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ac3enc.c
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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 //#define ASSERT_LEVEL 2
30 
31 #include <stdint.h>
32 
33 #include "libavutil/avassert.h"
34 #include "libavutil/avstring.h"
35 #include "libavutil/channel_layout.h"
36 #include "libavutil/crc.h"
37 #include "libavutil/internal.h"
38 #include "libavutil/opt.h"
39 #include "avcodec.h"
40 #include "put_bits.h"
41 #include "ac3dsp.h"
42 #include "ac3.h"
43 #include "fft.h"
44 #include "ac3enc.h"
45 #include "eac3enc.h"
46 
47 typedef struct AC3Mant {
48  int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
49  int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
50 } AC3Mant;
51 
52 #define CMIXLEV_NUM_OPTIONS 3
53 static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
54  LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
55 };
56 
57 #define SURMIXLEV_NUM_OPTIONS 3
58 static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
59  LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
60 };
61 
62 #define EXTMIXLEV_NUM_OPTIONS 8
63 static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
64  LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_4POINT5DB,
65  LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
66 };
67 
68 
69 /**
70  * LUT for number of exponent groups.
71  * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
72  */
73 static uint8_t exponent_group_tab[2][3][256];
74 
75 
76 /**
77  * List of supported channel layouts.
78  */
79 const uint64_t ff_ac3_channel_layouts[19] = {
80  AV_CH_LAYOUT_MONO,
81  AV_CH_LAYOUT_STEREO,
82  AV_CH_LAYOUT_2_1,
83  AV_CH_LAYOUT_SURROUND,
84  AV_CH_LAYOUT_2_2,
85  AV_CH_LAYOUT_QUAD,
86  AV_CH_LAYOUT_4POINT0,
87  AV_CH_LAYOUT_5POINT0,
88  AV_CH_LAYOUT_5POINT0_BACK,
89  (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
90  (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
91  (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
92  (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
93  (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
94  (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
95  (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
96  AV_CH_LAYOUT_5POINT1,
97  AV_CH_LAYOUT_5POINT1_BACK,
98  0
99 };
100 
101 
102 /**
103  * LUT to select the bandwidth code based on the bit rate, sample rate, and
104  * number of full-bandwidth channels.
105  * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
106  */
107 static const uint8_t ac3_bandwidth_tab[5][3][19] = {
108 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
109 
110  { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
111  { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
112  { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
113 
114  { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
115  { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
116  { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
117 
118  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
119  { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
120  { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
121 
122  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
123  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
124  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
125 
126  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
127  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
128  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
129 };
130 
131 
132 /**
133  * LUT to select the coupling start band based on the bit rate, sample rate, and
134  * number of full-bandwidth channels. -1 = coupling off
135  * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
136  *
137  * TODO: more testing for optimal parameters.
138  * multi-channel tests at 44.1kHz and 32kHz.
139  */
140 static const int8_t ac3_coupling_start_tab[6][3][19] = {
141 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
142 
143  // 2/0
144  { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
145  { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
146  { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
147 
148  // 3/0
149  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
150  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
151  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
152 
153  // 2/1 - untested
154  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
155  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
156  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
157 
158  // 3/1
159  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
160  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
161  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
162 
163  // 2/2 - untested
164  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
165  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
166  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
167 
168  // 3/2
169  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
170  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
171  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
172 };
173 
174 
175 /**
176  * Adjust the frame size to make the average bit rate match the target bit rate.
177  * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
178  *
179  * @param s AC-3 encoder private context
180  */
181 void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
182 {
183  while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
184  s->bits_written -= s->bit_rate;
185  s->samples_written -= s->sample_rate;
186  }
187  s->frame_size = s->frame_size_min +
188  2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
189  s->bits_written += s->frame_size * 8;
190  s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
191 }
192 
193 
194 /**
195  * Set the initial coupling strategy parameters prior to coupling analysis.
196  *
197  * @param s AC-3 encoder private context
198  */
199 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
200 {
201  int blk, ch;
202  int got_cpl_snr;
203  int num_cpl_blocks;
204 
205  /* set coupling use flags for each block/channel */
206  /* TODO: turn coupling on/off and adjust start band based on bit usage */
207  for (blk = 0; blk < s->num_blocks; blk++) {
208  AC3Block *block = &s->blocks[blk];
209  for (ch = 1; ch <= s->fbw_channels; ch++)
210  block->channel_in_cpl[ch] = s->cpl_on;
211  }
212 
213  /* enable coupling for each block if at least 2 channels have coupling
214  enabled for that block */
215  got_cpl_snr = 0;
216  num_cpl_blocks = 0;
217  for (blk = 0; blk < s->num_blocks; blk++) {
218  AC3Block *block = &s->blocks[blk];
219  block->num_cpl_channels = 0;
220  for (ch = 1; ch <= s->fbw_channels; ch++)
221  block->num_cpl_channels += block->channel_in_cpl[ch];
222  block->cpl_in_use = block->num_cpl_channels > 1;
223  num_cpl_blocks += block->cpl_in_use;
224  if (!block->cpl_in_use) {
225  block->num_cpl_channels = 0;
226  for (ch = 1; ch <= s->fbw_channels; ch++)
227  block->channel_in_cpl[ch] = 0;
228  }
229 
230  block->new_cpl_strategy = !blk;
231  if (blk) {
232  for (ch = 1; ch <= s->fbw_channels; ch++) {
233  if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
234  block->new_cpl_strategy = 1;
235  break;
236  }
237  }
238  }
239  block->new_cpl_leak = block->new_cpl_strategy;
240 
241  if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
242  block->new_snr_offsets = 1;
243  if (block->cpl_in_use)
244  got_cpl_snr = 1;
245  } else {
246  block->new_snr_offsets = 0;
247  }
248  }
249  if (!num_cpl_blocks)
250  s->cpl_on = 0;
251 
252  /* set bandwidth for each channel */
253  for (blk = 0; blk < s->num_blocks; blk++) {
254  AC3Block *block = &s->blocks[blk];
255  for (ch = 1; ch <= s->fbw_channels; ch++) {
256  if (block->channel_in_cpl[ch])
257  block->end_freq[ch] = s->start_freq[CPL_CH];
258  else
259  block->end_freq[ch] = s->bandwidth_code * 3 + 73;
260  }
261  }
262 }
263 
264 
265 /**
266  * Apply stereo rematrixing to coefficients based on rematrixing flags.
267  *
268  * @param s AC-3 encoder private context
269  */
270 void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
271 {
272  int nb_coefs;
273  int blk, bnd, i;
274  int start, end;
275  uint8_t *flags = NULL;
276 
277  if (!s->rematrixing_enabled)
278  return;
279 
280  for (blk = 0; blk < s->num_blocks; blk++) {
281  AC3Block *block = &s->blocks[blk];
282  if (block->new_rematrixing_strategy)
283  flags = block->rematrixing_flags;
284  nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
285  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
286  if (flags[bnd]) {
287  start = ff_ac3_rematrix_band_tab[bnd];
288  end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
289  for (i = start; i < end; i++) {
290  int32_t lt = block->fixed_coef[1][i];
291  int32_t rt = block->fixed_coef[2][i];
292  block->fixed_coef[1][i] = (lt + rt) >> 1;
293  block->fixed_coef[2][i] = (lt - rt) >> 1;
294  }
295  }
296  }
297  }
298 }
299 
300 
301 /*
302  * Initialize exponent tables.
303  */
304 static av_cold void exponent_init(AC3EncodeContext *s)
305 {
306  int expstr, i, grpsize;
307 
308  for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
309  grpsize = 3 << expstr;
310  for (i = 12; i < 256; i++) {
311  exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
312  exponent_group_tab[1][expstr][i] = (i ) / grpsize;
313  }
314  }
315  /* LFE */
316  exponent_group_tab[0][0][7] = 2;
317 
318  if (CONFIG_EAC3_ENCODER && s->eac3)
319  ff_eac3_exponent_init();
320 }
321 
322 
323 /*
324  * Extract exponents from the MDCT coefficients.
325  */
326 static void extract_exponents(AC3EncodeContext *s)
327 {
328  int ch = !s->cpl_on;
329  int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
330  AC3Block *block = &s->blocks[0];
331 
332  s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
333 }
334 
335 
336 /**
337  * Exponent Difference Threshold.
338  * New exponents are sent if their SAD exceed this number.
339  */
340 #define EXP_DIFF_THRESHOLD 500
341 
342 /**
343  * Table used to select exponent strategy based on exponent reuse block interval.
344  */
345 static const uint8_t exp_strategy_reuse_tab[4][6] = {
346  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
347  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
348  { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
349  { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
350 };
351 
352 /*
353  * Calculate exponent strategies for all channels.
354  * Array arrangement is reversed to simplify the per-channel calculation.
