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ac3dec.c
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1 /*
2  * AC-3 Audio Decoder
3  * This code was developed as part of Google Summer of Code 2006.
4  * E-AC-3 support was added as part of Google Summer of Code 2007.
5  *
6  * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com)
7  * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
8  * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
9  *
10  * This file is part of FFmpeg.
11  *
12  * FFmpeg is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU Lesser General Public
14  * License as published by the Free Software Foundation; either
15  * version 2.1 of the License, or (at your option) any later version.
16  *
17  * FFmpeg is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20  * Lesser General Public License for more details.
21  *
22  * You should have received a copy of the GNU Lesser General Public
23  * License along with FFmpeg; if not, write to the Free Software
24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25  */
26 
27 #include <stdio.h>
28 #include <stddef.h>
29 #include <math.h>
30 #include <string.h>
31 
33 #include "libavutil/crc.h"
34 #include "libavutil/downmix_info.h"
35 #include "libavutil/opt.h"
36 #include "bswapdsp.h"
37 #include "internal.h"
38 #include "aac_ac3_parser.h"
39 #include "ac3_parser.h"
40 #include "ac3dec.h"
41 #include "ac3dec_data.h"
42 #include "kbdwin.h"
43 
44 /**
45  * table for ungrouping 3 values in 7 bits.
46  * used for exponents and bap=2 mantissas
47  */
49 
50 /** tables for ungrouping mantissas */
51 static int b1_mantissas[32][3];
52 static int b2_mantissas[128][3];
53 static int b3_mantissas[8];
54 static int b4_mantissas[128][2];
55 static int b5_mantissas[16];
56 
57 /**
58  * Quantization table: levels for symmetric. bits for asymmetric.
59  * reference: Table 7.18 Mapping of bap to Quantizer
60  */
61 static const uint8_t quantization_tab[16] = {
62  0, 3, 5, 7, 11, 15,
63  5, 6, 7, 8, 9, 10, 11, 12, 14, 16
64 };
65 
66 #if (!USE_FIXED)
67 /** dynamic range table. converts codes to scale factors. */
68 static float dynamic_range_tab[256];
70 #endif
71 
72 /** Adjustments in dB gain */
73 static const float gain_levels[9] = {
76  LEVEL_ONE,
81  LEVEL_ZERO,
83 };
84 
85 /** Adjustments in dB gain (LFE, +10 to -21 dB) */
86 static const float gain_levels_lfe[32] = {
87  3.162275, 2.818382, 2.511886, 2.238719, 1.995261, 1.778278, 1.584893,
88  1.412536, 1.258924, 1.122018, 1.000000, 0.891251, 0.794328, 0.707946,
89  0.630957, 0.562341, 0.501187, 0.446683, 0.398107, 0.354813, 0.316227,
90  0.281838, 0.251188, 0.223872, 0.199526, 0.177828, 0.158489, 0.141253,
91  0.125892, 0.112201, 0.100000, 0.089125
92 };
93 
94 /**
95  * Table for default stereo downmixing coefficients
96  * reference: Section 7.8.2 Downmixing Into Two Channels
97  */
98 static const uint8_t ac3_default_coeffs[8][5][2] = {
99  { { 2, 7 }, { 7, 2 }, },
100  { { 4, 4 }, },
101  { { 2, 7 }, { 7, 2 }, },
102  { { 2, 7 }, { 5, 5 }, { 7, 2 }, },
103  { { 2, 7 }, { 7, 2 }, { 6, 6 }, },
104  { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 8, 8 }, },
105  { { 2, 7 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
106  { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
107 };
108 
109 /**
110  * Symmetrical Dequantization
111  * reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantization
112  * Tables 7.19 to 7.23
113  */
114 static inline int
115 symmetric_dequant(int code, int levels)
116 {
117  return ((code - (levels >> 1)) * (1 << 24)) / levels;
118 }
119 
120 /*
121  * Initialize tables at runtime.
122  */
123 static av_cold void ac3_tables_init(void)
124 {
125  int i;
126 
127  /* generate table for ungrouping 3 values in 7 bits
128  reference: Section 7.1.3 Exponent Decoding */
129  for (i = 0; i < 128; i++) {
130  ungroup_3_in_7_bits_tab[i][0] = i / 25;
131  ungroup_3_in_7_bits_tab[i][1] = (i % 25) / 5;
132  ungroup_3_in_7_bits_tab[i][2] = (i % 25) % 5;
133  }
134 
135  /* generate grouped mantissa tables
136  reference: Section 7.3.5 Ungrouping of Mantissas */
137  for (i = 0; i < 32; i++) {
138  /* bap=1 mantissas */
142  }
143  for (i = 0; i < 128; i++) {
144  /* bap=2 mantissas */
148 
149  /* bap=4 mantissas */
150  b4_mantissas[i][0] = symmetric_dequant(i / 11, 11);
151  b4_mantissas[i][1] = symmetric_dequant(i % 11, 11);
152  }
153  /* generate ungrouped mantissa tables
154  reference: Tables 7.21 and 7.23 */
155  for (i = 0; i < 7; i++) {
156  /* bap=3 mantissas */
157  b3_mantissas[i] = symmetric_dequant(i, 7);
158  }
159  for (i = 0; i < 15; i++) {
160  /* bap=5 mantissas */
161  b5_mantissas[i] = symmetric_dequant(i, 15);
162  }
163 
164 #if (!USE_FIXED)
165  /* generate dynamic range table
166  reference: Section 7.7.1 Dynamic Range Control */
167  for (i = 0; i < 256; i++) {
168  int v = (i >> 5) - ((i >> 7) << 3) - 5;
169  dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
170  }
171 
172  /* generate compr dynamic range table
173  reference: Section 7.7.2 Heavy Compression */
174  for (i = 0; i < 256; i++) {
175  int v = (i >> 4) - ((i >> 7) << 4) - 4;
176  ff_ac3_heavy_dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0xF) | 0x10);
177  }
178 #endif
179 }
180 
181 /**
182  * AVCodec initialization
183  */
185 {
186  AC3DecodeContext *s = avctx->priv_data;
187  int i;
188 
189  s->avctx = avctx;
190 
191  ac3_tables_init();
192  ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
193  ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
194  AC3_RENAME(ff_kbd_window_init)(s->window, 5.0, 256);
195  ff_bswapdsp_init(&s->bdsp);
196 
197 #if (USE_FIXED)
199 #else
201  ff_fmt_convert_init(&s->fmt_conv, avctx);
202 #endif
203 
205  av_lfg_init(&s->dith_state, 0);
206 
207  if (USE_FIXED)
209  else
211 
212  /* allow downmixing to stereo or mono */
213  if (avctx->channels > 1 &&
215  avctx->channels = 1;
216  else if (avctx->channels > 2 &&
218  avctx->channels = 2;
219  s->downmixed = 1;
220 
221  for (i = 0; i < AC3_MAX_CHANNELS; i++) {
222  s->xcfptr[i] = s->transform_coeffs[i];
223  s->dlyptr[i] = s->delay[i];
224  }
225 
226  return 0;
227 }
228 
229 /**
230  * Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
231  * GetBitContext within AC3DecodeContext must point to
232  * the start of the synchronized AC-3 bitstream.
233  */
235 {
236  GetBitContext *gbc = &s->gbc;
237  int i;
238 
239  /* read the rest of the bsi. read twice for dual mono mode. */
240  i = !s->channel_mode;
241  do {
242  s->dialog_normalization[(!s->channel_mode)-i] = -get_bits(gbc, 5);
243  if (s->dialog_normalization[(!s->channel_mode)-i] == 0) {
244  s->dialog_normalization[(!s->channel_mode)-i] = -31;
245  }
246  if (s->target_level != 0) {
247  s->level_gain[(!s->channel_mode)-i] = powf(2.0f,
248  (float)(s->target_level -
249  s->dialog_normalization[(!s->channel_mode)-i])/6.0f);
250  }
251  if (s->compression_exists[(!s->channel_mode)-i] = get_bits1(gbc)) {
252  s->heavy_dynamic_range[(!s->channel_mode)-i] =
253  AC3_HEAVY_RANGE(get_bits(gbc, 8));
254  }
255  if (get_bits1(gbc))
256  skip_bits(gbc, 8); //skip language code
257  if (get_bits1(gbc))
258  skip_bits(gbc, 7); //skip audio production information
259  } while (i--);
260 
261  skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
262 
263  /* skip the timecodes or parse the Alternate Bit Stream Syntax */
264  if (s->bitstream_id != 6) {
265  if (get_bits1(gbc))
266  skip_bits(gbc, 14); //skip timecode1
267  if (get_bits1(gbc))
268  skip_bits(gbc, 14); //skip timecode2
269  } else {
270  if (get_bits1(gbc)) {
271  s->preferred_downmix = get_bits(gbc, 2);
272  s->center_mix_level_ltrt = get_bits(gbc, 3);
273  s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
274  s->center_mix_level = get_bits(gbc, 3);
275  s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
276  }
277  if (get_bits1(gbc)) {
278  s->dolby_surround_ex_mode = get_bits(gbc, 2);
279  s->dolby_headphone_mode = get_bits(gbc, 2);
280  skip_bits(gbc, 10); // skip adconvtyp (1), xbsi2 (8), encinfo (1)
281  }
282  }
283 
284  /* skip additional bitstream info */
285  if (get_bits1(gbc)) {
286  i = get_bits(gbc, 6);
287  do {
288  skip_bits(gbc, 8);
289  } while (i--);
290  }
291 
292  return 0;
293 }
294 
295 /**
296  * Common function to parse AC-3 or E-AC-3 frame header
297  */
299 {
300  AC3HeaderInfo hdr, *phdr=&hdr;
301  int err;
302 
303  err = avpriv_ac3_parse_header(&s->gbc, &phdr);
304  if (err)
305  return err;
306 
307  /* get decoding parameters from header info */
309  s->bitstream_id = hdr.bitstream_id;
311  s->channel_mode = hdr.channel_mode;
312  s->lfe_on = hdr.lfe_on;
314  s->sample_rate = hdr.sample_rate;
315  s->bit_rate = hdr.bit_rate;
316  s->channels = hdr.channels;
317  s->fbw_channels = s->channels - s->lfe_on;
318  s->lfe_ch = s->fbw_channels + 1;
319  s->frame_size = hdr.frame_size;
322  s->center_mix_level_ltrt = 4; // -3.0dB
324  s->surround_mix_level_ltrt = 4; // -3.0dB
325  s->lfe_mix_level_exists = 0;
326  s->num_blocks = hdr.num_blocks;
327  s->frame_type = hdr.frame_type;
328  s->substreamid = hdr.substreamid;
332 
333  if (s->lfe_on) {
334  s->start_freq[s->lfe_ch] = 0;
335  s->end_freq[s->lfe_ch] = 7;
336  s->num_exp_groups[s->lfe_ch] = 2;
337  s->channel_in_cpl[s->lfe_ch] = 0;
338  }
339 
340  if (s->bitstream_id <= 10) {
341  s->eac3 = 0;
342  s->snr_offset_strategy = 2;
343  s->block_switch_syntax = 1;
344  s->dither_flag_syntax = 1;
345  s->bit_allocation_syntax = 1;
346  s->fast_gain_syntax = 0;
347  s->first_cpl_leak = 0;
348  s->dba_syntax = 1;
349  s->skip_syntax = 1;
350  memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
351  return ac3_parse_header(s);
352  } else if (CONFIG_EAC3_DECODER) {
353  s->eac3 = 1;
354  return ff_eac3_parse_header(s);
355  } else {
356  av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
357  return AVERROR(ENOSYS);
358  }
359 }
360 
361 /**
362  * Set stereo downmixing coefficients based on frame header info.
