FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
ac3enc.c
Go to the documentation of this file.
1 /*
2  * The simplest AC-3 encoder
3  * Copyright (c) 2000 Fabrice Bellard
4  * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
5  * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /**
25  * @file
26  * The simplest AC-3 encoder.
27  */
28 
29 #include <stdint.h>
30 
31 #include "libavutil/attributes.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/avstring.h"
35 #include "libavutil/crc.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/opt.h"
38 #include "avcodec.h"
39 #include "me_cmp.h"
40 #include "put_bits.h"
41 #include "audiodsp.h"
42 #include "ac3dsp.h"
43 #include "ac3.h"
44 #include "fft.h"
45 #include "ac3enc.h"
46 #include "eac3enc.h"
47 
48 typedef struct AC3Mant {
49  int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
50  int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
51 } AC3Mant;
52 
53 #define CMIXLEV_NUM_OPTIONS 3
54 static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
56 };
57 
58 #define SURMIXLEV_NUM_OPTIONS 3
61 };
62 
63 #define EXTMIXLEV_NUM_OPTIONS 8
67 };
68 
69 
70 /**
71  * LUT for number of exponent groups.
72  * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
73  */
74 static uint8_t exponent_group_tab[2][3][256];
75 
76 
77 /**
78  * List of supported channel layouts.
79  */
80 const uint64_t ff_ac3_channel_layouts[19] = {
91  (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
92  (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
93  (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
94  (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
95  (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
96  (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
99  0
100 };
101 
102 
103 /**
104  * LUT to select the bandwidth code based on the bit rate, sample rate, and
105  * number of full-bandwidth channels.
106  * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
107  */
108 static const uint8_t ac3_bandwidth_tab[5][3][19] = {
109 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
110 
111  { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
112  { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
113  { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
114 
115  { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
116  { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
117  { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
118 
119  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
120  { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
121  { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
122 
123  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
124  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
125  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
126 
127  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
128  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
129  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
130 };
131 
132 
133 /**
134  * LUT to select the coupling start band based on the bit rate, sample rate, and
135  * number of full-bandwidth channels. -1 = coupling off
136  * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
137  *
138  * TODO: more testing for optimal parameters.
139  * multi-channel tests at 44.1kHz and 32kHz.
140  */
141 static const int8_t ac3_coupling_start_tab[6][3][19] = {
142 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
143 
144  // 2/0
145  { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
146  { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
147  { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
148 
149  // 3/0
150  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
151  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
152  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
153 
154  // 2/1 - untested
155  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
156  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
157  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
158 
159  // 3/1
160  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
161  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
162  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
163 
164  // 2/2 - untested
165  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
166  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
167  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
168 
169  // 3/2
170  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
171  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
172  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
173 };
174 
175 
176 /**
177  * Adjust the frame size to make the average bit rate match the target bit rate.
178  * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
179  *
180  * @param s AC-3 encoder private context
181  */
183 {
184  while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
185  s->bits_written -= s->bit_rate;
186  s->samples_written -= s->sample_rate;
187  }
188  s->frame_size = s->frame_size_min +
189  2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
190  s->bits_written += s->frame_size * 8;
192 }
193 
194 
195 /**
196  * Set the initial coupling strategy parameters prior to coupling analysis.
197  *
198  * @param s AC-3 encoder private context
199  */
201 {
202  int blk, ch;
203  int got_cpl_snr;
204  int num_cpl_blocks;
205 
206  /* set coupling use flags for each block/channel */
207  /* TODO: turn coupling on/off and adjust start band based on bit usage */
208  for (blk = 0; blk < s->num_blocks; blk++) {
209  AC3Block *block = &s->blocks[blk];
210  for (ch = 1; ch <= s->fbw_channels; ch++)
211  block->channel_in_cpl[ch] = s->cpl_on;
212  }
213 
214  /* enable coupling for each block if at least 2 channels have coupling
215  enabled for that block */
216  got_cpl_snr = 0;
217  num_cpl_blocks = 0;
218  for (blk = 0; blk < s->num_blocks; blk++) {
219  AC3Block *block = &s->blocks[blk];
220  block->num_cpl_channels = 0;
221  for (ch = 1; ch <= s->fbw_channels; ch++)
222  block->num_cpl_channels += block->channel_in_cpl[ch];
223  block->cpl_in_use = block->num_cpl_channels > 1;
224  num_cpl_blocks += block->cpl_in_use;
225  if (!block->cpl_in_use) {
226  block->num_cpl_channels = 0;
227  for (ch = 1; ch <= s->fbw_channels; ch++)
228  block->channel_in_cpl[ch] = 0;
229  }
230 
231  block->new_cpl_strategy = !blk;
232  if (blk) {
233  for (ch = 1; ch <= s->fbw_channels; ch++) {
234  if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
235  block->new_cpl_strategy = 1;
236  break;
237  }
238  }
239  }
240  block->new_cpl_leak = block->new_cpl_strategy;
241 
242  if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
243  block->new_snr_offsets = 1;
244  if (block->cpl_in_use)
245  got_cpl_snr = 1;
246  } else {
247  block->new_snr_offsets = 0;
248  }
249  }
250  if (!num_cpl_blocks)
251  s->cpl_on = 0;
252 
253  /* set bandwidth for each channel */
254  for (blk = 0; blk < s->num_blocks; blk++) {
255  AC3Block *block = &s->blocks[blk];
256  for (ch = 1; ch <= s->fbw_channels; ch++) {
257  if (block->channel_in_cpl[ch])
258  block->end_freq[ch] = s->start_freq[CPL_CH];
259  else
260  block->end_freq[ch] = s->bandwidth_code * 3 + 73;
261  }
262  }
263 }
264 
265 
266 /**
267  * Apply stereo rematrixing to coefficients based on rematrixing flags.
268  *
269  * @param s AC-3 encoder private context
270  */
272 {
273  int nb_coefs;
274  int blk, bnd, i;
275  int start, end;
276  uint8_t *flags = NULL;
277 
278  if (!s->rematrixing_enabled)
279  return;
280 
281  for (blk = 0; blk < s->num_blocks; blk++) {
282  AC3Block *block = &s->blocks[blk];
283  if (block->new_rematrixing_strategy)
284  flags = block->rematrixing_flags;
285  nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
286  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
287  if (flags[bnd]) {
288  start = ff_ac3_rematrix_band_tab[bnd];
289  end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
290  for (i = start; i < end; i++) {
291  int32_t lt = block->fixed_coef[1][i];
292  int32_t rt = block->fixed_coef[2][i];
293  block->fixed_coef[1][i] = (lt + rt) >> 1;
294  block->fixed_coef[2][i] = (lt - rt) >> 1;
295  }
296  }
297  }
298  }
299 }
300 
301 
302 /*
303  * Initialize exponent tables.
304  */
306 {
307  int expstr, i, grpsize;
308 
309  for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
310  grpsize = 3 << expstr;
311  for (i = 12; i < 256; i++) {
312  exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
313  exponent_group_tab[1][expstr][i] = (i ) / grpsize;
314  }
315  }
316  /* LFE */
317  exponent_group_tab[0][0][7] = 2;
318 
319  if (CONFIG_EAC3_ENCODER && s->eac3)
321 }
322 
323 
324 /*
325  * Extract exponents from the MDCT coefficients.
326  */
328 {
329  int ch = !s->cpl_on;
330  int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
331  AC3Block *block = &s->blocks[0];
332 
333  s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
334 }
335 
336 
337 /**
338  * Exponent Difference Threshold.
339  * New exponents are sent if their SAD exceed this number.
340  */
341 #define EXP_DIFF_THRESHOLD 500
342 
343 /**
344  * Table used to select exponent strategy based on exponent reuse block interval.
345  */
346 static const uint8_t exp_strategy_reuse_tab[4][6] = {
347  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
348  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
349  { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
350  { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
351 };
352 
353 /*
354  * Calculate exponent strategies for all channels.
355  * Array arrangement is reversed to simplify the per-channel calculation.