355  */
356 static void compute_exp_strategy(AC3EncodeContext *s)
357 {
358  int ch, blk, blk1;
359 
360  for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
361  uint8_t *exp_strategy = s->exp_strategy[ch];
362  uint8_t *exp = s->blocks[0].exp[ch];
363  int exp_diff;
364 
365  /* estimate if the exponent variation & decide if they should be
366  reused in the next frame */
367  exp_strategy[0] = EXP_NEW;
368  exp += AC3_MAX_COEFS;
369  for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
370  if (ch == CPL_CH) {
371  if (!s->blocks[blk-1].cpl_in_use) {
372  exp_strategy[blk] = EXP_NEW;
373  continue;
374  } else if (!s->blocks[blk].cpl_in_use) {
375  exp_strategy[blk] = EXP_REUSE;
376  continue;
377  }
378  } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
379  exp_strategy[blk] = EXP_NEW;
380  continue;
381  }
382  exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
383  exp_strategy[blk] = EXP_REUSE;
384  if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
385  exp_strategy[blk] = EXP_NEW;
386  else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
387  exp_strategy[blk] = EXP_NEW;
388  }
389 
390  /* now select the encoding strategy type : if exponents are often
391  recoded, we use a coarse encoding */
392  blk = 0;
393  while (blk < s->num_blocks) {
394  blk1 = blk + 1;
395  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
396  blk1++;
397  exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
398  blk = blk1;
399  }
400  }
401  if (s->lfe_on) {
402  ch = s->lfe_channel;
403  s->exp_strategy[ch][0] = EXP_D15;
404  for (blk = 1; blk < s->num_blocks; blk++)
405  s->exp_strategy[ch][blk] = EXP_REUSE;
406  }
407 
408  /* for E-AC-3, determine frame exponent strategy */
409  if (CONFIG_EAC3_ENCODER && s->eac3)
410  ff_eac3_get_frame_exp_strategy(s);
411 }
412 
413 
414 /**
415  * Update the exponents so that they are the ones the decoder will decode.
416  *
417  * @param[in,out] exp array of exponents for 1 block in 1 channel
418  * @param nb_exps number of exponents in active bandwidth
419  * @param exp_strategy exponent strategy for the block
420  * @param cpl indicates if the block is in the coupling channel
421  */
422 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
423  int cpl)
424 {
425  int nb_groups, i, k;
426 
427  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
428 
429  /* for each group, compute the minimum exponent */
430  switch(exp_strategy) {
431  case EXP_D25:
432  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
433  uint8_t exp_min = exp[k];
434  if (exp[k+1] < exp_min)
435  exp_min = exp[k+1];
436  exp[i-cpl] = exp_min;
437  k += 2;
438  }
439  break;
440  case EXP_D45:
441  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
442  uint8_t exp_min = exp[k];
443  if (exp[k+1] < exp_min)
444  exp_min = exp[k+1];
445  if (exp[k+2] < exp_min)
446  exp_min = exp[k+2];
447  if (exp[k+3] < exp_min)
448  exp_min = exp[k+3];
449  exp[i-cpl] = exp_min;
450  k += 4;
451  }
452  break;
453  }
454 
455  /* constraint for DC exponent */
456  if (!cpl && exp[0] > 15)
457  exp[0] = 15;
458 
459  /* decrease the delta between each groups to within 2 so that they can be
460  differentially encoded */
461  for (i = 1; i <= nb_groups; i++)
462  exp[i] = FFMIN(exp[i], exp[i-1] + 2);
463  i--;
464  while (--i >= 0)
465  exp[i] = FFMIN(exp[i], exp[i+1] + 2);
466 
467  if (cpl)
468  exp[-1] = exp[0] & ~1;
469 
470  /* now we have the exponent values the decoder will see */
471  switch (exp_strategy) {
472  case EXP_D25:
473  for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
474  uint8_t exp1 = exp[i-cpl];
475  exp[k--] = exp1;
476  exp[k--] = exp1;
477  }
478  break;
479  case EXP_D45:
480  for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
481  exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
482  k -= 4;
483  }
484  break;
485  }
486 }
487 
488 
489 /*
490  * Encode exponents from original extracted form to what the decoder will see.
491  * This copies and groups exponents based on exponent strategy and reduces
492  * deltas between adjacent exponent groups so that they can be differentially
493  * encoded.
494  */
495 static void encode_exponents(AC3EncodeContext *s)
496 {
497  int blk, blk1, ch, cpl;
498  uint8_t *exp, *exp_strategy;
499  int nb_coefs, num_reuse_blocks;
500 
501  for (ch = !s->cpl_on; ch <= s->channels; ch++) {
502  exp = s->blocks[0].exp[ch] + s->start_freq[ch];
503  exp_strategy = s->exp_strategy[ch];
504 
505  cpl = (ch == CPL_CH);
506  blk = 0;
507  while (blk < s->num_blocks) {
508  AC3Block *block = &s->blocks[blk];
509  if (cpl && !block->cpl_in_use) {
510  exp += AC3_MAX_COEFS;
511  blk++;
512  continue;
513  }
514  nb_coefs = block->end_freq[ch] - s->start_freq[ch];
515  blk1 = blk + 1;
516 
517  /* count the number of EXP_REUSE blocks after the current block
518  and set exponent reference block numbers */
519  s->exp_ref_block[ch][blk] = blk;
520  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
521  s->exp_ref_block[ch][blk1] = blk;
522  blk1++;
523  }
524  num_reuse_blocks = blk1 - blk - 1;
525 
526  /* for the EXP_REUSE case we select the min of the exponents */
527  s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
528  AC3_MAX_COEFS);
529 
530  encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
531 
532  exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
533  blk = blk1;
534  }
535  }
536 
537  /* reference block numbers have been changed, so reset ref_bap_set */
538  s->ref_bap_set = 0;
539 }
540 
541 
542 /*
543  * Count exponent bits based on bandwidth, coupling, and exponent strategies.
544  */
545 static int count_exponent_bits(AC3EncodeContext *s)
546 {
547  int blk, ch;
548  int nb_groups, bit_count;
549 
550  bit_count = 0;
551  for (blk = 0; blk < s->num_blocks; blk++) {
552  AC3Block *block = &s->blocks[blk];
553  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
554  int exp_strategy = s->exp_strategy[ch][blk];
555  int cpl = (ch == CPL_CH);
556  int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
557 
558  if (exp_strategy == EXP_REUSE)
559  continue;
560 
561  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
562  bit_count += 4 + (nb_groups * 7);
563  }
564  }
565 
566  return bit_count;
567 }
568 
569 
570 /**
571  * Group exponents.
572  * 3 delta-encoded exponents are in each 7-bit group. The number of groups
573  * varies depending on exponent strategy and bandwidth.
574  *
575  * @param s AC-3 encoder private context
576  */
577 void ff_ac3_group_exponents(AC3EncodeContext *s)
578 {
579  int blk, ch, i, cpl;
580  int group_size, nb_groups;
581  uint8_t *p;
582  int delta0, delta1, delta2;
583  int exp0, exp1;
584 
585  for (blk = 0; blk < s->num_blocks; blk++) {
586  AC3Block *block = &s->blocks[blk];
587  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
588  int exp_strategy = s->exp_strategy[ch][blk];
589  if (exp_strategy == EXP_REUSE)
590  continue;
591  cpl = (ch == CPL_CH);
592  group_size = exp_strategy + (exp_strategy == EXP_D45);
593  nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
594  p = block->exp[ch] + s->start_freq[ch] - cpl;
595 
596  /* DC exponent */
597  exp1 = *p++;
598  block->grouped_exp[ch][0] = exp1;
599 
600  /* remaining exponents are delta encoded */
601  for (i = 1; i <= nb_groups; i++) {
602  /* merge three delta in one code */
603  exp0 = exp1;
604  exp1 = p[0];
605  p += group_size;
606  delta0 = exp1 - exp0 + 2;
607  av_assert2(delta0 >= 0 && delta0 <= 4);
608 
609  exp0 = exp1;
610  exp1 = p[0];
611  p += group_size;
612  delta1 = exp1 - exp0 + 2;
613  av_assert2(delta1 >= 0 && delta1 <= 4);
614 
615  exp0 = exp1;
616  exp1 = p[0];
617  p += group_size;
618  delta2 = exp1 - exp0 + 2;
619  av_assert2(delta2 >= 0 && delta2 <= 4);
620 
621  block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
622  }
623  }
624  }
625 }
626 
627 
628 /**
629  * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
630  * Extract exponents from MDCT coefficients, calculate exponent strategies,
631  * and encode final exponents.
632  *
633  * @param s AC-3 encoder private context
634  */
635 void ff_ac3_process_exponents(AC3EncodeContext *s)
636 {
637  extract_exponents(s);
638 
639  compute_exp_strategy(s);
640 
641  encode_exponents(s);
642 
643  emms_c();
644 }
645 
646 
647 /*
648  * Count frame bits that are based solely on fixed parameters.
649  * This only has to be run once when the encoder is initialized.
650  */
651 static void count_frame_bits_fixed(AC3EncodeContext *s)
652 {
653  static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
654  int blk;
655  int frame_bits;
656 
657  /* assumptions:
658  * no dynamic range codes
659  * bit allocation parameters do not change between blocks
660  * no delta bit allocation
661  * no skipped data
662  * no auxiliary data
663  * no E-AC-3 metadata
664  */
665 
666  /* header */
667  frame_bits = 16; /* sync info */
668  if (s->eac3) {
669  /* bitstream info header */
670  frame_bits += 35;
671  frame_bits += 1 + 1;
672  if (s->num_blocks != 0x6)
673  frame_bits++;
674  frame_bits++;
675  /* audio frame header */
676  if (s->num_blocks == 6)
677  frame_bits += 2;
678  frame_bits += 10;
679  /* exponent strategy */
680  if (s->use_frame_exp_strategy)
681  frame_bits += 5 * s->fbw_channels;
682  else
683  frame_bits += s->num_blocks * 2 * s->fbw_channels;
684  if (s->lfe_on)
685  frame_bits += s->num_blocks;
686  /* converter exponent strategy */
687  if (s->num_blks_code != 0x3)
688  frame_bits++;
689  else
690  frame_bits += s->fbw_channels * 5;
691  /* snr offsets */
692  frame_bits += 10;
693  /* block start info */
694  if (s->num_blocks != 1)
695  frame_bits++;
696  } else {
697  frame_bits += 49;
698  frame_bits += frame_bits_inc[s->channel_mode];
699  }
700 
701  /* audio blocks */
702  for (blk = 0; blk < s->num_blocks; blk++) {
703  if (!s->eac3) {
704  /* block switch flags */
705  frame_bits += s->fbw_channels;
706 
707  /* dither flags */
708  frame_bits += s->fbw_channels;
709  }
710 
711  /* dynamic range */
712  frame_bits++;
713 
714  /* spectral extension */
715  if (s->eac3)
716  frame_bits++;
717 
718  if (!s->eac3) {
719  /* exponent strategy */
720  frame_bits += 2 * s->fbw_channels;
721  if (s->lfe_on)
722  frame_bits++;
723 
724  /* bit allocation params */
725  frame_bits++;
726  if (!blk)
727  frame_bits += 2 + 2 + 2 + 2 + 3;
728  }
729 
730  /* converter snr offset */
731  if (s->eac3)
732  frame_bits++;
733 
734  if (!s->eac3) {
735  /* delta bit allocation */
736  frame_bits++;
737 
738  /* skipped data */
739  frame_bits++;
740  }
741  }
742 
743  /* auxiliary data */
744  frame_bits++;
745 
746  /* CRC */
747  frame_bits += 1 + 16;
748 
749  s->frame_bits_fixed = frame_bits;
750 }
751 
752 
753 /*
754  * Initialize bit allocation.
