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"
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/crc.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/opt.h"
38 #include "avcodec.h"
39 #include "put_bits.h"
40 #include "ac3dsp.h"
41 #include "ac3.h"
42 #include "fft.h"
43 #include "ac3enc.h"
44 #include "eac3enc.h"
45 
46 typedef struct AC3Mant {
47  int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
48  int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
49 } AC3Mant;
50 
51 #define CMIXLEV_NUM_OPTIONS 3
52 static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
53  LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
54 };
55 
56 #define SURMIXLEV_NUM_OPTIONS 3
57 static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
58  LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
59 };
60 
61 #define EXTMIXLEV_NUM_OPTIONS 8
62 static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
63  LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_4POINT5DB,
64  LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
65 };
66 
67 
68 /**
69  * LUT for number of exponent groups.
70  * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
71  */
72 static uint8_t exponent_group_tab[2][3][256];
73 
74 
75 /**
76  * List of supported channel layouts.
77  */
78 const uint64_t ff_ac3_channel_layouts[19] = {
79  AV_CH_LAYOUT_MONO,
80  AV_CH_LAYOUT_STEREO,
81  AV_CH_LAYOUT_2_1,
82  AV_CH_LAYOUT_SURROUND,
83  AV_CH_LAYOUT_2_2,
84  AV_CH_LAYOUT_QUAD,
85  AV_CH_LAYOUT_4POINT0,
86  AV_CH_LAYOUT_5POINT0,
87  AV_CH_LAYOUT_5POINT0_BACK,
88  (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
89  (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
90  (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
91  (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
92  (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
93  (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
94  (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
95  AV_CH_LAYOUT_5POINT1,
96  AV_CH_LAYOUT_5POINT1_BACK,
97  0
98 };
99 
100 
101 /**
102  * LUT to select the bandwidth code based on the bit rate, sample rate, and
103  * number of full-bandwidth channels.
104  * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
105  */
106 static const uint8_t ac3_bandwidth_tab[5][3][19] = {
107 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
108 
109  { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
110  { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
111  { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
112 
113  { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
114  { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
115  { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
116 
117  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
118  { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
119  { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
120 
121  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
122  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
123  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
124 
125  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
126  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
127  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
128 };
129 
130 
131 /**
132  * LUT to select the coupling start band based on the bit rate, sample rate, and
133  * number of full-bandwidth channels. -1 = coupling off
134  * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
135  *
136  * TODO: more testing for optimal parameters.
137  * multi-channel tests at 44.1kHz and 32kHz.
138  */
139 static const int8_t ac3_coupling_start_tab[6][3][19] = {
140 // 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
141 
142  // 2/0
143  { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
144  { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
145  { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
146 
147  // 3/0
148  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
149  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
150  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
151 
152  // 2/1 - untested
153  { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
154  { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
155  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
156 
157  // 3/1
158  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
159  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
160  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
161 
162  // 2/2 - untested
163  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
164  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
165  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
166 
167  // 3/2
168  { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
169  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
170  { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
171 };
172 
173 
174 /**
175  * Adjust the frame size to make the average bit rate match the target bit rate.
176  * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
177  *
178  * @param s AC-3 encoder private context
179  */
180 void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
181 {
182  while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
183  s->bits_written -= s->bit_rate;
184  s->samples_written -= s->sample_rate;
185  }
186  s->frame_size = s->frame_size_min +
187  2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
188  s->bits_written += s->frame_size * 8;
189  s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
190 }
191 
192 
193 /**
194  * Set the initial coupling strategy parameters prior to coupling analysis.