356  */
358 {
359  int ch, blk, blk1;
360 
361  for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
362  uint8_t *exp_strategy = s->exp_strategy[ch];
363  uint8_t *exp = s->blocks[0].exp[ch];
364  int exp_diff;
365 
366  /* estimate if the exponent variation & decide if they should be
367  reused in the next frame */
368  exp_strategy[0] = EXP_NEW;
369  exp += AC3_MAX_COEFS;
370  for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
371  if (ch == CPL_CH) {
372  if (!s->blocks[blk-1].cpl_in_use) {
373  exp_strategy[blk] = EXP_NEW;
374  continue;
375  } else if (!s->blocks[blk].cpl_in_use) {
376  exp_strategy[blk] = EXP_REUSE;
377  continue;
378  }
379  } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
380  exp_strategy[blk] = EXP_NEW;
381  continue;
382  }
383  exp_diff = s->mecc.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
384  exp_strategy[blk] = EXP_REUSE;
385  if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
386  exp_strategy[blk] = EXP_NEW;
387  else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
388  exp_strategy[blk] = EXP_NEW;
389  }
390 
391  /* now select the encoding strategy type : if exponents are often
392  recoded, we use a coarse encoding */
393  blk = 0;
394  while (blk < s->num_blocks) {
395  blk1 = blk + 1;
396  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
397  blk1++;
398  exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
399  blk = blk1;
400  }
401  }
402  if (s->lfe_on) {
403  ch = s->lfe_channel;
404  s->exp_strategy[ch][0] = EXP_D15;
405  for (blk = 1; blk < s->num_blocks; blk++)
406  s->exp_strategy[ch][blk] = EXP_REUSE;
407  }
408 
409  /* for E-AC-3, determine frame exponent strategy */
410  if (CONFIG_EAC3_ENCODER && s->eac3)
412 }
413 
414 
415 /**
416  * Update the exponents so that they are the ones the decoder will decode.
417  *
418  * @param[in,out] exp array of exponents for 1 block in 1 channel
419  * @param nb_exps number of exponents in active bandwidth
420  * @param exp_strategy exponent strategy for the block
421  * @param cpl indicates if the block is in the coupling channel
422  */
423 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
424  int cpl)
425 {
426  int nb_groups, i, k;
427 
428  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
429 
430  /* for each group, compute the minimum exponent */
431  switch(exp_strategy) {
432  case EXP_D25:
433  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
434  uint8_t exp_min = exp[k];
435  if (exp[k+1] < exp_min)
436  exp_min = exp[k+1];
437  exp[i-cpl] = exp_min;
438  k += 2;
439  }
440  break;
441  case EXP_D45:
442  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
443  uint8_t exp_min = exp[k];
444  if (exp[k+1] < exp_min)
445  exp_min = exp[k+1];
446  if (exp[k+2] < exp_min)
447  exp_min = exp[k+2];
448  if (exp[k+3] < exp_min)
449  exp_min = exp[k+3];
450  exp[i-cpl] = exp_min;
451  k += 4;
452  }
453  break;
454  }
455 
456  /* constraint for DC exponent */
457  if (!cpl && exp[0] > 15)
458  exp[0] = 15;
459 
460  /* decrease the delta between each groups to within 2 so that they can be
461  differentially encoded */
462  for (i = 1; i <= nb_groups; i++)
463  exp[i] = FFMIN(exp[i], exp[i-1] + 2);
464  i--;
465  while (--i >= 0)
466  exp[i] = FFMIN(exp[i], exp[i+1] + 2);
467 
468  if (cpl)
469  exp[-1] = exp[0] & ~1;
470 
471  /* now we have the exponent values the decoder will see */
472  switch (exp_strategy) {
473  case EXP_D25:
474  for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
475  uint8_t exp1 = exp[i-cpl];
476  exp[k--] = exp1;
477  exp[k--] = exp1;
478  }
479  break;
480  case EXP_D45:
481  for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
482  exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
483  k -= 4;
484  }
485  break;
486  }
487 }
488 
489 
490 /*
491  * Encode exponents from original extracted form to what the decoder will see.
492  * This copies and groups exponents based on exponent strategy and reduces
493  * deltas between adjacent exponent groups so that they can be differentially
494  * encoded.
495  */
497 {
498  int blk, blk1, ch, cpl;
499  uint8_t *exp, *exp_strategy;
500  int nb_coefs, num_reuse_blocks;
501 
502  for (ch = !s->cpl_on; ch <= s->channels; ch++) {
503  exp = s->blocks[0].exp[ch] + s->start_freq[ch];
504  exp_strategy = s->exp_strategy[ch];
505 
506  cpl = (ch == CPL_CH);
507  blk = 0;
508  while (blk < s->num_blocks) {
509  AC3Block *block = &s->blocks[blk];
510  if (cpl && !block->cpl_in_use) {
511  exp += AC3_MAX_COEFS;
512  blk++;
513  continue;
514  }
515  nb_coefs = block->end_freq[ch] - s->start_freq[ch];
516  blk1 = blk + 1;
517 
518  /* count the number of EXP_REUSE blocks after the current block
519  and set exponent reference block numbers */
520  s->exp_ref_block[ch][blk] = blk;
521  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
522  s->exp_ref_block[ch][blk1] = blk;
523  blk1++;
524  }
525  num_reuse_blocks = blk1 - blk - 1;
526 
527  /* for the EXP_REUSE case we select the min of the exponents */
528  s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
529  AC3_MAX_COEFS);
530 
531  encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
532 
533  exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
534  blk = blk1;
535  }
536  }
537 
538  /* reference block numbers have been changed, so reset ref_bap_set */
539  s->ref_bap_set = 0;
540 }
541 
542 
543 /*
544  * Count exponent bits based on bandwidth, coupling, and exponent strategies.
545  */
547 {
548  int blk, ch;
549  int nb_groups, bit_count;
550 
551  bit_count = 0;
552  for (blk = 0; blk < s->num_blocks; blk++) {
553  AC3Block *block = &s->blocks[blk];
554  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
555  int exp_strategy = s->exp_strategy[ch][blk];
556  int cpl = (ch == CPL_CH);
557  int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
558 
559  if (exp_strategy == EXP_REUSE)
560  continue;
561 
562  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
563  bit_count += 4 + (nb_groups * 7);
564  }
565  }
566 
567  return bit_count;
568 }
569 
570 
571 /**
572  * Group exponents.
573  * 3 delta-encoded exponents are in each 7-bit group. The number of groups
574  * varies depending on exponent strategy and bandwidth.
575  *
576  * @param s AC-3 encoder private context
577  */
579 {
580  int blk, ch, i, cpl;
581  int group_size, nb_groups;
582  uint8_t *p;
583  int delta0, delta1, delta2;
584  int exp0, exp1;
585 
586  for (blk = 0; blk < s->num_blocks; blk++) {
587  AC3Block *block = &s->blocks[blk];
588  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
589  int exp_strategy = s->exp_strategy[ch][blk];
590  if (exp_strategy == EXP_REUSE)
591  continue;
592  cpl = (ch == CPL_CH);
593  group_size = exp_strategy + (exp_strategy == EXP_D45);
594  nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
595  p = block->exp[ch] + s->start_freq[ch] - cpl;
596 
597  /* DC exponent */
598  exp1 = *p++;
599  block->grouped_exp[ch][0] = exp1;
600 
601  /* remaining exponents are delta encoded */
602  for (i = 1; i <= nb_groups; i++) {
603  /* merge three delta in one code */
604  exp0 = exp1;
605  exp1 = p[0];
606  p += group_size;
607  delta0 = exp1 - exp0 + 2;
608  av_assert2(delta0 >= 0 && delta0 <= 4);
609 
610  exp0 = exp1;
611  exp1 = p[0];
612  p += group_size;
613  delta1 = exp1 - exp0 + 2;
614  av_assert2(delta1 >= 0 && delta1 <= 4);
615 
616  exp0 = exp1;
617  exp1 = p[0];
618  p += group_size;
619  delta2 = exp1 - exp0 + 2;
620  av_assert2(delta2 >= 0 && delta2 <= 4);
621 
622  block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
623  }
624  }
625  }
626 }
627 
628 
629 /**
630  * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
631  * Extract exponents from MDCT coefficients, calculate exponent strategies,
632  * and encode final exponents.
633  *
634  * @param s AC-3 encoder private context
635  */
637 {
639 
641 
642  encode_exponents(s);
643 
644  emms_c();
645 }
646 
647 
648 /*
649  * Count frame bits that are based solely on fixed parameters.
650  * This only has to be run once when the encoder is initialized.
