FFmpeg  4.1.4
eac3dec.c
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1 /*
2  * E-AC-3 decoder
3  * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
4  * Copyright (c) 2008 Justin Ruggles
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /*
24  * There are several features of E-AC-3 that this decoder does not yet support.
25  *
26  * Enhanced Coupling
27  * No known samples exist. If any ever surface, this feature should not be
28  * too difficult to implement.
29  *
30  * Reduced Sample Rates
31  * No known samples exist. The spec also does not give clear information
32  * on how this is to be implemented.
33  *
34  * Dependent Streams
35  * Only the independent stream is currently decoded. Any dependent
36  * streams are skipped. We have only come across two examples of this, and
37  * they are both just test streams, one for HD-DVD and the other for
38  * Blu-ray.
39  *
40  * Transient Pre-noise Processing
41  * This is side information which a decoder should use to reduce artifacts
42  * caused by transients. There are samples which are known to have this
43  * information, but this decoder currently ignores it.
44  */
45 
46 
47 #include "avcodec.h"
48 #include "internal.h"
49 #include "aac_ac3_parser.h"
50 #include "ac3.h"
51 #include "ac3dec.h"
52 #include "ac3dec_data.h"
53 #include "eac3_data.h"
54 
55 /** gain adaptive quantization mode */
56 typedef enum {
61 } EAC3GaqMode;
62 
63 #define EAC3_SR_CODE_REDUCED 3
64 
65 static void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
66 {
67  int bin, bnd, ch, i;
68  uint8_t wrapflag[SPX_MAX_BANDS]={1,0,}, num_copy_sections, copy_sizes[SPX_MAX_BANDS];
69  float rms_energy[SPX_MAX_BANDS];
70 
71  /* Set copy index mapping table. Set wrap flags to apply a notch filter at
72  wrap points later on. */
73  bin = s->spx_dst_start_freq;
74  num_copy_sections = 0;
75  for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
76  int copysize;
77  int bandsize = s->spx_band_sizes[bnd];
78  if (bin + bandsize > s->spx_src_start_freq) {
79  copy_sizes[num_copy_sections++] = bin - s->spx_dst_start_freq;
80  bin = s->spx_dst_start_freq;
81  wrapflag[bnd] = 1;
82  }
83  for (i = 0; i < bandsize; i += copysize) {
84  if (bin == s->spx_src_start_freq) {
85  copy_sizes[num_copy_sections++] = bin - s->spx_dst_start_freq;
86  bin = s->spx_dst_start_freq;
87  }
88  copysize = FFMIN(bandsize - i, s->spx_src_start_freq - bin);
89  bin += copysize;
90  }
91  }
92  copy_sizes[num_copy_sections++] = bin - s->spx_dst_start_freq;
93 
94  for (ch = 1; ch <= s->fbw_channels; ch++) {
95  if (!s->channel_uses_spx[ch])
96  continue;
97 
98  /* Copy coeffs from normal bands to extension bands */
99  bin = s->spx_src_start_freq;
100  for (i = 0; i < num_copy_sections; i++) {
101  memcpy(&s->transform_coeffs[ch][bin],
102  &s->transform_coeffs[ch][s->spx_dst_start_freq],
103  copy_sizes[i]*sizeof(INTFLOAT));
104  bin += copy_sizes[i];
105  }
106 
107  /* Calculate RMS energy for each SPX band. */
108  bin = s->spx_src_start_freq;
109  for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
110  int bandsize = s->spx_band_sizes[bnd];
111  float accum = 0.0f;
112  for (i = 0; i < bandsize; i++) {
113  float coeff = s->transform_coeffs[ch][bin++];
114  accum += coeff * coeff;
115  }
116  rms_energy[bnd] = sqrtf(accum / bandsize);
117  }
118 
119  /* Apply a notch filter at transitions between normal and extension
