select = get_bits1(&s->gb);
1387  av_dlog(s->avctx, "block_type=%d switch_point=%d\n",
1388  g->block_type, g->switch_point);
1389  }
1390  }
1391 
1392  if (!s->adu_mode) {
1393  int skip;
1394  const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
1395  int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, EXTRABYTES);
1396  av_assert1((get_bits_count(&s->gb) & 7) == 0);
1397  /* now we get bits from the main_data_begin offset */
1398  av_dlog(s->avctx, "seekback:%d, lastbuf:%d\n",
1399  main_data_begin, s->last_buf_size);
1400 
1401  memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
1402  s->in_gb = s->gb;
1403  init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
1404 #if !UNCHECKED_BITSTREAM_READER
1405  s->gb.size_in_bits_plus8 += FFMAX(extrasize, LAST_BUF_SIZE - s->last_buf_size) * 8;
1406 #endif
1407  s->last_buf_size <<= 3;
1408  for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
1409  for (ch = 0; ch < s->nb_channels; ch++) {
1410  g = &s->granules[ch][gr];
1411  s->last_buf_size += g->part2_3_length;
1412  memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
1413  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1414  }
1415  }
1416  skip = s->last_buf_size - 8 * main_data_begin;
1417  if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
1418  skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
1419  s->gb = s->in_gb;
1420  s->in_gb.buffer = NULL;
1421  } else {
1422  skip_bits_long(&s->gb, skip);
1423  }
1424  } else {
1425  gr = 0;
1426  }
1427 
1428  for (; gr < nb_granules; gr++) {
1429  for (ch = 0; ch < s->nb_channels; ch++) {
1430  g = &s->granules[ch][gr];
1431  bits_pos = get_bits_count(&s->gb);
1432 
1433  if (!s->lsf) {
1434  uint8_t *sc;
1435  int slen, slen1, slen2;
1436 
1437  /* MPEG1 scale factors */
1438  slen1 = slen_table[0][g->scalefac_compress];
1439  slen2 = slen_table[1][g->scalefac_compress];
1440  av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
1441  if (g->block_type == 2) {
1442  n = g->switch_point ? 17 : 18;
1443  j = 0;
1444  if (slen1) {
1445  for (i = 0; i < n; i++)
1446  g->scale_factors[j++] = get_bits(&s->gb, slen1);
1447  } else {
1448  for (i = 0; i < n; i++)
1449  g->scale_factors[j++] = 0;
1450  }
1451  if (slen2) {
1452  for (i = 0; i < 18; i++)
1453  g->scale_factors[j++] = get_bits(&s->gb, slen2);
1454  for (i = 0; i < 3; i++)
1455  g->scale_factors[j++] = 0;
1456  } else {
1457  for (i = 0; i < 21; i++)
1458  g->scale_factors[j++] = 0;
1459  }
1460  } else {
1461  sc = s->granules[ch][0].scale_factors;
1462  j = 0;
1463  for (k = 0; k < 4; k++) {
1464  n = k == 0 ? 6 : 5;
1465  if ((g->scfsi & (0x8 >> k)) == 0) {
1466  slen = (k < 2) ? slen1 : slen2;
1467  if (slen) {
1468  for (i = 0; i < n; i++)
1469  g->scale_factors[j++] = get_bits(&s->gb, slen);
1470  } else {
1471  for (i = 0; i < n; i++)
1472  g->scale_factors[j++] = 0;
1473  }
1474  } else {
1475  /* simply copy from last granule */
1476  for (i = 0; i < n; i++) {
1477  g->scale_factors[j] = sc[j];
1478  j++;
1479  }
1480  }
1481  }
1482  g->scale_factors[j++] = 0;
1483  }
1484  } else {
1485  int tindex, tindex2, slen[4], sl, sf;
1486 
1487  /* LSF scale factors */
1488  if (g->block_type == 2)
1489  tindex = g->switch_point ? 2 : 1;
1490  else
1491  tindex = 0;
1492 
1493  sf = g->scalefac_compress;
1494  if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
1495  /* intensity stereo case */
1496  sf >>= 1;
1497  if (sf < 180) {
1498  lsf_sf_expand(slen, sf, 6, 6, 0);
1499  tindex2 = 3;
1500  } else if (sf < 244) {
1501  lsf_sf_expand(slen, sf - 180, 4, 4, 0);
1502  tindex2 = 4;
1503  } else {
1504  lsf_sf_expand(slen, sf - 244, 3, 0, 0);