195  *
196  * @param s AC-3 encoder private context
197  */
198 void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
199 {
200  int blk, ch;
201  int got_cpl_snr;
202  int num_cpl_blocks;
203 
204  /* set coupling use flags for each block/channel */
205  /* TODO: turn coupling on/off and adjust start band based on bit usage */
206  for (blk = 0; blk < s->num_blocks; blk++) {
207  AC3Block *block = &s->blocks[blk];
208  for (ch = 1; ch <= s->fbw_channels; ch++)
209  block->channel_in_cpl[ch] = s->cpl_on;
210  }
211 
212  /* enable coupling for each block if at least 2 channels have coupling
213  enabled for that block */
214  got_cpl_snr = 0;
215  num_cpl_blocks = 0;
216  for (blk = 0; blk < s->num_blocks; blk++) {
217  AC3Block *block = &s->blocks[blk];
218  block->num_cpl_channels = 0;
219  for (ch = 1; ch <= s->fbw_channels; ch++)
220  block->num_cpl_channels += block->channel_in_cpl[ch];
221  block->cpl_in_use = block->num_cpl_channels > 1;
222  num_cpl_blocks += block->cpl_in_use;
223  if (!block->cpl_in_use) {
224  block->num_cpl_channels = 0;
225  for (ch = 1; ch <= s->fbw_channels; ch++)
226  block->channel_in_cpl[ch] = 0;
227  }
228 
229  block->new_cpl_strategy = !blk;
230  if (blk) {
231  for (ch = 1; ch <= s->fbw_channels; ch++) {
232  if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
233  block->new_cpl_strategy = 1;
234  break;
235  }
236  }
237  }
238  block->new_cpl_leak = block->new_cpl_strategy;
239 
240  if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
241  block->new_snr_offsets = 1;
242  if (block->cpl_in_use)
243  got_cpl_snr = 1;
244  } else {
245  block->new_snr_offsets = 0;
246  }
247  }
248  if (!num_cpl_blocks)
249  s->cpl_on = 0;
250 
251  /* set bandwidth for each channel */
252  for (blk = 0; blk < s->num_blocks; blk++) {
253  AC3Block *block = &s->blocks[blk];
254  for (ch = 1; ch <= s->fbw_channels; ch++) {
255  if (block->channel_in_cpl[ch])
256  block->end_freq[ch] = s->start_freq[CPL_CH];
257  else
258  block->end_freq[ch] = s->bandwidth_code * 3 + 73;
259  }
260  }
261 }
262 
263 
264 /**
265  * Apply stereo rematrixing to coefficients based on rematrixing flags.
266  *
267  * @param s AC-3 encoder private context
268  */
269 void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
270 {
271  int nb_coefs;
272  int blk, bnd, i;
273  int start, end;
274  uint8_t *flags = NULL;
275 
276  if (!s->rematrixing_enabled)
277  return;
278 
279  for (blk = 0; blk < s->num_blocks; blk++) {
280  AC3Block *block = &s->blocks[blk];
281  if (block->new_rematrixing_strategy)
282  flags = block->rematrixing_flags;
283  nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
284  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
285  if (flags[bnd]) {
286  start = ff_ac3_rematrix_band_tab[bnd];
287  end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
288  for (i = start; i < end; i++) {
289  int32_t lt = block->fixed_coef[1][i];
290  int32_t rt = block->fixed_coef[2][i];
291  block->fixed_coef[1][i] = (lt + rt) >> 1;
292  block->fixed_coef[2][i] = (lt - rt) >> 1;
293  }
294  }
295  }
296  }
297 }
298 
299 
300 /*
301  * Initialize exponent tables.
302  */
303 static av_cold void exponent_init(AC3EncodeContext *s)
304 {
305  int expstr, i, grpsize;
306 
307  for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
308  grpsize = 3 << expstr;
309  for (i = 12; i < 256; i++) {
310  exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
311  exponent_group_tab[1][expstr][i] = (i ) / grpsize;
312  }
313  }
314  /* LFE */
315  exponent_group_tab[0][0][7] = 2;
316 
317  if (CONFIG_EAC3_ENCODER && s->eac3)
318  ff_eac3_exponent_init();
319 }
320 
321 
322 /*
323  * Extract exponents from the MDCT coefficients.
324  */
325 static void extract_exponents(AC3EncodeContext *s)
326 {
327  int ch = !s->cpl_on;
328  int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
329  AC3Block *block = &s->blocks[0];
330 
331  s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
332 }
333 
334 
335 /**
336  * Exponent Difference Threshold.
337  * New exponents are sent if their SAD exceed this number.
338  */
339 #define EXP_DIFF_THRESHOLD 500
340 
341 /**
342  * Table used to select exponent strategy based on exponent reuse block interval.
343  */
344 static const uint8_t exp_strategy_reuse_tab[4][6] = {
345  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
346  { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
347  { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
348  { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
349 };
350 
351 /*
352  * Calculate exponent strategies for all channels.
353  * Array arrangement is reversed to simplify the per-channel calculation.