651  */
653 {
654  static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
655  int blk;
656  int frame_bits;
657 
658  /* assumptions:
659  * no dynamic range codes
660  * bit allocation parameters do not change between blocks
661  * no delta bit allocation
662  * no skipped data
663  * no auxiliary data
664  * no E-AC-3 metadata
665  */
666 
667  /* header */
668  frame_bits = 16; /* sync info */
669  if (s->eac3) {
670  /* bitstream info header */
671  frame_bits += 35;
672  frame_bits += 1 + 1;
673  if (s->num_blocks != 0x6)
674  frame_bits++;
675  frame_bits++;
676  /* audio frame header */
677  if (s->num_blocks == 6)
678  frame_bits += 2;
679  frame_bits += 10;
680  /* exponent strategy */
681  if (s->use_frame_exp_strategy)
682  frame_bits += 5 * s->fbw_channels;
683  else
684  frame_bits += s->num_blocks * 2 * s->fbw_channels;
685  if (s->lfe_on)
686  frame_bits += s->num_blocks;
687  /* converter exponent strategy */
688  if (s->num_blks_code != 0x3)
689  frame_bits++;
690  else
691  frame_bits += s->fbw_channels * 5;
692  /* snr offsets */
693  frame_bits += 10;
694  /* block start info */
695  if (s->num_blocks != 1)
696  frame_bits++;
697  } else {
698  frame_bits += 49;
699  frame_bits += frame_bits_inc[s->channel_mode];
700  }
701 
702  /* audio blocks */
703  for (blk = 0; blk < s->num_blocks; blk++) {
704  if (!s->eac3) {
705  /* block switch flags */
706  frame_bits += s->fbw_channels;
707 
708  /* dither flags */
709  frame_bits += s->fbw_channels;
710  }
711 
712  /* dynamic range */
713  frame_bits++;
714 
715  /* spectral extension */
716  if (s->eac3)
717  frame_bits++;
718 
719  if (!s->eac3) {
720  /* exponent strategy */
721  frame_bits += 2 * s->fbw_channels;
722  if (s->lfe_on)
723  frame_bits++;
724 
725  /* bit allocation params */
726  frame_bits++;
727  if (!blk)
728  frame_bits += 2 + 2 + 2 + 2 + 3;
729  }
730 
731  /* converter snr offset */
732  if (s->eac3)
733  frame_bits++;
734 
735  if (!s->eac3) {
736  /* delta bit allocation */
737  frame_bits++;
738 
739  /* skipped data */
740  frame_bits++;
741  }
742  }
743 
744  /* auxiliary data */
745  frame_bits++;
746 
747  /* CRC */
748  frame_bits += 1 + 16;
749 
750  s->frame_bits_fixed = frame_bits;
751 }
752 
753 
754 /*
755  * Initialize bit allocation.
756  * Set default parameter codes and calculate parameter values.
757  */
759 {
760  int ch;
761 
762  /* init default parameters */
763  s->slow_decay_code = 2;
764  s->fast_decay_code = 1;
765  s->slow_gain_code = 1;
766  s->db_per_bit_code = s->eac3 ? 2 : 3;
767  s->floor_code = 7;
768  for (ch = 0; ch <= s->channels; ch++)
769  s->fast_gain_code[ch] = 4;
770 
771  /* initial snr offset */
772  s->coarse_snr_offset = 40;
773 
774  /* compute real values */
775  /* currently none of these values change during encoding, so we can just
776  set them once at initialization */
782  s->bit_alloc.cpl_fast_leak = 0;
783  s->bit_alloc.cpl_slow_leak = 0;
784 
786 }
787 
788 
789 /*
790  * Count the bits used to encode the frame, minus exponents and mantissas.
791  * Bits based on fixed parameters have already been counted, so now we just
792  * have to add the bits based on parameters that change during encoding.
793  */
795 {
796  AC3EncOptions *opt = &s->options;
797  int blk, ch;
798  int frame_bits = 0;
799 
800  /* header */
801  if (s->eac3) {
802  if (opt->eac3_mixing_metadata) {
804  frame_bits += 2;
805  if (s->has_center)
806  frame_bits += 6;
807  if (s->has_surround)
808  frame_bits += 6;
809  frame_bits += s->lfe_on;
810  frame_bits += 1 + 1 + 2;
812  frame_bits++;
813  frame_bits++;
814  }
815  if (opt->eac3_info_metadata) {
816  frame_bits += 3 + 1 + 1;
818  frame_bits += 2 + 2;
819  if (s->channel_mode >= AC3_CHMODE_2F2R)
820  frame_bits += 2;
821  frame_bits++;
822  if (opt->audio_production_info)
823  frame_bits += 5 + 2 + 1;
824  frame_bits++;
825  }
826  /* coupling */
827  if (s->channel_mode > AC3_CHMODE_MONO) {
828  frame_bits++;
829  for (blk = 1; blk < s->num_blocks; blk++) {
830  AC3Block *block = &s->blocks[blk];
831  frame_bits++;
832  if (block->new_cpl_strategy)
833  frame_bits++;
834  }
835  }
836  /* coupling exponent strategy */
837  if (s->cpl_on) {
838  if (s->use_frame_exp_strategy) {
839  frame_bits += 5 * s->cpl_on;
840  } else {
841  for (blk = 0; blk < s->num_blocks; blk++)
842  frame_bits += 2 * s->blocks[blk].cpl_in_use;
843  }
844  }
845  } else {
846  if (opt->audio_production_info)
847  frame_bits += 7;
848  if (s->bitstream_id == 6) {
849  if (opt->extended_bsi_1)
850  frame_bits += 14;
851  if (opt->extended_bsi_2)
852  frame_bits += 14;
853  }
854  }
855 
856  /* audio blocks */
857  for (blk = 0; blk < s->num_blocks; blk++) {
858  AC3Block *block = &s->blocks[blk];
859 
860  /* coupling strategy */
861  if (!s->eac3)
862  frame_bits++;
863  if (block->new_cpl_strategy) {
864  if (!s->eac3)
865  frame_bits++;
866  if (block->cpl_in_use) {
867  if (s->eac3)
868  frame_bits++;
869  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
870  frame_bits += s->fbw_channels;
872  frame_bits++;
873  frame_bits += 4 + 4;
874  if (s->eac3)
875  frame_bits++;
876  else
877  frame_bits += s->num_cpl_subbands - 1;
878  }
879  }
880 
881  /* coupling coordinates */
882  if (block->cpl_in_use) {
883  for (ch = 1; ch <= s->fbw_channels; ch++) {
884  if (block->channel_in_cpl[ch]) {
885  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
886  frame_bits++;
887  if (block->new_cpl_coords[ch]) {
888  frame_bits += 2;
889  frame_bits += (4 + 4) * s->num_cpl_bands;
890  }
891  }
892  }
893  }
894 
895  /* stereo rematrixing */
896  if (s->channel_mode == AC3_CHMODE_STEREO) {
897  if (!s->eac3 || blk > 0)
898  frame_bits++;
899  if (s->blocks[blk].new_rematrixing_strategy)
900  frame_bits += block->num_rematrixing_bands;
901  }
902 
903  /* bandwidth codes & gain range */
904  for (ch = 1; ch <= s->fbw_channels; ch++) {
905  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
906  if (!block->channel_in_cpl[ch])
907  frame_bits += 6;
908  frame_bits += 2;
909  }
910  }
911 
912  /* coupling exponent strategy */
913  if (!s->eac3 && block->cpl_in_use)
914  frame_bits += 2;
915 
916  /* snr offsets and fast gain codes */
917  if (!s->eac3) {
918  frame_bits++;
919  if (block->new_snr_offsets)
920  frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
921  }
922 
923  /* coupling leak info */
924  if (block->cpl_in_use) {
925  if (!s->eac3 || block->new_cpl_leak != 2)
926  frame_bits++;
927  if (block->new_cpl_leak)
928  frame_bits += 3 + 3;
929  }
930  }
931 
932  s->frame_bits = s->frame_bits_fixed + frame_bits;
933 }
934 
935 
936 /*
937  * Calculate masking curve based on the final exponents.
938  * Also calculate the power spectral densities to use in future calculations.
939  */
941 {
942  int blk, ch;
943 
944  for (blk = 0; blk < s->num_blocks; blk++) {
945  AC3Block *block = &s->blocks[blk];
946  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
947  /* We only need psd and mask for calculating bap.
948  Since we currently do not calculate bap when exponent
949  strategy is EXP_REUSE we do not need to calculate psd or mask. */
950  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
951  ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
952  block->end_freq[ch], block->psd[ch],
953  block->band_psd[ch]);
955  s->start_freq[ch], block->end_freq[ch],
957  ch == s->lfe_channel,
958  DBA_NONE, 0, NULL, NULL, NULL,
959  block->mask[ch]);
960  }
961  }
962  }
963 }
964 
965 
966 /*
967  * Ensure that bap for each block and channel point to the current bap_buffer.
968  * They may have been switched during the bit allocation search.
969  */
971 {
972  int blk, ch;
973  uint8_t *ref_bap;
974 
975  if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
976  return;
977 
978  ref_bap = s->bap_buffer;
979  for (ch = 0; ch <= s->channels; ch++) {
980  for (blk = 0; blk < s->num_blocks; blk++)
981  s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
982  ref_bap += AC3_MAX_COEFS * s->num_blocks;
983  }
984  s->ref_bap_set = 1;
985 }
986 
987 
988 /**
989  * Initialize mantissa counts.
990  * These are set so that they are padded to the next whole group size when bits
991  * are counted in compute_mantissa_size.
992  *
993  * @param[in,out] mant_cnt running counts for each bap value for each block
994  */
995 static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
996 {
997  int blk;
998 
999  for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1000  memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
1001  mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1002  mant_cnt[blk][4] = 1;
1003  }
1004 }
1005 
1006 
1007 /**
1008  * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1009  * range.