1505  tindex2 = 5;
1506  }
1507  } else {
1508  /* normal case */
1509  if (sf < 400) {
1510  lsf_sf_expand(slen, sf, 5, 4, 4);
1511  tindex2 = 0;
1512  } else if (sf < 500) {
1513  lsf_sf_expand(slen, sf - 400, 5, 4, 0);
1514  tindex2 = 1;
1515  } else {
1516  lsf_sf_expand(slen, sf - 500, 3, 0, 0);
1517  tindex2 = 2;
1518  g->preflag = 1;
1519  }
1520  }
1521 
1522  j = 0;
1523  for (k = 0; k < 4; k++) {
1524  n = lsf_nsf_table[tindex2][tindex][k];
1525  sl = slen[k];
1526  if (sl) {
1527  for (i = 0; i < n; i++)
1528  g->scale_factors[j++] = get_bits(&s->gb, sl);
1529  } else {
1530  for (i = 0; i < n; i++)
1531  g->scale_factors[j++] = 0;
1532  }
1533  }
1534  /* XXX: should compute exact size */
1535  for (; j < 40; j++)
1536  g->scale_factors[j] = 0;
1537  }
1538 
1539  exponents_from_scale_factors(s, g, exponents);
1540 
1541  /* read Huffman coded residue */
1542  huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
1543  } /* ch */
1544 
1545  if (s->mode == MPA_JSTEREO)
1546  compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
1547 
1548  for (ch = 0; ch < s->nb_channels; ch++) {
1549  g = &s->granules[ch][gr];
1550 
1551  reorder_block(s, g);
1552  compute_antialias(s, g);
1553  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1554  }
1555  } /* gr */
1556  if (get_bits_count(&s->gb) < 0)
1557  skip_bits_long(&s->gb, -get_bits_count(&s->gb));
1558  return nb_granules * 18;
1559 }
1560 
1561 static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples,
1562  const uint8_t *buf, int buf_size)
1563 {
1564  int i, nb_frames, ch, ret;
1565  OUT_INT *samples_ptr;
1566 
1567  init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
1568 
1569  /* skip error protection field */
1570  if (s->error_protection)
1571  skip_bits(&s->gb, 16);
1572 
1573  switch(s->layer) {
1574  case 1:
1575  s->avctx->frame_size = 384;
1576  nb_frames = mp_decode_layer1(s);
1577  break;
1578  case 2:
1579  s->avctx->frame_size = 1152;
1580  nb_frames = mp_decode_layer2(s);
1581  break;
1582  case 3:
1583  s->avctx->frame_size = s->lsf ? 576 : 1152;
1584  default:
1585  nb_frames = mp_decode_layer3(s);
1586 
1587  s->last_buf_size=0;
1588  if (s->in_gb.buffer) {
1589  align_get_bits(&s->gb);
1590  i = get_bits_left(&s->gb)>>3;
1591  if (i >= 0 && i <= BACKSTEP_SIZE) {
1592  memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
1593  s->last_buf_size=i;
1594  } else
1595  av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
1596  s->gb = s->in_gb;
1597  s->in_gb.buffer = NULL;
1598  }
1599 
1600  align_get_bits(&s->gb);
1601  av_assert1((get_bits_count(&s->gb) & 7) == 0);
1602  i = get_bits_left(&s->gb) >> 3;
1603 
1604  if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
1605  if (i < 0)
1606  av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
1607  i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
1608  }
1609  av_assert1(i <= buf_size - HEADER_SIZE && i >= 0);
1610  memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
1611  s->last_buf_size += i;
1612  }
1613 
1614  if(nb_frames < 0)
1615  return nb_frames;
1616 
1617  /* get output buffer */
1618  if (!samples) {
1619  av_assert0(s->frame);
1620  s->frame->nb_samples = s->avctx->frame_size;
1621  if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0)
1622  return ret;
1623  samples = (OUT_INT **)s->frame->extended_data;
1624  }
1625 
1626  /* apply the synthesis filter */
1627  for (ch = 0; ch < s->nb_channels; ch++) {
1628  int sample_stride;
1629  if (s->avctx->sample_fmt == OUT_FMT_P) {
1630  samples_ptr = samples[ch];
1631  sample_stride = 1;
1632  } else {
1633  samples_ptr = samples[0] + ch;
1634  sample_stride = s->nb_channels;