120  bands and at all wrap points. */
121  if (s->spx_atten_code[ch] >= 0) {
122  const float *atten_tab = ff_eac3_spx_atten_tab[s->spx_atten_code[ch]];
123  bin = s->spx_src_start_freq - 2;
124  for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
125  if (wrapflag[bnd]) {
126  INTFLOAT *coeffs = &s->transform_coeffs[ch][bin];
127  coeffs[0] *= atten_tab[0];
128  coeffs[1] *= atten_tab[1];
129  coeffs[2] *= atten_tab[2];
130  coeffs[3] *= atten_tab[1];
131  coeffs[4] *= atten_tab[0];
132  }
133  bin += s->spx_band_sizes[bnd];
134  }
135  }
136 
137  /* Apply noise-blended coefficient scaling based on previously
138  calculated RMS energy, blending factors, and SPX coordinates for
139  each band. */
140  bin = s->spx_src_start_freq;
141  for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
142  float nscale = s->spx_noise_blend[ch][bnd] * rms_energy[bnd] * (1.0f / INT32_MIN);
143  float sscale = s->spx_signal_blend[ch][bnd];
144 #if USE_FIXED
145  // spx_noise_blend and spx_signal_blend are both FP.23
146  nscale *= 1.0 / (1<<23);
147  sscale *= 1.0 / (1<<23);
148 #endif
149  for (i = 0; i < s->spx_band_sizes[bnd]; i++) {
150  float noise = nscale * (int32_t)av_lfg_get(&s->dith_state);
151  s->transform_coeffs[ch][bin] *= sscale;
152  s->transform_coeffs[ch][bin++] += noise;
153  }
154  }
155  }
156 }
157 
158 
159 /** lrint(M_SQRT2*cos(2*M_PI/12)*(1<<23)) */
160 #define COEFF_0 10273905LL
161 
162 /** lrint(M_SQRT2*cos(0*M_PI/12)*(1<<23)) = lrint(M_SQRT2*(1<<23)) */
163 #define COEFF_1 11863283LL
164 
165 /** lrint(M_SQRT2*cos(5*M_PI/12)*(1<<23)) */
166 #define COEFF_2 3070444LL
167 
168 /**
169  * Calculate 6-point IDCT of the pre-mantissas.
170  * All calculations are 24-bit fixed-point.
171  */
172 static void idct6(int pre_mant[6])
173 {
174  int tmp;
175  int even0, even1, even2, odd0, odd1, odd2;
176 
177  odd1 = pre_mant[1] - pre_mant[3] - pre_mant[5];
178 
179  even2 = ( pre_mant[2] * COEFF_0) >> 23;
180  tmp = ( pre_mant[4] * COEFF_1) >> 23;
181  odd0 = ((pre_mant[1] + pre_mant[5]) * COEFF_2) >> 23;
182 
183  even0 = pre_mant[0] + (tmp >> 1);
184  even1 = pre_mant[0] - tmp;
185 
186  tmp = even0;
187  even0 = tmp + even2;
188  even2 = tmp - even2;
189 
190  tmp = odd0;
191  odd0 = tmp + pre_mant[1] + pre_mant[3];
192  odd2 = tmp + pre_mant[5] - pre_mant[3];
193 
194  pre_mant[0] = even0 + odd0;
195  pre_mant[1] = even1 + odd1;
196  pre_mant[2] = even2 + odd2;
197  pre_mant[3] = even2 - odd2;
198  pre_mant[4] = even1 - odd1;
199  pre_mant[5] = even0 - odd0;
200 }
201 
202 static void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
203 {
204  int bin, blk, gs;
205  int end_bap, gaq_mode;
206  GetBitContext *gbc = &s->gbc;
207  int gaq_gain[AC3_MAX_COEFS];
208 
209  gaq_mode = get_bits(gbc, 2);
210  end_bap = (gaq_mode < 2) ? 12 : 17;
211 
212  /* if GAQ gain is used, decode gain codes for bins with hebap between
213  8 and end_bap */
214  gs = 0;
215  if (gaq_mode == EAC3_GAQ_12 || gaq_mode == EAC3_GAQ_14) {
216  /* read 1-bit GAQ gain codes */
217  for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
218  if (s->bap[ch][bin] > 7 && s->bap[ch][bin] < end_bap)
219  gaq_gain[gs++] = get_bits1(gbc) << (gaq_mode-1);
220  }
221  } else if (gaq_mode == EAC3_GAQ_124) {
222  /* read 1.67-bit GAQ gain codes (3 codes in 5 bits) */
223  int gc = 2;
224  for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
