FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mpegaudiodec_template.c
Go to the documentation of this file.
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 #if USE_FLOATS
432  s->fdsp = avpriv_float_dsp_alloc(avctx->flags & CODEC_FLAG_BITEXACT);
433  if (!s->fdsp)
434  return AVERROR(ENOMEM);
435 #endif
436 
437  ff_mpadsp_init(&s->mpadsp);
438 
439  if (avctx->request_sample_fmt == OUT_FMT &&
440  avctx->codec_id != AV_CODEC_ID_MP3ON4)
441  avctx->sample_fmt = OUT_FMT;
442  else
443  avctx->sample_fmt = OUT_FMT_P;
444  s->err_recognition = avctx->err_recognition;
445 
446  if (avctx->codec_id == AV_CODEC_ID_MP3ADU)
447  s->adu_mode = 1;
448 
449  return 0;
450 }
451 
452 #define C3 FIXHR(0.86602540378443864676/2)
453 #define C4 FIXHR(0.70710678118654752439/2) //0.5 / cos(pi*(9)/36)
454 #define C5 FIXHR(0.51763809020504152469/2) //0.5 / cos(pi*(5)/36)
455 #define C6 FIXHR(1.93185165257813657349/4) //0.5 / cos(pi*(15)/36)
456 
457 /* 12 points IMDCT. We compute it "by hand" by factorizing obvious
458  cases. */
459 static void imdct12(INTFLOAT *out, INTFLOAT *in)
460 {
461  INTFLOAT in0, in1, in2, in3, in4, in5, t1, t2;
462 
463  in0 = in[0*3];
464  in1 = in[1*3] + in[0*3];
465  in2 = in[2*3] + in[1*3];
466  in3 = in[3*3] + in[2*3];
467  in4 = in[4*3] + in[3*3];
468  in5 = in[5*3] + in[4*3];
469  in5 += in3;
470  in3 += in1;
471 
472  in2 = MULH3(in2, C3, 2);
473  in3 = MULH3(in3, C3, 4);
474 
475  t1 = in0 - in4;
476  t2 = MULH3(in1 - in5, C4, 2);
477 
478  out[ 7] =
479  out[10] = t1 + t2;
480  out[ 1] =
481  out[ 4] = t1 - t2;
482 
483  in0 += SHR(in4, 1);
484  in4 = in0 + in2;
485  in5 += 2*in1;
486  in1 = MULH3(in5 + in3, C5, 1);
487  out[ 8] =
488  out[ 9] = in4 + in1;
489  out[ 2] =
490  out[ 3] = in4 - in1;
491 
492  in0 -= in2;
493  in5 = MULH3(in5 - in3, C6, 2);
494  out[ 0] =
495  out[ 5] = in0 - in5;
496  out[ 6] =
497  out[11] = in0 + in5;
498 }
499 
500 /* return the number of decoded frames */
501 static int mp_decode_layer1(MPADecodeContext *s)
502 {
503  int bound, i, v, n, ch, j, mant;
504  uint8_t allocation[MPA_MAX_CHANNELS][SBLIMIT];
505  uint8_t scale_factors[MPA_MAX_CHANNELS][SBLIMIT];
506 
507  if (s->mode == MPA_JSTEREO)
508  bound = (s->mode_ext + 1) * 4;
509  else
510  bound = SBLIMIT;
511 
512  /* allocation bits */
513  for (i = 0; i < bound; i++) {
514  for (ch = 0; ch < s->nb_channels; ch++) {
515  allocation[ch][i] = get_bits(&s->gb, 4);
516  }
517  }
518  for (i = bound; i < SBLIMIT; i++)
519  allocation[0][i] = get_bits(&s->gb, 4);
520 
521  /* scale factors */
522  for (i = 0; i < bound; i++) {
523  for (ch = 0; ch < s->nb_channels; ch++) {
524  if (allocation[ch][i])
525  scale_factors[ch][i] = get_bits(&s->gb, 6);
526  }
527  }
528  for (i = bound; i < SBLIMIT; i++) {
529  if (allocation[0][i]) {
530  scale_factors[0][i] = get_bits(&s->gb, 6);
531  scale_factors[1][i] = get_bits(&s->gb, 6);
532  }
533  }
534 
535  /* compute samples */
536  for (j = 0; j < 12; j++) {
537  for (i = 0; i < bound; i++) {
538  for (ch = 0; ch < s->nb_channels; ch++) {
539  n = allocation[ch][i];
540  if (n) {
541  mant = get_bits(&s->gb, n + 1);
542  v = l1_unscale(n, mant, scale_factors[ch][i]);
543  } else {
544  v = 0;
545  }
546  s->sb_samples[ch][j][i] = v;
547  }
548  }
549  for (i = bound; i < SBLIMIT; i++) {
550  n = allocation[0][i];
551  if (n) {
552  mant = get_bits(&s->gb, n + 1);
553  v = l1_unscale(n, mant, scale_factors[0][i]);
554  s->sb_samples[0][j][i] = v;
555  v = l1_unscale(n, mant, scale_factors[1][i]);
556  s->sb_samples[1][j][i] = v;
557  } else {
558  s->sb_samples[0][j][i] = 0;
559  s->sb_samples[1][j][i] = 0;
560  }
561  }
562  }
563  return 12;
564 }
565 
566 static int mp_decode_layer2(MPADecodeContext *s)
567 {
568  int sblimit; /* number of used subbands */
569  const unsigned char *alloc_table;
570  int table, bit_alloc_bits, i, j, ch, bound, v;
571  unsigned char bit_alloc[MPA_MAX_CHANNELS][SBLIMIT];
572  unsigned char scale_code[MPA_MAX_CHANNELS][SBLIMIT];
573  unsigned char scale_factors[MPA_MAX_CHANNELS][SBLIMIT][3], *sf;
574  int scale, qindex, bits, steps, k, l, m, b;
575 
576  /* select decoding table */
577  table = ff_mpa_l2_select_table(s->bit_rate / 1000, s->nb_channels,
578  s->sample_rate, s->lsf);
579  sblimit = ff_mpa_sblimit_table[table];
580  alloc_table = ff_mpa_alloc_tables[table];
581 
582  if (s->mode == MPA_JSTEREO)
583  bound = (s->mode_ext + 1) * 4;
584  else
585  bound = sblimit;
586 
587  av_dlog(s->avctx, "bound=%d sblimit=%d\n", bound, sblimit);
588 
589  /* sanity check */
590  if (bound > sblimit)
591  bound = sblimit;
592 
593  /* parse bit allocation */
594  j = 0;
595  for (i = 0; i < bound; i++) {
596  bit_alloc_bits = alloc_table[j];
597  for (ch = 0; ch < s->nb_channels; ch++)
598  bit_alloc[ch][i] = get_bits(&s->gb, bit_alloc_bits);
599  j += 1 << bit_alloc_bits;
600  }
601  for (i = bound; i < sblimit; i++) {
602  bit_alloc_bits = alloc_table[j];
603  v = get_bits(&s->gb, bit_alloc_bits);
604  bit_alloc[0][i] = v;
605  bit_alloc[1][i] = v;
606  j += 1 << bit_alloc_bits;
607  }
608 
609  /* scale codes */
610  for (i = 0; i < sblimit; i++) {
611  for (ch = 0; ch < s->nb_channels; ch++) {
612  if (bit_alloc[ch][i])
613  scale_code[ch][i] = get_bits(&s->gb, 2);
614  }
615  }
616 
617  /* scale factors */
618  for (i = 0; i < sblimit; i++) {
619  for (ch = 0; ch < s->nb_channels; ch++) {
620  if (bit_alloc[ch][i]) {
621  sf = scale_factors[ch][i];
622  switch (scale_code[ch][i]) {
623  default:
624  case 0:
625  sf[0] = get_bits(&s->gb, 6);
626  sf[1] = get_bits(&s->gb, 6);
627  sf[2] = get_bits(&s->gb, 6);
628  break;
629  case 2:
630  sf[0] = get_bits(&s->gb, 6);
631  sf[1] = sf[0];
632  sf[2] = sf[0];
633  break;
634  case 1:
635  sf[0] = get_bits(&s->gb, 6);
636  sf[2] = get_bits(&s->gb, 6);
637  sf[1] = sf[0];
638  break;
639  case 3:
640  sf[0] = get_bits(&s->gb, 6);
641  sf[2] = get_bits(&s->gb, 6);
642  sf[1] = sf[2];
643  break;
644  }
645  }
646  }
647  }
648 
649  /* samples */
650  for (k = 0; k < 3; k++) {
651  for (l = 0; l < 12; l += 3) {
652  j = 0;