1635  }
1636  for (i = 0; i < nb_frames; i++) {
1637  RENAME(ff_mpa_synth_filter)(&s->mpadsp, s->synth_buf[ch],
1638  &(s->synth_buf_offset[ch]),
1639  RENAME(ff_mpa_synth_window),
1640  &s->dither_state, samples_ptr,
1641  sample_stride, s->sb_samples[ch][i]);
1642  samples_ptr += 32 * sample_stride;
1643  }
1644  }
1645 
1646  return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
1647 }
1648 
1649 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
1650  AVPacket *avpkt)
1651 {
1652  const uint8_t *buf = avpkt->data;
1653  int buf_size = avpkt->size;
1654  MPADecodeContext *s = avctx->priv_data;
1655  uint32_t header;
1656  int ret;
1657 
1658  while(buf_size && !*buf){
1659  buf++;
1660  buf_size--;
1661  }
1662 
1663  if (buf_size < HEADER_SIZE)
1664  return AVERROR_INVALIDDATA;
1665 
1666  header = AV_RB32(buf);
1667  if (header>>8 == AV_RB32("TAG")>>8) {
1668  av_log(avctx, AV_LOG_DEBUG, "discarding ID3 tag\n");
1669  return buf_size;
1670  }
1671  if (ff_mpa_check_header(header) < 0) {
1672  av_log(avctx, AV_LOG_ERROR, "Header missing\n");
1673  return AVERROR_INVALIDDATA;
1674  }
1675 
1676  if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
1677  /* free format: prepare to compute frame size */
1678  s->frame_size = -1;
1679  return AVERROR_INVALIDDATA;
1680  }
1681  /* update codec info */
1682  avctx->channels = s->nb_channels;
1683  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1684  if (!avctx->bit_rate)
1685  avctx->bit_rate = s->bit_rate;
1686 
1687  if (s->frame_size <= 0 || s->frame_size > buf_size) {
1688  av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
1689  return AVERROR_INVALIDDATA;
1690  } else if (s->frame_size < buf_size) {
1691  av_log(avctx, AV_LOG_DEBUG, "incorrect frame size - multiple frames in buffer?\n");
1692  buf_size= s->frame_size;
1693  }
1694 
1695  s->frame = data;
1696 
1697  ret = mp_decode_frame(s, NULL, buf, buf_size);
1698  if (ret >= 0) {
1699  s->frame->nb_samples = avctx->frame_size;
1700  *got_frame_ptr = 1;
1701  avctx->sample_rate = s->sample_rate;
1702  //FIXME maybe move the other codec info stuff from above here too
1703  } else {
1704  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1705  /* Only return an error if the bad frame makes up the whole packet or
1706  * the error is related to buffer management.
1707  * If there is more data in the packet, just consume the bad frame
1708  * instead of returning an error, which would discard the whole
1709  * packet. */
1710  *got_frame_ptr = 0;
1711  if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
1712  return ret;
1713  }
1714  s->frame_size = 0;
1715  return buf_size;
1716 }
1717 
1718 static void mp_flush(MPADecodeContext *ctx)
1719 {
1720  memset(ctx->synth_buf, 0, sizeof(ctx->synth_buf));
1721  memset(ctx->mdct_buf, 0, sizeof(ctx->mdct_buf));
1722  ctx->last_buf_size = 0;
1723  ctx->dither_state = 0;
1724 }
1725 
1726 static void flush(AVCodecContext *avctx)
1727 {
1728  mp_flush(avctx->priv_data);
1729 }
1730 
1731 #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
1732 static int decode_frame_adu(AVCodecContext *avctx, void *data,
1733  int *got_frame_ptr, AVPacket *avpkt)
1734 {
1735  const uint8_t *buf = avpkt->data;
1736  int buf_size = avpkt->size;
1737  MPADecodeContext *s = avctx->priv_data;
1738  uint32_t header;
1739  int len, ret;
1740  int av_unused out_size;
1741 
1742  len = buf_size;
1743 
1744  // Discard too short frames
1745  if (buf_size < HEADER_SIZE) {
1746  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
1747  return AVERROR_INVALIDDATA;
1748  }
1749 
1750 
1751  if (len > MPA_MAX_CODED_FRAME_SIZE)