1010  *
1011  * @param s AC-3 encoder private context
1012  * @param ch channel index
1013  * @param[in,out] mant_cnt running counts for each bap value for each block
1014  * @param start starting coefficient bin
1015  * @param end ending coefficient bin
1016  */
1018  uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1019  int start, int end)
1020 {
1021  int blk;
1022 
1023  for (blk = 0; blk < s->num_blocks; blk++) {
1024  AC3Block *block = &s->blocks[blk];
1025  if (ch == CPL_CH && !block->cpl_in_use)
1026  continue;
1027  s->ac3dsp.update_bap_counts(mant_cnt[blk],
1028  s->ref_bap[ch][blk] + start,
1029  FFMIN(end, block->end_freq[ch]) - start);
1030  }
1031 }
1032 
1033 
1034 /*
1035  * Count the number of mantissa bits in the frame based on the bap values.
1036  */
1038 {
1039  int ch, max_end_freq;
1040  LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1041 
1042  count_mantissa_bits_init(mant_cnt);
1043 
1044  max_end_freq = s->bandwidth_code * 3 + 73;
1045  for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1046  count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1047  max_end_freq);
1048 
1049  return s->ac3dsp.compute_mantissa_size(mant_cnt);
1050 }
1051 
1052 
1053 /**
1054  * Run the bit allocation with a given SNR offset.
1055  * This calculates the bit allocation pointers that will be used to determine
1056  * the quantization of each mantissa.
1057  *
1058  * @param s AC-3 encoder private context
1059  * @param snr_offset SNR offset, 0 to 1023
1060  * @return the number of bits needed for mantissas if the given SNR offset is
1061  * is used.
1062  */
1063 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1064 {
1065  int blk, ch;
1066 
1067  snr_offset = (snr_offset - 240) << 2;
1068 
1069  reset_block_bap(s);
1070  for (blk = 0; blk < s->num_blocks; blk++) {
1071  AC3Block *block = &s->blocks[blk];
1072 
1073  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1074  /* Currently the only bit allocation parameters which vary across
1075  blocks within a frame are the exponent values. We can take
1076  advantage of that by reusing the bit allocation pointers
1077  whenever we reuse exponents. */
1078  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1079  s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1080  s->start_freq[ch], block->end_freq[ch],
1081  snr_offset, s->bit_alloc.floor,
1082  ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1083  }
1084  }
1085  }
1086  return count_mantissa_bits(s);
1087 }
1088 
1089 
1090 /*
1091  * Constant bitrate bit allocation search.
1092  * Find the largest SNR offset that will allow data to fit in the frame.
1093  */
1095 {
1096  int ch;
1097  int bits_left;
1098  int snr_offset, snr_incr;
1099 
1100  bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1101  if (bits_left < 0)
1102  return AVERROR(EINVAL);
1103 
1104  snr_offset = s->coarse_snr_offset << 4;
1105 
1106  /* if previous frame SNR offset was 1023, check if current frame can also
1107  use SNR offset of 1023. if so, skip the search. */
1108  if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1109  if (bit_alloc(s, 1023) <= bits_left)
1110  return 0;
1111  }
1112 
1113  while (snr_offset >= 0 &&
1114  bit_alloc(s, snr_offset) > bits_left) {
1115  snr_offset -= 64;
1116  }
1117  if (snr_offset < 0)
1118  return AVERROR(EINVAL);
1119 
1120  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1121  for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1122  while (snr_offset + snr_incr <= 1023 &&
1123  bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1124  snr_offset += snr_incr;
1125  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1126  }
1127  }
1128  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1129  reset_block_bap(s);
1130 
1131  s->coarse_snr_offset = snr_offset >> 4;
1132  for (ch = !s->cpl_on; ch <= s->channels; ch++)
1133  s->fine_snr_offset[ch] = snr_offset & 0xF;
1134 
1135  return 0;
1136 }
1137 
1138 
1139 /*
1140  * Perform bit allocation search.
1141  * Finds the SNR offset value that maximizes quality and fits in the specified
1142  * frame size. Output is the SNR offset and a set of bit allocation pointers
1143  * used to quantize the mantissas.
1144  */
1146 {
1147  count_frame_bits(s);
1148 
1150 
1151  bit_alloc_masking(s);
1152 
1153  return cbr_bit_allocation(s);
1154 }
1155 
1156 
1157 /**
1158  * Symmetric quantization on 'levels' levels.
1159  *
1160  * @param c unquantized coefficient
1161  * @param e exponent
1162  * @param levels number of quantization levels
1163  * @return quantized coefficient
1164  */
1165 static inline int sym_quant(int c, int e, int levels)
1166 {
1167  int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1168  av_assert2(v >= 0 && v < levels);
1169  return v;
1170 }
1171 
1172 
1173 /**
1174  * Asymmetric quantization on 2^qbits levels.
1175  *
1176  * @param c unquantized coefficient
1177  * @param e exponent
1178  * @param qbits number of quantization bits
1179  * @return quantized coefficient
1180  */
1181 static inline int asym_quant(int c, int e, int qbits)
1182 {
1183  int m;
1184 
1185  c = (((c << e) >> (24 - qbits)) + 1) >> 1;
1186  m = (1 << (qbits-1));
1187  if (c >= m)
1188  c = m - 1;
1189  av_assert2(c >= -m);
1190  return c;
1191 }
1192 
1193 
1194 /**
1195  * Quantize a set of mantissas for a single channel in a single block.
1196  *
1197  * @param s Mantissa count context
1198  * @param fixed_coef unquantized fixed-point coefficients
1199  * @param exp exponents
1200  * @param bap bit allocation pointer indices
1201  * @param[out] qmant quantized coefficients
1202  * @param start_freq starting coefficient bin
1203  * @param end_freq ending coefficient bin
1204  */
1205 static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1206  uint8_t *exp, uint8_t *bap,
1207  int16_t *qmant, int start_freq,
1208  int end_freq)
1209 {
1210  int i;
1211 
1212  for (i = start_freq; i < end_freq; i++) {
1213  int c = fixed_coef[i];
1214  int e = exp[i];
1215  int v = bap[i];
1216  if (v)
1217  switch (v) {
1218  case 1:
1219  v = sym_quant(c, e, 3);
1220  switch (s->mant1_cnt) {
1221  case 0:
1222  s->qmant1_ptr = &qmant[i];
1223  v = 9 * v;
1224  s->mant1_cnt = 1;
1225  break;
1226  case 1:
1227  *s->qmant1_ptr += 3 * v;
1228  s->mant1_cnt = 2;
1229  v = 128;
1230  break;
1231  default:
1232  *s->qmant1_ptr += v;
1233  s->mant1_cnt = 0;
1234  v = 128;
1235  break;
1236  }
1237  break;
1238  case 2:
1239  v = sym_quant(c, e, 5);
1240  switch (s->mant2_cnt) {
1241  case 0:
1242  s->qmant2_ptr = &qmant[i];
1243  v = 25 * v;
1244  s->mant2_cnt = 1;
1245  break;
1246  case 1:
1247  *s->qmant2_ptr += 5 * v;
1248  s->mant2_cnt = 2;
1249  v = 128;
1250  break;
1251  default:
1252  *s->qmant2_ptr += v;
1253  s->mant2_cnt = 0;
1254  v = 128;
1255  break;
1256  }
1257  break;
1258  case 3:
1259  v = sym_quant(c, e, 7);
1260  break;
1261  case 4:
1262  v = sym_quant(c, e, 11);
1263  switch (s->mant4_cnt) {
1264  case 0:
1265  s->qmant4_ptr = &qmant[i];
1266  v = 11 * v;
1267  s->mant4_cnt = 1;
1268  break;
1269  default:
1270  *s->qmant4_ptr += v;
1271  s->mant4_cnt = 0;
1272  v = 128;
1273  break;
1274  }
1275  break;
1276  case 5:
1277  v = sym_quant(c, e, 15);
1278  break;
1279  case 14:
1280  v = asym_quant(c, e, 14);
1281  break;
1282  case 15:
1283  v = asym_quant(c, e, 16);
1284  break;
1285  default:
1286  v = asym_quant(c, e, v - 1);
1287  break;
1288  }
1289  qmant[i] = v;
1290  }
1291 }
1292 
1293 
1294 /**
1295  * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1296  *
1297  * @param s AC-3 encoder private context
1298  */
1300 {
1301  int blk, ch, ch0=0, got_cpl;
1302 
1303  for (blk = 0; blk < s->num_blocks; blk++) {
1304  AC3Block *block = &s->blocks[blk];
1305  AC3Mant m = { 0 };
1306 
1307  got_cpl = !block->cpl_in_use;
1308  for (ch = 1; ch <= s->channels; ch++) {
1309  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1310  ch0 = ch - 1;
1311  ch = CPL_CH;
1312  got_cpl = 1;
1313  }
1314  quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1315  s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1316  s->ref_bap[ch][blk], block->qmant[ch],
1317  s->start_freq[ch], block->end_freq[ch]);
1318  if (ch == CPL_CH)
1319  ch = ch0;
1320  }
1321  }
1322 }
1323 
1324 
1325 /*
1326  * Write the AC-3 frame header to the output bitstream.