653  for (i = 0; i < bound; i++) {
654  bit_alloc_bits = alloc_table[j];
655  for (ch = 0; ch < s->nb_channels; ch++) {
656  b = bit_alloc[ch][i];
657  if (b) {
658  scale = scale_factors[ch][i][k];
659  qindex = alloc_table[j+b];
660  bits = ff_mpa_quant_bits[qindex];
661  if (bits < 0) {
662  int v2;
663  /* 3 values at the same time */
664  v = get_bits(&s->gb, -bits);
665  v2 = division_tabs[qindex][v];
666  steps = ff_mpa_quant_steps[qindex];
667 
668  s->sb_samples[ch][k * 12 + l + 0][i] =
669  l2_unscale_group(steps, v2 & 15, scale);
670  s->sb_samples[ch][k * 12 + l + 1][i] =
671  l2_unscale_group(steps, (v2 >> 4) & 15, scale);
672  s->sb_samples[ch][k * 12 + l + 2][i] =
673  l2_unscale_group(steps, v2 >> 8 , scale);
674  } else {
675  for (m = 0; m < 3; m++) {
676  v = get_bits(&s->gb, bits);
677  v = l1_unscale(bits - 1, v, scale);
678  s->sb_samples[ch][k * 12 + l + m][i] = v;
679  }
680  }
681  } else {
682  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
683  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
684  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
685  }
686  }
687  /* next subband in alloc table */
688  j += 1 << bit_alloc_bits;
689  }
690  /* XXX: find a way to avoid this duplication of code */
691  for (i = bound; i < sblimit; i++) {
692  bit_alloc_bits = alloc_table[j];
693  b = bit_alloc[0][i];
694  if (b) {
695  int mant, scale0, scale1;
696  scale0 = scale_factors[0][i][k];
697  scale1 = scale_factors[1][i][k];
698  qindex = alloc_table[j+b];
699  bits = ff_mpa_quant_bits[qindex];
700  if (bits < 0) {
701  /* 3 values at the same time */
702  v = get_bits(&s->gb, -bits);
703  steps = ff_mpa_quant_steps[qindex];
704  mant = v % steps;
705  v = v / steps;
706  s->sb_samples[0][k * 12 + l + 0][i] =
707  l2_unscale_group(steps, mant, scale0);
708  s->sb_samples[1][k * 12 + l + 0][i] =
709  l2_unscale_group(steps, mant, scale1);
710  mant = v % steps;
711  v = v / steps;
712  s->sb_samples[0][k * 12 + l + 1][i] =
713  l2_unscale_group(steps, mant, scale0);
714  s->sb_samples[1][k * 12 + l + 1][i] =
715  l2_unscale_group(steps, mant, scale1);
716  s->sb_samples[0][k * 12 + l + 2][i] =
717  l2_unscale_group(steps, v, scale0);
718  s->sb_samples[1][k * 12 + l + 2][i] =
719  l2_unscale_group(steps, v, scale1);
720  } else {
721  for (m = 0; m < 3; m++) {
722  mant = get_bits(&s->gb, bits);
723  s->sb_samples[0][k * 12 + l + m][i] =
724  l1_unscale(bits - 1, mant, scale0);
725  s->sb_samples[1][k * 12 + l + m][i] =
726  l1_unscale(bits - 1, mant, scale1);
727  }
728  }
729  } else {
730  s->sb_samples[0][k * 12 + l + 0][i] = 0;
731  s->sb_samples[0][k * 12 + l + 1][i] = 0;
732  s->sb_samples[0][k * 12 + l + 2][i] = 0;
733  s->sb_samples[1][k * 12 + l + 0][i] = 0;
734  s->sb_samples[1][k * 12 + l + 1][i] = 0;
735  s->sb_samples[1][k * 12 + l + 2][i] = 0;
736  }
737  /* next subband in alloc table */
738  j += 1 << bit_alloc_bits;
739  }
740  /* fill remaining samples to zero */
741  for (i = sblimit; i < SBLIMIT; i++) {
742  for (ch = 0; ch < s->nb_channels; ch++) {
743  s->sb_samples[ch][k * 12 + l + 0][i] = 0;
744  s->sb_samples[ch][k * 12 + l + 1][i] = 0;
745  s->sb_samples[ch][k * 12 + l + 2][i] = 0;
746  }
747  }
748  }
749  }
750  return 3 * 12;
751 }
752 
753 #define SPLIT(dst,sf,n) \
754  if (n == 3) { \
755  int m = (sf * 171) >> 9; \
756  dst = sf - 3 * m; \
757  sf = m; \
758  } else if (n == 4) { \
759  dst = sf & 3; \
760  sf >>= 2; \
761  } else if (n == 5) { \
762  int m = (sf * 205) >> 10; \
763  dst = sf - 5 * m; \
764  sf = m; \
765  } else if (n == 6) { \
766  int m = (sf * 171) >> 10; \
767  dst = sf - 6 * m; \
768  sf = m; \
769  } else { \
770  dst = 0; \
771  }
772 
773 static av_always_inline void lsf_sf_expand(int *slen, int sf, int n1, int n2,
774  int n3)
775 {
776  SPLIT(slen[3], sf, n3)
777  SPLIT(slen[2], sf, n2)
778  SPLIT(slen[1], sf, n1)
779  slen[0] = sf;
780 }
781 
782 static void exponents_from_scale_factors(MPADecodeContext *s, GranuleDef *g,
783  int16_t *exponents)
784 {
785  const uint8_t *bstab, *pretab;
786  int len, i, j, k, l, v0, shift, gain, gains[3];
787  int16_t *exp_ptr;
788 
789  exp_ptr = exponents;
790  gain = g->global_gain - 210;
791  shift = g->scalefac_scale + 1;
792 
793  bstab = band_size_long[s->sample_rate_index];
794  pretab = mpa_pretab[g->preflag];
795  for (i = 0; i < g->long_end; i++) {
796  v0 = gain - ((g->scale_factors[i] + pretab[i]) << shift) + 400;
797  len = bstab[i];
798  for (j = len; j > 0; j--)
799  *exp_ptr++ = v0;
800  }
801 
802  if (g->short_start < 13) {
803  bstab = band_size_short[s->sample_rate_index];
804  gains[0] = gain - (g->subblock_gain[0] << 3);
805  gains[1] = gain - (g->subblock_gain[1] << 3);
806  gains[2] = gain - (g->subblock_gain[2] << 3);
807  k = g->long_end;
808  for (i = g->short_start; i < 13; i++) {
809  len = bstab[i];
810  for (l = 0; l < 3; l++) {
811  v0 = gains[l] - (g->scale_factors[k++] << shift) + 400;
812  for (j = len; j > 0; j--)
813  *exp_ptr++ = v0;
814  }
815  }
816  }
817 }
818 
819 /* handle n = 0 too */
820 static inline int get_bitsz(GetBitContext *s, int n)
821 {
822  return n ? get_bits(s, n) : 0;
823 }
824 
825 
826 static void switch_buffer(MPADecodeContext *s, int *pos, int *end_pos,
827  int *end_pos2)
828 {
829  if (s->in_gb.buffer && *pos >= s->gb.size_in_bits) {
830  s->gb = s->in_gb;
831  s->in_gb.buffer = NULL;
832  av_assert2((get_bits_count(&s->gb) & 7) == 0);
833  skip_bits_long(&s->gb, *pos - *end_pos);
834  *end_pos2 =
835  *end_pos = *end_pos2 + get_bits_count(&s->gb) - *pos;
836  *pos = get_bits_count(&s->gb);
837  }
838 }
839 
840 /* Following is a optimized code for
841  INTFLOAT v = *src
842  if(get_bits1(&s->gb))
843  v = -v;
844  *dst = v;
845 */
846 #if USE_FLOATS
847 #define READ_FLIP_SIGN(dst,src) \
848  v = AV_RN32A(src) ^ (get_bits1(&s->gb) << 31); \
849  AV_WN32A(dst, v);
850 #else
851 #define READ_FLIP_SIGN(dst,src) \
852  v = -get_bits1(&s->gb); \
853  *(dst) = (*(src) ^ v) - v;
854 #endif
855 
856 static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
857  int16_t *exponents, int end_pos2)