755  * Set default parameter codes and calculate parameter values.
756  */
757 static void bit_alloc_init(AC3EncodeContext *s)
758 {
759  int ch;
760 
761  /* init default parameters */
762  s->slow_decay_code = 2;
763  s->fast_decay_code = 1;
764  s->slow_gain_code = 1;
765  s->db_per_bit_code = s->eac3 ? 2 : 3;
766  s->floor_code = 7;
767  for (ch = 0; ch <= s->channels; ch++)
768  s->fast_gain_code[ch] = 4;
769 
770  /* initial snr offset */
771  s->coarse_snr_offset = 40;
772 
773  /* compute real values */
774  /* currently none of these values change during encoding, so we can just
775  set them once at initialization */
776  s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
777  s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
778  s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
779  s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
780  s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
781  s->bit_alloc.cpl_fast_leak = 0;
782  s->bit_alloc.cpl_slow_leak = 0;
783 
784  count_frame_bits_fixed(s);
785 }
786 
787 
788 /*
789  * Count the bits used to encode the frame, minus exponents and mantissas.
790  * Bits based on fixed parameters have already been counted, so now we just
791  * have to add the bits based on parameters that change during encoding.
792  */
793 static void count_frame_bits(AC3EncodeContext *s)
794 {
795  AC3EncOptions *opt = &s->options;
796  int blk, ch;
797  int frame_bits = 0;
798 
799  /* header */
800  if (s->eac3) {
801  if (opt->eac3_mixing_metadata) {
802  if (s->channel_mode > AC3_CHMODE_STEREO)
803  frame_bits += 2;
804  if (s->has_center)
805  frame_bits += 6;
806  if (s->has_surround)
807  frame_bits += 6;
808  frame_bits += s->lfe_on;
809  frame_bits += 1 + 1 + 2;
810  if (s->channel_mode < AC3_CHMODE_STEREO)
811  frame_bits++;
812  frame_bits++;
813  }
814  if (opt->eac3_info_metadata) {
815  frame_bits += 3 + 1 + 1;
816  if (s->channel_mode == AC3_CHMODE_STEREO)
817  frame_bits += 2 + 2;
818  if (s->channel_mode >= AC3_CHMODE_2F2R)
819  frame_bits += 2;
820  frame_bits++;
821  if (opt->audio_production_info)
822  frame_bits += 5 + 2 + 1;
823  frame_bits++;
824  }
825  /* coupling */
826  if (s->channel_mode > AC3_CHMODE_MONO) {
827  frame_bits++;
828  for (blk = 1; blk < s->num_blocks; blk++) {
829  AC3Block *block = &s->blocks[blk];
830  frame_bits++;
831  if (block->new_cpl_strategy)
832  frame_bits++;
833  }
834  }
835  /* coupling exponent strategy */
836  if (s->cpl_on) {
837  if (s->use_frame_exp_strategy) {
838  frame_bits += 5 * s->cpl_on;
839  } else {
840  for (blk = 0; blk < s->num_blocks; blk++)
841  frame_bits += 2 * s->blocks[blk].cpl_in_use;
842  }
843  }
844  } else {
845  if (opt->audio_production_info)
846  frame_bits += 7;
847  if (s->bitstream_id == 6) {
848  if (opt->extended_bsi_1)
849  frame_bits += 14;
850  if (opt->extended_bsi_2)
851  frame_bits += 14;
852  }
853  }
854 
855  /* audio blocks */
856  for (blk = 0; blk < s->num_blocks; blk++) {
857  AC3Block *block = &s->blocks[blk];
858 
859  /* coupling strategy */
860  if (!s->eac3)
861  frame_bits++;
862  if (block->new_cpl_strategy) {
863  if (!s->eac3)
864  frame_bits++;
865  if (block->cpl_in_use) {
866  if (s->eac3)
867  frame_bits++;
868  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
869  frame_bits += s->fbw_channels;
870  if (s->channel_mode == AC3_CHMODE_STEREO)
871  frame_bits++;
872  frame_bits += 4 + 4;
873  if (s->eac3)
874  frame_bits++;
875  else
876  frame_bits += s->num_cpl_subbands - 1;
877  }
878  }
879 
880  /* coupling coordinates */
881  if (block->cpl_in_use) {
882  for (ch = 1; ch <= s->fbw_channels; ch++) {
883  if (block->channel_in_cpl[ch]) {
884  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
885  frame_bits++;
886  if (block->new_cpl_coords[ch]) {
887  frame_bits += 2;
888  frame_bits += (4 + 4) * s->num_cpl_bands;
889  }
890  }
891  }
892  }
893 
894  /* stereo rematrixing */
895  if (s->channel_mode == AC3_CHMODE_STEREO) {
896  if (!s->eac3 || blk > 0)
897  frame_bits++;
898  if (s->blocks[blk].new_rematrixing_strategy)
899  frame_bits += block->num_rematrixing_bands;
900  }
901 
902  /* bandwidth codes & gain range */
903  for (ch = 1; ch <= s->fbw_channels; ch++) {
904  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
905  if (!block->channel_in_cpl[ch])
906  frame_bits += 6;
907  frame_bits += 2;
908  }
909  }
910 
911  /* coupling exponent strategy */
912  if (!s->eac3 && block->cpl_in_use)
913  frame_bits += 2;
914 
915  /* snr offsets and fast gain codes */
916  if (!s->eac3) {
917  frame_bits++;
918  if (block->new_snr_offsets)
919  frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
920  }
921 
922  /* coupling leak info */
923  if (block->cpl_in_use) {
924  if (!s->eac3 || block->new_cpl_leak != 2)
925  frame_bits++;
926  if (block->new_cpl_leak)
927  frame_bits += 3 + 3;
928  }
929  }
930 
931  s->frame_bits = s->frame_bits_fixed + frame_bits;
932 }
933 
934 
935 /*
936  * Calculate masking curve based on the final exponents.
937  * Also calculate the power spectral densities to use in future calculations.
938  */
939 static void bit_alloc_masking(AC3EncodeContext *s)
940 {
941  int blk, ch;
942 
943  for (blk = 0; blk < s->num_blocks; blk++) {
944  AC3Block *block = &s->blocks[blk];
945  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
946  /* We only need psd and mask for calculating bap.
947  Since we currently do not calculate bap when exponent
948  strategy is EXP_REUSE we do not need to calculate psd or mask. */
949  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
950  ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
951  block->end_freq[ch], block->psd[ch],
952  block->band_psd[ch]);
953  ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
954  s->start_freq[ch], block->end_freq[ch],
955  ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
956  ch == s->lfe_channel,
957  DBA_NONE, 0, NULL, NULL, NULL,
958  block->mask[ch]);
959  }
960  }
961  }
962 }
963 
964 
965 /*
966  * Ensure that bap for each block and channel point to the current bap_buffer.
967  * They may have been switched during the bit allocation search.
968  */
969 static void reset_block_bap(AC3EncodeContext *s)
970 {
971  int blk, ch;
972  uint8_t *ref_bap;
973 
974  if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
975  return;
976 
977  ref_bap = s->bap_buffer;
978  for (ch = 0; ch <= s->channels; ch++) {
979  for (blk = 0; blk < s->num_blocks; blk++)
980  s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
981  ref_bap += AC3_MAX_COEFS * s->num_blocks;
982  }
983  s->ref_bap_set = 1;
984 }
985 
986 
987 /**
988  * Initialize mantissa counts.
989  * These are set so that they are padded to the next whole group size when bits
990  * are counted in compute_mantissa_size.
991  *
992  * @param[in,out] mant_cnt running counts for each bap value for each block
993  */
994 static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
995 {
996  int blk;
997 
998  for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
999  memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
1000  mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1001  mant_cnt[blk][4] = 1;
1002  }
1003 }
1004 
1005 
1006 /**
1007  * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1008  * range.