363  * reference: Section 7.8.2 Downmixing Into Two Channels
364  */
366 {
367  int i;
368  float cmix = gain_levels[s-> center_mix_level];
369  float smix = gain_levels[s->surround_mix_level];
370  float norm0, norm1;
371  float downmix_coeffs[AC3_MAX_CHANNELS][2];
372 
373  for (i = 0; i < s->fbw_channels; i++) {
374  downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
375  downmix_coeffs[i][1] = gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
376  }
377  if (s->channel_mode > 1 && s->channel_mode & 1) {
378  downmix_coeffs[1][0] = downmix_coeffs[1][1] = cmix;
379  }
381  int nf = s->channel_mode - 2;
382  downmix_coeffs[nf][0] = downmix_coeffs[nf][1] = smix * LEVEL_MINUS_3DB;
383  }
385  int nf = s->channel_mode - 4;
386  downmix_coeffs[nf][0] = downmix_coeffs[nf+1][1] = smix;
387  }
388 
389  /* renormalize */
390  norm0 = norm1 = 0.0;
391  for (i = 0; i < s->fbw_channels; i++) {
392  norm0 += downmix_coeffs[i][0];
393  norm1 += downmix_coeffs[i][1];
394  }
395  norm0 = 1.0f / norm0;
396  norm1 = 1.0f / norm1;
397  for (i = 0; i < s->fbw_channels; i++) {
398  downmix_coeffs[i][0] *= norm0;
399  downmix_coeffs[i][1] *= norm1;
400  }
401 
402  if (s->output_mode == AC3_CHMODE_MONO) {
403  for (i = 0; i < s->fbw_channels; i++)
404  downmix_coeffs[i][0] = (downmix_coeffs[i][0] +
405  downmix_coeffs[i][1]) * LEVEL_MINUS_3DB;
406  }
407  for (i = 0; i < s->fbw_channels; i++) {
408  s->downmix_coeffs[i][0] = FIXR12(downmix_coeffs[i][0]);
409  s->downmix_coeffs[i][1] = FIXR12(downmix_coeffs[i][1]);
410  }
411 }
412 
413 /**
414  * Decode the grouped exponents according to exponent strategy.
415  * reference: Section 7.1.3 Exponent Decoding
416  */
418  GetBitContext *gbc, int exp_strategy, int ngrps,
419  uint8_t absexp, int8_t *dexps)
420 {
421  int i, j, grp, group_size;
422  int dexp[256];
423  int expacc, prevexp;
424 
425  /* unpack groups */
426  group_size = exp_strategy + (exp_strategy == EXP_D45);
427  for (grp = 0, i = 0; grp < ngrps; grp++) {
428  expacc = get_bits(gbc, 7);
429  if (expacc >= 125) {
430  av_log(s->avctx, AV_LOG_ERROR, "expacc %d is out-of-range\n", expacc);
431  return AVERROR_INVALIDDATA;
432  }
433  dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0];
434  dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1];
435  dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2];
436  }
437 
438  /* convert to absolute exps and expand groups */
439  prevexp = absexp;
440  for (i = 0, j = 0; i < ngrps * 3; i++) {
441  prevexp += dexp[i] - 2;
442  if (prevexp > 24U) {
443  av_log(s->avctx, AV_LOG_ERROR, "exponent %d is out-of-range\n", prevexp);
444  return -1;
445  }
446  switch (group_size) {
447  case 4: dexps[j++] = prevexp;
448  dexps[j++] = prevexp;
449  case 2: dexps[j++] = prevexp;
450  case 1: dexps[j++] = prevexp;
451  }
452  }
453  return 0;
454 }
455 
456 /**
457  * Generate transform coefficients for each coupled channel in the coupling
458  * range using the coupling coefficients and coupling coordinates.
459  * reference: Section 7.4.3 Coupling Coordinate Format
460  */
462 {
463  int bin, band, ch;
464 
465  bin = s->start_freq[CPL_CH];
466  for (band = 0; band < s->num_cpl_bands; band++) {
467  int band_start = bin;
468  int band_end = bin + s->cpl_band_sizes[band];
469  for (ch = 1; ch <= s->fbw_channels; ch++) {
470  if (s->channel_in_cpl[ch]) {
471  int cpl_coord = s->cpl_coords[ch][band] << 5;
472  for (bin = band_start; bin < band_end; bin++) {
473  s->fixed_coeffs[ch][bin] =
474  MULH(s->fixed_coeffs[CPL_CH][bin] * (1 << 4), cpl_coord);
475  }
476  if (ch == 2 && s->phase_flags[band]) {
477  for (bin = band_start; bin < band_end; bin++)
478  s->fixed_coeffs[2][bin] = -s->fixed_coeffs[2][bin];
479  }
480  }
481  }
482  bin = band_end;
483  }
484 }
485 
486 /**
487  * Grouped mantissas for 3-level 5-level and 11-level quantization
488  */
489 typedef struct mant_groups {
490  int b1_mant[2];
491  int b2_mant[2];
492  int b4_mant;
493  int b1;
494  int b2;
495  int b4;
496 } mant_groups;
497 
498 /**
499  * Decode the transform coefficients for a particular channel
500  * reference: Section 7.3 Quantization and Decoding of Mantissas
501  */
503 {
504  int start_freq = s->start_freq[ch_index];
505  int end_freq = s->end_freq[ch_index];
506  uint8_t *baps = s->bap[ch_index];
507  int8_t *exps = s->dexps[ch_index];
508  int32_t *coeffs = s->fixed_coeffs[ch_index];
509  int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
510  GetBitContext *gbc = &s->gbc;
511  int freq;
512 
513  for (freq = start_freq; freq < end_freq; freq++) {
514  int bap = baps[freq];
515  int mantissa;
516  switch (bap) {
517  case 0:
518  /* random noise with approximate range of -0.707 to 0.707 */
519  if (dither)
520  mantissa = (((av_lfg_get(&s->dith_state)>>8)*181)>>8) - 5931008;
521  else
522  mantissa = 0;
523  break;
524  case 1:
525  if (m->b1) {
526  m->b1--;
527  mantissa = m->b1_mant[m->b1];
528  } else {
529  int bits = get_bits(gbc, 5);
530  mantissa = b1_mantissas[bits][0];
531  m->b1_mant[1] = b1_mantissas[bits][1];
532  m->b1_mant[0] = b1_mantissas[bits][2];
533  m->b1 = 2;
534  }
535  break;
536  case 2:
537  if (m->b2) {
538  m->b2--;
539  mantissa = m->b2_mant[m->b2];
540  } else {
541  int bits = get_bits(gbc, 7);
542  mantissa = b2_mantissas[bits][0];
543  m->b2_mant[1] = b2_mantissas[bits][1];
544  m->b2_mant[0] = b2_mantissas[bits][2];
545  m->b2 = 2;
546  }
547  break;
548  case 3:
549  mantissa = b3_mantissas[get_bits(gbc, 3)];
550  break;
551  case 4:
552  if (m->b4) {
553  m->b4 = 0;
554  mantissa = m->b4_mant;
555  } else {
556  int bits = get_bits(gbc, 7);
557  mantissa = b4_mantissas[bits][0];
558  m->b4_mant = b4_mantissas[bits][1];
559  m->b4 = 1;
560  }
561  break;
562  case 5:
563  mantissa = b5_mantissas[get_bits(gbc, 4)];
564  break;
565  default: /* 6 to 15 */
566  /* Shift mantissa and sign-extend it. */
567  if (bap > 15) {
568  av_log(s->avctx, AV_LOG_ERROR, "bap %d is invalid in plain AC-3\n", bap);
569  bap = 15;
570  }
571  mantissa = (unsigned)get_sbits(gbc, quantization_tab[bap]) << (24 - quantization_tab[bap]);
572  break;
573  }
574  coeffs[freq] = mantissa >> exps[freq];
575  }
576 }
577 
578 /**
579  * Remove random dithering from coupling range coefficients with zero-bit
580  * mantissas for coupled channels which do not use dithering.
581  * reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
582  */
584  int ch, i;
585 
586  for (ch = 1; ch <= s->fbw_channels; ch++) {
587  if (!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
588  for (i = s->start_freq[CPL_CH]; i < s->end_freq[CPL_CH]; i++) {
589  if (!s->bap[CPL_CH][i])
590  s->fixed_coeffs[ch][i] = 0;
591  }
592  }
593  }
594 }
595 
597  mant_groups *m)
598 {
599  if (!s->channel_uses_aht[ch]) {
601  } else {
602  /* if AHT is used, mantissas for all blocks are encoded in the first
603  block of the frame. */
604  int bin;
605  if (CONFIG_EAC3_DECODER && !blk)
607  for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
608  s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
609  }
610  }
611 }
612 
613 /**
614  * Decode the transform coefficients.
615  */
617 {
618  int ch, end;
619  int got_cplchan = 0;
620  mant_groups m;
621 
622  m.b1 = m.b2 = m.b4 = 0;
623 
624  for (ch = 1; ch <= s->channels; ch++) {
625  /* transform coefficients for full-bandwidth channel */
626  decode_transform_coeffs_ch(s, blk, ch, &m);
627  /* transform coefficients for coupling channel come right after the
628  coefficients for the first coupled channel*/
629  if (s->channel_in_cpl[ch]) {
630  if (!got_cplchan) {
631  decode_transform_coeffs_ch(s, blk, CPL_CH, &m);
633  got_cplchan = 1;
634  }
635  end = s->end_freq[CPL_CH];
636  } else {
637  end = s->end_freq[ch];
638  }
639  do
640  s->fixed_coeffs[ch][end] = 0;
641  while (++end < 256);
642  }
643 
644  /* zero the dithered coefficients for appropriate channels */
645  remove_dithering(s);
646 }
647 
648 /**
649  * Stereo rematrixing.
650  * reference: Section 7.5.4 Rematrixing : Decoding Technique
651  */
653 {
654  int bnd, i;
655  int end, bndend;
656 
657  end = FFMIN(s->end_freq[1], s->end_freq[2]);
658 
659  for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
660  if (s->rematrixing_flags[bnd]) {
661  bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd + 1]);
662  for (i = ff_ac3_rematrix_band_tab[bnd]; i < bndend; i++) {
663  int tmp0 = s->fixed_coeffs[1][i];
664  s->fixed_coeffs[1][i] += s->fixed_coeffs[2][i];
665  s->fixed_coeffs[2][i] = tmp0 - s->fixed_coeffs[2][i];
666  }
667  }
668  }
669 }
670 
671 /**
672  * Inverse MDCT Transform.
673  * Convert frequency domain coefficients to time-domain audio samples.