858 {
859  int s_index;
860  int i;
861  int last_pos, bits_left;
862  VLC *vlc;
863  int end_pos = FFMIN(end_pos2, s->gb.size_in_bits);
864 
865  /* low frequencies (called big values) */
866  s_index = 0;
867  for (i = 0; i < 3; i++) {
868  int j, k, l, linbits;
869  j = g->region_size[i];
870  if (j == 0)
871  continue;
872  /* select vlc table */
873  k = g->table_select[i];
874  l = mpa_huff_data[k][0];
875  linbits = mpa_huff_data[k][1];
876  vlc = &huff_vlc[l];
877 
878  if (!l) {
879  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * 2 * j);
880  s_index += 2 * j;
881  continue;
882  }
883 
884  /* read huffcode and compute each couple */
885  for (; j > 0; j--) {
886  int exponent, x, y;
887  int v;
888  int pos = get_bits_count(&s->gb);
889 
890  if (pos >= end_pos){
891  switch_buffer(s, &pos, &end_pos, &end_pos2);
892  if (pos >= end_pos)
893  break;
894  }
895  y = get_vlc2(&s->gb, vlc->table, 7, 3);
896 
897  if (!y) {
898  g->sb_hybrid[s_index ] =
899  g->sb_hybrid[s_index+1] = 0;
900  s_index += 2;
901  continue;
902  }
903 
904  exponent= exponents[s_index];
905 
906  av_dlog(s->avctx, "region=%d n=%d x=%d y=%d exp=%d\n",
907  i, g->region_size[i] - j, x, y, exponent);
908  if (y & 16) {
909  x = y >> 5;
910  y = y & 0x0f;
911  if (x < 15) {
912  READ_FLIP_SIGN(g->sb_hybrid + s_index, RENAME(expval_table)[exponent] + x)
913  } else {
914  x += get_bitsz(&s->gb, linbits);
915  v = l3_unscale(x, exponent);
916  if (get_bits1(&s->gb))
917  v = -v;
918  g->sb_hybrid[s_index] = v;
919  }
920  if (y < 15) {
921  READ_FLIP_SIGN(g->sb_hybrid + s_index + 1, RENAME(expval_table)[exponent] + y)
922  } else {
923  y += get_bitsz(&s->gb, linbits);
924  v = l3_unscale(y, exponent);
925  if (get_bits1(&s->gb))
926  v = -v;
927  g->sb_hybrid[s_index+1] = v;
928  }
929  } else {
930  x = y >> 5;
931  y = y & 0x0f;
932  x += y;
933  if (x < 15) {
934  READ_FLIP_SIGN(g->sb_hybrid + s_index + !!y, RENAME(expval_table)[exponent] + x)
935  } else {
936  x += get_bitsz(&s->gb, linbits);
937  v = l3_unscale(x, exponent);
938  if (get_bits1(&s->gb))
939  v = -v;
940  g->sb_hybrid[s_index+!!y] = v;
941  }
942  g->sb_hybrid[s_index + !y] = 0;
943  }
944  s_index += 2;
945  }
946  }
947 
948  /* high frequencies */
949  vlc = &huff_quad_vlc[g->count1table_select];
950  last_pos = 0;
951  while (s_index <= 572) {
952  int pos, code;
953  pos = get_bits_count(&s->gb);
954  if (pos >= end_pos) {
955  if (pos > end_pos2 && last_pos) {
956  /* some encoders generate an incorrect size for this
957  part. We must go back into the data */
958  s_index -= 4;
959  skip_bits_long(&s->gb, last_pos - pos);
960  av_log(s->avctx, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
961  if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
962  s_index=0;
963  break;
964  }
965  switch_buffer(s, &pos, &end_pos, &end_pos2);
966  if (pos >= end_pos)
967  break;
968  }
969  last_pos = pos;
970 
971  code = get_vlc2(&s->gb, vlc->table, vlc->bits, 1);
972  av_dlog(s->avctx, "t=%d code=%d\n", g->count1table_select, code);
973  g->sb_hybrid[s_index+0] =
974  g->sb_hybrid[s_index+1] =
975  g->sb_hybrid[s_index+2] =
976  g->sb_hybrid[s_index+3] = 0;
977  while (code) {
978  static const int idxtab[16] = { 3,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0 };
979  int v;
980  int pos = s_index + idxtab[code];
981  code ^= 8 >> idxtab[code];
982  READ_FLIP_SIGN(g->sb_hybrid + pos, RENAME(exp_table)+exponents[pos])
983  }
984  s_index += 4;
985  }
986  /* skip extension bits */
987  bits_left = end_pos2 - get_bits_count(&s->gb);
988  if (bits_left < 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_COMPLIANT))) {
989  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
990  s_index=0;
991  } else if (bits_left > 0 && (s->err_recognition & (AV_EF_BUFFER|AV_EF_AGGRESSIVE))) {
992  av_log(s->avctx, AV_LOG_ERROR, "bits_left=%d\n", bits_left);
993  s_index = 0;
994  }
995  memset(&g->sb_hybrid[s_index], 0, sizeof(*g->sb_hybrid) * (576 - s_index));
996  skip_bits_long(&s->gb, bits_left);
997 
998  i = get_bits_count(&s->gb);
999  switch_buffer(s, &i, &end_pos, &end_pos2);
1000 
1001  return 0;
1002 }
1003 
1004 /* Reorder short blocks from bitstream order to interleaved order. It
1005  would be faster to do it in parsing, but the code would be far more
1006  complicated */
1007 static void reorder_block(MPADecodeContext *s, GranuleDef *g)
1008 {
1009  int i, j, len;
1010  INTFLOAT *ptr, *dst, *ptr1;
1011  INTFLOAT tmp[576];
1012 
1013  if (g->block_type != 2)
1014  return;
1015 
1016  if (g->switch_point) {
1017  if (s->sample_rate_index != 8)
1018  ptr = g->sb_hybrid + 36;
1019  else
1020  ptr = g->sb_hybrid + 72;
1021  } else {
1022  ptr = g->sb_hybrid;
1023  }
1024 
1025  for (i = g->short_start; i < 13; i++) {
1026  len = band_size_short[s->sample_rate_index][i];
1027  ptr1 = ptr;
1028  dst = tmp;
1029  for (j = len; j > 0; j--) {
1030  *dst++ = ptr[0*len];
1031  *dst++ = ptr[1*len];
1032  *dst++ = ptr[2*len];
1033  ptr++;
1034  }
1035  ptr += 2 * len;
1036  memcpy(ptr1, tmp, len * 3 * sizeof(*ptr1));
1037  }
1038 }
1039 
1040 #define ISQRT2 FIXR(0.70710678118654752440)
1041 
1042 static void compute_stereo(MPADecodeContext *s, GranuleDef *g0, GranuleDef *g1)
1043 {
1044  int i, j, k, l;
1045  int sf_max, sf, len, non_zero_found;
1046  INTFLOAT (*is_tab)[16], *tab0, *tab1, tmp0, tmp1, v1, v2;
1047  int non_zero_found_short[3];
1048 
1049  /* intensity stereo */
1050  if (s->mode_ext & MODE_EXT_I_STEREO) {
1051  if (!s->lsf) {
1052  is_tab = is_table;
1053  sf_max = 7;
1054  } else {
1055  is_tab = is_table_lsf[g1->scalefac_compress & 1];
1056  sf_max = 16;
1057  }
1058 
1059  tab0 = g0->sb_hybrid + 576;
1060  tab1 = g1->sb_hybrid + 576;
1061 
1062  non_zero_found_short[0] = 0;
1063  non_zero_found_short[1] = 0;
1064  non_zero_found_short[2] = 0;
1065  k = (13 - g1->short_start) * 3 + g1->long_end - 3;
1066  for (i = 12; i >= g1->short_start; i--) {
1067  /* for last band, use previous scale factor */
1068  if (i != 11)
1069  k -= 3;
1070  len = band_size_short[s->sample_rate_index][i];