354  */
355 static void compute_exp_strategy(AC3EncodeContext *s)
356 {
357  int ch, blk, blk1;
358 
359  for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
360  uint8_t *exp_strategy = s->exp_strategy[ch];
361  uint8_t *exp = s->blocks[0].exp[ch];
362  int exp_diff;
363 
364  /* estimate if the exponent variation & decide if they should be
365  reused in the next frame */
366  exp_strategy[0] = EXP_NEW;
367  exp += AC3_MAX_COEFS;
368  for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
369  if (ch == CPL_CH) {
370  if (!s->blocks[blk-1].cpl_in_use) {
371  exp_strategy[blk] = EXP_NEW;
372  continue;
373  } else if (!s->blocks[blk].cpl_in_use) {
374  exp_strategy[blk] = EXP_REUSE;
375  continue;
376  }
377  } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
378  exp_strategy[blk] = EXP_NEW;
379  continue;
380  }
381  exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
382  exp_strategy[blk] = EXP_REUSE;
383  if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
384  exp_strategy[blk] = EXP_NEW;
385  else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
386  exp_strategy[blk] = EXP_NEW;
387  }
388 
389  /* now select the encoding strategy type : if exponents are often
390  recoded, we use a coarse encoding */
391  blk = 0;
392  while (blk < s->num_blocks) {
393  blk1 = blk + 1;
394  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
395  blk1++;
396  exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
397  blk = blk1;
398  }
399  }
400  if (s->lfe_on) {
401  ch = s->lfe_channel;
402  s->exp_strategy[ch][0] = EXP_D15;
403  for (blk = 1; blk < s->num_blocks; blk++)
404  s->exp_strategy[ch][blk] = EXP_REUSE;
405  }
406 
407  /* for E-AC-3, determine frame exponent strategy */
408  if (CONFIG_EAC3_ENCODER && s->eac3)
409  ff_eac3_get_frame_exp_strategy(s);
410 }
411 
412 
413 /**
414  * Update the exponents so that they are the ones the decoder will decode.
415  *
416  * @param[in,out] exp array of exponents for 1 block in 1 channel
417  * @param nb_exps number of exponents in active bandwidth
418  * @param exp_strategy exponent strategy for the block
419  * @param cpl indicates if the block is in the coupling channel
420  */
421 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
422  int cpl)
423 {
424  int nb_groups, i, k;
425 
426  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
427 
428  /* for each group, compute the minimum exponent */
429  switch(exp_strategy) {
430  case EXP_D25:
431  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
432  uint8_t exp_min = exp[k];
433  if (exp[k+1] < exp_min)
434  exp_min = exp[k+1];
435  exp[i-cpl] = exp_min;
436  k += 2;
437  }
438  break;
439  case EXP_D45:
440  for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
441  uint8_t exp_min = exp[k];
442  if (exp[k+1] < exp_min)
443  exp_min = exp[k+1];
444  if (exp[k+2] < exp_min)
445  exp_min = exp[k+2];
446  if (exp[k+3] < exp_min)
447  exp_min = exp[k+3];
448  exp[i-cpl] = exp_min;
449  k += 4;
450  }
451  break;
452  }
453 
454  /* constraint for DC exponent */
455  if (!cpl && exp[0] > 15)
456  exp[0] = 15;
457 
458  /* decrease the delta between each groups to within 2 so that they can be
459  differentially encoded */
460  for (i = 1; i <= nb_groups; i++)
461  exp[i] = FFMIN(exp[i], exp[i-1] + 2);
462  i--;
463  while (--i >= 0)
464  exp[i] = FFMIN(exp[i], exp[i+1] + 2);
465 
466  if (cpl)
467  exp[-1] = exp[0] & ~1;
468 
469  /* now we have the exponent values the decoder will see */
470  switch (exp_strategy) {
471  case EXP_D25:
472  for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
473  uint8_t exp1 = exp[i-cpl];
474  exp[k--] = exp1;
475  exp[k--] = exp1;
476  }
477  break;
478  case EXP_D45:
479  for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
480  exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
481  k -= 4;
482  }
483  break;
484  }
485 }
486 
487 
488 /*
489  * Encode exponents from original extracted form to what the decoder will see.
490  * This copies and groups exponents based on exponent strategy and reduces
491  * deltas between adjacent exponent groups so that they can be differentially
492  * encoded.
493  */
494 static void encode_exponents(AC3EncodeContext *s)
495 {
496  int blk, blk1, ch, cpl;
497  uint8_t *exp, *exp_strategy;
498  int nb_coefs, num_reuse_blocks;
499 
500  for (ch = !s->cpl_on; ch <= s->channels; ch++) {
501  exp = s->blocks[0].exp[ch] + s->start_freq[ch];
502  exp_strategy = s->exp_strategy[ch];
503 
504  cpl = (ch == CPL_CH);
505  blk = 0;
506  while (blk < s->num_blocks) {
507  AC3Block *block = &s->blocks[blk];
508  if (cpl && !block->cpl_in_use) {
509  exp += AC3_MAX_COEFS;
510  blk++;
511  continue;
512  }
513  nb_coefs = block->end_freq[ch] - s->start_freq[ch];
514  blk1 = blk + 1;
515 
516  /* count the number of EXP_REUSE blocks after the current block
517  and set exponent reference block numbers */
518  s->exp_ref_block[ch][blk] = blk;
519  while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
520  s->exp_ref_block[ch][blk1] = blk;
521  blk1++;
522  }
523  num_reuse_blocks = blk1 - blk - 1;
524 
525  /* for the EXP_REUSE case we select the min of the exponents */
526  s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
527  AC3_MAX_COEFS);
528 
529  encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
530 
531  exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
532  blk = blk1;
533  }
534  }
535 
536  /* reference block numbers have been changed, so reset ref_bap_set */
537  s->ref_bap_set = 0;
538 }
539 
540 
541 /*
542  * Count exponent bits based on bandwidth, coupling, and exponent strategies.