674  * reference: Section 7.9.4 Transformation Equations
675  */
676 static inline void do_imdct(AC3DecodeContext *s, int channels)
677 {
678  int ch;
679 
680  for (ch = 1; ch <= channels; ch++) {
681  if (s->block_switch[ch]) {
682  int i;
683  FFTSample *x = s->tmp_output + 128;
684  for (i = 0; i < 128; i++)
685  x[i] = s->transform_coeffs[ch][2 * i];
686  s->imdct_256.imdct_half(&s->imdct_256, s->tmp_output, x);
687 #if USE_FIXED
688  s->fdsp->vector_fmul_window_scaled(s->outptr[ch - 1], s->delay[ch - 1],
689  s->tmp_output, s->window, 128, 8);
690 #else
691  s->fdsp->vector_fmul_window(s->outptr[ch - 1], s->delay[ch - 1],
692  s->tmp_output, s->window, 128);
693 #endif
694  for (i = 0; i < 128; i++)
695  x[i] = s->transform_coeffs[ch][2 * i + 1];
696  s->imdct_256.imdct_half(&s->imdct_256, s->delay[ch - 1], x);
697  } else {
699 #if USE_FIXED
700  s->fdsp->vector_fmul_window_scaled(s->outptr[ch - 1], s->delay[ch - 1],
701  s->tmp_output, s->window, 128, 8);
702 #else
703  s->fdsp->vector_fmul_window(s->outptr[ch - 1], s->delay[ch - 1],
704  s->tmp_output, s->window, 128);
705 #endif
706  memcpy(s->delay[ch - 1], s->tmp_output + 128, 128 * sizeof(FFTSample));
707  }
708  }
709 }
710 
711 /**
712  * Upmix delay samples from stereo to original channel layout.
713  */
715 {
716  int channel_data_size = sizeof(s->delay[0]);
717  switch (s->channel_mode) {
718  case AC3_CHMODE_DUALMONO:
719  case AC3_CHMODE_STEREO:
720  /* upmix mono to stereo */
721  memcpy(s->delay[1], s->delay[0], channel_data_size);
722  break;
723  case AC3_CHMODE_2F2R:
724  memset(s->delay[3], 0, channel_data_size);
725  case AC3_CHMODE_2F1R:
726  memset(s->delay[2], 0, channel_data_size);
727  break;
728  case AC3_CHMODE_3F2R:
729  memset(s->delay[4], 0, channel_data_size);
730  case AC3_CHMODE_3F1R:
731  memset(s->delay[3], 0, channel_data_size);
732  case AC3_CHMODE_3F:
733  memcpy(s->delay[2], s->delay[1], channel_data_size);
734  memset(s->delay[1], 0, channel_data_size);
735  break;
736  }
737 }
738 
739 /**
740  * Decode band structure for coupling, spectral extension, or enhanced coupling.
741  * The band structure defines how many subbands are in each band. For each
742  * subband in the range, 1 means it is combined with the previous band, and 0
743  * means that it starts a new band.
744  *
745  * @param[in] gbc bit reader context
746  * @param[in] blk block number
747  * @param[in] eac3 flag to indicate E-AC-3
748  * @param[in] ecpl flag to indicate enhanced coupling
749  * @param[in] start_subband subband number for start of range
750  * @param[in] end_subband subband number for end of range
751  * @param[in] default_band_struct default band structure table
752  * @param[out] num_bands number of bands (optionally NULL)
753  * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
754  */
755 static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
756  int ecpl, int start_subband, int end_subband,
757  const uint8_t *default_band_struct,
758  int *num_bands, uint8_t *band_sizes)
759 {
760  int subbnd, bnd, n_subbands, n_bands=0;
761  uint8_t bnd_sz[22];
762  uint8_t coded_band_struct[22];
763  const uint8_t *band_struct;
764 
765  n_subbands = end_subband - start_subband;
766 
767  /* decode band structure from bitstream or use default */
768  if (!eac3 || get_bits1(gbc)) {
769  for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
770  coded_band_struct[subbnd] = get_bits1(gbc);
771  }
772  band_struct = coded_band_struct;
773  } else if (!blk) {
774  band_struct = &default_band_struct[start_subband+1];
775  } else {
776  /* no change in band structure */
777  return;
778  }
779 
780  /* calculate number of bands and band sizes based on band structure.
781  note that the first 4 subbands in enhanced coupling span only 6 bins
782  instead of 12. */
783  if (num_bands || band_sizes ) {
784  n_bands = n_subbands;
785  bnd_sz[0] = ecpl ? 6 : 12;
786  for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
787  int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
788  if (band_struct[subbnd - 1]) {
789  n_bands--;
790  bnd_sz[bnd] += subbnd_size;
791  } else {
792  bnd_sz[++bnd] = subbnd_size;
793  }
794  }
795  }
796 
797  /* set optional output params */
798  if (num_bands)
799  *num_bands = n_bands;
800  if (band_sizes)
801  memcpy(band_sizes, bnd_sz, n_bands);
802 }
803 
804 /**
805  * Decode a single audio block from the AC-3 bitstream.
806  */
808 {
809  int fbw_channels = s->fbw_channels;
810  int channel_mode = s->channel_mode;
811  int i, bnd, seg, ch;
812  int different_transforms;
813  int downmix_output;
814  int cpl_in_use;
815  GetBitContext *gbc = &s->gbc;
816  uint8_t bit_alloc_stages[AC3_MAX_CHANNELS] = { 0 };
817 
818  /* block switch flags */
819  different_transforms = 0;
820  if (s->block_switch_syntax) {
821  for (ch = 1; ch <= fbw_channels; ch++) {
822  s->block_switch[ch] = get_bits1(gbc);
823  if (ch > 1 && s->block_switch[ch] != s->block_switch[1])
824  different_transforms = 1;
825  }
826  }
827 
828  /* dithering flags */
829  if (s->dither_flag_syntax) {
830  for (ch = 1; ch <= fbw_channels; ch++) {
831  s->dither_flag[ch] = get_bits1(gbc);
832  }
833  }
834 
835  /* dynamic range */
836  i = !s->channel_mode;
837  do {
838  if (get_bits1(gbc)) {
839  /* Allow asymmetric application of DRC when drc_scale > 1.
840  Amplification of quiet sounds is enhanced */
841  int range_bits = get_bits(gbc, 8);
842  INTFLOAT range = AC3_RANGE(range_bits);
843  if (range_bits <= 127 || s->drc_scale <= 1.0)
844  s->dynamic_range[i] = AC3_DYNAMIC_RANGE(range);
845  else
846  s->dynamic_range[i] = range;
847  } else if (blk == 0) {
849  }
850  } while (i--);
851 
852  /* spectral extension strategy */
853  if (s->eac3 && (!blk || get_bits1(gbc))) {
854  s->spx_in_use = get_bits1(gbc);
855  if (s->spx_in_use) {
856  int dst_start_freq, dst_end_freq, src_start_freq,
857  start_subband, end_subband;
858 
859  /* determine which channels use spx */
860  if (s->channel_mode == AC3_CHMODE_MONO) {
861  s->channel_uses_spx[1] = 1;
862  } else {
863  for (ch = 1; ch <= fbw_channels; ch++)
864  s->channel_uses_spx[ch] = get_bits1(gbc);
865  }
866 
867  /* get the frequency bins of the spx copy region and the spx start
868  and end subbands */
869  dst_start_freq = get_bits(gbc, 2);
870  start_subband = get_bits(gbc, 3) + 2;
871  if (start_subband > 7)
872  start_subband += start_subband - 7;
873  end_subband = get_bits(gbc, 3) + 5;
874 #if USE_FIXED
875  s->spx_dst_end_freq = end_freq_inv_tab[end_subband-5];
876 #endif
877  if (end_subband > 7)
878  end_subband += end_subband - 7;
879  dst_start_freq = dst_start_freq * 12 + 25;
880  src_start_freq = start_subband * 12 + 25;
881  dst_end_freq = end_subband * 12 + 25;
882 
883  /* check validity of spx ranges */
884  if (start_subband >= end_subband) {
885  av_log(s->avctx, AV_LOG_ERROR, "invalid spectral extension "
886  "range (%d >= %d)\n", start_subband, end_subband);
887  return AVERROR_INVALIDDATA;
888  }
889  if (dst_start_freq >= src_start_freq) {
890  av_log(s->avctx, AV_LOG_ERROR, "invalid spectral extension "
891  "copy start bin (%d >= %d)\n", dst_start_freq, src_start_freq);
892  return AVERROR_INVALIDDATA;
893  }
894 
895  s->spx_dst_start_freq = dst_start_freq;
896  s->spx_src_start_freq = src_start_freq;
897  if (!USE_FIXED)
898  s->spx_dst_end_freq = dst_end_freq;
899 
900  decode_band_structure(gbc, blk, s->eac3, 0,
901  start_subband, end_subband,
903  &s->num_spx_bands,
904  s->spx_band_sizes);
905  }
906  }
907  if (!s->eac3 || !s->spx_in_use) {
908  s->spx_in_use = 0;
909  for (ch = 1; ch <= fbw_channels; ch++) {
910  s->channel_uses_spx[ch] = 0;
911  s->first_spx_coords[ch] = 1;
912  }
913  }
914 
915  /* spectral extension coordinates */
916  if (s->spx_in_use) {
917  for (ch = 1; ch <= fbw_channels; ch++) {
918  if (s->channel_uses_spx[ch]) {
919  if (s->first_spx_coords[ch] || get_bits1(gbc)) {
920  INTFLOAT spx_blend;
921  int bin, master_spx_coord;
922 
923  s->first_spx_coords[ch] = 0;
924  spx_blend = AC3_SPX_BLEND(get_bits(gbc, 5));
925  master_spx_coord = get_bits(gbc, 2) * 3;
926 
927  bin = s->spx_src_start_freq;
928  for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
929  int bandsize = s->spx_band_sizes[bnd];
930  int spx_coord_exp, spx_coord_mant;
931  INTFLOAT nratio, sblend, nblend;
932 #if USE_FIXED
933  /* calculate blending factors */
934  int64_t accu = ((bin << 23) + (bandsize << 22))
935  * (int64_t)s->spx_dst_end_freq;
936  nratio = (int)(accu >> 32);
937  nratio -= spx_blend << 18;
938 
939  if (nratio < 0) {
940  nblend = 0;
941  sblend = 0x800000;
942  } else if (nratio > 0x7fffff) {
943  nblend = 14529495; // sqrt(3) in FP.23
944  sblend = 0;
945  } else {
946  nblend = fixed_sqrt(nratio, 23);
947  accu = (int64_t)nblend * 1859775393;
948  nblend = (int)((accu + (1<<29)) >> 30);
949  sblend = fixed_sqrt(0x800000 - nratio, 23);
950  }
951 #else
952  float spx_coord;
953 
954  /* calculate blending factors */
955  nratio = ((float)((bin + (bandsize >> 1))) / s->spx_dst_end_freq) - spx_blend;
956  nratio = av_clipf(nratio, 0.0f, 1.0f);
957  nblend = sqrtf(3.0f * nratio); // noise is scaled by sqrt(3)
958  // to give unity variance
959  sblend = sqrtf(1.0f - nratio);
960 #endif
961  bin += bandsize;
962 
963  /* decode spx coordinates */
964  spx_coord_exp = get_bits(gbc, 4);
965  spx_coord_mant = get_bits(gbc, 2);
966  if (spx_coord_exp == 15) spx_coord_mant <<= 1;
967  else spx_coord_mant += 4;
968  spx_coord_mant <<= (25 - spx_coord_exp - master_spx_coord);
969 
970  /* multiply noise and signal blending factors by spx coordinate */
971 #if USE_FIXED
972  accu = (int64_t)nblend * spx_coord_mant;
973  s->spx_noise_blend[ch][bnd] = (int)((accu + (1<<22)) >> 23);
974  accu = (int64_t)sblend * spx_coord_mant;
975  s->spx_signal_blend[ch][bnd] = (int)((accu + (1<<22)) >> 23);
976 #else
977  spx_coord = spx_coord_mant * (1.0f / (1 << 23));