1071  for (l = 2; l >= 0; l--) {
1072  tab0 -= len;
1073  tab1 -= len;
1074  if (!non_zero_found_short[l]) {
1075  /* test if non zero band. if so, stop doing i-stereo */
1076  for (j = 0; j < len; j++) {
1077  if (tab1[j] != 0) {
1078  non_zero_found_short[l] = 1;
1079  goto found1;
1080  }
1081  }
1082  sf = g1->scale_factors[k + l];
1083  if (sf >= sf_max)
1084  goto found1;
1085 
1086  v1 = is_tab[0][sf];
1087  v2 = is_tab[1][sf];
1088  for (j = 0; j < len; j++) {
1089  tmp0 = tab0[j];
1090  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1091  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1092  }
1093  } else {
1094 found1:
1095  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1096  /* lower part of the spectrum : do ms stereo
1097  if enabled */
1098  for (j = 0; j < len; j++) {
1099  tmp0 = tab0[j];
1100  tmp1 = tab1[j];
1101  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1102  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1103  }
1104  }
1105  }
1106  }
1107  }
1108 
1109  non_zero_found = non_zero_found_short[0] |
1110  non_zero_found_short[1] |
1111  non_zero_found_short[2];
1112 
1113  for (i = g1->long_end - 1;i >= 0;i--) {
1114  len = band_size_long[s->sample_rate_index][i];
1115  tab0 -= len;
1116  tab1 -= len;
1117  /* test if non zero band. if so, stop doing i-stereo */
1118  if (!non_zero_found) {
1119  for (j = 0; j < len; j++) {
1120  if (tab1[j] != 0) {
1121  non_zero_found = 1;
1122  goto found2;
1123  }
1124  }
1125  /* for last band, use previous scale factor */
1126  k = (i == 21) ? 20 : i;
1127  sf = g1->scale_factors[k];
1128  if (sf >= sf_max)
1129  goto found2;
1130  v1 = is_tab[0][sf];
1131  v2 = is_tab[1][sf];
1132  for (j = 0; j < len; j++) {
1133  tmp0 = tab0[j];
1134  tab0[j] = MULLx(tmp0, v1, FRAC_BITS);
1135  tab1[j] = MULLx(tmp0, v2, FRAC_BITS);
1136  }
1137  } else {
1138 found2:
1139  if (s->mode_ext & MODE_EXT_MS_STEREO) {
1140  /* lower part of the spectrum : do ms stereo
1141  if enabled */
1142  for (j = 0; j < len; j++) {
1143  tmp0 = tab0[j];
1144  tmp1 = tab1[j];
1145  tab0[j] = MULLx(tmp0 + tmp1, ISQRT2, FRAC_BITS);
1146  tab1[j] = MULLx(tmp0 - tmp1, ISQRT2, FRAC_BITS);
1147  }
1148  }
1149  }
1150  }
1151  } else if (s->mode_ext & MODE_EXT_MS_STEREO) {
1152  /* ms stereo ONLY */
1153  /* NOTE: the 1/sqrt(2) normalization factor is included in the
1154  global gain */
1155 #if USE_FLOATS
1156  s->fdsp->butterflies_float(g0->sb_hybrid, g1->sb_hybrid, 576);
1157 #else
1158  tab0 = g0->sb_hybrid;
1159  tab1 = g1->sb_hybrid;
1160  for (i = 0; i < 576; i++) {
1161  tmp0 = tab0[i];
1162  tmp1 = tab1[i];
1163  tab0[i] = tmp0 + tmp1;
1164  tab1[i] = tmp0 - tmp1;
1165  }
1166 #endif
1167  }
1168 }
1169 
1170 #if USE_FLOATS
1171 #if HAVE_MIPSFPU
1172 # include "mips/compute_antialias_float.h"
1173 #endif /* HAVE_MIPSFPU */
1174 #else
1175 #if HAVE_MIPSDSPR1
1176 # include "mips/compute_antialias_fixed.h"
1177 #endif /* HAVE_MIPSDSPR1 */
1178 #endif /* USE_FLOATS */
1179 
1180 #ifndef compute_antialias
1181 #if USE_FLOATS
1182 #define AA(j) do { \
1183  float tmp0 = ptr[-1-j]; \
1184  float tmp1 = ptr[ j]; \
1185  ptr[-1-j] = tmp0 * csa_table[j][0] - tmp1 * csa_table[j][1]; \
1186  ptr[ j] = tmp0 * csa_table[j][1] + tmp1 * csa_table[j][0]; \
1187  } while (0)
1188 #else
1189 #define AA(j) do { \
1190  int tmp0 = ptr[-1-j]; \
1191  int tmp1 = ptr[ j]; \
1192  int tmp2 = MULH(tmp0 + tmp1, csa_table[j][0]); \
1193  ptr[-1-j] = 4 * (tmp2 - MULH(tmp1, csa_table[j][2])); \
1194  ptr[ j] = 4 * (tmp2 + MULH(tmp0, csa_table[j][3])); \
1195  } while (0)
1196 #endif
1197 
1198 static void compute_antialias(MPADecodeContext *s, GranuleDef *g)
1199 {
1200  INTFLOAT *ptr;
1201  int n, i;
1202 
1203  /* we antialias only "long" bands */
1204  if (g->block_type == 2) {
1205  if (!g->switch_point)
1206  return;
1207  /* XXX: check this for 8000Hz case */
1208  n = 1;
1209  } else {
1210  n = SBLIMIT - 1;
1211  }
1212 
1213  ptr = g->sb_hybrid + 18;
1214  for (i = n; i > 0; i--) {
1215  AA(0);
1216  AA(1);
1217  AA(2);
1218  AA(3);
1219  AA(4);
1220  AA(5);
1221  AA(6);
1222  AA(7);
1223 
1224  ptr += 18;
1225  }
1226 }
1227 #endif /* compute_antialias */
1228 
1229 static void compute_imdct(MPADecodeContext *s, GranuleDef *g,
1230  INTFLOAT *sb_samples, INTFLOAT *mdct_buf)
1231 {
1232  INTFLOAT *win, *out_ptr, *ptr, *buf, *ptr1;
1233  INTFLOAT out2[12];
1234  int i, j, mdct_long_end, sblimit;
1235 
1236  /* find last non zero block */
1237  ptr = g->sb_hybrid + 576;
1238  ptr1 = g->sb_hybrid + 2 * 18;
1239  while (ptr >= ptr1) {
1240  int32_t *p;
1241  ptr -= 6;
1242  p = (int32_t*)ptr;
1243  if (p[0] | p[1] | p[2] | p[3] | p[4] | p[5])
1244  break;
1245  }
1246  sblimit = ((ptr - g->sb_hybrid) / 18) + 1;
1247 
1248  if (g->block_type == 2) {
1249  /* XXX: check for 8000 Hz */
1250  if (g->switch_point)
1251  mdct_long_end = 2;
1252  else
1253  mdct_long_end = 0;
1254  } else {
1255  mdct_long_end = sblimit;
1256  }
1257 
1258  s->mpadsp.RENAME(imdct36_blocks)(sb_samples, mdct_buf, g->sb_hybrid,
1259  mdct_long_end, g->switch_point,
1260  g->block_type);
1261 
1262  buf = mdct_buf + 4*18*(mdct_long_end >> 2) + (mdct_long_end & 3);
1263  ptr = g->sb_hybrid + 18 * mdct_long_end;
1264 
1265  for (j = mdct_long_end; j < sblimit; j++) {
1266  /* select frequency inversion */
1267  win = RENAME(ff_mdct_win)[2 + (4 & -(j & 1))];
1268  out_ptr = sb_samples + j;
1269 
1270  for (i = 0; i < 6; i++) {
1271  *out_ptr = buf[4*i];
1272  out_ptr += SBLIMIT;
1273  }
1274  imdct12(out2, ptr + 0);
1275  for (i = 0; i < 6; i++) {
1276  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*1)];
1277  buf[4*(i + 6*2)] = MULH3(out2[i + 6], win[i + 6], 1);
1278  out_ptr += SBLIMIT;
1279  }
1280  imdct12(out2, ptr + 1);
1281  for (i = 0; i < 6; i++) {
1282  *out_ptr = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*2)];
1283  buf[4*(i + 6*0)] = MULH3(out2[i + 6], win[i + 6], 1);
1284  out_ptr += SBLIMIT;
1285  }
1286  imdct12(out2, ptr + 2);
1287  for (i = 0; i < 6; i++) {
1288  buf[4*(i + 6*0)] = MULH3(out2[i ], win[i ], 1) + buf[4*(i + 6*0)];