543  */
544 static int count_exponent_bits(AC3EncodeContext *s)
545 {
546  int blk, ch;
547  int nb_groups, bit_count;
548 
549  bit_count = 0;
550  for (blk = 0; blk < s->num_blocks; blk++) {
551  AC3Block *block = &s->blocks[blk];
552  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
553  int exp_strategy = s->exp_strategy[ch][blk];
554  int cpl = (ch == CPL_CH);
555  int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
556 
557  if (exp_strategy == EXP_REUSE)
558  continue;
559 
560  nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
561  bit_count += 4 + (nb_groups * 7);
562  }
563  }
564 
565  return bit_count;
566 }
567 
568 
569 /**
570  * Group exponents.
571  * 3 delta-encoded exponents are in each 7-bit group. The number of groups
572  * varies depending on exponent strategy and bandwidth.
573  *
574  * @param s AC-3 encoder private context
575  */
576 void ff_ac3_group_exponents(AC3EncodeContext *s)
577 {
578  int blk, ch, i, cpl;
579  int group_size, nb_groups;
580  uint8_t *p;
581  int delta0, delta1, delta2;
582  int exp0, exp1;
583 
584  for (blk = 0; blk < s->num_blocks; blk++) {
585  AC3Block *block = &s->blocks[blk];
586  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
587  int exp_strategy = s->exp_strategy[ch][blk];
588  if (exp_strategy == EXP_REUSE)
589  continue;
590  cpl = (ch == CPL_CH);
591  group_size = exp_strategy + (exp_strategy == EXP_D45);
592  nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
593  p = block->exp[ch] + s->start_freq[ch] - cpl;
594 
595  /* DC exponent */
596  exp1 = *p++;
597  block->grouped_exp[ch][0] = exp1;
598 
599  /* remaining exponents are delta encoded */
600  for (i = 1; i <= nb_groups; i++) {
601  /* merge three delta in one code */
602  exp0 = exp1;
603  exp1 = p[0];
604  p += group_size;
605  delta0 = exp1 - exp0 + 2;
606  av_assert2(delta0 >= 0 && delta0 <= 4);
607 
608  exp0 = exp1;
609  exp1 = p[0];
610  p += group_size;
611  delta1 = exp1 - exp0 + 2;
612  av_assert2(delta1 >= 0 && delta1 <= 4);
613 
614  exp0 = exp1;
615  exp1 = p[0];
616  p += group_size;
617  delta2 = exp1 - exp0 + 2;
618  av_assert2(delta2 >= 0 && delta2 <= 4);
619 
620  block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
621  }
622  }
623  }
624 }
625 
626 
627 /**
628  * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
629  * Extract exponents from MDCT coefficients, calculate exponent strategies,
630  * and encode final exponents.
631  *
632  * @param s AC-3 encoder private context
633  */
634 void ff_ac3_process_exponents(AC3EncodeContext *s)
635 {
636  extract_exponents(s);
637 
638  compute_exp_strategy(s);
639 
640  encode_exponents(s);
641 
642  emms_c();
643 }
644 
645 
646 /*
647  * Count frame bits that are based solely on fixed parameters.
648  * This only has to be run once when the encoder is initialized.