1009  *
1010  * @param s AC-3 encoder private context
1011  * @param ch channel index
1012  * @param[in,out] mant_cnt running counts for each bap value for each block
1013  * @param start starting coefficient bin
1014  * @param end ending coefficient bin
1015  */
1016 static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
1017  uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1018  int start, int end)
1019 {
1020  int blk;
1021 
1022  for (blk = 0; blk < s->num_blocks; blk++) {
1023  AC3Block *block = &s->blocks[blk];
1024  if (ch == CPL_CH && !block->cpl_in_use)
1025  continue;
1026  s->ac3dsp.update_bap_counts(mant_cnt[blk],
1027  s->ref_bap[ch][blk] + start,
1028  FFMIN(end, block->end_freq[ch]) - start);
1029  }
1030 }
1031 
1032 
1033 /*
1034  * Count the number of mantissa bits in the frame based on the bap values.
1035  */
1036 static int count_mantissa_bits(AC3EncodeContext *s)
1037 {
1038  int ch, max_end_freq;
1039  LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1040 
1041  count_mantissa_bits_init(mant_cnt);
1042 
1043  max_end_freq = s->bandwidth_code * 3 + 73;
1044  for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1045  count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1046  max_end_freq);
1047 
1048  return s->ac3dsp.compute_mantissa_size(mant_cnt);
1049 }
1050 
1051 
1052 /**
1053  * Run the bit allocation with a given SNR offset.
1054  * This calculates the bit allocation pointers that will be used to determine
1055  * the quantization of each mantissa.
1056  *
1057  * @param s AC-3 encoder private context
1058  * @param snr_offset SNR offset, 0 to 1023
1059  * @return the number of bits needed for mantissas if the given SNR offset is
1060  * is used.
1061  */
1062 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1063 {
1064  int blk, ch;
1065 
1066  snr_offset = (snr_offset - 240) << 2;
1067 
1068  reset_block_bap(s);
1069  for (blk = 0; blk < s->num_blocks; blk++) {
1070  AC3Block *block = &s->blocks[blk];
1071 
1072  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1073  /* Currently the only bit allocation parameters which vary across
1074  blocks within a frame are the exponent values. We can take
1075  advantage of that by reusing the bit allocation pointers
1076  whenever we reuse exponents. */
1077  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1078  s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1079  s->start_freq[ch], block->end_freq[ch],
1080  snr_offset, s->bit_alloc.floor,
1081  ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1082  }
1083  }
1084  }
1085  return count_mantissa_bits(s);
1086 }
1087 
1088 
1089 /*
1090  * Constant bitrate bit allocation search.
1091  * Find the largest SNR offset that will allow data to fit in the frame.
1092  */
1093 static int cbr_bit_allocation(AC3EncodeContext *s)
1094 {
1095  int ch;
1096  int bits_left;
1097  int snr_offset, snr_incr;
1098 
1099  bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1100  if (bits_left < 0)
1101  return AVERROR(EINVAL);
1102 
1103  snr_offset = s->coarse_snr_offset << 4;
1104 
1105  /* if previous frame SNR offset was 1023, check if current frame can also
1106  use SNR offset of 1023. if so, skip the search. */
1107  if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1108  if (bit_alloc(s, 1023) <= bits_left)
1109  return 0;
1110  }
1111 
1112  while (snr_offset >= 0 &&
1113  bit_alloc(s, snr_offset) > bits_left) {
1114  snr_offset -= 64;
1115  }
1116  if (snr_offset < 0)
1117  return AVERROR(EINVAL);
1118 
1119  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1120  for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1121  while (snr_offset + snr_incr <= 1023 &&
1122  bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1123  snr_offset += snr_incr;
1124  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1125  }
1126  }
1127  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1128  reset_block_bap(s);
1129 
1130  s->coarse_snr_offset = snr_offset >> 4;
1131  for (ch = !s->cpl_on; ch <= s->channels; ch++)
1132  s->fine_snr_offset[ch] = snr_offset & 0xF;
1133 
1134  return 0;
1135 }
1136 
1137 
1138 /*
1139  * Perform bit allocation search.
1140  * Finds the SNR offset value that maximizes quality and fits in the specified
1141  * frame size. Output is the SNR offset and a set of bit allocation pointers
1142  * used to quantize the mantissas.
1143  */
1144 int ff_ac3_compute_bit_allocation(AC3EncodeContext *s)
1145 {
1146  count_frame_bits(s);
1147 
1148  s->exponent_bits = count_exponent_bits(s);
1149 
1150  bit_alloc_masking(s);
1151 
1152  return cbr_bit_allocation(s);
1153 }
1154 
1155 
1156 /**
1157  * Symmetric quantization on 'levels' levels.
1158  *
1159  * @param c unquantized coefficient
1160  * @param e exponent
1161  * @param levels number of quantization levels
1162  * @return quantized coefficient
1163  */
1164 static inline int sym_quant(int c, int e, int levels)
1165 {
1166  int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1167  av_assert2(v >= 0 && v < levels);
1168  return v;
1169 }
1170 
1171 
1172 /**
1173  * Asymmetric quantization on 2^qbits levels.
1174  *
1175  * @param c unquantized coefficient
1176  * @param e exponent
1177  * @param qbits number of quantization bits
1178  * @return quantized coefficient
1179  */
1180 static inline int asym_quant(int c, int e, int qbits)
1181 {
1182  int m;
1183 
1184  c = (((c << e) >> (24 - qbits)) + 1) >> 1;
1185  m = (1 << (qbits-1));
1186  if (c >= m)
1187  c = m - 1;
1188  av_assert2(c >= -m);
1189  return c;
1190 }
1191 
1192 
1193 /**
1194  * Quantize a set of mantissas for a single channel in a single block.
1195  *
1196  * @param s Mantissa count context
1197  * @param fixed_coef unquantized fixed-point coefficients
1198  * @param exp exponents
1199  * @param bap bit allocation pointer indices
1200  * @param[out] qmant quantized coefficients
1201  * @param start_freq starting coefficient bin
1202  * @param end_freq ending coefficient bin
1203  */
1204 static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1205  uint8_t *exp, uint8_t *bap,
1206  int16_t *qmant, int start_freq,
1207  int end_freq)
1208 {
1209  int i;
1210 
1211  for (i = start_freq; i < end_freq; i++) {
1212  int c = fixed_coef[i];
1213  int e = exp[i];
1214  int v = bap[i];
1215  if (v)
1216  switch (v) {
1217  case 1:
1218  v = sym_quant(c, e, 3);
1219  switch (s->mant1_cnt) {
1220  case 0:
1221  s->qmant1_ptr = &qmant[i];
1222  v = 9 * v;
1223  s->mant1_cnt = 1;
1224  break;
1225  case 1:
1226  *s->qmant1_ptr += 3 * v;
1227  s->mant1_cnt = 2;
1228  v = 128;
1229  break;
1230  default:
1231  *s->qmant1_ptr += v;
1232  s->mant1_cnt = 0;
1233  v = 128;
1234  break;
1235  }
1236  break;
1237  case 2:
1238  v = sym_quant(c, e, 5);
1239  switch (s->mant2_cnt) {
1240  case 0:
1241  s->qmant2_ptr = &qmant[i];
1242  v = 25 * v;
1243  s->mant2_cnt = 1;
1244  break;
1245  case 1:
1246  *s->qmant2_ptr += 5 * v;
1247  s->mant2_cnt = 2;
1248  v = 128;
1249  break;
1250  default:
1251  *s->qmant2_ptr += v;
1252  s->mant2_cnt = 0;
1253  v = 128;
1254  break;
1255  }
1256  break;
1257  case 3:
1258  v = sym_quant(c, e, 7);
1259  break;
1260  case 4:
1261  v = sym_quant(c, e, 11);
1262  switch (s->mant4_cnt) {
1263  case 0:
1264  s->qmant4_ptr = &qmant[i];
1265  v = 11 * v;
1266  s->mant4_cnt = 1;
1267  break;
1268  default:
1269  *s->qmant4_ptr += v;
1270  s->mant4_cnt = 0;
1271  v = 128;
1272  break;
1273  }
1274  break;
1275  case 5:
1276  v = sym_quant(c, e, 15);
1277  break;
1278  case 14:
1279  v = asym_quant(c, e, 14);
1280  break;
1281  case 15:
1282  v = asym_quant(c, e, 16);
1283  break;
1284  default:
1285  v = asym_quant(c, e, v - 1);
1286  break;
1287  }
1288  qmant[i] = v;
1289  }
1290 }
1291 
1292 
1293 /**
1294  * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1295  *
1296  * @param s AC-3 encoder private context
1297  */
1298 void ff_ac3_quantize_mantissas(AC3EncodeContext *s)
1299 {
1300  int blk, ch, ch0=0, got_cpl;
1301 
1302  for (blk = 0; blk < s->num_blocks; blk++) {
1303  AC3Block *block = &s->blocks[blk];
1304  AC3Mant m = { 0 };
1305 
1306  got_cpl = !block->cpl_in_use;
1307  for (ch = 1; ch <= s->channels; ch++) {
1308  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1309  ch0 = ch - 1;
1310  ch = CPL_CH;
1311  got_cpl = 1;
1312  }
1313  quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1314  s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1315  s->ref_bap[ch][blk], block->qmant[ch],
1316  s->start_freq[ch], block->end_freq[ch]);
1317  if (ch == CPL_CH)
1318  ch = ch0;
1319  }
1320  }
1321 }
1322 
1323 
1324 /*
1325  * Write the AC-3 frame header to the output bitstream.