1752  len = MPA_MAX_CODED_FRAME_SIZE;
1753 
1754  // Get header and restore sync word
1755  header = AV_RB32(buf) | 0xffe00000;
1756 
1757  if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
1758  av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
1759  return AVERROR_INVALIDDATA;
1760  }
1761 
1762  avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);
1763  /* update codec info */
1764  avctx->sample_rate = s->sample_rate;
1765  avctx->channels = s->nb_channels;
1766  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1767  if (!avctx->bit_rate)
1768  avctx->bit_rate = s->bit_rate;
1769 
1770  s->frame_size = len;
1771 
1772  s->frame = data;
1773 
1774  ret = mp_decode_frame(s, NULL, buf, buf_size);
1775  if (ret < 0) {
1776  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1777  return ret;
1778  }
1779 
1780  *got_frame_ptr = 1;
1781 
1782  return buf_size;
1783 }
1784 #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
1785 
1786 #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
1787 
1788 /**
1789  * Context for MP3On4 decoder
1790  */
1791 typedef struct MP3On4DecodeContext {
1792  int frames; ///< number of mp3 frames per block (number of mp3 decoder instances)
1793  int syncword; ///< syncword patch
1794  const uint8_t *coff; ///< channel offsets in output buffer
1795  MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance
1796 } MP3On4DecodeContext;
1797 
1798 #include "mpeg4audio.h"
1799 
1800 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
1801 
1802 /* number of mp3 decoder instances */
1803 static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
1804 
1805 /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
1806 static const uint8_t chan_offset[8][5] = {
1807  { 0 },
1808  { 0 }, // C
1809  { 0 }, // FLR
1810  { 2, 0 }, // C FLR
1811  { 2, 0, 3 }, // C FLR BS
1812  { 2, 0, 3 }, // C FLR BLRS
1813  { 2, 0, 4, 3 }, // C FLR BLRS LFE
1814  { 2, 0, 6, 4, 3 }, // C FLR BLRS BLR LFE
1815 };
1816 
1817 /* mp3on4 channel layouts */
1818 static const int16_t chan_layout[8] = {
1819  0,
1820  AV_CH_LAYOUT_MONO,
1821  AV_CH_LAYOUT_STEREO,
1822  AV_CH_LAYOUT_SURROUND,
1823  AV_CH_LAYOUT_4POINT0,
1824  AV_CH_LAYOUT_5POINT0,
1825  AV_CH_LAYOUT_5POINT1,
1826  AV_CH_LAYOUT_7POINT1
1827 };
1828 
1829 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
1830 {
1831  MP3On4DecodeContext *s = avctx->priv_data;
1832  int i;
1833 
1834  for (i = 0; i < s->frames; i++)
1835  av_freep(&s->mp3decctx[i]);
1836 
1837  return 0;
1838 }
1839 
1840 
1841 static av_cold int decode_init_mp3on4(AVCodecContext * avctx)
1842 {
1843  MP3On4DecodeContext *s = avctx->priv_data;
1844  MPEG4AudioConfig cfg;
1845  int i;
1846 
1847  if ((avctx->extradata_size < 2) || !avctx->extradata) {
1848  av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
1849  return AVERROR_INVALIDDATA;
1850  }
1851 
1852  avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,
1853  avctx->extradata_size * 8, 1);
1854  if (!cfg.chan_config || cfg.chan_config > 7) {
1855  av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
1856  return AVERROR_INVALIDDATA;
1857  }
1858  s->frames = mp3Frames[cfg.chan_config];
1859  s->coff = chan_offset[cfg.chan_config];
1860  avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];
1861  avctx->channel_layout = chan_layout[cfg.chan_config];
1862 
1863  if (cfg.sample_rate < 16000)
1864  s->syncword = 0xffe00000;
1865  else
1866  s->syncword = 0xfff00000;
1867 
1868  /* Init the first mp3 decoder in standard way, so that all tables get builded
1869  * We replace avctx->priv_data with the context of the first decoder so that
1870  * decode_init() does not have to be changed.