978  s->spx_noise_blend [ch][bnd] = nblend * spx_coord;
979  s->spx_signal_blend[ch][bnd] = sblend * spx_coord;
980 #endif
981  }
982  }
983  } else {
984  s->first_spx_coords[ch] = 1;
985  }
986  }
987  }
988 
989  /* coupling strategy */
990  if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
991  memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
992  if (!s->eac3)
993  s->cpl_in_use[blk] = get_bits1(gbc);
994  if (s->cpl_in_use[blk]) {
995  /* coupling in use */
996  int cpl_start_subband, cpl_end_subband;
997 
998  if (channel_mode < AC3_CHMODE_STEREO) {
999  av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
1000  return AVERROR_INVALIDDATA;
1001  }
1002 
1003  /* check for enhanced coupling */
1004  if (s->eac3 && get_bits1(gbc)) {
1005  /* TODO: parse enhanced coupling strategy info */
1006  avpriv_request_sample(s->avctx, "Enhanced coupling");
1007  return AVERROR_PATCHWELCOME;
1008  }
1009 
1010  /* determine which channels are coupled */
1011  if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
1012  s->channel_in_cpl[1] = 1;
1013  s->channel_in_cpl[2] = 1;
1014  } else {
1015  for (ch = 1; ch <= fbw_channels; ch++)
1016  s->channel_in_cpl[ch] = get_bits1(gbc);
1017  }
1018 
1019  /* phase flags in use */
1020  if (channel_mode == AC3_CHMODE_STEREO)
1021  s->phase_flags_in_use = get_bits1(gbc);
1022 
1023  /* coupling frequency range */
1024  cpl_start_subband = get_bits(gbc, 4);
1025  cpl_end_subband = s->spx_in_use ? (s->spx_src_start_freq - 37) / 12 :
1026  get_bits(gbc, 4) + 3;
1027  if (cpl_start_subband >= cpl_end_subband) {
1028  av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
1029  cpl_start_subband, cpl_end_subband);
1030  return AVERROR_INVALIDDATA;
1031  }
1032  s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
1033  s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
1034 
1035  decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
1036  cpl_end_subband,
1038  &s->num_cpl_bands, s->cpl_band_sizes);
1039  } else {
1040  /* coupling not in use */
1041  for (ch = 1; ch <= fbw_channels; ch++) {
1042  s->channel_in_cpl[ch] = 0;
1043  s->first_cpl_coords[ch] = 1;
1044  }
1045  s->first_cpl_leak = s->eac3;
1046  s->phase_flags_in_use = 0;
1047  }
1048  } else if (!s->eac3) {
1049  if (!blk) {
1050  av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must "
1051  "be present in block 0\n");
1052  return AVERROR_INVALIDDATA;
1053  } else {
1054  s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
1055  }
1056  }
1057  cpl_in_use = s->cpl_in_use[blk];
1058 
1059  /* coupling coordinates */
1060  if (cpl_in_use) {
1061  int cpl_coords_exist = 0;
1062 
1063  for (ch = 1; ch <= fbw_channels; ch++) {
1064  if (s->channel_in_cpl[ch]) {
1065  if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
1066  int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
1067  s->first_cpl_coords[ch] = 0;
1068  cpl_coords_exist = 1;
1069  master_cpl_coord = 3 * get_bits(gbc, 2);
1070  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1071  cpl_coord_exp = get_bits(gbc, 4);
1072  cpl_coord_mant = get_bits(gbc, 4);
1073  if (cpl_coord_exp == 15)
1074  s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
1075  else
1076  s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
1077  s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
1078  }
1079  } else if (!blk) {
1080  av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must "
1081  "be present in block 0\n");
1082  return AVERROR_INVALIDDATA;
1083  }
1084  } else {
1085  /* channel not in coupling */
1086  s->first_cpl_coords[ch] = 1;
1087  }
1088  }
1089  /* phase flags */
1090  if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
1091  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1092  s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
1093  }
1094  }
1095  }
1096 
1097  /* stereo rematrixing strategy and band structure */
1098  if (channel_mode == AC3_CHMODE_STEREO) {
1099  if ((s->eac3 && !blk) || get_bits1(gbc)) {
1100  s->num_rematrixing_bands = 4;
1101  if (cpl_in_use && s->start_freq[CPL_CH] <= 61) {
1102  s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
1103  } else if (s->spx_in_use && s->spx_src_start_freq <= 61) {
1104  s->num_rematrixing_bands--;
1105  }
1106  for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++)
1107  s->rematrixing_flags[bnd] = get_bits1(gbc);
1108  } else if (!blk) {
1109  av_log(s->avctx, AV_LOG_WARNING, "Warning: "
1110  "new rematrixing strategy not present in block 0\n");
1111  s->num_rematrixing_bands = 0;
1112  }
1113  }
1114 
1115  /* exponent strategies for each channel */
1116  for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1117  if (!s->eac3)
1118  s->exp_strategy[blk][ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
1119  if (s->exp_strategy[blk][ch] != EXP_REUSE)
1120  bit_alloc_stages[ch] = 3;
1121  }
1122 
1123  /* channel bandwidth */
1124  for (ch = 1; ch <= fbw_channels; ch++) {
1125  s->start_freq[ch] = 0;
1126  if (s->exp_strategy[blk][ch] != EXP_REUSE) {
1127  int group_size;
1128  int prev = s->end_freq[ch];
1129  if (s->channel_in_cpl[ch])
1130  s->end_freq[ch] = s->start_freq[CPL_CH];
1131  else if (s->channel_uses_spx[ch])
1132  s->end_freq[ch] = s->spx_src_start_freq;
1133  else {
1134  int bandwidth_code = get_bits(gbc, 6);
1135  if (bandwidth_code > 60) {
1136  av_log(s->avctx, AV_LOG_ERROR, "bandwidth code = %d > 60\n", bandwidth_code);
1137  return AVERROR_INVALIDDATA;
1138  }
1139  s->end_freq[ch] = bandwidth_code * 3 + 73;
1140  }
1141  group_size = 3 << (s->exp_strategy[blk][ch] - 1);
1142  s->num_exp_groups[ch] = (s->end_freq[ch] + group_size-4) / group_size;
1143  if (blk > 0 && s->end_freq[ch] != prev)
1144  memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
1145  }
1146  }
1147  if (cpl_in_use && s->exp_strategy[blk][CPL_CH] != EXP_REUSE) {
1149  (3 << (s->exp_strategy[blk][CPL_CH] - 1));
1150  }
1151 
1152  /* decode exponents for each channel */
1153  for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1154  if (s->exp_strategy[blk][ch] != EXP_REUSE) {
1155  s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
1156  if (decode_exponents(s, gbc, s->exp_strategy[blk][ch],
1157  s->num_exp_groups[ch], s->dexps[ch][0],
1158  &s->dexps[ch][s->start_freq[ch]+!!ch])) {
1159  return AVERROR_INVALIDDATA;
1160  }
1161  if (ch != CPL_CH && ch != s->lfe_ch)
1162  skip_bits(gbc, 2); /* skip gainrng */
1163  }
1164  }
1165 
1166  /* bit allocation information */
1167  if (s->bit_allocation_syntax) {
1168  if (get_bits1(gbc)) {
1174  for (ch = !cpl_in_use; ch <= s->channels; ch++)
1175  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1176  } else if (!blk) {
1177  av_log(s->avctx, AV_LOG_ERROR, "new bit allocation info must "
1178  "be present in block 0\n");
1179  return AVERROR_INVALIDDATA;
1180  }
1181  }
1182 
1183  /* signal-to-noise ratio offsets and fast gains (signal-to-mask ratios) */
1184  if (!s->eac3 || !blk) {
1185  if (s->snr_offset_strategy && get_bits1(gbc)) {
1186  int snr = 0;
1187  int csnr;
1188  csnr = (get_bits(gbc, 6) - 15) << 4;
1189  for (i = ch = !cpl_in_use; ch <= s->channels; ch++) {
1190  /* snr offset */
1191  if (ch == i || s->snr_offset_strategy == 2)
1192  snr = (csnr + get_bits(gbc, 4)) << 2;
1193  /* run at least last bit allocation stage if snr offset changes */
1194  if (blk && s->snr_offset[ch] != snr) {
1195  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 1);
1196  }
1197  s->snr_offset[ch] = snr;
1198 
1199  /* fast gain (normal AC-3 only) */
1200  if (!s->eac3) {
1201  int prev = s->fast_gain[ch];
1202  s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
1203  /* run last 2 bit allocation stages if fast gain changes */
1204  if (blk && prev != s->fast_gain[ch])
1205  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1206  }
1207  }
1208  } else if (!s->eac3 && !blk) {
1209  av_log(s->avctx, AV_LOG_ERROR, "new snr offsets must be present in block 0\n");
1210  return AVERROR_INVALIDDATA;
1211  }
1212  }
1213 
1214  /* fast gain (E-AC-3 only) */
1215  if (s->fast_gain_syntax && get_bits1(gbc)) {
1216  for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1217  int prev = s->fast_gain[ch];
1218  s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
1219  /* run last 2 bit allocation stages if fast gain changes */
1220  if (blk && prev != s->fast_gain[ch])
1221  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1222  }
1223  } else if (s->eac3 && !blk) {
1224  for (ch = !cpl_in_use; ch <= s->channels; ch++)
1225  s->fast_gain[ch] = ff_ac3_fast_gain_tab[4];
1226  }
1227 
1228  /* E-AC-3 to AC-3 converter SNR offset */
1229  if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && get_bits1(gbc)) {
1230  skip_bits(gbc, 10); // skip converter snr offset
1231  }
1232 
1233  /* coupling leak information */
1234  if (cpl_in_use) {
1235  if (s->first_cpl_leak || get_bits1(gbc)) {
1236  int fl = get_bits(gbc, 3);
1237  int sl = get_bits(gbc, 3);
1238  /* run last 2 bit allocation stages for coupling channel if
1239  coupling leak changes */
1240  if (blk && (fl != s->bit_alloc_params.cpl_fast_leak ||
1241  sl != s->bit_alloc_params.cpl_slow_leak)) {
1242  bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
1243  }
1246  } else if (!s->eac3 && !blk) {
1247  av_log(s->avctx, AV_LOG_ERROR, "new coupling leak info must "
1248  "be present in block 0\n");
1249  return AVERROR_INVALIDDATA;
1250  }
1251  s->first_cpl_leak = 0;
1252  }
1253 
1254  /* delta bit allocation information */
1255  if (s->dba_syntax && get_bits1(gbc)) {
1256  /* delta bit allocation exists (strategy) */
1257  for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
1258  s->dba_mode[ch] = get_bits(gbc, 2);
1259  if (s->dba_mode[ch] == DBA_RESERVED) {
1260  av_log(s->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
1261  return AVERROR_INVALIDDATA;