649  */
650 static void count_frame_bits_fixed(AC3EncodeContext *s)
651 {
652  static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
653  int blk;
654  int frame_bits;
655 
656  /* assumptions:
657  * no dynamic range codes
658  * bit allocation parameters do not change between blocks
659  * no delta bit allocation
660  * no skipped data
661  * no auxiliary data
662  * no E-AC-3 metadata
663  */
664 
665  /* header */
666  frame_bits = 16; /* sync info */
667  if (s->eac3) {
668  /* bitstream info header */
669  frame_bits += 35;
670  frame_bits += 1 + 1;
671  if (s->num_blocks != 0x6)
672  frame_bits++;
673  frame_bits++;
674  /* audio frame header */
675  if (s->num_blocks == 6)
676  frame_bits += 2;
677  frame_bits += 10;
678  /* exponent strategy */
679  if (s->use_frame_exp_strategy)
680  frame_bits += 5 * s->fbw_channels;
681  else
682  frame_bits += s->num_blocks * 2 * s->fbw_channels;
683  if (s->lfe_on)
684  frame_bits += s->num_blocks;
685  /* converter exponent strategy */
686  if (s->num_blks_code != 0x3)
687  frame_bits++;
688  else
689  frame_bits += s->fbw_channels * 5;
690  /* snr offsets */
691  frame_bits += 10;
692  /* block start info */
693  if (s->num_blocks != 1)
694  frame_bits++;
695  } else {
696  frame_bits += 49;
697  frame_bits += frame_bits_inc[s->channel_mode];
698  }
699 
700  /* audio blocks */
701  for (blk = 0; blk < s->num_blocks; blk++) {
702  if (!s->eac3) {
703  /* block switch flags */
704  frame_bits += s->fbw_channels;
705 
706  /* dither flags */
707  frame_bits += s->fbw_channels;
708  }
709 
710  /* dynamic range */
711  frame_bits++;
712 
713  /* spectral extension */
714  if (s->eac3)
715  frame_bits++;
716 
717  if (!s->eac3) {
718  /* exponent strategy */
719  frame_bits += 2 * s->fbw_channels;
720  if (s->lfe_on)
721  frame_bits++;
722 
723  /* bit allocation params */
724  frame_bits++;
725  if (!blk)
726  frame_bits += 2 + 2 + 2 + 2 + 3;
727  }
728 
729  /* converter snr offset */
730  if (s->eac3)
731  frame_bits++;
732 
733  if (!s->eac3) {
734  /* delta bit allocation */
735  frame_bits++;
736 
737  /* skipped data */
738  frame_bits++;
739  }
740  }
741 
742  /* auxiliary data */
743  frame_bits++;
744 
745  /* CRC */
746  frame_bits += 1 + 16;
747 
748  s->frame_bits_fixed = frame_bits;
749 }
750 
751 
752 /*
753  * Initialize bit allocation.
754  * Set default parameter codes and calculate parameter values.
755  */
756 static av_cold void bit_alloc_init(AC3EncodeContext *s)
757 {
758  int ch;
759 
760  /* init default parameters */
761  s->slow_decay_code = 2;
762  s->fast_decay_code = 1;
763  s->slow_gain_code = 1;
764  s->db_per_bit_code = s->eac3 ? 2 : 3;
765  s->floor_code = 7;
766  for (ch = 0; ch <= s->channels; ch++)
767  s->fast_gain_code[ch] = 4;
768 
769  /* initial snr offset */
770  s->coarse_snr_offset = 40;
771 
772  /* compute real values */
773  /* currently none of these values change during encoding, so we can just
774  set them once at initialization */
775  s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
776  s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
777  s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
778  s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
779  s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
780  s->bit_alloc.cpl_fast_leak = 0;
781  s->bit_alloc.cpl_slow_leak = 0;
782 
783  count_frame_bits_fixed(s);
784 }
785 
786 
787 /*
788  * Count the bits used to encode the frame, minus exponents and mantissas.
789  * Bits based on fixed parameters have already been counted, so now we just
790  * have to add the bits based on parameters that change during encoding.
791  */
792 static void count_frame_bits(AC3EncodeContext *s)
793 {
794  AC3EncOptions *opt = &s->options;
795  int blk, ch;
796  int frame_bits = 0;
797 
798  /* header */
799  if (s->eac3) {
800  if (opt->eac3_mixing_metadata) {
801  if (s->channel_mode > AC3_CHMODE_STEREO)
802  frame_bits += 2;
803  if (s->has_center)
804  frame_bits += 6;
805  if (s->has_surround)
806  frame_bits += 6;
807  frame_bits += s->lfe_on;
808  frame_bits += 1 + 1 + 2;
809  if (s->channel_mode < AC3_CHMODE_STEREO)
810  frame_bits++;
811  frame_bits++;
812  }
813  if (opt->eac3_info_metadata) {
814  frame_bits += 3 + 1 + 1;
815  if (s->channel_mode == AC3_CHMODE_STEREO)
816  frame_bits += 2 + 2;
817  if (s->channel_mode >= AC3_CHMODE_2F2R)
818  frame_bits += 2;
819  frame_bits++;
820  if (opt->audio_production_info)
821  frame_bits += 5 + 2 + 1;
822  frame_bits++;
823  }
824  /* coupling */
825  if (s->channel_mode > AC3_CHMODE_MONO) {
826  frame_bits++;
827  for (blk = 1; blk < s->num_blocks; blk++) {
828  AC3Block *block = &s->blocks[blk];
829  frame_bits++;
830  if (block->new_cpl_strategy)
831  frame_bits++;
832  }
833  }
834  /* coupling exponent strategy */
835  if (s->cpl_on) {