225  if (s->bap[ch][bin] > 7 && s->bap[ch][bin] < 17) {
226  if (gc++ == 2) {
227  int group_code = get_bits(gbc, 5);
228  if (group_code > 26) {
229  av_log(s->avctx, AV_LOG_WARNING, "GAQ gain group code out-of-range\n");
230  group_code = 26;
231  }
232  gaq_gain[gs++] = ff_ac3_ungroup_3_in_5_bits_tab[group_code][0];
233  gaq_gain[gs++] = ff_ac3_ungroup_3_in_5_bits_tab[group_code][1];
234  gaq_gain[gs++] = ff_ac3_ungroup_3_in_5_bits_tab[group_code][2];
235  gc = 0;
236  }
237  }
238  }
239  }
240 
241  gs=0;
242  for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
243  int hebap = s->bap[ch][bin];
244  int bits = ff_eac3_bits_vs_hebap[hebap];
245  if (!hebap) {
246  /* zero-mantissa dithering */
247  for (blk = 0; blk < 6; blk++) {
248  s->pre_mantissa[ch][bin][blk] = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
249  }
250  } else if (hebap < 8) {
251  /* Vector Quantization */
252  int v = get_bits(gbc, bits);
253  for (blk = 0; blk < 6; blk++) {
254  s->pre_mantissa[ch][bin][blk] = ff_eac3_mantissa_vq[hebap][v][blk] * (1 << 8);
255  }
256  } else {
257  /* Gain Adaptive Quantization */
258  int gbits, log_gain;
259  if (gaq_mode != EAC3_GAQ_NO && hebap < end_bap) {
260  log_gain = gaq_gain[gs++];
261  } else {
262  log_gain = 0;
263  }
264  gbits = bits - log_gain;
265 
266  for (blk = 0; blk < 6; blk++) {
267  int mant = get_sbits(gbc, gbits);
268  if (log_gain && mant == -(1 << (gbits-1))) {
269  /* large mantissa */
270  int b;
271  int mbits = bits - (2 - log_gain);
272  mant = get_sbits(gbc, mbits);
273  mant = ((unsigned)mant) << (23 - (mbits - 1));
274  /* remap mantissa value to correct for asymmetric quantization */
275  if (mant >= 0)
276  b = 1 << (23 - log_gain);
277  else
278  b = ff_eac3_gaq_remap_2_4_b[hebap-8][log_gain-1] * (1 << 8);
279  mant += ((ff_eac3_gaq_remap_2_4_a[hebap-8][log_gain-1] * (int64_t)mant) >> 15) + b;
280  } else {
281  /* small mantissa, no GAQ, or Gk=1 */
282  mant *= (1 << 24 - bits);
283  if (!log_gain) {
284  /* remap mantissa value for no GAQ or Gk=1 */
285  mant += (ff_eac3_gaq_remap_1[hebap-8] * (int64_t)mant) >> 15;
286  }
287  }
288  s->pre_mantissa[ch][bin][blk] = mant;
289  }
290  }
291  idct6(s->pre_mantissa[ch][bin]);
292  }
293 }
294 
295 static int ff_eac3_parse_header(AC3DecodeContext *s)
296 {
297  int i, blk, ch;
298  int ac3_exponent_strategy, parse_aht_info, parse_spx_atten_data;
299  int parse_transient_proc_info;
300  int num_cpl_blocks;
301  GetBitContext *gbc = &s->gbc;
302 
303  /* An E-AC-3 stream can have multiple independent streams which the
304  application can select from. each independent stream can also contain
305  dependent streams which are used to add or replace channels. */
306  if (s->frame_type == EAC3_FRAME_TYPE_RESERVED) {
307  av_log(s->avctx, AV_LOG_ERROR, "Reserved frame type\n");
309  }
310 
311  /* The substream id indicates which substream this frame belongs to. each
312  independent stream has its own substream id, and the dependent streams
313  associated to an independent stream have matching substream id's. */
314  if (s->substreamid) {
315  /* only decode substream with id=0. skip any additional substreams. */
316  if (!s->eac3_subsbtreamid_found) {
317  s->eac3_subsbtreamid_found = 1;
318  avpriv_request_sample(s->avctx, "Additional substreams");
319  }
321  }
322 
323  if (s->bit_alloc_params.sr_code == EAC3_SR_CODE_REDUCED) {