1262  }
1263  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1264  }
1265  /* channel delta offset, len and bit allocation */
1266  for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
1267  if (s->dba_mode[ch] == DBA_NEW) {
1268  s->dba_nsegs[ch] = get_bits(gbc, 3) + 1;
1269  for (seg = 0; seg < s->dba_nsegs[ch]; seg++) {
1270  s->dba_offsets[ch][seg] = get_bits(gbc, 5);
1271  s->dba_lengths[ch][seg] = get_bits(gbc, 4);
1272  s->dba_values[ch][seg] = get_bits(gbc, 3);
1273  }
1274  /* run last 2 bit allocation stages if new dba values */
1275  bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1276  }
1277  }
1278  } else if (blk == 0) {
1279  for (ch = 0; ch <= s->channels; ch++) {
1280  s->dba_mode[ch] = DBA_NONE;
1281  }
1282  }
1283 
1284  /* Bit allocation */
1285  for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1286  if (bit_alloc_stages[ch] > 2) {
1287  /* Exponent mapping into PSD and PSD integration */
1289  s->start_freq[ch], s->end_freq[ch],
1290  s->psd[ch], s->band_psd[ch]);
1291  }
1292  if (bit_alloc_stages[ch] > 1) {
1293  /* Compute excitation function, Compute masking curve, and
1294  Apply delta bit allocation */
1296  s->start_freq[ch], s->end_freq[ch],
1297  s->fast_gain[ch], (ch == s->lfe_ch),
1298  s->dba_mode[ch], s->dba_nsegs[ch],
1299  s->dba_offsets[ch], s->dba_lengths[ch],
1300  s->dba_values[ch], s->mask[ch])) {
1301  av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
1302  return AVERROR_INVALIDDATA;
1303  }
1304  }
1305  if (bit_alloc_stages[ch] > 0) {
1306  /* Compute bit allocation */
1307  const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
1309  s->ac3dsp.bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
1310  s->start_freq[ch], s->end_freq[ch],
1311  s->snr_offset[ch],
1313  bap_tab, s->bap[ch]);
1314  }
1315  }
1316 
1317  /* unused dummy data */
1318  if (s->skip_syntax && get_bits1(gbc)) {
1319  int skipl = get_bits(gbc, 9);
1320  while (skipl--)
1321  skip_bits(gbc, 8);
1322  }
1323 
1324  /* unpack the transform coefficients
1325  this also uncouples channels if coupling is in use. */
1326  decode_transform_coeffs(s, blk);
1327 
1328  /* TODO: generate enhanced coupling coordinates and uncouple */
1329 
1330  /* recover coefficients if rematrixing is in use */
1331  if (s->channel_mode == AC3_CHMODE_STEREO)
1332  do_rematrixing(s);
1333 
1334  /* apply scaling to coefficients (headroom, dynrng) */
1335  for (ch = 1; ch <= s->channels; ch++) {
1336  int audio_channel = 0;
1337  INTFLOAT gain;
1339  audio_channel = 2-ch;
1340  if (s->heavy_compression && s->compression_exists[audio_channel])
1341  gain = s->heavy_dynamic_range[audio_channel];
1342  else
1343  gain = s->dynamic_range[audio_channel];
1344 
1345 #if USE_FIXED
1346  scale_coefs(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
1347 #else
1348  if (s->target_level != 0)
1349  gain = gain * s->level_gain[audio_channel];
1350  gain *= 1.0 / 4194304.0f;
1352  s->fixed_coeffs[ch], gain, 256);
1353 #endif
1354  }
1355 
1356  /* apply spectral extension to high frequency bins */
1357  if (CONFIG_EAC3_DECODER && s->spx_in_use) {
1359  }
1360 
1361  /* downmix and MDCT. order depends on whether block switching is used for
1362  any channel in this block. this is because coefficients for the long
1363  and short transforms cannot be mixed. */
1364  downmix_output = s->channels != s->out_channels &&
1365  !((s->output_mode & AC3_OUTPUT_LFEON) &&
1366  s->fbw_channels == s->out_channels);
1367  if (different_transforms) {
1368  /* the delay samples have already been downmixed, so we upmix the delay
1369  samples in order to reconstruct all channels before downmixing. */
1370  if (s->downmixed) {
1371  s->downmixed = 0;
1372  ac3_upmix_delay(s);
1373  }
1374 
1375  do_imdct(s, s->channels);
1376 
1377  if (downmix_output) {
1378 #if USE_FIXED
1380  s->out_channels, s->fbw_channels, 256);
1381 #else
1382  s->ac3dsp.downmix(s->outptr, s->downmix_coeffs,
1383  s->out_channels, s->fbw_channels, 256);
1384 #endif
1385  }
1386  } else {
1387  if (downmix_output) {
1388  s->ac3dsp.AC3_RENAME(downmix)(s->xcfptr + 1, s->downmix_coeffs,
1389  s->out_channels, s->fbw_channels, 256);
1390  }
1391 
1392  if (downmix_output && !s->downmixed) {
1393  s->downmixed = 1;
1394  s->ac3dsp.AC3_RENAME(downmix)(s->dlyptr, s->downmix_coeffs,
1395  s->out_channels, s->fbw_channels, 128);
1396  }
1397 
1398  do_imdct(s, s->out_channels);
1399  }
1400 
1401  return 0;
1402 }
1403 
1404 /**
1405  * Decode a single AC-3 frame.
1406  */
1407 static int ac3_decode_frame(AVCodecContext * avctx, void *data,
1408  int *got_frame_ptr, AVPacket *avpkt)
1409 {
1410  AVFrame *frame = data;
1411  const uint8_t *buf = avpkt->data;
1412  int buf_size = avpkt->size;
1413  AC3DecodeContext *s = avctx->priv_data;
1414  int blk, ch, err, ret;
1415  const uint8_t *channel_map;
1416  const SHORTFLOAT *output[AC3_MAX_CHANNELS];
1417  enum AVMatrixEncoding matrix_encoding;
1418  AVDownmixInfo *downmix_info;
1419 
1420  /* copy input buffer to decoder context to avoid reading past the end
1421  of the buffer, which can be caused by a damaged input stream. */
1422  if (buf_size >= 2 && AV_RB16(buf) == 0x770B) {
1423  // seems to be byte-swapped AC-3
1424  int cnt = FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE) >> 1;
1425  s->bdsp.bswap16_buf((uint16_t *) s->input_buffer,
1426  (const uint16_t *) buf, cnt);
1427  } else
1428  memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
1429  buf = s->input_buffer;
1430  /* initialize the GetBitContext with the start of valid AC-3 Frame */
1431  if ((ret = init_get_bits8(&s->gbc, buf, buf_size)) < 0)
1432  return ret;
1433 
1434  /* parse the syncinfo */
1435  err = parse_frame_header(s);
1436 
1437  if (err) {
1438  switch (err) {
1440  av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
1441  return AVERROR_INVALIDDATA;
1443  av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
1444  break;
1446  av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
1447  break;
1449  av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
1450  break;
1452  /* skip frame if CRC is ok. otherwise use error concealment. */
1453  /* TODO: add support for substreams and dependent frames */
1455  av_log(avctx, AV_LOG_DEBUG,
1456  "unsupported frame type %d: skipping frame\n",
1457  s->frame_type);
1458  *got_frame_ptr = 0;
1459  return buf_size;
1460  } else {
1461  av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
1462  }
1463  break;
1466  break;
1467  default: // Normal AVERROR do not try to recover.
1468  *got_frame_ptr = 0;
1469  return err;
1470  }
1471  } else {
1472  /* check that reported frame size fits in input buffer */
1473  if (s->frame_size > buf_size) {
1474  av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
1476  } else if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {
1477  /* check for crc mismatch */
1478  if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2],
1479  s->frame_size - 2)) {
1480  av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
1481  if (avctx->err_recognition & AV_EF_EXPLODE)
1482  return AVERROR_INVALIDDATA;
1484  }
1485  }
1486  }
1487 
1488  /* if frame is ok, set audio parameters */
1489  if (!err) {
1490  avctx->sample_rate = s->sample_rate;
1491  avctx->bit_rate = s->bit_rate;
1492  }
1493 
1494  /* channel config */
1495  if (!err || (s->channels && s->out_channels != s->channels)) {
1496  s->out_channels = s->channels;
1497  s->output_mode = s->channel_mode;
1498  if (s->lfe_on)
1500  if (s->channels > 1 &&
1502  s->out_channels = 1;
1504  } else if (s->channels > 2 &&
1506  s->out_channels = 2;
1508  }
1509 
1510  s->loro_center_mix_level = gain_levels[s-> center_mix_level];
1514  /* set downmixing coefficients if needed */
1515  if (s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
1516  s->fbw_channels == s->out_channels)) {
1517  set_downmix_coeffs(s);
1518  }
1519  } else if (!s->channels) {
1520  av_log(avctx, AV_LOG_ERROR, "unable to determine channel mode\n");
1521  return AVERROR_INVALIDDATA;
1522  }
1523  avctx->channels = s->out_channels;
1525  if (s->output_mode & AC3_OUTPUT_LFEON)
1527 
1528  /* set audio service type based on bitstream mode for AC-3 */
1529  avctx->audio_service_type = s->bitstream_mode;
1530  if (s->bitstream_mode == 0x7 && s->channels > 1)
1532 
1533  /* get output buffer */
1534  frame->nb_samples = s->num_blocks * AC3_BLOCK_SIZE;
1535  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1536  return ret;
1537 
1538  /* decode the audio blocks */
1539  channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
1540  for (ch = 0; ch < AC3_MAX_CHANNELS; ch++) {
1541  output[ch] = s->output[ch];
1542  s->outptr[ch] = s->output[ch];
1543  }
1544  for (ch = 0; ch < s->channels; ch++) {
1545  if (ch < s->out_channels)
1546  s->outptr[channel_map[ch]] = (SHORTFLOAT *)frame->data[ch];
1547  }
1548  for (blk = 0; blk < s->num_blocks; blk++) {
1549  if (!err && decode_audio_block(s, blk)) {
1550  av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
1551  err = 1;
1552  }
1553  if (err)
1554  for (ch = 0; ch < s->out_channels; ch++)
1555  memcpy(((SHORTFLOAT*)frame->data[ch]) + AC3_BLOCK_SIZE*blk, output[ch], AC3_BLOCK_SIZE*sizeof(SHORTFLOAT));
1556  for (ch = 0; ch < s->out_channels; ch++)
1557  output[ch] = s->outptr[channel_map[ch]];
1558  for (ch = 0; ch < s->out_channels; ch++) {
1559  if (!ch || channel_map[ch])
1560  s->outptr[channel_map[ch]] += AC3_BLOCK_SIZE;
1561  }
1562  }
1563 
1565 
1566  /* keep last block for error concealment in next frame */
1567  for (ch = 0; ch < s->out_channels; ch++)
1568  memcpy(s->output[ch], output[ch], AC3_BLOCK_SIZE*sizeof(SHORTFLOAT));
1569 
1570  /*
1571  * AVMatrixEncoding
1572  *
1573  * Check whether the input layout is compatible, and make sure we're not
1574  * downmixing (else the matrix encoding is no longer applicable).