1326  */
1327 static void ac3_output_frame_header(AC3EncodeContext *s)
1328 {
1329  AC3EncOptions *opt = &s->options;
1330 
1331  put_bits(&s->pb, 16, 0x0b77); /* frame header */
1332  put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
1333  put_bits(&s->pb, 2, s->bit_alloc.sr_code);
1334  put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1335  put_bits(&s->pb, 5, s->bitstream_id);
1336  put_bits(&s->pb, 3, s->bitstream_mode);
1337  put_bits(&s->pb, 3, s->channel_mode);
1338  if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1339  put_bits(&s->pb, 2, s->center_mix_level);
1340  if (s->channel_mode & 0x04)
1341  put_bits(&s->pb, 2, s->surround_mix_level);
1342  if (s->channel_mode == AC3_CHMODE_STEREO)
1343  put_bits(&s->pb, 2, opt->dolby_surround_mode);
1344  put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1345  put_bits(&s->pb, 5, -opt->dialogue_level);
1346  put_bits(&s->pb, 1, 0); /* no compression control word */
1347  put_bits(&s->pb, 1, 0); /* no lang code */
1348  put_bits(&s->pb, 1, opt->audio_production_info);
1349  if (opt->audio_production_info) {
1350  put_bits(&s->pb, 5, opt->mixing_level - 80);
1351  put_bits(&s->pb, 2, opt->room_type);
1352  }
1353  put_bits(&s->pb, 1, opt->copyright);
1354  put_bits(&s->pb, 1, opt->original);
1355  if (s->bitstream_id == 6) {
1356  /* alternate bit stream syntax */
1357  put_bits(&s->pb, 1, opt->extended_bsi_1);
1358  if (opt->extended_bsi_1) {
1359  put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1360  put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1361  put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1362  put_bits(&s->pb, 3, s->loro_center_mix_level);
1363  put_bits(&s->pb, 3, s->loro_surround_mix_level);
1364  }
1365  put_bits(&s->pb, 1, opt->extended_bsi_2);
1366  if (opt->extended_bsi_2) {
1367  put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1368  put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1369  put_bits(&s->pb, 1, opt->ad_converter_type);
1370  put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
1371  }
1372  } else {
1373  put_bits(&s->pb, 1, 0); /* no time code 1 */
1374  put_bits(&s->pb, 1, 0); /* no time code 2 */
1375  }
1376  put_bits(&s->pb, 1, 0); /* no additional bit stream info */
1377 }
1378 
1379 
1380 /*
1381  * Write one audio block to the output bitstream.
1382  */
1383 static void output_audio_block(AC3EncodeContext *s, int blk)
1384 {
1385  int ch, i, baie, bnd, got_cpl, ch0;
1386  AC3Block *block = &s->blocks[blk];
1387 
1388  /* block switching */
1389  if (!s->eac3) {
1390  for (ch = 0; ch < s->fbw_channels; ch++)
1391  put_bits(&s->pb, 1, 0);
1392  }
1393 
1394  /* dither flags */
1395  if (!s->eac3) {
1396  for (ch = 0; ch < s->fbw_channels; ch++)
1397  put_bits(&s->pb, 1, 1);
1398  }
1399 
1400  /* dynamic range codes */
1401  put_bits(&s->pb, 1, 0);
1402 
1403  /* spectral extension */
1404  if (s->eac3)
1405  put_bits(&s->pb, 1, 0);
1406 
1407  /* channel coupling */
1408  if (!s->eac3)
1409  put_bits(&s->pb, 1, block->new_cpl_strategy);
1410  if (block->new_cpl_strategy) {
1411  if (!s->eac3)
1412  put_bits(&s->pb, 1, block->cpl_in_use);
1413  if (block->cpl_in_use) {
1414  int start_sub, end_sub;
1415  if (s->eac3)
1416  put_bits(&s->pb, 1, 0); /* enhanced coupling */
1417  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1418  for (ch = 1; ch <= s->fbw_channels; ch++)
1419  put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1420  }
1421  if (s->channel_mode == AC3_CHMODE_STEREO)
1422  put_bits(&s->pb, 1, 0); /* phase flags in use */
1423  start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1424  end_sub = (s->cpl_end_freq - 37) / 12;
1425  put_bits(&s->pb, 4, start_sub);
1426  put_bits(&s->pb, 4, end_sub - 3);
1427  /* coupling band structure */
1428  if (s->eac3) {
1429  put_bits(&s->pb, 1, 0); /* use default */
1430  } else {
1431  for (bnd = start_sub+1; bnd < end_sub; bnd++)
1432  put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
1433  }
1434  }
1435  }
1436 
1437  /* coupling coordinates */
1438  if (block->cpl_in_use) {
1439  for (ch = 1; ch <= s->fbw_channels; ch++) {
1440  if (block->channel_in_cpl[ch]) {
1441  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1442  put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1443  if (block->new_cpl_coords[ch]) {
1444  put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1445  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1446  put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1447  put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1448  }
1449  }
1450  }
1451  }
1452  }
1453 
1454  /* stereo rematrixing */
1455  if (s->channel_mode == AC3_CHMODE_STEREO) {
1456  if (!s->eac3 || blk > 0)
1457  put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1458  if (block->new_rematrixing_strategy) {
1459  /* rematrixing flags */
1460  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1461  put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1462  }
1463  }
1464 
1465  /* exponent strategy */
1466  if (!s->eac3) {
1467  for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1468  put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1469  if (s->lfe_on)
1470  put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1471  }
1472 
1473  /* bandwidth */
1474  for (ch = 1; ch <= s->fbw_channels; ch++) {
1475  if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1476  put_bits(&s->pb, 6, s->bandwidth_code);
1477  }
1478 
1479  /* exponents */
1480  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1481  int nb_groups;
1482  int cpl = (ch == CPL_CH);
1483 
1484  if (s->exp_strategy[ch][blk] == EXP_REUSE)
1485  continue;
1486 
1487  /* DC exponent */
1488  put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1489 
1490  /* exponent groups */
1491  nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1492  for (i = 1; i <= nb_groups; i++)
1493  put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1494 
1495  /* gain range info */
1496  if (ch != s->lfe_channel && !cpl)
1497  put_bits(&s->pb, 2, 0);
1498  }
1499 
1500  /* bit allocation info */
1501  if (!s->eac3) {
1502  baie = (blk == 0);
1503  put_bits(&s->pb, 1, baie);
1504  if (baie) {
1505  put_bits(&s->pb, 2, s->slow_decay_code);
1506  put_bits(&s->pb, 2, s->fast_decay_code);
1507  put_bits(&s->pb, 2, s->slow_gain_code);
1508  put_bits(&s->pb, 2, s->db_per_bit_code);
1509  put_bits(&s->pb, 3, s->floor_code);
1510  }
1511  }
1512 
1513  /* snr offset */
1514  if (!s->eac3) {
1515  put_bits(&s->pb, 1, block->new_snr_offsets);
1516  if (block->new_snr_offsets) {
1517  put_bits(&s->pb, 6, s->coarse_snr_offset);
1518  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1519  put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1520  put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1521  }
1522  }
1523  } else {
1524  put_bits(&s->pb, 1, 0); /* no converter snr offset */
1525  }
1526 
1527  /* coupling leak */
1528  if (block->cpl_in_use) {
1529  if (!s->eac3 || block->new_cpl_leak != 2)
1530  put_bits(&s->pb, 1, block->new_cpl_leak);
1531  if (block->new_cpl_leak) {
1532  put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1533  put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1534  }
1535  }
1536 
1537  if (!s->eac3) {
1538  put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1539  put_bits(&s->pb, 1, 0); /* no data to skip */
1540  }
1541 
1542  /* mantissas */
1543  got_cpl = !block->cpl_in_use;
1544  for (ch = 1; ch <= s->channels; ch++) {
1545  int b, q;
1546 
1547  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1548  ch0 = ch - 1;
1549  ch = CPL_CH;
1550  got_cpl = 1;
1551  }
1552  for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1553  q = block->qmant[ch][i];
1554  b = s->ref_bap[ch][blk][i];
1555  switch (b) {
1556  case 0: break;
1557  case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
1558  case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
1559  case 3: put_sbits(&s->pb, 3, q); break;
1560  case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
1561  case 14: put_sbits(&s->pb, 14, q); break;
1562  case 15: put_sbits(&s->pb, 16, q); break;
1563  default: put_sbits(&s->pb, b-1, q); break;
1564  }
1565  }
1566  if (ch == CPL_CH)
1567  ch = ch0;
1568  }
1569 }
1570 
1571 
1572 /** CRC-16 Polynomial */
1573 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1574 
1575 
1576 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1577 {
1578  unsigned int c;
1579 
1580  c = 0;
1581  while (a) {
1582  if (a & 1)
1583  c ^= b;
1584  a = a >> 1;
1585  b = b << 1;
1586  if (b & (1 << 16))
1587  b ^= poly;
1588  }
1589  return c;
1590 }
1591 
1592 
1593 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1594 {
1595  unsigned int r;
1596  r = 1;
1597  while (n) {
1598  if (n & 1)
1599  r = mul_poly(r, a, poly);
1600  a = mul_poly(a, a, poly);
1601  n >>= 1;
1602  }
1603  return r;
1604 }
1605 
1606 
1607 /*
1608  * Fill the end of the frame with 0's and compute the two CRCs.
1609  */
1610 static void output_frame_end(AC3EncodeContext *s)
1611 {
1612  const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1613  int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1614  uint8_t *frame;
1615 
1616  frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1617 
1618  /* pad the remainder of the frame with zeros */
1619  av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1620  flush_put_bits(&s->pb);
1621  frame = s->pb.buf;
1622  pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1623  av_assert2(pad_bytes >= 0);
1624  if (pad_bytes > 0)
1625  memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1626 
1627  if (s->eac3) {
1628  /* compute crc2 */
1629  crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1630  } else {
1631  /* compute crc1 */
1632  /* this is not so easy because it is at the beginning of the data... */
1633  crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1634  crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1635  crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
1636  AV_WB16(frame + 2, crc1);
1637 
1638  /* compute crc2 */
1639  crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1640  s->frame_size - frame_size_58 - 3);
1641  }
1642  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1643  /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1644  if (crc2 == 0x770B) {
1645  frame[s->frame_size - 3] ^= 0x1;
1646  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1647  }
1648  crc2 = av_bswap16(crc2);
1649  AV_WB16(frame + s->frame_size - 2, crc2);
1650 }
1651 
1652 
1653 /**
1654  * Write the frame to the output bitstream.