324  /* The E-AC-3 specification does not tell how to handle reduced sample
325  rates in bit allocation. The best assumption would be that it is
326  handled like AC-3 DolbyNet, but we cannot be sure until we have a
327  sample which utilizes this feature. */
328  avpriv_request_sample(s->avctx, "Reduced sampling rate");
329  return AVERROR_PATCHWELCOME;
330  }
331  skip_bits(gbc, 5); // skip bitstream id
332 
333  /* volume control params */
334  for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
335  s->dialog_normalization[i] = -get_bits(gbc, 5);
336  if (s->dialog_normalization[i] == 0) {
337  s->dialog_normalization[i] = -31;
338  }
339  if (s->target_level != 0) {
340  s->level_gain[i] = powf(2.0f,
341  (float)(s->target_level - s->dialog_normalization[i])/6.0f);
342  }
343  s->compression_exists[i] = get_bits1(gbc);
344  if (s->compression_exists[i]) {
345  s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(get_bits(gbc, 8));
346  }
347  }
348 
349  /* dependent stream channel map */
350  if (s->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
351  if (get_bits1(gbc)) {
352  int64_t channel_layout = 0;
353  int channel_map = get_bits(gbc, 16);
354  av_log(s->avctx, AV_LOG_DEBUG, "channel_map: %0X\n", channel_map);
355 
356  for (i = 0; i < 16; i++)
357  if (channel_map & (1 << (EAC3_MAX_CHANNELS - i - 1)))
358  channel_layout |= ff_eac3_custom_channel_map_locations[i][1];
359 
360  if (av_popcount64(channel_layout) > EAC3_MAX_CHANNELS) {
361  return AVERROR_INVALIDDATA;
362  }
363  s->channel_map = channel_map;
364  }
365  }
366 
367  /* mixing metadata */
368  if (get_bits1(gbc)) {
369  /* center and surround mix levels */
370  if (s->channel_mode > AC3_CHMODE_STEREO) {
371  s->preferred_downmix = get_bits(gbc, 2);
372  if (s->channel_mode & 1) {
373  /* if three front channels exist */
374  s->center_mix_level_ltrt = get_bits(gbc, 3);
375  s->center_mix_level = get_bits(gbc, 3);
376  }
377  if (s->channel_mode & 4) {
378  /* if a surround channel exists */
379  s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
380  s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
381  }
382  }
383 
384  /* lfe mix level */
385  if (s->lfe_on && (s->lfe_mix_level_exists = get_bits1(gbc))) {
386  s->lfe_mix_level = get_bits(gbc, 5);
387  }
388 
389  /* info for mixing with other streams and substreams */
390  if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
391  for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
392  // TODO: apply program scale factor
393  if (get_bits1(gbc)) {
394  skip_bits(gbc, 6); // skip program scale factor
395  }
396  }
397  if (get_bits1(gbc)) {
398  skip_bits(gbc, 6); // skip external program scale factor
399  }
400  /* skip mixing parameter data */
401  switch(get_bits(gbc, 2)) {
402  case 1: skip_bits(gbc, 5); break;
403  case 2: skip_bits(gbc, 12); break;
404  case 3: {
405  int mix_data_size = (get_bits(gbc, 5) + 2) << 3;
406  skip_bits_long(gbc, mix_data_size);
407  break;
408  }
409  }
410  /* skip pan information for mono or dual mono source */
411  if (s->channel_mode < AC3_CHMODE_STEREO) {
412  for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
413  if (get_bits1(gbc)) {
414  /* note: this is not in the ATSC A/52B specification
415  reference: ETSI TS 102 366 V1.1.1
416  section: E.1.3.1.25 */
417  skip_bits(gbc, 8); // skip pan mean direction index