1575  */
1576  matrix_encoding = AV_MATRIX_ENCODING_NONE;
1577  if (s->channel_mode == AC3_CHMODE_STEREO &&
1578  s->channel_mode == (s->output_mode & ~AC3_OUTPUT_LFEON)) {
1580  matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
1582  matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
1583  } else if (s->channel_mode >= AC3_CHMODE_2F2R &&
1584  s->channel_mode == (s->output_mode & ~AC3_OUTPUT_LFEON)) {
1585  switch (s->dolby_surround_ex_mode) {
1586  case AC3_DSUREXMOD_ON: // EX or PLIIx
1587  matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;
1588  break;
1589  case AC3_DSUREXMOD_PLIIZ:
1590  matrix_encoding = AV_MATRIX_ENCODING_DPLIIZ;
1591  break;
1592  default: // not indicated or off
1593  break;
1594  }
1595  }
1596  if ((ret = ff_side_data_update_matrix_encoding(frame, matrix_encoding)) < 0)
1597  return ret;
1598 
1599  /* AVDownmixInfo */
1600  if ((downmix_info = av_downmix_info_update_side_data(frame))) {
1601  switch (s->preferred_downmix) {
1602  case AC3_DMIXMOD_LTRT:
1604  break;
1605  case AC3_DMIXMOD_LORO:
1607  break;
1608  case AC3_DMIXMOD_DPLII:
1610  break;
1611  default:
1613  break;
1614  }
1615  downmix_info->center_mix_level = gain_levels[s-> center_mix_level];
1616  downmix_info->center_mix_level_ltrt = gain_levels[s-> center_mix_level_ltrt];
1617  downmix_info->surround_mix_level = gain_levels[s-> surround_mix_level];
1619  if (s->lfe_mix_level_exists)
1620  downmix_info->lfe_mix_level = gain_levels_lfe[s->lfe_mix_level];
1621  else
1622  downmix_info->lfe_mix_level = 0.0; // -inf dB
1623  } else
1624  return AVERROR(ENOMEM);
1625 
1626  *got_frame_ptr = 1;
1627 
1628  return FFMIN(buf_size, s->frame_size);
1629 }
1630 
1631 /**
1632  * Uninitialize the AC-3 decoder.
1633  */
1635 {
1636  AC3DecodeContext *s = avctx->priv_data;
1637  ff_mdct_end(&s->imdct_512);
1638  ff_mdct_end(&s->imdct_256);
1639  av_freep(&s->fdsp);
1640 
1641  return 0;
1642 }
1643 
1644 #define OFFSET(x) offsetof(AC3DecodeContext, x)
1645 #define PAR (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
audio downmix medatata
uint8_t bitstream_mode
Definition: ac3.h:184
float, planar
Definition: samplefmt.h:69
const uint8_t ff_ac3_bap_tab[64]
Definition: ac3tab.c:270
static const uint8_t ac3_default_coeffs[8][5][2]
Table for default stereo downmixing coefficients reference: Section 7.8.2 Downmixing Into Two Channel...
Definition: ac3dec.c:98
int dba_nsegs[AC3_MAX_CHANNELS]
number of delta segments
Definition: ac3dec.h:201
const char * s
Definition: avisynth_c.h:768
uint8_t input_buffer[AC3_FRAME_BUFFER_SIZE+AV_INPUT_BUFFER_PADDING_SIZE]
temp buffer to prevent overread
Definition: ac3dec.h:240
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
scaled exponents
Definition: ac3dec.h:197
int spx_in_use
spectral extension in use (spxinu)
Definition: ac3dec.h:139
static void decode_band_structure(GetBitContext *gbc, int blk, int eac3, int ecpl, int start_subband, int end_subband, const uint8_t *default_band_struct, int *num_bands, uint8_t *band_sizes)
Decode band structure for coupling, spectral extension, or enhanced coupling.
Definition: ac3dec.c:755
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
uint8_t dba_offsets[AC3_MAX_CHANNELS][8]
delta segment offsets
Definition: ac3dec.h:202
const uint8_t ff_eac3_default_spx_band_struct[17]
Table E2.15 Default Spectral Extension Banding Structure.
Definition: ac3dec_data.c:59
const uint8_t ff_ac3_slow_decay_tab[4]
Definition: ac3tab.c:280
int dither_flag[AC3_MAX_CHANNELS]
dither flags (dithflg)
Definition: ac3dec.h:208
int16_t mask[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]
masking curve values
Definition: ac3dec.h:199
int preferred_downmix
Preferred 2-channel downmix mode (dmixmod)
Definition: ac3dec.h:91
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:247
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
av_cold void ff_kbd_window_init(float *window, float alpha, int n)
Generate a Kaiser-Bessel Derived Window.
Definition: kbdwin.c:26
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1741
static void ac3_downmix_c_fixed16(int16_t **samples, int16_t(*matrix)[2], int out_ch, int in_ch, int len)
Downmix samples from original signal to stereo or mono (this is for 16-bit samples and fixed point de...
Definition: ac3dec_fixed.c:142
const uint8_t ff_ac3_ungroup_3_in_5_bits_tab[32][3]
Table used to ungroup 3 values stored in 5 bits.
Definition: ac3dec_data.c:35
void(* bswap16_buf)(uint16_t *dst, const uint16_t *src, int len)
Definition: bswapdsp.h:26
double center_mix_level_ltrt
Absolute scale factor representing the nominal level of the center channel during an Lt/Rt compatible...
Definition: downmix_info.h:74
#define LEVEL_PLUS_1POINT5DB
Definition: ac3.h:104
AVDownmixInfo * av_downmix_info_update_side_data(AVFrame *frame)
Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
Definition: downmix_info.c:24
int size
Definition: avcodec.h:1602
static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
Decode the transform coefficients for a particular channel reference: Section 7.3 Quantization and De...
Definition: ac3dec.c:502
int channels
number of total channels
Definition: ac3dec.h:160
int b4
Definition: ac3dec.c:495
AVFloatDSPContext * fdsp
Definition: ac3dec.h:223
int spx_dst_end_freq
spx end frequency bin
Definition: ac3dec.h:143
static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch, mant_groups *m)
Definition: ac3dec.c:596
#define EXP_REUSE
Definition: ac3.h:47
int exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]
exponent strategies (expstr)
Definition: ac3dec.h:188
int lfe_on
lfe channel in use
Definition: ac3dec.h:86
#define AV_CH_LAYOUT_STEREO
const uint16_t ff_ac3_slow_gain_tab[4]
Definition: ac3tab.c:288
int block_switch[AC3_MAX_CHANNELS]
block switch flags (blksw)
Definition: ac3dec.h:213
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
#define blk(i)
Definition: sha.c:185
int dba_syntax
delta bit allocation syntax enabled (dbaflde)
Definition: ac3dec.h:120
int dialog_normalization[2]
dialog level in dBFS (dialnorm)
Definition: ac3dec.h:87
int spx_src_start_freq
spx start frequency bin
Definition: ac3dec.h:142
int heavy_compression
apply heavy compression
Definition: ac3dec.h:171
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:232
Not indicated.
Definition: downmix_info.h:45
uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]
number of coeffs in each coupling band
Definition: ac3dec.h:131
static void scale_coefs(int32_t *dst, const int32_t *src, int dynrng, int len)
Definition: ac3dec_fixed.c:61
SHORTFLOAT output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]
output after imdct transform and windowing
Definition: ac3dec.h:239
#define USE_FIXED
Definition: aac_defines.h:25
#define AC3_FRAME_BUFFER_SIZE
Large enough for maximum possible frame size when the specification limit is ignored.
Definition: ac3dec.h:68
enum AVAudioServiceType audio_service_type
Type of service that the audio stream conveys.
Definition: avcodec.h:2503
int lfe_mix_level_exists
indicates if lfemixlevcod is specified (lfemixlevcode)
Definition: ac3dec.h:96
float INTFLOAT
Definition: aac_defines.h:85
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
void(* vector_fmul_window)(float *dst, const float *src0, const float *src1, const float *win, int len)
Overlap/add with window function.
Definition: float_dsp.h:103
uint8_t bits
Definition: crc.c:296
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2446
float ltrt_center_mix_level
Definition: ac3dec.h:107
uint8_t
#define av_cold
Definition: attributes.h:82
int first_cpl_coords[AC3_MAX_CHANNELS]
first coupling coordinates states (firstcplcos)
Definition: ac3dec.h:133
AVOptions.
uint8_t lfe_on
Definition: ac3.h:186
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
INTFLOAT spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]
spx noise blending factor (nblendfact)
Definition: ac3dec.h:149
static void do_imdct(AC3DecodeContext *s, int channels)
Inverse MDCT Transform.
Definition: ac3dec.c:676
static av_cold int ac3_decode_end(AVCodecContext *avctx)
Uninitialize the AC-3 decoder.
Definition: ac3dec.c:1634
static uint8_t ungroup_3_in_7_bits_tab[128][3]
table for ungrouping 3 values in 7 bits.
Definition: ac3dec.c:48
static void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
Decode mantissas in a single channel for the entire frame.
int num_rematrixing_bands
number of rematrixing bands (nrematbnd)
Definition: ac3dec.h:181
#define AV_CH_LOW_FREQUENCY
int fast_gain[AC3_MAX_CHANNELS]
fast gain values/SMR's (fgain)
Definition: ac3dec.h:195
static AVFrame * frame
Public header for CRC hash function implementation.
float ltrt_surround_mix_level
Definition: ac3dec.h:108
uint8_t * data
Definition: avcodec.h:1601
double surround_mix_level_ltrt
Absolute scale factor representing the nominal level of the surround channels during an Lt/Rt compati...
Definition: downmix_info.h:86
int cpl_coords[AC3_MAX_CHANNELS][AC3_MAX_CPL_BANDS]
coupling coordinates (cplco)
Definition: ac3dec.h:134
static int b1_mantissas[32][3]
tables for ungrouping mantissas
Definition: ac3dec.c:51
int num_exp_groups[AC3_MAX_CHANNELS]
Number of exponent groups (nexpgrp)
Definition: ac3dec.h:186
uint8_t sr_shift
Definition: ac3.h:199
#define FIXR12(x)
Definition: ac3.h:82
Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible.
Definition: downmix_info.h:48
uint8_t bitstream_id
Definition: ac3.h:183
AVFixedDSPContext * avpriv_alloc_fixed_dsp(int bit_exact)
Allocate and initialize a fixed DSP context.
Definition: fixed_dsp.c:148
#define LEVEL_MINUS_1POINT5DB
Definition: ac3.h:105
static av_always_inline int fixed_sqrt(int x, int bits)
Calculate the square root.
Definition: fixed_dsp.h:176
static int ff_eac3_parse_header(AC3DecodeContext *s)
Parse the E-AC-3 frame header.
int bit_allocation_syntax
bit allocation model syntax enabled (bamode)
Definition: ac3dec.h:118
int phase_flags_in_use
phase flags in use (phsflginu)
Definition: ac3dec.h:128
#define av_log(a,...)
double lfe_mix_level
Absolute scale factor representing the level at which the LFE data is mixed into L/R channels during ...
Definition: downmix_info.h:92
Common code between the AC-3 and E-AC-3 decoders.