1871  * Other decoders will be initialized here copying data from the first context
1872  */
1873  // Allocate zeroed memory for the first decoder context
1874  s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
1875  if (!s->mp3decctx[0])
1876  goto alloc_fail;
1877  // Put decoder context in place to make init_decode() happy
1878  avctx->priv_data = s->mp3decctx[0];
1879  decode_init(avctx);
1880  // Restore mp3on4 context pointer
1881  avctx->priv_data = s;
1882  s->mp3decctx[0]->adu_mode = 1; // Set adu mode
1883 
1884  /* Create a separate codec/context for each frame (first is already ok).
1885  * Each frame is 1 or 2 channels - up to 5 frames allowed
1886  */
1887  for (i = 1; i < s->frames; i++) {
1888  s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
1889  if (!s->mp3decctx[i])
1890  goto alloc_fail;
1891  s->mp3decctx[i]->adu_mode = 1;
1892  s->mp3decctx[i]->avctx = avctx;
1893  s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
1894  }
1895 
1896  return 0;
1897 alloc_fail:
1898  decode_close_mp3on4(avctx);
1899  return AVERROR(ENOMEM);
1900 }
1901 
1902 
1903 static void flush_mp3on4(AVCodecContext *avctx)
1904 {
1905  int i;
1906  MP3On4DecodeContext *s = avctx->priv_data;
1907 
1908  for (i = 0; i < s->frames; i++)
1909  mp_flush(s->mp3decctx[i]);
1910 }
1911 
1912 
1913 static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
1914  int *got_frame_ptr, AVPacket *avpkt)
1915 {
1916  AVFrame *frame = data;
1917  const uint8_t *buf = avpkt->data;
1918  int buf_size = avpkt->size;
1919  MP3On4DecodeContext *s = avctx->priv_data;
1920  MPADecodeContext *m;
1921  int fsize, len = buf_size, out_size = 0;
1922  uint32_t header;
1923  OUT_INT **out_samples;
1924  OUT_INT *outptr[2];
1925  int fr, ch, ret;
1926 
1927  /* get output buffer */
1928  frame->nb_samples = MPA_FRAME_SIZE;
1929  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1930  return ret;
1931  out_samples = (OUT_INT **)frame->extended_data;
1932 
1933  // Discard too short frames
1934  if (buf_size < HEADER_SIZE)
1935  return AVERROR_INVALIDDATA;
1936 
1937  avctx->bit_rate = 0;
1938 
1939  ch = 0;
1940  for (fr = 0; fr < s->frames; fr++) {
1941  fsize = AV_RB16(buf) >> 4;
1942  fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
1943  m = s->mp3decctx[fr];
1944  av_assert1(m);
1945 
1946  if (fsize < HEADER_SIZE) {
1947  av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
1948  return AVERROR_INVALIDDATA;
1949  }
1950  header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
1951 
1952  if (ff_mpa_check_header(header) < 0) {
1953  av_log(avctx, AV_LOG_ERROR, "Bad header, discard block\n");
1954  return AVERROR_INVALIDDATA;
1955  }
1956 
1957  avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);
1958 
1959  if (ch + m->nb_channels > avctx->channels ||
1960  s->coff[fr] + m->nb_channels > avctx->channels) {
1961  av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
1962  "channel count\n");
1963  return AVERROR_INVALIDDATA;
1964  }
1965  ch += m->nb_channels;
1966 
1967  outptr[0] = out_samples[s->coff[fr]];
1968  if (m->nb_channels > 1)
1969  outptr[1] = out_samples[s->coff[fr] + 1];
1970 
1971  if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0) {
1972  av_log(avctx, AV_LOG_ERROR, "failed to decode channel %d\n", ch);
1973  memset(outptr[0], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
1974  if (m->nb_channels > 1)
1975  memset(outptr[1], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
1976  ret = m->nb_channels * MPA_FRAME_SIZE*sizeof(OUT_INT);
1977  }
1978 
1979  out_size += ret;
1980  buf += fsize;
1981  len -= fsize;
1982 
1983  avctx->bit_rate += m->bit_rate;
1984  }
1985  if (ch != avctx->channels) {
1986  av_log(avctx, AV_LOG_ERROR, "failed to decode all channels\n");
1987  return AVERROR_INVALIDDATA;
1988  }
1989 
1990  /* update codec info */
1991  avctx->sample_rate = s->mp3decctx[0]->sample_rate;
1992 
1993  frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
1994  *got_frame_ptr = 1;
1995 
1996  return buf_size;
1997 }
1998 #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */
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