1327  */
1329 {
1330  AC3EncOptions *opt = &s->options;
1331 
1332  put_bits(&s->pb, 16, 0x0b77); /* frame header */
1333  put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
1334  put_bits(&s->pb, 2, s->bit_alloc.sr_code);
1335  put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1336  put_bits(&s->pb, 5, s->bitstream_id);
1337  put_bits(&s->pb, 3, s->bitstream_mode);
1338  put_bits(&s->pb, 3, s->channel_mode);
1339  if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1340  put_bits(&s->pb, 2, s->center_mix_level);
1341  if (s->channel_mode & 0x04)
1342  put_bits(&s->pb, 2, s->surround_mix_level);
1343  if (s->channel_mode == AC3_CHMODE_STEREO)
1344  put_bits(&s->pb, 2, opt->dolby_surround_mode);
1345  put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1346  put_bits(&s->pb, 5, -opt->dialogue_level);
1347  put_bits(&s->pb, 1, 0); /* no compression control word */
1348  put_bits(&s->pb, 1, 0); /* no lang code */
1349  put_bits(&s->pb, 1, opt->audio_production_info);
1350  if (opt->audio_production_info) {
1351  put_bits(&s->pb, 5, opt->mixing_level - 80);
1352  put_bits(&s->pb, 2, opt->room_type);
1353  }
1354  put_bits(&s->pb, 1, opt->copyright);
1355  put_bits(&s->pb, 1, opt->original);
1356  if (s->bitstream_id == 6) {
1357  /* alternate bit stream syntax */
1358  put_bits(&s->pb, 1, opt->extended_bsi_1);
1359  if (opt->extended_bsi_1) {
1360  put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1361  put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1362  put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1363  put_bits(&s->pb, 3, s->loro_center_mix_level);
1364  put_bits(&s->pb, 3, s->loro_surround_mix_level);
1365  }
1366  put_bits(&s->pb, 1, opt->extended_bsi_2);
1367  if (opt->extended_bsi_2) {
1368  put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1369  put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1370  put_bits(&s->pb, 1, opt->ad_converter_type);
1371  put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
1372  }
1373  } else {
1374  put_bits(&s->pb, 1, 0); /* no time code 1 */
1375  put_bits(&s->pb, 1, 0); /* no time code 2 */
1376  }
1377  put_bits(&s->pb, 1, 0); /* no additional bit stream info */
1378 }
1379 
1380 
1381 /*
1382  * Write one audio block to the output bitstream.
1383  */
1385 {
1386  int ch, i, baie, bnd, got_cpl, av_uninit(ch0);
1387  AC3Block *block = &s->blocks[blk];
1388 
1389  /* block switching */
1390  if (!s->eac3) {
1391  for (ch = 0; ch < s->fbw_channels; ch++)
1392  put_bits(&s->pb, 1, 0);
1393  }
1394 
1395  /* dither flags */
1396  if (!s->eac3) {
1397  for (ch = 0; ch < s->fbw_channels; ch++)
1398  put_bits(&s->pb, 1, 1);
1399  }
1400 
1401  /* dynamic range codes */
1402  put_bits(&s->pb, 1, 0);
1403 
1404  /* spectral extension */
1405  if (s->eac3)
1406  put_bits(&s->pb, 1, 0);
1407 
1408  /* channel coupling */
1409  if (!s->eac3)
1410  put_bits(&s->pb, 1, block->new_cpl_strategy);
1411  if (block->new_cpl_strategy) {
1412  if (!s->eac3)
1413  put_bits(&s->pb, 1, block->cpl_in_use);
1414  if (block->cpl_in_use) {
1415  int start_sub, end_sub;
1416  if (s->eac3)
1417  put_bits(&s->pb, 1, 0); /* enhanced coupling */
1418  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1419  for (ch = 1; ch <= s->fbw_channels; ch++)
1420  put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1421  }
1422  if (s->channel_mode == AC3_CHMODE_STEREO)
1423  put_bits(&s->pb, 1, 0); /* phase flags in use */
1424  start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1425  end_sub = (s->cpl_end_freq - 37) / 12;
1426  put_bits(&s->pb, 4, start_sub);
1427  put_bits(&s->pb, 4, end_sub - 3);
1428  /* coupling band structure */
1429  if (s->eac3) {
1430  put_bits(&s->pb, 1, 0); /* use default */
1431  } else {
1432  for (bnd = start_sub+1; bnd < end_sub; bnd++)
1434  }
1435  }
1436  }
1437 
1438  /* coupling coordinates */
1439  if (block->cpl_in_use) {
1440  for (ch = 1; ch <= s->fbw_channels; ch++) {
1441  if (block->channel_in_cpl[ch]) {
1442  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1443  put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1444  if (block->new_cpl_coords[ch]) {
1445  put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1446  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1447  put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1448  put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1449  }
1450  }
1451  }
1452  }
1453  }
1454 
1455  /* stereo rematrixing */
1456  if (s->channel_mode == AC3_CHMODE_STEREO) {
1457  if (!s->eac3 || blk > 0)
1458  put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1459  if (block->new_rematrixing_strategy) {
1460  /* rematrixing flags */
1461  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1462  put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1463  }
1464  }
1465 
1466  /* exponent strategy */
1467  if (!s->eac3) {
1468  for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1469  put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1470  if (s->lfe_on)
1471  put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1472  }
1473 
1474  /* bandwidth */
1475  for (ch = 1; ch <= s->fbw_channels; ch++) {
1476  if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1477  put_bits(&s->pb, 6, s->bandwidth_code);
1478  }
1479 
1480  /* exponents */
1481  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1482  int nb_groups;
1483  int cpl = (ch == CPL_CH);
1484 
1485  if (s->exp_strategy[ch][blk] == EXP_REUSE)
1486  continue;
1487 
1488  /* DC exponent */
1489  put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1490 
1491  /* exponent groups */
1492  nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1493  for (i = 1; i <= nb_groups; i++)
1494  put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1495 
1496  /* gain range info */
1497  if (ch != s->lfe_channel && !cpl)
1498  put_bits(&s->pb, 2, 0);
1499  }
1500 
1501  /* bit allocation info */
1502  if (!s->eac3) {
1503  baie = (blk == 0);
1504  put_bits(&s->pb, 1, baie);
1505  if (baie) {
1506  put_bits(&s->pb, 2, s->slow_decay_code);
1507  put_bits(&s->pb, 2, s->fast_decay_code);
1508  put_bits(&s->pb, 2, s->slow_gain_code);
1509  put_bits(&s->pb, 2, s->db_per_bit_code);
1510  put_bits(&s->pb, 3, s->floor_code);
1511  }
1512  }
1513 
1514  /* snr offset */
1515  if (!s->eac3) {
1516  put_bits(&s->pb, 1, block->new_snr_offsets);
1517  if (block->new_snr_offsets) {
1518  put_bits(&s->pb, 6, s->coarse_snr_offset);
1519  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1520  put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1521  put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1522  }
1523  }
1524  } else {
1525  put_bits(&s->pb, 1, 0); /* no converter snr offset */
1526  }
1527 
1528  /* coupling leak */
1529  if (block->cpl_in_use) {
1530  if (!s->eac3 || block->new_cpl_leak != 2)
1531  put_bits(&s->pb, 1, block->new_cpl_leak);
1532  if (block->new_cpl_leak) {
1533  put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1534  put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1535  }
1536  }
1537 
1538  if (!s->eac3) {
1539  put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1540  put_bits(&s->pb, 1, 0); /* no data to skip */
1541  }
1542 
1543  /* mantissas */
1544  got_cpl = !block->cpl_in_use;
1545  for (ch = 1; ch <= s->channels; ch++) {
1546  int b, q;
1547 
1548  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1549  ch0 = ch - 1;
1550  ch = CPL_CH;
1551  got_cpl = 1;
1552  }
1553  for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1554  q = block->qmant[ch][i];
1555  b = s->ref_bap[ch][blk][i];
1556  switch (b) {
1557  case 0: break;
1558  case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
1559  case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
1560  case 3: put_sbits(&s->pb, 3, q); break;
1561  case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
1562  case 14: put_sbits(&s->pb, 14, q); break;
1563  case 15: put_sbits(&s->pb, 16, q); break;
1564  default: put_sbits(&s->pb, b-1, q); break;
1565  }
1566  }
1567  if (ch == CPL_CH)
1568  ch = ch0;
1569  }
1570 }
1571 
1572 
1573 /** CRC-16 Polynomial */
1574 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1575 
1576 
1577 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1578 {
1579  unsigned int c;
1580 
1581  c = 0;
1582  while (a) {
1583  if (a & 1)
1584  c ^= b;
1585  a = a >> 1;
1586  b = b << 1;
1587  if (b & (1 << 16))
1588  b ^= poly;
1589  }
1590  return c;
1591 }
1592 
1593 
1594 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1595 {
1596  unsigned int r;
1597  r = 1;
1598  while (n) {
1599  if (n & 1)
1600  r = mul_poly(r, a, poly);
1601  a = mul_poly(a, a, poly);
1602  n >>= 1;
1603  }
1604  return r;
1605 }
1606 
1607 
1608 /*
1609  * Fill the end of the frame with 0's and compute the two CRCs.