836  if (s->use_frame_exp_strategy) {
837  frame_bits += 5 * s->cpl_on;
838  } else {
839  for (blk = 0; blk < s->num_blocks; blk++)
840  frame_bits += 2 * s->blocks[blk].cpl_in_use;
841  }
842  }
843  } else {
844  if (opt->audio_production_info)
845  frame_bits += 7;
846  if (s->bitstream_id == 6) {
847  if (opt->extended_bsi_1)
848  frame_bits += 14;
849  if (opt->extended_bsi_2)
850  frame_bits += 14;
851  }
852  }
853 
854  /* audio blocks */
855  for (blk = 0; blk < s->num_blocks; blk++) {
856  AC3Block *block = &s->blocks[blk];
857 
858  /* coupling strategy */
859  if (!s->eac3)
860  frame_bits++;
861  if (block->new_cpl_strategy) {
862  if (!s->eac3)
863  frame_bits++;
864  if (block->cpl_in_use) {
865  if (s->eac3)
866  frame_bits++;
867  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
868  frame_bits += s->fbw_channels;
869  if (s->channel_mode == AC3_CHMODE_STEREO)
870  frame_bits++;
871  frame_bits += 4 + 4;
872  if (s->eac3)
873  frame_bits++;
874  else
875  frame_bits += s->num_cpl_subbands - 1;
876  }
877  }
878 
879  /* coupling coordinates */
880  if (block->cpl_in_use) {
881  for (ch = 1; ch <= s->fbw_channels; ch++) {
882  if (block->channel_in_cpl[ch]) {
883  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
884  frame_bits++;
885  if (block->new_cpl_coords[ch]) {
886  frame_bits += 2;
887  frame_bits += (4 + 4) * s->num_cpl_bands;
888  }
889  }
890  }
891  }
892 
893  /* stereo rematrixing */
894  if (s->channel_mode == AC3_CHMODE_STEREO) {
895  if (!s->eac3 || blk > 0)
896  frame_bits++;
897  if (s->blocks[blk].new_rematrixing_strategy)
898  frame_bits += block->num_rematrixing_bands;
899  }
900 
901  /* bandwidth codes & gain range */
902  for (ch = 1; ch <= s->fbw_channels; ch++) {
903  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
904  if (!block->channel_in_cpl[ch])
905  frame_bits += 6;
906  frame_bits += 2;
907  }
908  }
909 
910  /* coupling exponent strategy */
911  if (!s->eac3 && block->cpl_in_use)
912  frame_bits += 2;
913 
914  /* snr offsets and fast gain codes */
915  if (!s->eac3) {
916  frame_bits++;
917  if (block->new_snr_offsets)
918  frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
919  }
920 
921  /* coupling leak info */
922  if (block->cpl_in_use) {
923  if (!s->eac3 || block->new_cpl_leak != 2)
924  frame_bits++;
925  if (block->new_cpl_leak)
926  frame_bits += 3 + 3;
927  }
928  }
929 
930  s->frame_bits = s->frame_bits_fixed + frame_bits;
931 }
932 
933 
934 /*
935  * Calculate masking curve based on the final exponents.
936  * Also calculate the power spectral densities to use in future calculations.
937  */
938 static void bit_alloc_masking(AC3EncodeContext *s)
939 {
940  int blk, ch;
941 
942  for (blk = 0; blk < s->num_blocks; blk++) {
943  AC3Block *block = &s->blocks[blk];
944  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
945  /* We only need psd and mask for calculating bap.
946  Since we currently do not calculate bap when exponent
947  strategy is EXP_REUSE we do not need to calculate psd or mask. */
948  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
949  ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
950  block->end_freq[ch], block->psd[ch],
951  block->band_psd[ch]);
952  ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
953  s->start_freq[ch], block->end_freq[ch],
954  ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
955  ch == s->lfe_channel,
956  DBA_NONE, 0, NULL, NULL, NULL,
957  block->mask[ch]);
958  }
959  }
960  }
961 }
962 
963 
964 /*
965  * Ensure that bap for each block and channel point to the current bap_buffer.
966  * They may have been switched during the bit allocation search.
967  */
968 static void reset_block_bap(AC3EncodeContext *s)
969 {
970  int blk, ch;
971  uint8_t *ref_bap;
972 
973  if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
974  return;
975 
976  ref_bap = s->bap_buffer;
977  for (ch = 0; ch <= s->channels; ch++) {
978  for (blk = 0; blk < s->num_blocks; blk++)
979  s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
980  ref_bap += AC3_MAX_COEFS * s->num_blocks;
981  }
982  s->ref_bap_set = 1;
983 }
984 
985 
986 /**
987  * Initialize mantissa counts.
988  * These are set so that they are padded to the next whole group size when bits
989  * are counted in compute_mantissa_size.
990  *
991  * @param[in,out] mant_cnt running counts for each bap value for each block
992  */
993 static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
994 {
995  int blk;
996 
997  for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
998  memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
999  mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1000  mant_cnt[blk][4] = 1;
1001  }
1002 }
1003 
1004 
1005 /**
1006  * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1007  * range.