1289  buf[4*(i + 6*1)] = MULH3(out2[i + 6], win[i + 6], 1);
1290  buf[4*(i + 6*2)] = 0;
1291  }
1292  ptr += 18;
1293  buf += (j&3) != 3 ? 1 : (4*18-3);
1294  }
1295  /* zero bands */
1296  for (j = sblimit; j < SBLIMIT; j++) {
1297  /* overlap */
1298  out_ptr = sb_samples + j;
1299  for (i = 0; i < 18; i++) {
1300  *out_ptr = buf[4*i];
1301  buf[4*i] = 0;
1302  out_ptr += SBLIMIT;
1303  }
1304  buf += (j&3) != 3 ? 1 : (4*18-3);
1305  }
1306 }
1307 
1308 /* main layer3 decoding function */
1309 static int mp_decode_layer3(MPADecodeContext *s)
1310 {
1311  int nb_granules, main_data_begin;
1312  int gr, ch, blocksplit_flag, i, j, k, n, bits_pos;
1313  GranuleDef *g;
1314  int16_t exponents[576]; //FIXME try INTFLOAT
1315 
1316  /* read side info */
1317  if (s->lsf) {
1318  main_data_begin = get_bits(&s->gb, 8);
1319  skip_bits(&s->gb, s->nb_channels);
1320  nb_granules = 1;
1321  } else {
1322  main_data_begin = get_bits(&s->gb, 9);
1323  if (s->nb_channels == 2)
1324  skip_bits(&s->gb, 3);
1325  else
1326  skip_bits(&s->gb, 5);
1327  nb_granules = 2;
1328  for (ch = 0; ch < s->nb_channels; ch++) {
1329  s->granules[ch][0].scfsi = 0;/* all scale factors are transmitted */
1330  s->granules[ch][1].scfsi = get_bits(&s->gb, 4);
1331  }
1332  }
1333 
1334  for (gr = 0; gr < nb_granules; gr++) {
1335  for (ch = 0; ch < s->nb_channels; ch++) {
1336  av_dlog(s->avctx, "gr=%d ch=%d: side_info\n", gr, ch);
1337  g = &s->granules[ch][gr];
1338  g->part2_3_length = get_bits(&s->gb, 12);
1339  g->big_values = get_bits(&s->gb, 9);
1340  if (g->big_values > 288) {
1341  av_log(s->avctx, AV_LOG_ERROR, "big_values too big\n");
1342  return AVERROR_INVALIDDATA;
1343  }
1344 
1345  g->global_gain = get_bits(&s->gb, 8);
1346  /* if MS stereo only is selected, we precompute the
1347  1/sqrt(2) renormalization factor */
1348  if ((s->mode_ext & (MODE_EXT_MS_STEREO | MODE_EXT_I_STEREO)) ==
1349  MODE_EXT_MS_STEREO)
1350  g->global_gain -= 2;
1351  if (s->lsf)
1352  g->scalefac_compress = get_bits(&s->gb, 9);
1353  else
1354  g->scalefac_compress = get_bits(&s->gb, 4);
1355  blocksplit_flag = get_bits1(&s->gb);
1356  if (blocksplit_flag) {
1357  g->block_type = get_bits(&s->gb, 2);
1358  if (g->block_type == 0) {
1359  av_log(s->avctx, AV_LOG_ERROR, "invalid block type\n");
1360  return AVERROR_INVALIDDATA;
1361  }
1362  g->switch_point = get_bits1(&s->gb);
1363  for (i = 0; i < 2; i++)
1364  g->table_select[i] = get_bits(&s->gb, 5);
1365  for (i = 0; i < 3; i++)
1366  g->subblock_gain[i] = get_bits(&s->gb, 3);
1367  init_short_region(s, g);
1368  } else {
1369  int region_address1, region_address2;
1370  g->block_type = 0;
1371  g->switch_point = 0;
1372  for (i = 0; i < 3; i++)
1373  g->table_select[i] = get_bits(&s->gb, 5);
1374  /* compute huffman coded region sizes */
1375  region_address1 = get_bits(&s->gb, 4);
1376  region_address2 = get_bits(&s->gb, 3);
1377  av_dlog(s->avctx, "region1=%d region2=%d\n",
1378  region_address1, region_address2);
1379  init_long_region(s, g, region_address1, region_address2);
1380  }
1381  region_offset2size(g);
1382  compute_band_indexes(s, g);
1383 
1384  g->preflag = 0;
1385  if (!s->lsf)
1386  g->preflag = get_bits1(&s->gb);
1387  g->scalefac_scale = get_bits1(&s->gb);
1388  g->count1table_select = get_bits1(&s->gb);
1389  av_dlog(s->avctx, "block_type=%d switch_point=%d\n",
1390  g->block_type, g->switch_point);
1391  }
1392  }
1393 
1394  if (!s->adu_mode) {
1395  int skip;
1396  const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
1397  int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, EXTRABYTES);
1398  av_assert1((get_bits_count(&s->gb) & 7) == 0);
1399  /* now we get bits from the main_data_begin offset */
1400  av_dlog(s->avctx, "seekback:%d, lastbuf:%d\n",
1401  main_data_begin, s->last_buf_size);
1402 
1403  memcpy(s->last_buf + s->last_buf_size, ptr, extrasize);
1404  s->in_gb = s->gb;
1405  init_get_bits(&s->gb, s->last_buf, s->last_buf_size*8);
1406 #if !UNCHECKED_BITSTREAM_READER
1407  s->gb.size_in_bits_plus8 += FFMAX(extrasize, LAST_BUF_SIZE - s->last_buf_size) * 8;
1408 #endif
1409  s->last_buf_size <<= 3;
1410  for (gr = 0; gr < nb_granules && (s->last_buf_size >> 3) < main_data_begin; gr++) {
1411  for (ch = 0; ch < s->nb_channels; ch++) {
1412  g = &s->granules[ch][gr];
1413  s->last_buf_size += g->part2_3_length;
1414  memset(g->sb_hybrid, 0, sizeof(g->sb_hybrid));
1415  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1416  }
1417  }
1418  skip = s->last_buf_size - 8 * main_data_begin;
1419  if (skip >= s->gb.size_in_bits && s->in_gb.buffer) {
1420  skip_bits_long(&s->in_gb, skip - s->gb.size_in_bits);
1421  s->gb = s->in_gb;
1422  s->in_gb.buffer = NULL;
1423  } else {
1424  skip_bits_long(&s->gb, skip);
1425  }
1426  } else {
1427  gr = 0;
1428  }
1429 
1430  for (; gr < nb_granules; gr++) {
1431  for (ch = 0; ch < s->nb_channels; ch++) {
1432  g = &s->granules[ch][gr];
1433  bits_pos = get_bits_count(&s->gb);
1434 
1435  if (!s->lsf) {
1436  uint8_t *sc;
1437  int slen, slen1, slen2;
1438 
1439  /* MPEG1 scale factors */
1440  slen1 = slen_table[0][g->scalefac_compress];
1441  slen2 = slen_table[1][g->scalefac_compress];
1442  av_dlog(s->avctx, "slen1=%d slen2=%d\n", slen1, slen2);
1443  if (g->block_type == 2) {
1444  n = g->switch_point ? 17 : 18;
1445  j = 0;
1446  if (slen1) {
1447  for (i = 0; i < n; i++)
1448  g->scale_factors[j++] = get_bits(&s->gb, slen1);
1449  } else {
1450  for (i = 0; i < n; i++)
1451  g->scale_factors[j++] = 0;
1452  }
1453  if (slen2) {
1454  for (i = 0; i < 18; i++)
1455  g->scale_factors[j++] = get_bits(&s->gb, slen2);
1456  for (i = 0; i < 3; i++)
1457  g->scale_factors[j++] = 0;
1458  } else {
1459  for (i = 0; i < 21; i++)
1460  g->scale_factors[j++] = 0;
1461  }
1462  } else {
1463  sc = s->granules[ch][0].scale_factors;
1464  j = 0;
1465  for (k = 0; k < 4; k++) {
1466  n = k == 0 ? 6 : 5;
1467  if ((g->scfsi & (0x8 >> k)) == 0) {
1468  slen = (k < 2) ? slen1 : slen2;
1469  if (slen) {
1470  for (i = 0; i < n; i++)
1471  g->scale_factors[j++] = get_bits(&s->gb, slen);