418  skip_bits(gbc, 6); // skip reserved paninfo bits
419  }
420  }
421  }
422  /* skip mixing configuration information */
423  if (get_bits1(gbc)) {
424  for (blk = 0; blk < s->num_blocks; blk++) {
425  if (s->num_blocks == 1 || get_bits1(gbc)) {
426  skip_bits(gbc, 5);
427  }
428  }
429  }
430  }
431  }
432 
433  /* informational metadata */
434  if (get_bits1(gbc)) {
435  s->bitstream_mode = get_bits(gbc, 3);
436  skip_bits(gbc, 2); // skip copyright bit and original bitstream bit
437  if (s->channel_mode == AC3_CHMODE_STEREO) {
438  s->dolby_surround_mode = get_bits(gbc, 2);
439  s->dolby_headphone_mode = get_bits(gbc, 2);
440  }
441  if (s->channel_mode >= AC3_CHMODE_2F2R) {
442  s->dolby_surround_ex_mode = get_bits(gbc, 2);
443  }
444  for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
445  if (get_bits1(gbc)) {
446  skip_bits(gbc, 8); // skip mix level, room type, and A/D converter type
447  }
448  }
449  if (s->bit_alloc_params.sr_code != EAC3_SR_CODE_REDUCED) {
450  skip_bits1(gbc); // skip source sample rate code
451  }
452  }
453 
454  /* converter synchronization flag
455  If frames are less than six blocks, this bit should be turned on
456  once every 6 blocks to indicate the start of a frame set.
457  reference: RFC 4598, Section 2.1.3 Frame Sets */
458  if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && s->num_blocks != 6) {
459  skip_bits1(gbc); // skip converter synchronization flag
460  }
461 
462  /* original frame size code if this stream was converted from AC-3 */
463  if (s->frame_type == EAC3_FRAME_TYPE_AC3_CONVERT &&
464  (s->num_blocks == 6 || get_bits1(gbc))) {
465  skip_bits(gbc, 6); // skip frame size code
466  }
467 
468  /* additional bitstream info */
469  if (get_bits1(gbc)) {
470  int addbsil = get_bits(gbc, 6);
471  for (i = 0; i < addbsil + 1; i++) {
472  skip_bits(gbc, 8); // skip additional bit stream info
473  }
474  }
475 
476  /* audio frame syntax flags, strategy data, and per-frame data */
477 
478  if (s->num_blocks == 6) {
479  ac3_exponent_strategy = get_bits1(gbc);
480  parse_aht_info = get_bits1(gbc);
481  } else {
482  /* less than 6 blocks, so use AC-3-style exponent strategy syntax, and
483  do not use AHT */
484  ac3_exponent_strategy = 1;
485  parse_aht_info = 0;
486  }
487 
488  s->snr_offset_strategy = get_bits(gbc, 2);
489  parse_transient_proc_info = get_bits1(gbc);
490 
491  s->block_switch_syntax = get_bits1(gbc);
492  if (!s->block_switch_syntax)
493  memset(s->block_switch, 0, sizeof(s->block_switch));
494 
495  s->dither_flag_syntax = get_bits1(gbc);
496  if (!s->dither_flag_syntax) {
497  for (ch = 1; ch <= s->fbw_channels; ch++)
498  s->dither_flag[ch] = 1;
499  }
500  s->dither_flag[CPL_CH] = s->dither_flag[s->lfe_ch] = 0;
501 
502  s->bit_allocation_syntax = get_bits1(gbc);
503  if (!s->bit_allocation_syntax) {
504  /* set default bit allocation parameters */
505  s->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[2];
506  s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[1];
507  s->bit_alloc_params.slow_gain = ff_ac3_slow_gain_tab [1];
508  s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[2];
509  s->bit_alloc_params.floor = ff_ac3_floor_tab [7];
510  }
511 
512  s->fast_gain_syntax = get_bits1(gbc);
513  s->dba_syntax = get_bits1(gbc);
514  s->skip_syntax = get_bits1(gbc);
515  parse_spx_atten_data = get_bits1(gbc);
516 