1655  *
1656  * @param s AC-3 encoder private context
1657  * @param frame output data buffer
1658  */
1659 void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
1660 {
1661  int blk;
1662 
1663  init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
1664 
1665  s->output_frame_header(s);
1666 
1667  for (blk = 0; blk < s->num_blocks; blk++)
1668  output_audio_block(s, blk);
1669 
1670  output_frame_end(s);
1671 }
1672 
1673 
1674 static void dprint_options(AC3EncodeContext *s)
1675 {
1676 #ifdef DEBUG
1677  AVCodecContext *avctx = s->avctx;
1678  AC3EncOptions *opt = &s->options;
1679  char strbuf[32];
1680 
1681  switch (s->bitstream_id) {
1682  case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
1683  case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
1684  case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
1685  case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1686  case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
1687  default: snprintf(strbuf, 32, "ERROR");
1688  }
1689  av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1690  av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1691  av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1692  av_dlog(avctx, "channel_layout: %s\n", strbuf);
1693  av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1694  av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1695  av_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1696  if (s->cutoff)
1697  av_dlog(avctx, "cutoff: %d\n", s->cutoff);
1698 
1699  av_dlog(avctx, "per_frame_metadata: %s\n",
1700  opt->allow_per_frame_metadata?"on":"off");
1701  if (s->has_center)
1702  av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1703  s->center_mix_level);
1704  else
1705  av_dlog(avctx, "center_mixlev: {not written}\n");
1706  if (s->has_surround)
1707  av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1708  s->surround_mix_level);
1709  else
1710  av_dlog(avctx, "surround_mixlev: {not written}\n");
1711  if (opt->audio_production_info) {
1712  av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1713  switch (opt->room_type) {
1714  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1715  case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
1716  case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
1717  default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1718  }
1719  av_dlog(avctx, "room_type: %s\n", strbuf);
1720  } else {
1721  av_dlog(avctx, "mixing_level: {not written}\n");
1722  av_dlog(avctx, "room_type: {not written}\n");
1723  }
1724  av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1725  av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1726  if (s->channel_mode == AC3_CHMODE_STEREO) {
1727  switch (opt->dolby_surround_mode) {
1728  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1729  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1730  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1731  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1732  }
1733  av_dlog(avctx, "dsur_mode: %s\n", strbuf);
1734  } else {
1735  av_dlog(avctx, "dsur_mode: {not written}\n");
1736  }
1737  av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1738 
1739  if (s->bitstream_id == 6) {
1740  if (opt->extended_bsi_1) {
1741  switch (opt->preferred_stereo_downmix) {
1742  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1743  case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
1744  case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
1745  default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1746  }
1747  av_dlog(avctx, "dmix_mode: %s\n", strbuf);
1748  av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1749  opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1750  av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1751  opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1752  av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1753  opt->loro_center_mix_level, s->loro_center_mix_level);
1754  av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1755  opt->loro_surround_mix_level, s->loro_surround_mix_level);
1756  } else {
1757  av_dlog(avctx, "extended bitstream info 1: {not written}\n");
1758  }
1759  if (opt->extended_bsi_2) {
1760  switch (opt->dolby_surround_ex_mode) {
1761  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1762  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1763  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1764  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1765  }
1766  av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1767  switch (opt->dolby_headphone_mode) {
1768  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1769  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1770  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1771  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1772  }
1773  av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1774 
1775  switch (opt->ad_converter_type) {
1776  case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1777  case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
1778  default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1779  }
1780  av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1781  } else {
1782  av_dlog(avctx, "extended bitstream info 2: {not written}\n");
1783  }
1784  }
1785 #endif
1786 }
1787 
1788 
1789 #define FLT_OPTION_THRESHOLD 0.01
1790 
1791 static int validate_float_option(float v, const float *v_list, int v_list_size)
1792 {
1793  int i;
1794 
1795  for (i = 0; i < v_list_size; i++) {
1796  if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1797  v > (v_list[i] - FLT_OPTION_THRESHOLD))
1798  break;
1799  }
1800  if (i == v_list_size)
1801  return -1;
1802 
1803  return i;
1804 }
1805 
1806 
1807 static void validate_mix_level(void *log_ctx, const char *opt_name,
1808  float *opt_param, const float *list,
1809  int list_size, int default_value, int min_value,
1810  int *ctx_param)
1811 {
1812  int mixlev = validate_float_option(*opt_param, list, list_size);
1813  if (mixlev < min_value) {
1814  mixlev = default_value;
1815  if (*opt_param >= 0.0) {
1816  av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1817  "default value: %0.3f\n", opt_name, list[mixlev]);
1818  }
1819  }
1820  *opt_param = list[mixlev];
1821  *ctx_param = mixlev;
1822 }
1823 
1824 
1825 /**
1826  * Validate metadata options as set by AVOption system.
1827  * These values can optionally be changed per-frame.
1828  *
1829  * @param s AC-3 encoder private context
1830  */
1831 int ff_ac3_validate_metadata(AC3EncodeContext *s)
1832 {
1833  AVCodecContext *avctx = s->avctx;
1834  AC3EncOptions *opt = &s->options;
1835 
1836  opt->audio_production_info = 0;
1837  opt->extended_bsi_1 = 0;
1838  opt->extended_bsi_2 = 0;
1839  opt->eac3_mixing_metadata = 0;
1840  opt->eac3_info_metadata = 0;
1841 
1842  /* determine mixing metadata / xbsi1 use */
1843  if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
1844  opt->extended_bsi_1 = 1;
1845  opt->eac3_mixing_metadata = 1;
1846  }
1847  if (s->has_center &&
1848  (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
1849  opt->extended_bsi_1 = 1;
1850  opt->eac3_mixing_metadata = 1;
1851  }
1852  if (s->has_surround &&
1853  (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
1854  opt->extended_bsi_1 = 1;
1855  opt->eac3_mixing_metadata = 1;
1856  }
1857 
1858  if (s->eac3) {
1859  /* determine info metadata use */
1860  if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
1861  opt->eac3_info_metadata = 1;
1862  if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
1863  opt->eac3_info_metadata = 1;
1864  if (s->channel_mode == AC3_CHMODE_STEREO &&
1865  (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
1866  opt->eac3_info_metadata = 1;
1867  if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1868  opt->eac3_info_metadata = 1;
1869  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
1870  opt->ad_converter_type != AC3ENC_OPT_NONE) {
1871  opt->audio_production_info = 1;
1872  opt->eac3_info_metadata = 1;
1873  }
1874  } else {
1875  /* determine audio production info use */
1876  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
1877  opt->audio_production_info = 1;
1878 
1879  /* determine xbsi2 use */
1880  if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1881  opt->extended_bsi_2 = 1;
1882  if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
1883  opt->extended_bsi_2 = 1;
1884  if (opt->ad_converter_type != AC3ENC_OPT_NONE)
1885  opt->extended_bsi_2 = 1;
1886  }
1887 
1888  /* validate AC-3 mixing levels */
1889  if (!s->eac3) {
1890  if (s->has_center) {
1891  validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1892  cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
1893  &s->center_mix_level);
1894  }
1895  if (s->has_surround) {
1896  validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1897  surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
1898  &s->surround_mix_level);
1899  }
1900  }
1901 
1902  /* validate extended bsi 1 / mixing metadata */
1903  if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
1904  /* default preferred stereo downmix */
1905  if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
1906  opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
1907  if (!s->eac3 || s->has_center) {
1908  /* validate Lt/Rt center mix level */
1909  validate_mix_level(avctx, "ltrt_center_mix_level",
1910  &opt->ltrt_center_mix_level, extmixlev_options,
1911  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1912  &s->ltrt_center_mix_level);
1913  /* validate Lo/Ro center mix level */
1914  validate_mix_level(avctx, "loro_center_mix_level",
1915  &opt->loro_center_mix_level, extmixlev_options,
1916  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1917  &s->loro_center_mix_level);
1918  }
1919  if (!s->eac3 || s->has_surround) {
1920  /* validate Lt/Rt surround mix level */
1921  validate_mix_level(avctx, "ltrt_surround_mix_level",
1922  &opt->ltrt_surround_mix_level, extmixlev_options,
1923  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1924  &s->ltrt_surround_mix_level);
1925  /* validate Lo/Ro surround mix level */
1926  validate_mix_level(avctx, "loro_surround_mix_level",
1927  &opt->loro_surround_mix_level, extmixlev_options,
1928  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1929  &s->loro_surround_mix_level);
1930  }
1931  }
1932 
1933  /* validate audio service type / channels combination */
1934  if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
1935  avctx->channels == 1) ||
1936  ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
1937  avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY ||
1938  avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
1939  && avctx->channels > 1)) {
1940  av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
1941  "specified number of channels\n");
1942  return AVERROR(EINVAL);
1943  }
1944 
1945  /* validate extended bsi 2 / info metadata */
1946  if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
1947  /* default dolby headphone mode */
1948  if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
1949  opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
1950  /* default dolby surround ex mode */
1951  if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
1952  opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
1953  /* default A/D converter type */
1954  if (opt->ad_converter_type == AC3ENC_OPT_NONE)
1955  opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
1956  }
1957 
1958  /* copyright & original defaults */
1959  if (!s->eac3 || opt->eac3_info_metadata) {
1960  /* default copyright */
1961  if (opt->copyright == AC3ENC_OPT_NONE)
1962  opt->copyright = AC3ENC_OPT_OFF;
1963  /* default original */
1964  if (opt->original == AC3ENC_OPT_NONE)
1965  opt->original = AC3ENC_OPT_ON;
1966  }
1967 
1968  /* dolby surround mode default */
1969  if (!s->eac3 || opt->eac3_info_metadata) {
1970  if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
1971  opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
1972  }
1973 
1974  /* validate audio production info */
1975  if (opt->audio_production_info) {
1976  if (opt->mixing_level == AC3ENC_OPT_NONE) {
1977  av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
1978  "room_type is set\n");
1979  return AVERROR(EINVAL);
1980  }
1981  if (opt->mixing_level < 80) {
1982  av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
1983  "80dB and 111dB\n");
1984  return AVERROR(EINVAL);
1985  }
1986  /* default room type */
1987  if (opt->room_type == AC3ENC_OPT_NONE)
1988  opt->room_type = AC3ENC_OPT_NOT_INDICATED;
1989  }
1990 
1991  /* set bitstream id for alternate bitstream syntax */
1992  if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
1993  if (s->bitstream_id > 8 && s->bitstream_id < 11) {
1994  static int warn_once = 1;
1995  if (warn_once) {
1996  av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
1997  "not compatible with reduced samplerates. writing of "
1998  "extended bitstream information will be disabled.\n");
1999  warn_once = 0;
2000  }
2001  } else {
2002  s->bitstream_id = 6;
2003  }
2004  }
2005 
2006  return 0;
2007 }
2008 
2009 
2010 /**
2011  * Finalize encoding and free any memory allocated by the encoder.