1472  } else {
1473  for (i = 0; i < n; i++)
1474  g->scale_factors[j++] = 0;
1475  }
1476  } else {
1477  /* simply copy from last granule */
1478  for (i = 0; i < n; i++) {
1479  g->scale_factors[j] = sc[j];
1480  j++;
1481  }
1482  }
1483  }
1484  g->scale_factors[j++] = 0;
1485  }
1486  } else {
1487  int tindex, tindex2, slen[4], sl, sf;
1488 
1489  /* LSF scale factors */
1490  if (g->block_type == 2)
1491  tindex = g->switch_point ? 2 : 1;
1492  else
1493  tindex = 0;
1494 
1495  sf = g->scalefac_compress;
1496  if ((s->mode_ext & MODE_EXT_I_STEREO) && ch == 1) {
1497  /* intensity stereo case */
1498  sf >>= 1;
1499  if (sf < 180) {
1500  lsf_sf_expand(slen, sf, 6, 6, 0);
1501  tindex2 = 3;
1502  } else if (sf < 244) {
1503  lsf_sf_expand(slen, sf - 180, 4, 4, 0);
1504  tindex2 = 4;
1505  } else {
1506  lsf_sf_expand(slen, sf - 244, 3, 0, 0);
1507  tindex2 = 5;
1508  }
1509  } else {
1510  /* normal case */
1511  if (sf < 400) {
1512  lsf_sf_expand(slen, sf, 5, 4, 4);
1513  tindex2 = 0;
1514  } else if (sf < 500) {
1515  lsf_sf_expand(slen, sf - 400, 5, 4, 0);
1516  tindex2 = 1;
1517  } else {
1518  lsf_sf_expand(slen, sf - 500, 3, 0, 0);
1519  tindex2 = 2;
1520  g->preflag = 1;
1521  }
1522  }
1523 
1524  j = 0;
1525  for (k = 0; k < 4; k++) {
1526  n = lsf_nsf_table[tindex2][tindex][k];
1527  sl = slen[k];
1528  if (sl) {
1529  for (i = 0; i < n; i++)
1530  g->scale_factors[j++] = get_bits(&s->gb, sl);
1531  } else {
1532  for (i = 0; i < n; i++)
1533  g->scale_factors[j++] = 0;
1534  }
1535  }
1536  /* XXX: should compute exact size */
1537  for (; j < 40; j++)
1538  g->scale_factors[j] = 0;
1539  }
1540 
1541  exponents_from_scale_factors(s, g, exponents);
1542 
1543  /* read Huffman coded residue */
1544  huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
1545  } /* ch */
1546 
1547  if (s->mode == MPA_JSTEREO)
1548  compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
1549 
1550  for (ch = 0; ch < s->nb_channels; ch++) {
1551  g = &s->granules[ch][gr];
1552 
1553  reorder_block(s, g);
1554  compute_antialias(s, g);
1555  compute_imdct(s, g, &s->sb_samples[ch][18 * gr][0], s->mdct_buf[ch]);
1556  }
1557  } /* gr */
1558  if (get_bits_count(&s->gb) < 0)
1559  skip_bits_long(&s->gb, -get_bits_count(&s->gb));
1560  return nb_granules * 18;
1561 }
1562 
1563 static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples,
1564  const uint8_t *buf, int buf_size)
1565 {
1566  int i, nb_frames, ch, ret;
1567  OUT_INT *samples_ptr;
1568 
1569  init_get_bits(&s->gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE) * 8);
1570 
1571  /* skip error protection field */
1572  if (s->error_protection)
1573  skip_bits(&s->gb, 16);
1574 
1575  switch(s->layer) {
1576  case 1:
1577  s->avctx->frame_size = 384;
1578  nb_frames = mp_decode_layer1(s);
1579  break;
1580  case 2:
1581  s->avctx->frame_size = 1152;
1582  nb_frames = mp_decode_layer2(s);
1583  break;
1584  case 3:
1585  s->avctx->frame_size = s->lsf ? 576 : 1152;
1586  default:
1587  nb_frames = mp_decode_layer3(s);
1588 
1589  s->last_buf_size=0;
1590  if (s->in_gb.buffer) {
1591  align_get_bits(&s->gb);
1592  i = get_bits_left(&s->gb)>>3;
1593  if (i >= 0 && i <= BACKSTEP_SIZE) {
1594  memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
1595  s->last_buf_size=i;
1596  } else
1597  av_log(s->avctx, AV_LOG_ERROR, "invalid old backstep %d\n", i);
1598  s->gb = s->in_gb;
1599  s->in_gb.buffer = NULL;
1600  }
1601 
1602  align_get_bits(&s->gb);
1603  av_assert1((get_bits_count(&s->gb) & 7) == 0);
1604  i = get_bits_left(&s->gb) >> 3;
1605 
1606  if (i < 0 || i > BACKSTEP_SIZE || nb_frames < 0) {
1607  if (i < 0)
1608  av_log(s->avctx, AV_LOG_ERROR, "invalid new backstep %d\n", i);
1609  i = FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
1610  }
1611  av_assert1(i <= buf_size - HEADER_SIZE && i >= 0);
1612  memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
1613  s->last_buf_size += i;
1614  }
1615 
1616  if(nb_frames < 0)
1617  return nb_frames;
1618 
1619  /* get output buffer */
1620  if (!samples) {
1621  av_assert0(s->frame);
1622  s->frame->nb_samples = s->avctx->frame_size;
1623  if ((ret = ff_get_buffer(s->avctx, s->frame, 0)) < 0)
1624  return ret;
1625  samples = (OUT_INT **)s->frame->extended_data;
1626  }
1627 
1628  /* apply the synthesis filter */
1629  for (ch = 0; ch < s->nb_channels; ch++) {
1630  int sample_stride;
1631  if (s->avctx->sample_fmt == OUT_FMT_P) {
1632  samples_ptr = samples[ch];
1633  sample_stride = 1;
1634  } else {
1635  samples_ptr = samples[0] + ch;
1636  sample_stride = s->nb_channels;
1637  }
1638  for (i = 0; i < nb_frames; i++) {
1639  RENAME(ff_mpa_synth_filter)(&s->mpadsp, s->synth_buf[ch],
1640  &(s->synth_buf_offset[ch]),
1641  RENAME(ff_mpa_synth_window),
1642  &s->dither_state, samples_ptr,
1643  sample_stride, s->sb_samples[ch][i]);
1644  samples_ptr += 32 * sample_stride;
1645  }
1646  }
1647 
1648  return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
1649 }
1650 
1651 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr,
1652  AVPacket *avpkt)
1653 {
1654  const uint8_t *buf = avpkt->data;
1655  int buf_size = avpkt->size;
1656  MPADecodeContext *s = avctx->priv_data;
1657  uint32_t header;
1658  int ret;
1659 
1660  while(buf_size && !*buf){
1661  buf++;
1662  buf_size--;
1663  }
1664 
1665  if (buf_size < HEADER_SIZE)
1666  return AVERROR_INVALIDDATA;
1667 
1668  header = AV_RB32(buf);
1669  if (header>>8 == AV_RB32("TAG")>>8) {
1670  av_log(avctx, AV_LOG_DEBUG, "discarding ID3 tag\n");
1671  return buf_size;
1672  }
1673  if (ff_mpa_check_header(header) < 0) {
1674  av_log(avctx, AV_LOG_ERROR, "Header missing\n");
1675  return AVERROR_INVALIDDATA;
1676  }
1677 
1678  if (avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header) == 1) {
1679  /* free format: prepare to compute frame size */
1680  s->frame_size = -1;
1681  return AVERROR_INVALIDDATA;
1682  }
1683  /* update codec info */
1684  avctx->channels = s->nb_channels;
1685  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1686  if (!avctx->bit_rate)