517  /* coupling strategy occurrence and coupling use per block */
518  num_cpl_blocks = 0;
519  if (s->channel_mode > 1) {
520  for (blk = 0; blk < s->num_blocks; blk++) {
521  s->cpl_strategy_exists[blk] = (!blk || get_bits1(gbc));
522  if (s->cpl_strategy_exists[blk]) {
523  s->cpl_in_use[blk] = get_bits1(gbc);
524  } else {
525  s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
526  }
527  num_cpl_blocks += s->cpl_in_use[blk];
528  }
529  } else {
530  memset(s->cpl_in_use, 0, sizeof(s->cpl_in_use));
531  }
532 
533  /* exponent strategy data */
534  if (ac3_exponent_strategy) {
535  /* AC-3-style exponent strategy syntax */
536  for (blk = 0; blk < s->num_blocks; blk++) {
537  for (ch = !s->cpl_in_use[blk]; ch <= s->fbw_channels; ch++) {
538  s->exp_strategy[blk][ch] = get_bits(gbc, 2);
539  }
540  }
541  } else {
542  /* LUT-based exponent strategy syntax */
543  for (ch = !((s->channel_mode > 1) && num_cpl_blocks); ch <= s->fbw_channels; ch++) {
544  int frmchexpstr = get_bits(gbc, 5);
545  for (blk = 0; blk < 6; blk++) {
546  s->exp_strategy[blk][ch] = ff_eac3_frm_expstr[frmchexpstr][blk];
547  }
548  }
549  }
550  /* LFE exponent strategy */
551  if (s->lfe_on) {
552  for (blk = 0; blk < s->num_blocks; blk++) {
553  s->exp_strategy[blk][s->lfe_ch] = get_bits1(gbc);
554  }
555  }
556  /* original exponent strategies if this stream was converted from AC-3 */
557  if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT &&
558  (s->num_blocks == 6 || get_bits1(gbc))) {
559  skip_bits(gbc, 5 * s->fbw_channels); // skip converter channel exponent strategy
560  }
561 
562  /* determine which channels use AHT */
563  if (parse_aht_info) {
564  /* For AHT to be used, all non-zero blocks must reuse exponents from
565  the first block. Furthermore, for AHT to be used in the coupling
566  channel, all blocks must use coupling and use the same coupling
567  strategy. */
568  s->channel_uses_aht[CPL_CH]=0;
569  for (ch = (num_cpl_blocks != 6); ch <= s->channels; ch++) {
570  int use_aht = 1;
571  for (blk = 1; blk < 6; blk++) {
572  if ((s->exp_strategy[blk][ch] != EXP_REUSE) ||
573  (!ch && s->cpl_strategy_exists[blk])) {
574  use_aht = 0;
575  break;
576  }
577  }
578  s->channel_uses_aht[ch] = use_aht && get_bits1(gbc);
579  }
580  } else {
581  memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
582  }
583 
584  /* per-frame SNR offset */
585  if (!s->snr_offset_strategy) {
586  int csnroffst = (get_bits(gbc, 6) - 15) << 4;
587  int snroffst = (csnroffst + get_bits(gbc, 4)) << 2;
588  for (ch = 0; ch <= s->channels; ch++)
589  s->snr_offset[ch] = snroffst;
590  }
591 
592  /* transient pre-noise processing data */
593  if (parse_transient_proc_info) {
594  for (ch = 1; ch <= s->fbw_channels; ch++) {
595  if (get_bits1(gbc)) { // channel in transient processing
596  skip_bits(gbc, 10); // skip transient processing location
597  skip_bits(gbc, 8); // skip transient processing length
598  }
599  }
600  }
601 
602  /* spectral extension attenuation data */
603  for (ch = 1; ch <= s->fbw_channels; ch++) {
604  if (parse_spx_atten_data && get_bits1(gbc)) {
605  s->spx_atten_code[ch] = get_bits(gbc, 5);
606  } else {
607  s->spx_atten_code[ch] = -1;
608  }
609  }
610 
611  /* block start information */
612  if (s->num_blocks > 1 && get_bits1(gbc)) {
613  /* reference: Section E2.3.2.27
614  nblkstrtbits = (numblks - 1) * (4 + ceiling(log2(words_per_frame)))