1610  */
1612 {
1613  const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1614  int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1615  uint8_t *frame;
1616 
1617  frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1618 
1619  /* pad the remainder of the frame with zeros */
1620  av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1621  flush_put_bits(&s->pb);
1622  frame = s->pb.buf;
1623  pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1624  av_assert2(pad_bytes >= 0);
1625  if (pad_bytes > 0)
1626  memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1627 
1628  if (s->eac3) {
1629  /* compute crc2 */
1630  crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1631  } else {
1632  /* compute crc1 */
1633  /* this is not so easy because it is at the beginning of the data... */
1634  crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1635  crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1636  crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
1637  AV_WB16(frame + 2, crc1);
1638 
1639  /* compute crc2 */
1640  crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1641  s->frame_size - frame_size_58 - 3);
1642  }
1643  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1644  /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1645  if (crc2 == 0x770B) {
1646  frame[s->frame_size - 3] ^= 0x1;
1647  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1648  }
1649  crc2 = av_bswap16(crc2);
1650  AV_WB16(frame + s->frame_size - 2, crc2);
1651 }
1652 
1653 
1654 /**
1655  * Write the frame to the output bitstream.
1656  *
1657  * @param s AC-3 encoder private context
1658  * @param frame output data buffer
1659  */
1661 {
1662  int blk;
1663 
1665 
1666  s->output_frame_header(s);
1667 
1668  for (blk = 0; blk < s->num_blocks; blk++)
1669  output_audio_block(s, blk);
1670 
1671  output_frame_end(s);
1672 }
1673 
1674 
1676 {
1677 #ifdef DEBUG
1678  AVCodecContext *avctx = s->avctx;
1679  AC3EncOptions *opt = &s->options;
1680  char strbuf[32];
1681 
1682  switch (s->bitstream_id) {
1683  case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
1684  case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
1685  case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
1686  case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1687  case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
1688  default: snprintf(strbuf, 32, "ERROR");
1689  }
1690  av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1691  av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1692  av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1693  av_dlog(avctx, "channel_layout: %s\n", strbuf);
1694  av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1695  av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1696  av_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1697  if (s->cutoff)
1698  av_dlog(avctx, "cutoff: %d\n", s->cutoff);
1699 
1700  av_dlog(avctx, "per_frame_metadata: %s\n",
1701  opt->allow_per_frame_metadata?"on":"off");
1702  if (s->has_center)
1703  av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1704  s->center_mix_level);
1705  else
1706  av_dlog(avctx, "center_mixlev: {not written}\n");
1707  if (s->has_surround)
1708  av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1709  s->surround_mix_level);
1710  else
1711  av_dlog(avctx, "surround_mixlev: {not written}\n");
1712  if (opt->audio_production_info) {
1713  av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1714  switch (opt->room_type) {
1715  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1716  case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
1717  case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
1718  default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1719  }
1720  av_dlog(avctx, "room_type: %s\n", strbuf);
1721  } else {
1722  av_dlog(avctx, "mixing_level: {not written}\n");
1723  av_dlog(avctx, "room_type: {not written}\n");
1724  }
1725  av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1726  av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1727  if (s->channel_mode == AC3_CHMODE_STEREO) {
1728  switch (opt->dolby_surround_mode) {
1729  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1730  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1731  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1732  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1733  }
1734  av_dlog(avctx, "dsur_mode: %s\n", strbuf);
1735  } else {
1736  av_dlog(avctx, "dsur_mode: {not written}\n");
1737  }
1738  av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1739 
1740  if (s->bitstream_id == 6) {
1741  if (opt->extended_bsi_1) {
1742  switch (opt->preferred_stereo_downmix) {
1743  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1744  case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
1745  case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
1746  default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1747  }
1748  av_dlog(avctx, "dmix_mode: %s\n", strbuf);
1749  av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1751  av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1753  av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1755  av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1757  } else {
1758  av_dlog(avctx, "extended bitstream info 1: {not written}\n");
1759  }
1760  if (opt->extended_bsi_2) {
1761  switch (opt->dolby_surround_ex_mode) {
1762  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1763  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1764  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1765  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1766  }
1767  av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1768  switch (opt->dolby_headphone_mode) {
1769  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1770  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1771  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1772  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1773  }
1774  av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1775 
1776  switch (opt->ad_converter_type) {
1777  case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1778  case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
1779  default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1780  }
1781  av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1782  } else {
1783  av_dlog(avctx, "extended bitstream info 2: {not written}\n");
1784  }
1785  }
1786 #endif
1787 }
1788 
1789 
1790 #define FLT_OPTION_THRESHOLD 0.01
1791 
1792 static int validate_float_option(float v, const float *v_list, int v_list_size)
1793 {
1794  int i;
1795 
1796  for (i = 0; i < v_list_size; i++) {
1797  if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1798  v > (v_list[i] - FLT_OPTION_THRESHOLD))
1799  break;
1800  }
1801  if (i == v_list_size)
1802  return -1;
1803 
1804  return i;
1805 }
1806 
1807 
1808 static void validate_mix_level(void *log_ctx, const char *opt_name,
1809  float *opt_param, const float *list,
1810  int list_size, int default_value, int min_value,
1811  int *ctx_param)
1812 {
1813  int mixlev = validate_float_option(*opt_param, list, list_size);
1814  if (mixlev < min_value) {
1815  mixlev = default_value;
1816  if (*opt_param >= 0.0) {
1817  av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1818  "default value: %0.3f\n", opt_name, list[mixlev]);
1819  }
1820  }
1821  *opt_param = list[mixlev];
1822  *ctx_param = mixlev;
1823 }
1824 
1825 
1826 /**
1827  * Validate metadata options as set by AVOption system.
1828  * These values can optionally be changed per-frame.
1829  *
1830  * @param s AC-3 encoder private context
1831  */
1833 {
1834  AVCodecContext *avctx = s->avctx;
1835  AC3EncOptions *opt = &s->options;
1836 
1837  opt->audio_production_info = 0;
1838  opt->extended_bsi_1 = 0;
1839  opt->extended_bsi_2 = 0;
1840  opt->eac3_mixing_metadata = 0;
1841  opt->eac3_info_metadata = 0;
1842 
1843  /* determine mixing metadata / xbsi1 use */
1845  opt->extended_bsi_1 = 1;
1846  opt->eac3_mixing_metadata = 1;
1847  }
1848  if (s->has_center &&
1849  (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
1850  opt->extended_bsi_1 = 1;
1851  opt->eac3_mixing_metadata = 1;
1852  }
1853  if (s->has_surround &&
1854  (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
1855  opt->extended_bsi_1 = 1;
1856  opt->eac3_mixing_metadata = 1;
1857  }
1858 
1859  if (s->eac3) {
1860  /* determine info metadata use */
1862  opt->eac3_info_metadata = 1;
1863  if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
1864  opt->eac3_info_metadata = 1;
1865  if (s->channel_mode == AC3_CHMODE_STEREO &&
1867  opt->eac3_info_metadata = 1;
1869  opt->eac3_info_metadata = 1;
1870  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
1872  opt->audio_production_info = 1;
1873  opt->eac3_info_metadata = 1;
1874  }
1875  } else {
1876  /* determine audio production info use */
1877  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
1878  opt->audio_production_info = 1;
1879 
1880  /* determine xbsi2 use */
1882  opt->extended_bsi_2 = 1;
1884  opt->extended_bsi_2 = 1;
1885  if (opt->ad_converter_type != AC3ENC_OPT_NONE)
1886  opt->extended_bsi_2 = 1;
1887  }
1888 
1889  /* validate AC-3 mixing levels */
1890  if (!s->eac3) {
1891  if (s->has_center) {
1892  validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1894  &s->center_mix_level);
1895  }
1896  if (s->has_surround) {
1897  validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1899  &s->surround_mix_level);
1900  }
1901  }
1902 
1903  /* validate extended bsi 1 / mixing metadata */
1904  if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
1905  /* default preferred stereo downmix */
1908  if (!s->eac3 || s->has_center) {
1909  /* validate Lt/Rt center mix level */
1910  validate_mix_level(avctx, "ltrt_center_mix_level",
1912  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1913  &s->ltrt_center_mix_level);
1914  /* validate Lo/Ro center mix level */
1915  validate_mix_level(avctx, "loro_center_mix_level",
1917  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1918  &s->loro_center_mix_level);
1919  }
1920  if (!s->eac3 || s->has_surround) {
1921  /* validate Lt/Rt surround mix level */
1922  validate_mix_level(avctx, "ltrt_surround_mix_level",
1924  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1926  /* validate Lo/Ro surround mix level */
1927  validate_mix_level(avctx, "loro_surround_mix_level",
1929  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1931  }
1932  }
1933 
1934  /* validate audio service type / channels combination */
1936  avctx->channels == 1) ||
1940  && avctx->channels > 1)) {
1941  av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
1942  "specified number of channels\n");
1943  return AVERROR(EINVAL);
1944  }
1945 
1946  /* validate extended bsi 2 / info metadata */
1947  if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
1948  /* default dolby headphone mode */
1951  /* default dolby surround ex mode */
1954  /* default A/D converter type */
1955  if (opt->ad_converter_type == AC3ENC_OPT_NONE)
1957  }
1958 
1959  /* copyright & original defaults */
1960  if (!s->eac3 || opt->eac3_info_metadata) {
1961  /* default copyright */
1962  if (opt->copyright == AC3ENC_OPT_NONE)
1963  opt->copyright = AC3ENC_OPT_OFF;
1964  /* default original */
1965  if (opt->original == AC3ENC_OPT_NONE)
1966  opt->original = AC3ENC_OPT_ON;
1967  }
1968 
1969  /* dolby surround mode default */
1970  if (!s->eac3 || opt->eac3_info_metadata) {
1973  }
1974 
1975  /* validate audio production info */
1976  if (opt->audio_production_info) {
1977  if (opt->mixing_level == AC3ENC_OPT_NONE) {
1978  av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
1979  "room_type is set\n");
1980  return AVERROR(EINVAL);
1981  }
1982  if (opt->mixing_level < 80) {
1983  av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
1984  "80dB and 111dB\n");
1985  return AVERROR(EINVAL);
1986  }
1987  /* default room type */
1988  if (opt->room_type == AC3ENC_OPT_NONE)
1990  }
1991 
1992  /* set bitstream id for alternate bitstream syntax */
1993  if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
1994  if (s->bitstream_id > 8 && s->bitstream_id < 11) {
1995  static int warn_once = 1;
1996  if (warn_once) {
1997  av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
1998  "not compatible with reduced samplerates. writing of "
1999  "extended bitstream information will be disabled.\n");
2000  warn_once = 0;
2001  }
2002  } else {
2003  s->bitstream_id = 6;
2004  }
2005  }
2006 
2007  return 0;
2008 }
2009 
2010 
2011 /**
2012  * Finalize encoding and free any memory allocated by the encoder.