Grouped mantissas for 3-level 5-level and 11-level quantization.
Definition: ac3dec.c:489
INTFLOAT delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]
delay - added to the next block
Definition: ac3dec.h:236
int phase_flags[AC3_MAX_CPL_BANDS]
phase flags (phsflg)
Definition: ac3dec.h:129
int out_channels
number of output channels
Definition: ac3dec.h:165
const uint16_t avpriv_ac3_channel_layout_tab[8]
Map audio coding mode (acmod) to channel layout mask.
Definition: ac3tab.c:89
This structure describes optional metadata relevant to a downmix procedure.
Definition: downmix_info.h:58
#define U(x)
Definition: vp56_arith.h:37
int substreamid
substream identification
Definition: ac3dec.h:78
FFTContext imdct_256
for 256 sample IMDCT
Definition: ac3dec.h:215
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static int decode_audio_block(AC3DecodeContext *s, int blk)
Decode a single audio block from the AC-3 bitstream.
Definition: ac3dec.c:807
#define AC3_DYNAMIC_RANGE1
Definition: ac3.h:93
const uint8_t ff_ac3_fast_decay_tab[4]
Definition: ac3tab.c:284
int bit_rate
stream bit rate, in bits-per-second
Definition: ac3dec.h:80
uint8_t frame_type
Definition: ac3.h:187
int lfe_ch
index of LFE channel
Definition: ac3dec.h:161
#define AVERROR(e)
Definition: error.h:43
uint8_t first_spx_coords[AC3_MAX_CHANNELS]
first spx coordinates states (firstspxcos)
Definition: ac3dec.h:148
AC3BitAllocParameters bit_alloc_params
bit allocation parameters
Definition: ac3dec.h:192
int dolby_surround_mode
dolby surround mode (dsurmod)
Definition: ac3dec.h:101
static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
Decode the transform coefficients.
Definition: ac3dec.c:616
GetBitContext gbc
bitstream reader
Definition: ac3dec.h:73
uint8_t sr_code
Definition: ac3.h:182
static const uint8_t dither[8][8]
Definition: vf_fspp.c:57
AC3DSPContext ac3dsp
Definition: ac3dec.h:225
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
#define LEVEL_MINUS_9DB
Definition: ac3.h:109
#define AC3_MAX_CHANNELS
maximum number of channels, including coupling channel
Definition: ac3.h:31
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1771
int ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, int start, int end, int fast_gain, int is_lfe, int dba_mode, int dba_nsegs, uint8_t *dba_offsets, uint8_t *dba_lengths, uint8_t *dba_values, int16_t *mask)
Calculate the masking curve.
Definition: ac3.c:118
Definition: ac3.h:116
int dolby_headphone_mode
dolby headphone mode (dheadphonmod)
Definition: ac3dec.h:103
float loro_center_mix_level
Definition: ac3dec.h:109
Coded AC-3 header values up to the lfeon element, plus derived values.
Definition: ac3.h:176
int compression_exists[2]
compression field is valid for frame (compre)
Definition: ac3dec.h:88
#define ff_mdct_init
Definition: fft.h:169
uint16_t sample_rate
Definition: ac3.h:200
INTFLOAT transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
transform coefficients
Definition: ac3dec.h:235
#define FFMAX(a, b)
Definition: common.h:94
#define LEVEL_MINUS_3DB
Definition: ac3.h:106
float FFTSample
Definition: avfft.h:35
static int ac3_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Decode a single AC-3 frame.
Definition: ac3dec.c:1407
int block_switch_syntax
block switch syntax enabled (blkswe)
Definition: ac3dec.h:116
float level_gain[2]
Definition: ac3dec.h:112
int fast_gain_syntax
fast gain codes enabled (frmfgaincode)
Definition: ac3dec.h:119
int16_t band_psd[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]
interpolated exponents
Definition: ac3dec.h:198
uint8_t channel_uses_spx[AC3_MAX_CHANNELS]
channel uses spectral extension (chinspx)
Definition: ac3dec.h:140
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2489
#define LEVEL_MINUS_4POINT5DB
Definition: ac3.h:107
static int b3_mantissas[8]
Definition: ac3dec.c:53
#define AC3_BLOCK_SIZE
Definition: ac3.h:35
INTFLOAT dynamic_range[2]
dynamic range
Definition: ac3dec.h:169
#define powf(x, y)
Definition: libm.h:50
static float dynamic_range_tab[256]
dynamic range table.
Definition: ac3dec.c:68
INTFLOAT window[AC3_BLOCK_SIZE]
window coefficients
Definition: ac3dec.h:237
static void do_rematrixing(AC3DecodeContext *s)
Stereo rematrixing.
Definition: ac3dec.c:652
#define AC3_HEAVY_RANGE(x)
Definition: ac3.h:90
SHORTFLOAT * outptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:229
audio channel layout utility functions
int b4_mant
Definition: ac3dec.c:492
int surround_mix_level_ltrt
Surround mix level index for Lt/Rt (ltrtsurmixlev)
Definition: ac3dec.h:95
BswapDSPContext bdsp
Definition: ac3dec.h:219
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:886
static int b5_mantissas[16]
Definition: ac3dec.c:55
int err_recognition
Error recognition; may misdetect some more or less valid parts as errors.
Definition: avcodec.h:2965
float loro_surround_mix_level
Definition: ac3dec.h:110
#define FFMIN(a, b)
Definition: common.h:96
Lt/Rt 2-channel downmix, Dolby Surround compatible.
Definition: downmix_info.h:47
int dither_flag_syntax
dither flag syntax enabled (dithflage)
Definition: ac3dec.h:117
int end_freq[AC3_MAX_CHANNELS]
end frequency bin (endmant)
Definition: ac3dec.h:177
INTFLOAT heavy_dynamic_range[2]
heavy dynamic range compression
Definition: ac3dec.h:172
uint32_t bit_rate
Definition: ac3.h:201
av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
Definition: ac3dsp.c:279
INTFLOAT tmp_output[AC3_BLOCK_SIZE]
temporary storage for output before windowing
Definition: ac3dec.h:238
uint8_t dba_values[AC3_MAX_CHANNELS][8]
delta values for each segment
Definition: ac3dec.h:204
FFTContext imdct_512
for 512 sample IMDCT
Definition: ac3dec.h:214
int32_t
const uint16_t ff_ac3_fast_gain_tab[8]
Definition: ac3tab.c:300
uint32_t av_crc(const AVCRC *ctx, uint32_t crc, const uint8_t *buffer, size_t length)
Calculate the CRC of a block.
Definition: crc.c:357
void(* int32_to_float_fmul_scalar)(float *dst, const int32_t *src, float mul, int len)
Convert an array of int32_t to float and multiply by a float value.
Definition: fmtconvert.h:38
static int b2_mantissas[128][3]
Definition: ac3dec.c:52
Lo/Ro 2-channel downmix (Stereo).
Definition: downmix_info.h:46
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: avcodec.h:2976
float SHORTFLOAT
Definition: aac_defines.h:87
av_cold void ff_fmt_convert_init(FmtConvertContext *c, AVCodecContext *avctx)
Definition: fmtconvert.c:52
Definition: ac3.h:117
int dolby_surround_mode
Definition: ac3.h:193
AVCodecContext * avctx
parent context
Definition: ac3dec.h:72
static int b4_mantissas[128][2]
Definition: ac3dec.c:54
#define AC3_RANGE(x)
Definition: ac3.h:89
int ff_side_data_update_matrix_encoding(AVFrame *frame, enum AVMatrixEncoding matrix_encoding)
Add or update AV_FRAME_DATA_MATRIXENCODING side data.
Definition: utils.c:240
int channel_in_cpl[AC3_MAX_CHANNELS]
channel in coupling (chincpl)
Definition: ac3dec.h:127
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
int fbw_channels
number of full-bandwidth channels
Definition: ac3dec.h:159
void(* bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end, int snr_offset, int floor, const uint8_t *bap_tab, uint8_t *bap)
Calculate bit allocation pointers.
Definition: ac3dsp.h:106
INTFLOAT * xcfptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:230
uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
bit allocation pointers
Definition: ac3dec.h:196
double surround_mix_level
Absolute scale factor representing the nominal level of the surround channels during a regular downmi...
Definition: downmix_info.h:80
#define CPL_CH
coupling channel index
Definition: ac3.h:32
const uint8_t ff_eac3_default_cpl_band_struct[18]
Table E2.16 Default Coupling Banding Structure.
Definition: ac3tab.c:146
int sample_rate
samples per second
Definition: avcodec.h:2438
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:441
main external API structure.
Definition: avcodec.h:1676
#define LEVEL_ZERO
Definition: ac3.h:110
#define LEVEL_ONE
Definition: ac3.h:111
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:947
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:38
int num_cpl_bands
number of coupling bands (ncplbnd)
Definition: ac3dec.h:130
int num_spx_bands
number of spx bands (nspxbnds)
Definition: ac3dec.h:146
void * buf
Definition: avisynth_c.h:690
void(* imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:108
static const float gain_levels[9]
Adjustments in dB gain.
Definition: ac3dec.c:73
#define AV_EF_CAREFUL
consider things that violate the spec, are fast to calculate and have not been seen in the wild as er...
Definition: avcodec.h:2979
static void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
Apply spectral extension to each channel by copying lower frequency coefficients to higher frequency ...
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:299
int b1
Definition: ac3dec.c:493
static const int end_freq_inv_tab[8]
Definition: ac3dec_fixed.c:56
INTFLOAT spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]
spx signal blending factor (sblendfact)
Definition: ac3dec.h:150
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:292
int bitstream_mode
bitstream mode (bsmod)
Definition: ac3dec.h:84
int center_mix_level_ltrt
Center mix level index for Lt/Rt (ltrtcmixlev)
Definition: ac3dec.h:93
static void set_downmix_coeffs(AC3DecodeContext *s)
Set stereo downmixing coefficients based on frame header info.
Definition: ac3dec.c:365
int frame_type
frame type (strmtyp)
Definition: ac3dec.h:77
uint16_t frame_size
Definition: ac3.h:203
static int decode_exponents(AC3DecodeContext *s, GetBitContext *gbc, int exp_strategy, int ngrps, uint8_t absexp, int8_t *dexps)
Decode the grouped exponents according to exponent strategy.
Definition: ac3dec.c:417
static const uint8_t quantization_tab[16]
Quantization table: levels for symmetric.
Definition: ac3dec.c:61
#define AV_EF_CRCCHECK
Verify checksums embedded in the bitstream (could be of either encoded or decoded data...
Definition: avcodec.h:2973
void av_frame_set_decode_error_flags(AVFrame *frame, int val)
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
av_cold AVFloatDSPContext * avpriv_float_dsp_alloc(int bit_exact)
Allocate a float DSP context.