2012  *
2013  * @param avctx Codec context
2014  */
2015 av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
2016 {
2017  int blk, ch;
2018  AC3EncodeContext *s = avctx->priv_data;
2019 
2020  av_freep(&s->windowed_samples);
2021  for (ch = 0; ch < s->channels; ch++)
2022  av_freep(&s->planar_samples[ch]);
2023  av_freep(&s->planar_samples);
2024  av_freep(&s->bap_buffer);
2025  av_freep(&s->bap1_buffer);
2026  av_freep(&s->mdct_coef_buffer);
2027  av_freep(&s->fixed_coef_buffer);
2028  av_freep(&s->exp_buffer);
2029  av_freep(&s->grouped_exp_buffer);
2030  av_freep(&s->psd_buffer);
2031  av_freep(&s->band_psd_buffer);
2032  av_freep(&s->mask_buffer);
2033  av_freep(&s->qmant_buffer);
2034  av_freep(&s->cpl_coord_exp_buffer);
2035  av_freep(&s->cpl_coord_mant_buffer);
2036  for (blk = 0; blk < s->num_blocks; blk++) {
2037  AC3Block *block = &s->blocks[blk];
2038  av_freep(&block->mdct_coef);
2039  av_freep(&block->fixed_coef);
2040  av_freep(&block->exp);
2041  av_freep(&block->grouped_exp);
2042  av_freep(&block->psd);
2043  av_freep(&block->band_psd);
2044  av_freep(&block->mask);
2045  av_freep(&block->qmant);
2046  av_freep(&block->cpl_coord_exp);
2047  av_freep(&block->cpl_coord_mant);
2048  }
2049 
2050  s->mdct_end(s);
2051 
2052 #if FF_API_OLD_ENCODE_AUDIO
2053  av_freep(&avctx->coded_frame);
2054 #endif
2055  return 0;
2056 }
2057 
2058 
2059 /*
2060  * Set channel information during initialization.
2061  */
2062 static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
2063  uint64_t *channel_layout)
2064 {
2065  int ch_layout;
2066 
2067  if (channels < 1 || channels > AC3_MAX_CHANNELS)
2068  return AVERROR(EINVAL);
2069  if (*channel_layout > 0x7FF)
2070  return AVERROR(EINVAL);
2071  ch_layout = *channel_layout;
2072  if (!ch_layout)
2073  ch_layout = av_get_default_channel_layout(channels);
2074 
2075  s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
2076  s->channels = channels;
2077  s->fbw_channels = channels - s->lfe_on;
2078  s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
2079  if (s->lfe_on)
2080  ch_layout -= AV_CH_LOW_FREQUENCY;
2081 
2082  switch (ch_layout) {
2083  case AV_CH_LAYOUT_MONO: s->channel_mode = AC3_CHMODE_MONO; break;
2084  case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
2085  case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
2086  case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
2087  case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
2088  case AV_CH_LAYOUT_QUAD:
2089  case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
2090  case AV_CH_LAYOUT_5POINT0:
2091  case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
2092  default:
2093  return AVERROR(EINVAL);
2094  }
2095  s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2096  s->has_surround = s->channel_mode & 0x04;
2097 
2098  s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
2099  *channel_layout = ch_layout;
2100  if (s->lfe_on)
2101  *channel_layout |= AV_CH_LOW_FREQUENCY;
2102 
2103  return 0;
2104 }
2105 
2106 
2107 static av_cold int validate_options(AC3EncodeContext *s)
2108 {
2109  AVCodecContext *avctx = s->avctx;
2110  int i, ret, max_sr;
2111 
2112  /* validate channel layout */
2113  if (!avctx->channel_layout) {
2114  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2115  "encoder will guess the layout, but it "
2116  "might be incorrect.\n");
2117  }
2118  ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
2119  if (ret) {
2120  av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2121  return ret;
2122  }
2123 
2124  /* validate sample rate */
2125  /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2126  decoder that supports half sample rate so we can validate that
2127  the generated files are correct. */
2128  max_sr = s->eac3 ? 2 : 8;
2129  for (i = 0; i <= max_sr; i++) {
2130  if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2131  break;
2132  }
2133  if (i > max_sr) {
2134  av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2135  return AVERROR(EINVAL);
2136  }
2137  s->sample_rate = avctx->sample_rate;
2138  s->bit_alloc.sr_shift = i / 3;
2139  s->bit_alloc.sr_code = i % 3;
2140  s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2141 
2142  /* select a default bit rate if not set by the user */
2143  if (!avctx->bit_rate) {
2144  switch (s->fbw_channels) {
2145  case 1: avctx->bit_rate = 96000; break;
2146  case 2: avctx->bit_rate = 192000; break;
2147  case 3: avctx->bit_rate = 320000; break;
2148  case 4: avctx->bit_rate = 384000; break;
2149  case 5: avctx->bit_rate = 448000; break;
2150  }
2151  }
2152 
2153  /* validate bit rate */
2154  if (s->eac3) {
2155  int max_br, min_br, wpf, min_br_dist, min_br_code;
2156  int num_blks_code, num_blocks, frame_samples;
2157 
2158  /* calculate min/max bitrate */
2159  /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2160  found use either 6 blocks or 1 block, even though 2 or 3 blocks
2161  would work as far as the bit rate is concerned. */
2162  for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2163  num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2164  frame_samples = AC3_BLOCK_SIZE * num_blocks;
2165  max_br = 2048 * s->sample_rate / frame_samples * 16;
2166  min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2167  if (avctx->bit_rate <= max_br)
2168  break;
2169  }
2170  if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2171  av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2172  "for this sample rate\n", min_br, max_br);
2173  return AVERROR(EINVAL);
2174  }
2175  s->num_blks_code = num_blks_code;
2176  s->num_blocks = num_blocks;
2177 
2178  /* calculate words-per-frame for the selected bitrate */
2179  wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2180  av_assert1(wpf > 0 && wpf <= 2048);
2181 
2182  /* find the closest AC-3 bitrate code to the selected bitrate.
2183  this is needed for lookup tables for bandwidth and coupling
2184  parameter selection */
2185  min_br_code = -1;
2186  min_br_dist = INT_MAX;
2187  for (i = 0; i < 19; i++) {
2188  int br_dist = abs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2189  if (br_dist < min_br_dist) {
2190  min_br_dist = br_dist;
2191  min_br_code = i;
2192  }
2193  }
2194 
2195  /* make sure the minimum frame size is below the average frame size */
2196  s->frame_size_code = min_br_code << 1;
2197  while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2198  wpf--;
2199  s->frame_size_min = 2 * wpf;
2200  } else {
2201  int best_br = 0, best_code = 0, best_diff = INT_MAX;
2202  for (i = 0; i < 19; i++) {
2203  int br = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2204  int diff = abs(br - avctx->bit_rate);
2205  if (diff < best_diff) {
2206  best_br = br;
2207  best_code = i;
2208  best_diff = diff;
2209  }
2210  if (!best_diff)
2211  break;
2212  }
2213  avctx->bit_rate = best_br;
2214  s->frame_size_code = best_code << 1;
2215  s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2216  s->num_blks_code = 0x3;
2217  s->num_blocks = 6;
2218  }
2219  s->bit_rate = avctx->bit_rate;
2220  s->frame_size = s->frame_size_min;
2221 
2222  /* validate cutoff */
2223  if (avctx->cutoff < 0) {
2224  av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2225  return AVERROR(EINVAL);
2226  }
2227  s->cutoff = avctx->cutoff;
2228  if (s->cutoff > (s->sample_rate >> 1))
2229  s->cutoff = s->sample_rate >> 1;
2230 
2231  ret = ff_ac3_validate_metadata(s);
2232  if (ret)
2233  return ret;
2234 
2235  s->rematrixing_enabled = s->options.stereo_rematrixing &&
2236  (s->channel_mode == AC3_CHMODE_STEREO);
2237 
2238  s->cpl_enabled = s->options.channel_coupling &&
2239  s->channel_mode >= AC3_CHMODE_STEREO;
2240 
2241  return 0;
2242 }
2243 
2244 
2245 /*
2246  * Set bandwidth for all channels.