2013  *
2014  * @param avctx Codec context
2015  */
2017 {
2018  int blk, ch;
2019  AC3EncodeContext *s = avctx->priv_data;
2020 
2022  if (s->planar_samples)
2023  for (ch = 0; ch < s->channels; ch++)
2024  av_freep(&s->planar_samples[ch]);
2025  av_freep(&s->planar_samples);
2026  av_freep(&s->bap_buffer);
2027  av_freep(&s->bap1_buffer);
2030  av_freep(&s->exp_buffer);
2032  av_freep(&s->psd_buffer);
2034  av_freep(&s->mask_buffer);
2035  av_freep(&s->qmant_buffer);
2038  for (blk = 0; blk < s->num_blocks; blk++) {
2039  AC3Block *block = &s->blocks[blk];
2040  av_freep(&block->mdct_coef);
2041  av_freep(&block->fixed_coef);
2042  av_freep(&block->exp);
2043  av_freep(&block->grouped_exp);
2044  av_freep(&block->psd);
2045  av_freep(&block->band_psd);
2046  av_freep(&block->mask);
2047  av_freep(&block->qmant);
2048  av_freep(&block->cpl_coord_exp);
2049  av_freep(&block->cpl_coord_mant);
2050  }
2051 
2052  s->mdct_end(s);
2053 
2054  return 0;
2055 }
2056 
2057 
2058 /*
2059  * Set channel information during initialization.
2060  */
2061 static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
2062  uint64_t *channel_layout)
2063 {
2064  int ch_layout;
2065 
2066  if (channels < 1 || channels > AC3_MAX_CHANNELS)
2067  return AVERROR(EINVAL);
2068  if (*channel_layout > 0x7FF)
2069  return AVERROR(EINVAL);
2070  ch_layout = *channel_layout;
2071  if (!ch_layout)
2072  ch_layout = av_get_default_channel_layout(channels);
2073 
2074  s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
2075  s->channels = channels;
2076  s->fbw_channels = channels - s->lfe_on;
2077  s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
2078  if (s->lfe_on)
2079  ch_layout -= AV_CH_LOW_FREQUENCY;
2080 
2081  switch (ch_layout) {
2083  case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
2084  case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
2085  case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
2086  case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
2087  case AV_CH_LAYOUT_QUAD:
2088  case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
2089  case AV_CH_LAYOUT_5POINT0:
2090  case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
2091  default:
2092  return AVERROR(EINVAL);
2093  }
2094  s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2095  s->has_surround = s->channel_mode & 0x04;
2096 
2098  *channel_layout = ch_layout;
2099  if (s->lfe_on)
2100  *channel_layout |= AV_CH_LOW_FREQUENCY;
2101 
2102  return 0;
2103 }
2104 
2105 
2107 {
2108  AVCodecContext *avctx = s->avctx;
2109  int i, ret, max_sr;
2110 
2111  /* validate channel layout */
2112  if (!avctx->channel_layout) {
2113  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2114  "encoder will guess the layout, but it "
2115  "might be incorrect.\n");
2116  }
2117  ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
2118  if (ret) {
2119  av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2120  return ret;
2121  }
2122 
2123  /* validate sample rate */
2124  /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2125  decoder that supports half sample rate so we can validate that
2126  the generated files are correct. */
2127  max_sr = s->eac3 ? 2 : 8;
2128  for (i = 0; i <= max_sr; i++) {
2129  if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2130  break;
2131  }
2132  if (i > max_sr) {
2133  av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2134  return AVERROR(EINVAL);
2135  }
2136  s->sample_rate = avctx->sample_rate;
2137  s->bit_alloc.sr_shift = i / 3;
2138  s->bit_alloc.sr_code = i % 3;
2139  s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2140 
2141  /* select a default bit rate if not set by the user */
2142  if (!avctx->bit_rate) {
2143  switch (s->fbw_channels) {
2144  case 1: avctx->bit_rate = 96000; break;
2145  case 2: avctx->bit_rate = 192000; break;
2146  case 3: avctx->bit_rate = 320000; break;
2147  case 4: avctx->bit_rate = 384000; break;
2148  case 5: avctx->bit_rate = 448000; break;
2149  }
2150  }
2151 
2152  /* validate bit rate */
2153  if (s->eac3) {
2154  int max_br, min_br, wpf, min_br_dist, min_br_code;
2155  int num_blks_code, num_blocks, frame_samples;
2156 
2157  /* calculate min/max bitrate */
2158  /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2159  found use either 6 blocks or 1 block, even though 2 or 3 blocks
2160  would work as far as the bit rate is concerned. */
2161  for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2162  num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2163  frame_samples = AC3_BLOCK_SIZE * num_blocks;
2164  max_br = 2048 * s->sample_rate / frame_samples * 16;
2165  min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2166  if (avctx->bit_rate <= max_br)
2167  break;
2168  }
2169  if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2170  av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2171  "for this sample rate\n", min_br, max_br);
2172  return AVERROR(EINVAL);
2173  }
2174  s->num_blks_code = num_blks_code;
2175  s->num_blocks = num_blocks;
2176 
2177  /* calculate words-per-frame for the selected bitrate */
2178  wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2179  av_assert1(wpf > 0 && wpf <= 2048);
2180 
2181  /* find the closest AC-3 bitrate code to the selected bitrate.
2182  this is needed for lookup tables for bandwidth and coupling
2183  parameter selection */
2184  min_br_code = -1;
2185  min_br_dist = INT_MAX;
2186  for (i = 0; i < 19; i++) {
2187  int br_dist = abs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2188  if (br_dist < min_br_dist) {
2189  min_br_dist = br_dist;
2190  min_br_code = i;
2191  }
2192  }
2193 
2194  /* make sure the minimum frame size is below the average frame size */
2195  s->frame_size_code = min_br_code << 1;
2196  while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2197  wpf--;
2198  s->frame_size_min = 2 * wpf;
2199  } else {
2200  int best_br = 0, best_code = 0, best_diff = INT_MAX;
2201  for (i = 0; i < 19; i++) {
2202  int br = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2203  int diff = abs(br - avctx->bit_rate);
2204  if (diff < best_diff) {
2205  best_br = br;
2206  best_code = i;
2207  best_diff = diff;
2208  }
2209  if (!best_diff)
2210  break;
2211  }
2212  avctx->bit_rate = best_br;
2213  s->frame_size_code = best_code << 1;
2215  s->num_blks_code = 0x3;
2216  s->num_blocks = 6;
2217  }
2218  s->bit_rate = avctx->bit_rate;
2219  s->frame_size = s->frame_size_min;
2220 
2221  /* validate cutoff */
2222  if (avctx->cutoff < 0) {
2223  av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2224  return AVERROR(EINVAL);
2225  }
2226  s->cutoff = avctx->cutoff;
2227  if (s->cutoff > (s->sample_rate >> 1))
2228  s->cutoff = s->sample_rate >> 1;
2229 
2230  ret = ff_ac3_validate_metadata(s);
2231  if (ret)
2232  return ret;
2233 
2236 
2239 
2240  return 0;
2241 }
2242 
2243 
2244 /*
2245  * Set bandwidth for all channels.