1687  avctx->bit_rate = s->bit_rate;
1688 
1689  if (s->frame_size <= 0 || s->frame_size > buf_size) {
1690  av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
1691  return AVERROR_INVALIDDATA;
1692  } else if (s->frame_size < buf_size) {
1693  av_log(avctx, AV_LOG_DEBUG, "incorrect frame size - multiple frames in buffer?\n");
1694  buf_size= s->frame_size;
1695  }
1696 
1697  s->frame = data;
1698 
1699  ret = mp_decode_frame(s, NULL, buf, buf_size);
1700  if (ret >= 0) {
1701  s->frame->nb_samples = avctx->frame_size;
1702  *got_frame_ptr = 1;
1703  avctx->sample_rate = s->sample_rate;
1704  //FIXME maybe move the other codec info stuff from above here too
1705  } else {
1706  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1707  /* Only return an error if the bad frame makes up the whole packet or
1708  * the error is related to buffer management.
1709  * If there is more data in the packet, just consume the bad frame
1710  * instead of returning an error, which would discard the whole
1711  * packet. */
1712  *got_frame_ptr = 0;
1713  if (buf_size == avpkt->size || ret != AVERROR_INVALIDDATA)
1714  return ret;
1715  }
1716  s->frame_size = 0;
1717  return buf_size;
1718 }
1719 
1720 static void mp_flush(MPADecodeContext *ctx)
1721 {
1722  memset(ctx->synth_buf, 0, sizeof(ctx->synth_buf));
1723  memset(ctx->mdct_buf, 0, sizeof(ctx->mdct_buf));
1724  ctx->last_buf_size = 0;
1725  ctx->dither_state = 0;
1726 }
1727 
1728 static void flush(AVCodecContext *avctx)
1729 {
1730  mp_flush(avctx->priv_data);
1731 }
1732 
1733 #if CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER
1734 static int decode_frame_adu(AVCodecContext *avctx, void *data,
1735  int *got_frame_ptr, AVPacket *avpkt)
1736 {
1737  const uint8_t *buf = avpkt->data;
1738  int buf_size = avpkt->size;
1739  MPADecodeContext *s = avctx->priv_data;
1740  uint32_t header;
1741  int len, ret;
1742  int av_unused out_size;
1743 
1744  len = buf_size;
1745 
1746  // Discard too short frames
1747  if (buf_size < HEADER_SIZE) {
1748  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
1749  return AVERROR_INVALIDDATA;
1750  }
1751 
1752 
1753  if (len > MPA_MAX_CODED_FRAME_SIZE)
1754  len = MPA_MAX_CODED_FRAME_SIZE;
1755 
1756  // Get header and restore sync word
1757  header = AV_RB32(buf) | 0xffe00000;
1758 
1759  if (ff_mpa_check_header(header) < 0) { // Bad header, discard frame
1760  av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n");
1761  return AVERROR_INVALIDDATA;
1762  }
1763 
1764  avpriv_mpegaudio_decode_header((MPADecodeHeader *)s, header);
1765  /* update codec info */
1766  avctx->sample_rate = s->sample_rate;
1767  avctx->channels = s->nb_channels;
1768  avctx->channel_layout = s->nb_channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
1769  if (!avctx->bit_rate)
1770  avctx->bit_rate = s->bit_rate;
1771 
1772  s->frame_size = len;
1773 
1774  s->frame = data;
1775 
1776  ret = mp_decode_frame(s, NULL, buf, buf_size);
1777  if (ret < 0) {
1778  av_log(avctx, AV_LOG_ERROR, "Error while decoding MPEG audio frame.\n");
1779  return ret;
1780  }
1781 
1782  *got_frame_ptr = 1;
1783 
1784  return buf_size;
1785 }
1786 #endif /* CONFIG_MP3ADU_DECODER || CONFIG_MP3ADUFLOAT_DECODER */
1787 
1788 #if CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER
1789 
1790 /**
1791  * Context for MP3On4 decoder
1792  */
1793 typedef struct MP3On4DecodeContext {
1794  int frames; ///< number of mp3 frames per block (number of mp3 decoder instances)
1795  int syncword; ///< syncword patch
1796  const uint8_t *coff; ///< channel offsets in output buffer
1797  MPADecodeContext *mp3decctx[5]; ///< MPADecodeContext for every decoder instance
1798 } MP3On4DecodeContext;
1799 
1800 #include "mpeg4audio.h"
1801 
1802 /* Next 3 arrays are indexed by channel config number (passed via codecdata) */
1803 
1804 /* number of mp3 decoder instances */
1805 static const uint8_t mp3Frames[8] = { 0, 1, 1, 2, 3, 3, 4, 5 };
1806 
1807 /* offsets into output buffer, assume output order is FL FR C LFE BL BR SL SR */
1808 static const uint8_t chan_offset[8][5] = {
1809  { 0 },
1810  { 0 }, // C
1811  { 0 }, // FLR
1812  { 2, 0 }, // C FLR
1813  { 2, 0, 3 }, // C FLR BS
1814  { 2, 0, 3 }, // C FLR BLRS
1815  { 2, 0, 4, 3 }, // C FLR BLRS LFE
1816  { 2, 0, 6, 4, 3 }, // C FLR BLRS BLR LFE
1817 };
1818 
1819 /* mp3on4 channel layouts */
1820 static const int16_t chan_layout[8] = {
1821  0,
1822  AV_CH_LAYOUT_MONO,
1823  AV_CH_LAYOUT_STEREO,
1824  AV_CH_LAYOUT_SURROUND,
1825  AV_CH_LAYOUT_4POINT0,
1826  AV_CH_LAYOUT_5POINT0,
1827  AV_CH_LAYOUT_5POINT1,
1828  AV_CH_LAYOUT_7POINT1
1829 };
1830 
1831 static av_cold int decode_close_mp3on4(AVCodecContext * avctx)
1832 {
1833  MP3On4DecodeContext *s = avctx->priv_data;
1834  int i;
1835 
1836  for (i = 0; i < s->frames; i++)
1837  av_freep(&s->mp3decctx[i]);
1838 
1839  return 0;
1840 }
1841 
1842 
1843 static av_cold int decode_init_mp3on4(AVCodecContext * avctx)
1844 {
1845  MP3On4DecodeContext *s = avctx->priv_data;
1846  MPEG4AudioConfig cfg;
1847  int i;
1848 
1849  if ((avctx->extradata_size < 2) || !avctx->extradata) {
1850  av_log(avctx, AV_LOG_ERROR, "Codec extradata missing or too short.\n");
1851  return AVERROR_INVALIDDATA;
1852  }
1853 
1854  avpriv_mpeg4audio_get_config(&cfg, avctx->extradata,
1855  avctx->extradata_size * 8, 1);
1856  if (!cfg.chan_config || cfg.chan_config > 7) {
1857  av_log(avctx, AV_LOG_ERROR, "Invalid channel config number.\n");
1858  return AVERROR_INVALIDDATA;
1859  }
1860  s->frames = mp3Frames[cfg.chan_config];
1861  s->coff = chan_offset[cfg.chan_config];
1862  avctx->channels = ff_mpeg4audio_channels[cfg.chan_config];
1863  avctx->channel_layout = chan_layout[cfg.chan_config];
1864 
1865  if (cfg.sample_rate < 16000)
1866  s->syncword = 0xffe00000;
1867  else
1868  s->syncword = 0xfff00000;
1869 
1870  /* Init the first mp3 decoder in standard way, so that all tables get builded
1871  * We replace avctx->priv_data with the context of the first decoder so that
1872  * decode_init() does not have to be changed.