615  The spec does not say what this data is or what it's used for.
616  It is likely the offset of each block within the frame. */
617  int block_start_bits = (s->num_blocks-1) * (4 + av_log2(s->frame_size-2));
618  skip_bits_long(gbc, block_start_bits);
619  avpriv_request_sample(s->avctx, "Block start info");
620  }
621 
622  /* syntax state initialization */
623  for (ch = 1; ch <= s->fbw_channels; ch++) {
624  s->first_spx_coords[ch] = 1;
625  s->first_cpl_coords[ch] = 1;
626  }
627  s->first_cpl_leak = 1;
628 
629  return 0;
630 }
EAC3GaqMode
gain adaptive quantization mode
Definition: eac3dec.c:56
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
const uint8_t ff_ac3_slow_decay_tab[4]
Definition: ac3tab.c:280
const float ff_eac3_spx_atten_tab[32][3]
Table E.25: Spectral Extension Attenuation Table ff_eac3_spx_atten_tab[code][bin]=pow(2.0,(bin+1)*(code+1)/-15.0);.
Definition: eac3_data.c:1101
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:381
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
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
static int ff_eac3_parse_header(AC3DecodeContext *s)
Definition: eac3dec.c:295
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition: get_bits.h:293
#define AC3_MAX_COEFS
Definition: ac3.h:35
uint8_t pi<< 24) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_U8,(uint64_t)((*(const uint8_t *) pi - 0x80U))<< 56) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8,(*(const uint8_t *) pi - 0x80) *(1.0f/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8,(*(const uint8_t *) pi - 0x80) *(1.0/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16,(*(const int16_t *) pi >>8)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S16,(uint64_t)(*(const int16_t *) pi)<< 48) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, *(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, *(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32,(*(const int32_t *) pi >>24)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S32,(uint64_t)(*(const int32_t *) pi)<< 32) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, *(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, *(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S64,(*(const int64_t *) pi >>56)+0x80) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S64, *(const int64_t *) pi *(1.0f/(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S64, *(const int64_t *) pi *(1.0/(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_FLT, llrintf(*(const float *) pi *(INT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_DBL, llrint(*(const double *) pi *(INT64_C(1)<< 63))) #define FMT_PAIR_FUNC(out, in) static conv_func_type *const fmt_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), };static void cpy1(uint8_t **dst, const uint8_t **src, int len){ memcpy(*dst, *src, len);} static void cpy2(uint8_t **dst, const uint8_t **src, int len){ memcpy(*dst, *src, 2 *len);} static void cpy4(uint8_t **dst, const uint8_t **src, int len){ memcpy(*dst, *src, 4 *len);} static void cpy8(uint8_t **dst, const uint8_t **src, int len){ memcpy(*dst, *src, 8 *len);} AudioConvert *swri_audio_convert_alloc(enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, const int *ch_map, int flags) { 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) return NULL;ctx=av_mallocz(sizeof(*ctx));if(!ctx) return NULL;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)){ case 1:ctx->simd_f=cpy1;break;case 2:ctx->simd_f=cpy2;break;case 4:ctx->simd_f=cpy4;break;case 8:ctx->simd_f=cpy8;break;} } if(HAVE_X86ASM &&HAVE_MMX) 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);return ctx;} void swri_audio_convert_free(AudioConvert **ctx) { av_freep(ctx);} int swri_audio_convert(AudioConvert *ctx, AudioData *out, AudioData *in, int len) { int ch;int off=0;const int os=(out->planar ? 1 :out->ch_count) *out->bps;unsigned misaligned=0;av_assert0(ctx->channels==out->ch_count);if(ctx->in_simd_align_mask) { int planes=in->planar ? in->ch_count :1;unsigned m=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) { int planes=out->planar ? out->ch_count :1;unsigned m=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){ int planes=out->planar ? out->ch_count :1;for(ch=0;ch< planes;ch++){ ctx->simd_f(out-> ch ch
Definition: audioconvert.c:56
const char * b
Definition: vf_curves.c:116
#define EXP_REUSE
Definition: ac3.h:48
const uint16_t ff_ac3_slow_gain_tab[4]
Definition: ac3tab.c:288
#define blk(i)
Definition: sha.c:185
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:361
float INTFLOAT
Definition: aac_defines.h:86
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
#define COEFF_0
lrint(M_SQRT2*cos(2*M_PI/12)*(1<<23))
Definition: eac3dec.c:160
uint8_t
#define f(width, name)
Definition: cbs_vp9.c:255
#define av_log(a,...)