1008  *
1009  * @param s AC-3 encoder private context
1010  * @param ch channel index
1011  * @param[in,out] mant_cnt running counts for each bap value for each block
1012  * @param start starting coefficient bin
1013  * @param end ending coefficient bin
1014  */
1015 static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
1016  uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1017  int start, int end)
1018 {
1019  int blk;
1020 
1021  for (blk = 0; blk < s->num_blocks; blk++) {
1022  AC3Block *block = &s->blocks[blk];
1023  if (ch == CPL_CH && !block->cpl_in_use)
1024  continue;
1025  s->ac3dsp.update_bap_counts(mant_cnt[blk],
1026  s->ref_bap[ch][blk] + start,
1027  FFMIN(end, block->end_freq[ch]) - start);
1028  }
1029 }
1030 
1031 
1032 /*
1033  * Count the number of mantissa bits in the frame based on the bap values.
1034  */
1035 static int count_mantissa_bits(AC3EncodeContext *s)
1036 {
1037  int ch, max_end_freq;
1038  LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1039 
1040  count_mantissa_bits_init(mant_cnt);
1041 
1042  max_end_freq = s->bandwidth_code * 3 + 73;
1043  for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1044  count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1045  max_end_freq);
1046 
1047  return s->ac3dsp.compute_mantissa_size(mant_cnt);
1048 }
1049 
1050 
1051 /**
1052  * Run the bit allocation with a given SNR offset.
1053  * This calculates the bit allocation pointers that will be used to determine
1054  * the quantization of each mantissa.
1055  *
1056  * @param s AC-3 encoder private context
1057  * @param snr_offset SNR offset, 0 to 1023
1058  * @return the number of bits needed for mantissas if the given SNR offset is
1059  * is used.
1060  */
1061 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1062 {
1063  int blk, ch;
1064 
1065  snr_offset = (snr_offset - 240) << 2;
1066 
1067  reset_block_bap(s);
1068  for (blk = 0; blk < s->num_blocks; blk++) {
1069  AC3Block *block = &s->blocks[blk];
1070 
1071  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1072  /* Currently the only bit allocation parameters which vary across
1073  blocks within a frame are the exponent values. We can take
1074  advantage of that by reusing the bit allocation pointers
1075  whenever we reuse exponents. */
1076  if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1077  s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1078  s->start_freq[ch], block->end_freq[ch],
1079  snr_offset, s->bit_alloc.floor,
1080  ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1081  }
1082  }
1083  }
1084  return count_mantissa_bits(s);
1085 }
1086 
1087 
1088 /*
1089  * Constant bitrate bit allocation search.
1090  * Find the largest SNR offset that will allow data to fit in the frame.
1091  */
1092 static int cbr_bit_allocation(AC3EncodeContext *s)
1093 {
1094  int ch;
1095  int bits_left;
1096  int snr_offset, snr_incr;
1097 
1098  bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1099  if (bits_left < 0)
1100  return AVERROR(EINVAL);
1101 
1102  snr_offset = s->coarse_snr_offset << 4;
1103 
1104  /* if previous frame SNR offset was 1023, check if current frame can also
1105  use SNR offset of 1023. if so, skip the search. */
1106  if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1107  if (bit_alloc(s, 1023) <= bits_left)
1108  return 0;
1109  }
1110 
1111  while (snr_offset >= 0 &&
1112  bit_alloc(s, snr_offset) > bits_left) {
1113  snr_offset -= 64;
1114  }
1115  if (snr_offset < 0)
1116  return AVERROR(EINVAL);
1117 
1118  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1119  for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1120  while (snr_offset + snr_incr <= 1023 &&
1121  bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1122  snr_offset += snr_incr;
1123  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1124  }
1125  }
1126  FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1127  reset_block_bap(s);
1128 
1129  s->coarse_snr_offset = snr_offset >> 4;
1130  for (ch = !s->cpl_on; ch <= s->channels; ch++)
1131  s->fine_snr_offset[ch] = snr_offset & 0xF;
1132 
1133  return 0;
1134 }
1135 
1136 
1137 /*
1138  * Perform bit allocation search.
1139  * Finds the SNR offset value that maximizes quality and fits in the specified
1140  * frame size. Output is the SNR offset and a set of bit allocation pointers
1141  * used to quantize the mantissas.
1142  */
1143 int ff_ac3_compute_bit_allocation(AC3EncodeContext *s)
1144 {
1145  count_frame_bits(s);
1146 
1147  s->exponent_bits = count_exponent_bits(s);
1148 
1149  bit_alloc_masking(s);
1150 
1151  return cbr_bit_allocation(s);
1152 }
1153 
1154 
1155 /**
1156  * Symmetric quantization on 'levels' levels.