Definition: float_dsp.c:119
#define FF_DECODE_ERROR_INVALID_BITSTREAM
Definition: frame.h:486
int eac3
indicates if current frame is E-AC-3
Definition: ac3dec.h:98
int channel_uses_aht[AC3_MAX_CHANNELS]
channel AHT in use (chahtinu)
Definition: ac3dec.h:154
const int16_t ff_ac3_floor_tab[8]
Definition: ac3tab.c:296
uint8_t dba_lengths[AC3_MAX_CHANNELS][8]
delta segment lengths
Definition: ac3dec.h:203
static int ac3_parse_header(AC3DecodeContext *s)
Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
Definition: ac3dec.c:234
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
int cpl_in_use[AC3_MAX_BLOCKS]
coupling in use (cplinu)
Definition: ac3dec.h:125
#define AC3_DYNAMIC_RANGE(x)
Definition: ac3.h:91
int dba_mode[AC3_MAX_CHANNELS]
delta bit allocation mode
Definition: ac3dec.h:200
const AVCRC * av_crc_get_table(AVCRCId crc_id)
Get an initialized standard CRC table.
Definition: crc.c:343
int first_cpl_leak
first coupling leak state (firstcplleak)
Definition: ac3dec.h:193
int surround_mix_level
Surround mix level index.
Definition: ac3dec.h:94
int snr_offset[AC3_MAX_CHANNELS]
signal-to-noise ratio offsets (snroffst)
Definition: ac3dec.h:194
int downmixed
indicates if coeffs are currently downmixed
Definition: ac3dec.h:163
int
common internal api header.
INTFLOAT * dlyptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:231
#define ff_mdct_end
Definition: fft.h:170
SHORTFLOAT downmix_coeffs[AC3_MAX_CHANNELS][2]
stereo downmix coefficients
Definition: ac3dec.h:162
int surround_mix_level
Surround mix level index.
Definition: ac3.h:190
int num_blocks
number of audio blocks
Definition: ac3dec.h:82
#define AC3_OUTPUT_LFEON
Definition: ac3dec.h:63
FmtConvertContext fmt_conv
optimized conversion functions
Definition: ac3dec.h:226
int b1_mant[2]
Definition: ac3dec.c:490
uint8_t pi<< 24) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_U8,(uint64_t)((*(constuint8_t *) pi-0x80U))<< 56) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S16,(uint64_t)(*(constint16_t *) pi)<< 48) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S32,(uint64_t)(*(constint32_t *) pi)<< 32) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S64,(*(constint64_t *) pi >>56)+0x80) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S64,*(constint64_t *) pi *(1.0f/(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S64,*(constint64_t *) pi *(1.0/(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_FLT, llrintf(*(constfloat *) pi *(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_DBL, llrint(*(constdouble *) pi *(INT64_C(1)<< 63)))#defineFMT_PAIR_FUNC(out, in) staticconv_func_type *constfmt_pair_to_conv_functions[AV_SAMPLE_FMT_NB *AV_SAMPLE_FMT_NB]={FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S64),};staticvoidcpy1(uint8_t **dst, constuint8_t **src, intlen){memcpy(*dst,*src, len);}staticvoidcpy2(uint8_t **dst, constuint8_t **src, intlen){memcpy(*dst,*src, 2 *len);}staticvoidcpy4(uint8_t **dst, constuint8_t **src, intlen){memcpy(*dst,*src, 4 *len);}staticvoidcpy8(uint8_t **dst, constuint8_t **src, intlen){memcpy(*dst,*src, 8 *len);}AudioConvert *swri_audio_convert_alloc(enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, constint *ch_map, intflags){AudioConvert *ctx;conv_func_type *f=fmt_pair_to_conv_functions[av_get_packed_sample_fmt(out_fmt)+AV_SAMPLE_FMT_NB *av_get_packed_sample_fmt(in_fmt)];if(!f) returnNULL;ctx=av_mallocz(sizeof(*ctx));if(!ctx) returnNULL;if(channels==1){in_fmt=av_get_planar_sample_fmt(in_fmt);out_fmt=av_get_planar_sample_fmt(out_fmt);}ctx->channels=channels;ctx->conv_f=f;ctx->ch_map=ch_map;if(in_fmt==AV_SAMPLE_FMT_U8||in_fmt==AV_SAMPLE_FMT_U8P) memset(ctx->silence, 0x80, sizeof(ctx->silence));if(out_fmt==in_fmt &&!ch_map){switch(av_get_bytes_per_sample(in_fmt)){case1:ctx->simd_f=cpy1;break;case2:ctx->simd_f=cpy2;break;case4:ctx->simd_f=cpy4;break;case8:ctx->simd_f=cpy8;break;}}if(HAVE_YASM &&1) swri_audio_convert_init_x86(ctx, out_fmt, in_fmt, channels);if(ARCH_ARM) swri_audio_convert_init_arm(ctx, out_fmt, in_fmt, channels);if(ARCH_AARCH64) swri_audio_convert_init_aarch64(ctx, out_fmt, in_fmt, channels);returnctx;}voidswri_audio_convert_free(AudioConvert **ctx){av_freep(ctx);}intswri_audio_convert(AudioConvert *ctx, AudioData *out, AudioData *in, intlen){intch;intoff=0;constintos=(out->planar?1:out->ch_count)*out->bps;unsignedmisaligned=0;av_assert0(ctx->channels==out->ch_count);if(ctx->in_simd_align_mask){intplanes=in->planar?in->ch_count:1;unsignedm=0;for(ch=0;ch< planes;ch++) m|=(intptr_t) in->ch[ch];misaligned|=m &ctx->in_simd_align_mask;}if(ctx->out_simd_align_mask){intplanes=out->planar?out->ch_count:1;unsignedm=0;for(ch=0;ch< planes;ch++) m|=(intptr_t) out->ch[ch];misaligned|=m &ctx->out_simd_align_mask;}if(ctx->simd_f &&!ctx->ch_map &&!misaligned){off=len &~15;av_assert1(off >=0);av_assert1(off<=len);av_assert2(ctx->channels==SWR_CH_MAX||!in->ch[ctx->channels]);if(off >0){if(out->planar==in->planar){intplanes=out->planar?out->ch_count:1;for(ch=0;ch< planes;ch++){ctx->simd_f(out-> ch ch
Definition: audioconvert.c:56
int center_mix_level
Center mix level index.
Definition: ac3.h:189
static av_cold void ac3_tables_init(void)
Definition: ac3dec.c:123
int target_level
target level in dBFS
Definition: ac3dec.h:111
double center_mix_level
Absolute scale factor representing the nominal level of the center channel during a regular downmix...
Definition: downmix_info.h:68
int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][AC3_MAX_BLOCKS]
pre-IDCT mantissas
Definition: ac3dec.h:155
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
void * priv_data
Definition: avcodec.h:1718
void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd, int16_t *band_psd)
Calculate the log power-spectral density of the input signal.
Definition: ac3.c:92
int rematrixing_flags[4]
rematrixing flags (rematflg)
Definition: ac3dec.h:182
int fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
fixed-point transform coefficients
Definition: ac3dec.h:234
uint8_t spx_band_sizes[SPX_MAX_BANDS]
number of bins in each spx band
Definition: ac3dec.h:147
int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo **phdr)
Parse AC-3 frame header.
Definition: ac3_parser.c:50
int lfe_mix_level
LFE mix level index (lfemixlevcod)
Definition: ac3dec.h:97
#define AC3_SPX_BLEND(x)
Definition: ac3.h:92
static int parse_frame_header(AC3DecodeContext *s)
Common function to parse AC-3 or E-AC-3 frame header.
Definition: ac3dec.c:298
#define LEVEL_PLUS_3DB
Definition: ac3.h:103
int snr_offset_strategy
SNR offset strategy (snroffststr)
Definition: ac3dec.h:115
int b2_mant[2]
Definition: ac3dec.c:491
static const int16_t coeffs[]
int start_freq[AC3_MAX_CHANNELS]
start frequency bin (strtmant)
Definition: ac3dec.h:176
int substreamid
substream identification
Definition: ac3.h:188
int channels
number of audio channels
Definition: avcodec.h:2439
int sample_rate
sample frequency, in Hz
Definition: ac3dec.h:81
int center_mix_level
Center mix level index.
Definition: ac3dec.h:92
uint8_t channels
Definition: ac3.h:202
int output_mode
output channel configuration
Definition: ac3dec.h:164
static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
Generate transform coefficients for each coupled channel in the coupling range using the coupling coe...
Definition: ac3dec.c:461
static const float gain_levels_lfe[32]
Adjustments in dB gain (LFE, +10 to -21 dB)
Definition: ac3dec.c:86
#define LEVEL_MINUS_6DB
Definition: ac3.h:108
void(* downmix)(float **samples, float(*matrix)[2], int out_ch, int in_ch, int len)
Definition: ac3dsp.h:135
int frame_size
current frame size, in bytes
Definition: ac3dec.h:79
static int symmetric_dequant(int code, int levels)
Symmetrical Dequantization reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantizati...
Definition: ac3dec.c:115
#define av_freep(p)
static void ac3_upmix_delay(AC3DecodeContext *s)
Upmix delay samples from stereo to original channel layout.
Definition: ac3dec.c:714
const uint8_t ff_ac3_rematrix_band_tab[5]
Table of bin locations for rematrixing bands reference: Section 7.5.2 Rematrixing : Frequency Band De...
Definition: ac3tab.c:141
signed 16 bits, planar
Definition: samplefmt.h:67
const uint8_t ff_eac3_hebap_tab[64]
Definition: ac3dec_data.c:46
int dolby_surround_ex_mode
dolby surround ex mode (dsurexmod)
Definition: ac3dec.h:102
const uint8_t ff_ac3_dec_channel_map[8][2][6]
Table to remap channels from AC-3 order to SMPTE order.
Definition: ac3tab.c:122
AVMatrixEncoding
int num_blocks
number of audio blocks
Definition: ac3.h:192
uint8_t channel_mode
Definition: ac3.h:185
AVLFG dith_state
for dither generation
Definition: ac3dec.h:209
int cpl_strategy_exists[AC3_MAX_BLOCKS]
coupling strategy exists (cplstre)
Definition: ac3dec.h:126
static av_cold int ac3_decode_init(AVCodecContext *avctx)
AVCodec initialization.
Definition: ac3dec.c:184
const uint16_t ff_ac3_db_per_bit_tab[4]
Definition: ac3tab.c:292
int bitstream_id
bitstream id (bsid)
Definition: ac3dec.h:83
#define AV_CH_LAYOUT_MONO
uint64_t request_channel_layout
Request decoder to use this channel layout if it can (0 for default)
Definition: avcodec.h:2496
static void remove_dithering(AC3DecodeContext *s)
Remove random dithering from coupling range coefficients with zero-bit mantissas for coupled channels...
Definition: ac3dec.c:583
This structure stores compressed data.
Definition: avcodec.h:1578
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:241
#define EXP_D45
Definition: ac3.h:52
int channel_mode
channel mode (acmod)
Definition: ac3dec.h:85
float ff_ac3_heavy_dynamic_range_tab[256]
Definition: ac3dec.c:69
for(j=16;j >0;--j)
int spx_dst_start_freq
spx starting frequency bin for copying (copystartmant) the copy region ends at the start of the spx r...
Definition: ac3dec.h:144
#define AC3_RENAME(x)
Definition: ac3.h:86
int skip_syntax
skip field syntax enabled (skipflde)
Definition: ac3dec.h:121
enum AVDownmixType preferred_downmix_type
Type of downmix preferred by the mastering engineer.
Definition: downmix_info.h:62
int b2
Definition: ac3dec.c:494
int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
decoded exponents
Definition: ac3dec.h:187
#define MULH
Definition: mathops.h:42