static void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
Definition: eac3dec.c:202
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
const uint8_t ff_ac3_fast_decay_tab[4]
Definition: ac3tab.c:284
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
#define COEFF_2
lrint(M_SQRT2*cos(5*M_PI/12)*(1<<23))
Definition: eac3dec.c:166
#define EAC3_SR_CODE_REDUCED
Definition: eac3dec.c:63
#define powf(x, y)
Definition: libm.h:50
static void idct6(int pre_mant[6])
Calculate 6-point IDCT of the pre-mantissas.
Definition: eac3dec.c:172
#define AC3_HEAVY_RANGE(x)
Definition: ac3.h:91
#define FFMIN(a, b)
Definition: common.h:96
int32_t
const int16_t ff_eac3_gaq_remap_1[12]
Table E3.6, Gk=1 No gain (Gk=1) inverse quantization, remapping scale factors ff_eac3_gaq_remap[hebap...
Definition: eac3_data.c:40
#define s(width, name)
Definition: cbs_vp9.c:257
const int16_t ff_eac3_gaq_remap_2_4_a[9][2]
Table E3.6, Gk=2 & Gk=4, A Large mantissa inverse quantization, remapping scale factors ff_eac3_gaq_r...
Definition: eac3_data.c:49
#define COEFF_1
lrint(M_SQRT2*cos(0*M_PI/12)*(1<<23)) = lrint(M_SQRT2*(1<<23))
Definition: eac3dec.c:163
const uint8_t ff_eac3_bits_vs_hebap[20]
Definition: eac3_data.c:30
#define av_log2
Definition: intmath.h:83
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define CPL_CH
coupling channel index
Definition: ac3.h:33
Libavcodec external API header.
const int16_t ff_eac3_gaq_remap_2_4_b[9][2]
Table E3.6, Gk=2 & Gk=4, B Large mantissa inverse quantization, negative mantissa remapping offsets f...
Definition: eac3_data.c:66
static void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
Definition: eac3dec.c:65
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:47
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:487
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:523
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:460
const int16_t ff_ac3_floor_tab[8]
Definition: ac3tab.c:296
static int noise(AVBSFContext *ctx, AVPacket *pkt)
Definition: noise_bsf.c:38
const uint64_t ff_eac3_custom_channel_map_locations[16][2]
Definition: ac3tab.c:317
common internal api header.
const uint8_t ff_eac3_frm_expstr[32][6]
Table E2.14 Frame Exponent Strategy Combinations.
Definition: eac3_data.c:1062
#define EAC3_MAX_CHANNELS
maximum number of channels in EAC3
Definition: ac3.h:31
static const double coeff[2][5]
Definition: vf_owdenoise.c:72
const int16_t(*const [8] ff_eac3_mantissa_vq)[6]
Definition: eac3_data.c:1048
const uint16_t ff_ac3_db_per_bit_tab[4]
Definition: ac3tab.c:292
Common code between the AC-3 encoder and decoder.
static uint8_t tmp[11]
Definition: aes_ctr.c:26