2246  * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2247  * default value will be used.
2248  */
2250 {
2251  int blk, ch, av_uninit(cpl_start);
2252 
2253  if (s->cutoff) {
2254  /* calculate bandwidth based on user-specified cutoff frequency */
2255  int fbw_coeffs;
2256  fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2257  s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2258  } else {
2259  /* use default bandwidth setting */
2260  s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2261  }
2262 
2263  /* set number of coefficients for each channel */
2264  for (ch = 1; ch <= s->fbw_channels; ch++) {
2265  s->start_freq[ch] = 0;
2266  for (blk = 0; blk < s->num_blocks; blk++)
2267  s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2268  }
2269  /* LFE channel always has 7 coefs */
2270  if (s->lfe_on) {
2271  s->start_freq[s->lfe_channel] = 0;
2272  for (blk = 0; blk < s->num_blocks; blk++)
2273  s->blocks[blk].end_freq[ch] = 7;
2274  }
2275 
2276  /* initialize coupling strategy */
2277  if (s->cpl_enabled) {
2278  if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2279  cpl_start = s->options.cpl_start;
2280  } else {
2281  cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2282  if (cpl_start < 0) {
2284  s->cpl_enabled = 0;
2285  else
2286  cpl_start = 15;
2287  }
2288  }
2289  }
2290  if (s->cpl_enabled) {
2291  int i, cpl_start_band, cpl_end_band;
2292  uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2293 
2294  cpl_end_band = s->bandwidth_code / 4 + 3;
2295  cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2296 
2297  s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2298 
2299  s->num_cpl_bands = 1;
2300  *cpl_band_sizes = 12;
2301  for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2303  *cpl_band_sizes += 12;
2304  } else {
2305  s->num_cpl_bands++;
2306  cpl_band_sizes++;
2307  *cpl_band_sizes = 12;
2308  }
2309  }
2310 
2311  s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2312  s->cpl_end_freq = cpl_end_band * 12 + 37;
2313  for (blk = 0; blk < s->num_blocks; blk++)
2314  s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2315  }
2316 }
2317 
2318 
2320 {
2321  AVCodecContext *avctx = s->avctx;
2322  int blk, ch;
2323  int channels = s->channels + 1; /* includes coupling channel */
2324  int channel_blocks = channels * s->num_blocks;
2325  int total_coefs = AC3_MAX_COEFS * channel_blocks;
2326 
2327  if (s->allocate_sample_buffers(s))
2328  goto alloc_fail;
2329 
2330  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->bap_buffer, total_coefs,
2331  sizeof(*s->bap_buffer), alloc_fail);
2332  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->bap1_buffer, total_coefs,
2333  sizeof(*s->bap1_buffer), alloc_fail);
2334  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, s->mdct_coef_buffer, total_coefs,
2335  sizeof(*s->mdct_coef_buffer), alloc_fail);
2336  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->exp_buffer, total_coefs,
2337  sizeof(*s->exp_buffer), alloc_fail);
2338  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->grouped_exp_buffer, channel_blocks, 128 *
2339  sizeof(*s->grouped_exp_buffer), alloc_fail);
2340  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->psd_buffer, total_coefs,
2341  sizeof(*s->psd_buffer), alloc_fail);
2342  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->band_psd_buffer, channel_blocks, 64 *
2343  sizeof(*s->band_psd_buffer), alloc_fail);
2344  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->mask_buffer, channel_blocks, 64 *
2345  sizeof(*s->mask_buffer), alloc_fail);
2346  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->qmant_buffer, total_coefs,
2347  sizeof(*s->qmant_buffer), alloc_fail);
2348  if (s->cpl_enabled) {
2349  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->cpl_coord_exp_buffer, channel_blocks, 16 *
2350  sizeof(*s->cpl_coord_exp_buffer), alloc_fail);
2351  FF_ALLOC_ARRAY_OR_GOTO(avctx, s->cpl_coord_mant_buffer, channel_blocks, 16 *
2352  sizeof(*s->cpl_coord_mant_buffer), alloc_fail);
2353  }
2354  for (blk = 0; blk < s->num_blocks; blk++) {
2355  AC3Block *block = &s->blocks[blk];
2356  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->mdct_coef, channels, sizeof(*block->mdct_coef),
2357  alloc_fail);
2358  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->exp, channels, sizeof(*block->exp),
2359  alloc_fail);
2360  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->grouped_exp, channels, sizeof(*block->grouped_exp),
2361  alloc_fail);
2362  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->psd, channels, sizeof(*block->psd),
2363  alloc_fail);
2364  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->band_psd, channels, sizeof(*block->band_psd),
2365  alloc_fail);
2366  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->mask, channels, sizeof(*block->mask),
2367  alloc_fail);
2368  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->qmant, channels, sizeof(*block->qmant),
2369  alloc_fail);
2370  if (s->cpl_enabled) {
2371  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->cpl_coord_exp, channels, sizeof(*block->cpl_coord_exp),
2372  alloc_fail);
2373  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->cpl_coord_mant, channels, sizeof(*block->cpl_coord_mant),
2374  alloc_fail);
2375  }
2376 
2377  for (ch = 0; ch < channels; ch++) {
2378  /* arrangement: block, channel, coeff */
2379  block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
2380  block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2381  block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
2382  block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
2383  block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2384  if (s->cpl_enabled) {
2385  block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
2386  block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
2387  }
2388 
2389  /* arrangement: channel, block, coeff */
2390  block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2391  block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2392  }
2393  }
2394 
2395  if (!s->fixed_point) {
2396  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, s->fixed_coef_buffer, total_coefs,
2397  sizeof(*s->fixed_coef_buffer), alloc_fail);
2398  for (blk = 0; blk < s->num_blocks; blk++) {
2399  AC3Block *block = &s->blocks[blk];
2400  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->fixed_coef, channels,
2401  sizeof(*block->fixed_coef), alloc_fail);
2402  for (ch = 0; ch < channels; ch++)
2403  block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2404  }
2405  } else {
2406  for (blk = 0; blk < s->num_blocks; blk++) {
2407  AC3Block *block = &s->blocks[blk];
2408  FF_ALLOCZ_ARRAY_OR_GOTO(avctx, block->fixed_coef, channels,
2409  sizeof(*block->fixed_coef), alloc_fail);
2410  for (ch = 0; ch < channels; ch++)
2411  block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2412  }
2413  }
2414 
2415  return 0;
2416 alloc_fail:
2417  return AVERROR(ENOMEM);
2418 }
2419 
2420 
2422 {
2423  AC3EncodeContext *s = avctx->priv_data;
2424  int ret, frame_size_58;
2425 
2426  s->avctx = avctx;
2427 
2428  s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2429 
2431 
2432  ret = validate_options(s);
2433  if (ret)
2434  return ret;
2435 
2436  avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2438 
2439  s->bitstream_mode = avctx->audio_service_type;
2441  s->bitstream_mode = 0x7;
2442 
2443  s->bits_written = 0;
2444  s->samples_written = 0;
2445 
2446  /* calculate crc_inv for both possible frame sizes */
2447  frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
2448  s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2449  if (s->bit_alloc.sr_code == 1) {
2450  frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2451  s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2452  }
2453 
2454  /* set function pointers */
2455  if (CONFIG_AC3_FIXED_ENCODER && s->fixed_point) {
2459  } else if (CONFIG_AC3_ENCODER || CONFIG_EAC3_ENCODER) {
2463  }
2464  if (CONFIG_EAC3_ENCODER && s->eac3)
2466  else
2468 
2469  set_bandwidth(s);
2470 
2471  exponent_init(s);
2472 
2473  bit_alloc_init(s);
2474 
2475  ret = s->mdct_init(s);
2476  if (ret)
2477  goto init_fail;
2478 
2479  ret = allocate_buffers(s);
2480  if (ret)
2481  goto init_fail;
2482 
2483  ff_audiodsp_init(&s->adsp);
2484  ff_me_cmp_init(&s->mecc, avctx);
2486 
2487  dprint_options(s);
2488 
2489  return 0;
2490 init_fail:
2491  ff_ac3_encode_close(avctx);
2492  return ret;
2493 }