1873  * Other decoders will be initialized here copying data from the first context
1874  */
1875  // Allocate zeroed memory for the first decoder context
1876  s->mp3decctx[0] = av_mallocz(sizeof(MPADecodeContext));
1877  if (!s->mp3decctx[0])
1878  goto alloc_fail;
1879  // Put decoder context in place to make init_decode() happy
1880  avctx->priv_data = s->mp3decctx[0];
1881  decode_init(avctx);
1882  // Restore mp3on4 context pointer
1883  avctx->priv_data = s;
1884  s->mp3decctx[0]->adu_mode = 1; // Set adu mode
1885 
1886  /* Create a separate codec/context for each frame (first is already ok).
1887  * Each frame is 1 or 2 channels - up to 5 frames allowed
1888  */
1889  for (i = 1; i < s->frames; i++) {
1890  s->mp3decctx[i] = av_mallocz(sizeof(MPADecodeContext));
1891  if (!s->mp3decctx[i])
1892  goto alloc_fail;
1893  s->mp3decctx[i]->adu_mode = 1;
1894  s->mp3decctx[i]->avctx = avctx;
1895  s->mp3decctx[i]->mpadsp = s->mp3decctx[0]->mpadsp;
1896  }
1897 
1898  return 0;
1899 alloc_fail:
1900  decode_close_mp3on4(avctx);
1901  return AVERROR(ENOMEM);
1902 }
1903 
1904 
1905 static void flush_mp3on4(AVCodecContext *avctx)
1906 {
1907  int i;
1908  MP3On4DecodeContext *s = avctx->priv_data;
1909 
1910  for (i = 0; i < s->frames; i++)
1911  mp_flush(s->mp3decctx[i]);
1912 }
1913 
1914 
1915 static int decode_frame_mp3on4(AVCodecContext *avctx, void *data,
1916  int *got_frame_ptr, AVPacket *avpkt)
1917 {
1918  AVFrame *frame = data;
1919  const uint8_t *buf = avpkt->data;
1920  int buf_size = avpkt->size;
1921  MP3On4DecodeContext *s = avctx->priv_data;
1922  MPADecodeContext *m;
1923  int fsize, len = buf_size, out_size = 0;
1924  uint32_t header;
1925  OUT_INT **out_samples;
1926  OUT_INT *outptr[2];
1927  int fr, ch, ret;
1928 
1929  /* get output buffer */
1930  frame->nb_samples = MPA_FRAME_SIZE;
1931  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1932  return ret;
1933  out_samples = (OUT_INT **)frame->extended_data;
1934 
1935  // Discard too short frames
1936  if (buf_size < HEADER_SIZE)
1937  return AVERROR_INVALIDDATA;
1938 
1939  avctx->bit_rate = 0;
1940 
1941  ch = 0;
1942  for (fr = 0; fr < s->frames; fr++) {
1943  fsize = AV_RB16(buf) >> 4;
1944  fsize = FFMIN3(fsize, len, MPA_MAX_CODED_FRAME_SIZE);
1945  m = s->mp3decctx[fr];
1946  av_assert1(m);
1947 
1948  if (fsize < HEADER_SIZE) {
1949  av_log(avctx, AV_LOG_ERROR, "Frame size smaller than header size\n");
1950  return AVERROR_INVALIDDATA;
1951  }
1952  header = (AV_RB32(buf) & 0x000fffff) | s->syncword; // patch header
1953 
1954  if (ff_mpa_check_header(header) < 0) {
1955  av_log(avctx, AV_LOG_ERROR, "Bad header, discard block\n");
1956  return AVERROR_INVALIDDATA;
1957  }
1958 
1959  avpriv_mpegaudio_decode_header((MPADecodeHeader *)m, header);
1960 
1961  if (ch + m->nb_channels > avctx->channels ||
1962  s->coff[fr] + m->nb_channels > avctx->channels) {
1963  av_log(avctx, AV_LOG_ERROR, "frame channel count exceeds codec "
1964  "channel count\n");
1965  return AVERROR_INVALIDDATA;
1966  }
1967  ch += m->nb_channels;
1968 
1969  outptr[0] = out_samples[s->coff[fr]];
1970  if (m->nb_channels > 1)
1971  outptr[1] = out_samples[s->coff[fr] + 1];
1972 
1973  if ((ret = mp_decode_frame(m, outptr, buf, fsize)) < 0) {
1974  av_log(avctx, AV_LOG_ERROR, "failed to decode channel %d\n", ch);
1975  memset(outptr[0], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
1976  if (m->nb_channels > 1)
1977  memset(outptr[1], 0, MPA_FRAME_SIZE*sizeof(OUT_INT));
1978  ret = m->nb_channels * MPA_FRAME_SIZE*sizeof(OUT_INT);
1979  }
1980 
1981  out_size += ret;
1982  buf += fsize;
1983  len -= fsize;
1984 
1985  avctx->bit_rate += m->bit_rate;
1986  }
1987  if (ch != avctx->channels) {
1988  av_log(avctx, AV_LOG_ERROR, "failed to decode all channels\n");
1989  return AVERROR_INVALIDDATA;
1990  }
1991 
1992  /* update codec info */
1993  avctx->sample_rate = s->mp3decctx[0]->sample_rate;
1994 
1995  frame->nb_samples = out_size / (avctx->channels * sizeof(OUT_INT));
1996  *got_frame_ptr = 1;
1997 
1998  return buf_size;
1999 }
2000 #endif /* CONFIG_MP3ON4_DECODER || CONFIG_MP3ON4FLOAT_DECODER */
Generated on Sun Mar 8 2015 02:34:56 for FFmpeg by   doxygen 1.8.2