2247  * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2248  * default value will be used.
2249  */
2250 static av_cold void set_bandwidth(AC3EncodeContext *s)
2251 {
2252  int blk, ch, cpl_start;
2253 
2254  if (s->cutoff) {
2255  /* calculate bandwidth based on user-specified cutoff frequency */
2256  int fbw_coeffs;
2257  fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2258  s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2259  } else {
2260  /* use default bandwidth setting */
2261  s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2262  }
2263 
2264  /* set number of coefficients for each channel */
2265  for (ch = 1; ch <= s->fbw_channels; ch++) {
2266  s->start_freq[ch] = 0;
2267  for (blk = 0; blk < s->num_blocks; blk++)
2268  s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2269  }
2270  /* LFE channel always has 7 coefs */
2271  if (s->lfe_on) {
2272  s->start_freq[s->lfe_channel] = 0;
2273  for (blk = 0; blk < s->num_blocks; blk++)
2274  s->blocks[blk].end_freq[ch] = 7;
2275  }
2276 
2277  /* initialize coupling strategy */
2278  if (s->cpl_enabled) {
2279  if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2280  cpl_start = s->options.cpl_start;
2281  } else {
2282  cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2283  if (cpl_start < 0) {
2284  if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
2285  s->cpl_enabled = 0;
2286  else
2287  cpl_start = 15;
2288  }
2289  }
2290  }
2291  if (s->cpl_enabled) {
2292  int i, cpl_start_band, cpl_end_band;
2293  uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2294 
2295  cpl_end_band = s->bandwidth_code / 4 + 3;
2296  cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2297 
2298  s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2299 
2300  s->num_cpl_bands = 1;
2301  *cpl_band_sizes = 12;
2302  for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2303  if (ff_eac3_default_cpl_band_struct[i]) {
2304  *cpl_band_sizes += 12;
2305  } else {
2306  s->num_cpl_bands++;
2307  cpl_band_sizes++;
2308  *cpl_band_sizes = 12;
2309  }
2310  }
2311 
2312  s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2313  s->cpl_end_freq = cpl_end_band * 12 + 37;
2314  for (blk = 0; blk < s->num_blocks; blk++)
2315  s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2316  }
2317 }
2318 
2319 
2320 static av_cold int allocate_buffers(AC3EncodeContext *s)
2321 {
2322  AVCodecContext *avctx = s->avctx;
2323  int blk, ch;
2324  int channels = s->channels + 1; /* includes coupling channel */
2325  int channel_blocks = channels * s->num_blocks;
2326  int total_coefs = AC3_MAX_COEFS * channel_blocks;
2327 
2328  if (s->allocate_sample_buffers(s))
2329  goto alloc_fail;
2330 
2331  FF_ALLOC_OR_GOTO(avctx, s->bap_buffer, total_coefs *
2332  sizeof(*s->bap_buffer), alloc_fail);
2333  FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, total_coefs *
2334  sizeof(*s->bap1_buffer), alloc_fail);
2335  FF_ALLOCZ_OR_GOTO(avctx, s->mdct_coef_buffer, total_coefs *
2336  sizeof(*s->mdct_coef_buffer), alloc_fail);
2337  FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, total_coefs *
2338  sizeof(*s->exp_buffer), alloc_fail);
2339  FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, channel_blocks * 128 *
2340  sizeof(*s->grouped_exp_buffer), alloc_fail);
2341  FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, total_coefs *
2342  sizeof(*s->psd_buffer), alloc_fail);
2343  FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, channel_blocks * 64 *
2344  sizeof(*s->band_psd_buffer), alloc_fail);
2345  FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, channel_blocks * 64 *
2346  sizeof(*s->mask_buffer), alloc_fail);
2347  FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, total_coefs *
2348  sizeof(*s->qmant_buffer), alloc_fail);
2349  if (s->cpl_enabled) {
2350  FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_exp_buffer, channel_blocks * 16 *
2351  sizeof(*s->cpl_coord_exp_buffer), alloc_fail);
2352  FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_mant_buffer, channel_blocks * 16 *
2353  sizeof(*s->cpl_coord_mant_buffer), alloc_fail);
2354  }
2355  for (blk = 0; blk < s->num_blocks; blk++) {
2356  AC3Block *block = &s->blocks[blk];
2357  FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, channels * sizeof(*block->mdct_coef),
2358  alloc_fail);
2359  FF_ALLOCZ_OR_GOTO(avctx, block->exp, channels * sizeof(*block->exp),
2360  alloc_fail);
2361  FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, channels * sizeof(*block->grouped_exp),
2362  alloc_fail);
2363  FF_ALLOCZ_OR_GOTO(avctx, block->psd, channels * sizeof(*block->psd),
2364  alloc_fail);
2365  FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, channels * sizeof(*block->band_psd),
2366  alloc_fail);
2367  FF_ALLOCZ_OR_GOTO(avctx, block->mask, channels * sizeof(*block->mask),
2368  alloc_fail);
2369  FF_ALLOCZ_OR_GOTO(avctx, block->qmant, channels * sizeof(*block->qmant),
2370  alloc_fail);
2371  if (s->cpl_enabled) {
2372  FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_exp, channels * sizeof(*block->cpl_coord_exp),
2373  alloc_fail);
2374  FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_mant, channels * sizeof(*block->cpl_coord_mant),
2375  alloc_fail);
2376  }
2377 
2378  for (ch = 0; ch < channels; ch++) {
2379  /* arrangement: block, channel, coeff */
2380  block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
2381  block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2382  block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
2383  block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
2384  block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2385  if (s->cpl_enabled) {
2386  block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
2387  block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
2388  }
2389 
2390  /* arrangement: channel, block, coeff */
2391  block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2392  block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2393  }
2394  }
2395 
2396  if (!s->fixed_point) {
2397  FF_ALLOCZ_OR_GOTO(avctx, s->fixed_coef_buffer, total_coefs *
2398  sizeof(*s->fixed_coef_buffer), alloc_fail);
2399  for (blk = 0; blk < s->num_blocks; blk++) {
2400  AC3Block *block = &s->blocks[blk];
2401  FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2402  sizeof(*block->fixed_coef), alloc_fail);
2403  for (ch = 0; ch < channels; ch++)
2404  block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2405  }
2406  } else {
2407  for (blk = 0; blk < s->num_blocks; blk++) {
2408  AC3Block *block = &s->blocks[blk];
2409  FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2410  sizeof(*block->fixed_coef), alloc_fail);
2411  for (ch = 0; ch < channels; ch++)
2412  block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2413  }
2414  }
2415 
2416  return 0;
2417 alloc_fail:
2418  return AVERROR(ENOMEM);
2419 }
2420 
2421 
2422 av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
2423 {
2424  AC3EncodeContext *s = avctx->priv_data;
2425  int ret, frame_size_58;
2426 
2427  s->avctx = avctx;
2428 
2429  s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2430 
2431  ff_ac3_common_init();
2432 
2433  ret = validate_options(s);
2434  if (ret)
2435  return ret;
2436 
2437  avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2438  avctx->delay = AC3_BLOCK_SIZE;
2439 
2440  s->bitstream_mode = avctx->audio_service_type;
2441  if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2442  s->bitstream_mode = 0x7;
2443 
2444  s->bits_written = 0;
2445  s->samples_written = 0;
2446 
2447  /* calculate crc_inv for both possible frame sizes */
2448  frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
2449  s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2450  if (s->bit_alloc.sr_code == 1) {
2451  frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2452  s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2453  }
2454 
2455  /* set function pointers */
2456  if (CONFIG_AC3_FIXED_ENCODER && s->fixed_point) {
2457  s->mdct_end = ff_ac3_fixed_mdct_end;
2458  s->mdct_init = ff_ac3_fixed_mdct_init;
2459  s->allocate_sample_buffers = ff_ac3_fixed_allocate_sample_buffers;
2460  } else if (CONFIG_AC3_ENCODER || CONFIG_EAC3_ENCODER) {
2461  s->mdct_end = ff_ac3_float_mdct_end;
2462  s->mdct_init = ff_ac3_float_mdct_init;
2463  s->allocate_sample_buffers = ff_ac3_float_allocate_sample_buffers;
2464  }
2465  if (CONFIG_EAC3_ENCODER && s->eac3)
2466  s->output_frame_header = ff_eac3_output_frame_header;
2467  else
2468  s->output_frame_header = ac3_output_frame_header;
2469 
2470  set_bandwidth(s);
2471 
2472  exponent_init(s);
2473 
2474  bit_alloc_init(s);
2475 
2476  ret = s->mdct_init(s);
2477  if (ret)
2478  goto init_fail;
2479 
2480  ret = allocate_buffers(s);
2481  if (ret)
2482  goto init_fail;
2483 
2484 #if FF_API_OLD_ENCODE_AUDIO
2485  avctx->coded_frame= avcodec_alloc_frame();
2486  if (!avctx->coded_frame) {
2487  ret = AVERROR(ENOMEM);
2488  goto init_fail;
2489  }
2490 #endif
2491 
2492  ff_dsputil_init(&s->dsp, avctx);
2493  avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
2494  ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
2495 
2496  dprint_options(s);
2497 
2498  return 0;
2499 init_fail:
2500  ff_ac3_encode_close(avctx);
2501  return ret;
2502 }
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