1157  *
1158  * @param c unquantized coefficient
1159  * @param e exponent
1160  * @param levels number of quantization levels
1161  * @return quantized coefficient
1162  */
1163 static inline int sym_quant(int c, int e, int levels)
1164 {
1165  int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1166  av_assert2(v >= 0 && v < levels);
1167  return v;
1168 }
1169 
1170 
1171 /**
1172  * Asymmetric quantization on 2^qbits levels.
1173  *
1174  * @param c unquantized coefficient
1175  * @param e exponent
1176  * @param qbits number of quantization bits
1177  * @return quantized coefficient
1178  */
1179 static inline int asym_quant(int c, int e, int qbits)
1180 {
1181  int m;
1182 
1183  c = (((c << e) >> (24 - qbits)) + 1) >> 1;
1184  m = (1 << (qbits-1));
1185  if (c >= m)
1186  c = m - 1;
1187  av_assert2(c >= -m);
1188  return c;
1189 }
1190 
1191 
1192 /**
1193  * Quantize a set of mantissas for a single channel in a single block.
1194  *
1195  * @param s Mantissa count context
1196  * @param fixed_coef unquantized fixed-point coefficients
1197  * @param exp exponents
1198  * @param bap bit allocation pointer indices
1199  * @param[out] qmant quantized coefficients
1200  * @param start_freq starting coefficient bin
1201  * @param end_freq ending coefficient bin
1202  */
1203 static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1204  uint8_t *exp, uint8_t *bap,
1205  int16_t *qmant, int start_freq,
1206  int end_freq)
1207 {
1208  int i;
1209 
1210  for (i = start_freq; i < end_freq; i++) {
1211  int c = fixed_coef[i];
1212  int e = exp[i];
1213  int v = bap[i];
1214  if (v)
1215  switch (v) {
1216  case 1:
1217  v = sym_quant(c, e, 3);
1218  switch (s->mant1_cnt) {
1219  case 0:
1220  s->qmant1_ptr = &qmant[i];
1221  v = 9 * v;
1222  s->mant1_cnt = 1;
1223  break;
1224  case 1:
1225  *s->qmant1_ptr += 3 * v;
1226  s->mant1_cnt = 2;
1227  v = 128;
1228  break;
1229  default:
1230  *s->qmant1_ptr += v;
1231  s->mant1_cnt = 0;
1232  v = 128;
1233  break;
1234  }
1235  break;
1236  case 2:
1237  v = sym_quant(c, e, 5);
1238  switch (s->mant2_cnt) {
1239  case 0:
1240  s->qmant2_ptr = &qmant[i];
1241  v = 25 * v;
1242  s->mant2_cnt = 1;
1243  break;
1244  case 1:
1245  *s->qmant2_ptr += 5 * v;
1246  s->mant2_cnt = 2;
1247  v = 128;
1248  break;
1249  default:
1250  *s->qmant2_ptr += v;
1251  s->mant2_cnt = 0;
1252  v = 128;
1253  break;
1254  }
1255  break;
1256  case 3:
1257  v = sym_quant(c, e, 7);
1258  break;
1259  case 4:
1260  v = sym_quant(c, e, 11);
1261  switch (s->mant4_cnt) {
1262  case 0:
1263  s->qmant4_ptr = &qmant[i];
1264  v = 11 * v;
1265  s->mant4_cnt = 1;
1266  break;
1267  default:
1268  *s->qmant4_ptr += v;
1269  s->mant4_cnt = 0;
1270  v = 128;
1271  break;
1272  }
1273  break;
1274  case 5:
1275  v = sym_quant(c, e, 15);
1276  break;
1277  case 14:
1278  v = asym_quant(c, e, 14);
1279  break;
1280  case 15:
1281  v = asym_quant(c, e, 16);
1282  break;
1283  default:
1284  v = asym_quant(c, e, v - 1);
1285  break;
1286  }
1287  qmant[i] = v;
1288  }
1289 }
1290 
1291 
1292 /**
1293  * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1294  *
1295  * @param s AC-3 encoder private context
1296  */
1297 void ff_ac3_quantize_mantissas(AC3EncodeContext *s)
1298 {
1299  int blk, ch, ch0=0, got_cpl;
1300 
1301  for (blk = 0; blk < s->num_blocks; blk++) {
1302  AC3Block *block = &s->blocks[blk];
1303  AC3Mant m = { 0 };
1304 
1305  got_cpl = !block->cpl_in_use;
1306  for (ch = 1; ch <= s->channels; ch++) {
1307  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1308  ch0 = ch - 1;
1309  ch = CPL_CH;
1310  got_cpl = 1;
1311  }
1312  quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1313  s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1314  s->ref_bap[ch][blk], block->qmant[ch],
1315  s->start_freq[ch], block->end_freq[ch]);
1316  if (ch == CPL_CH)
1317  ch = ch0;
1318  }
1319  }
1320 }
1321 
1322 
1323 /*
1324  * Write the AC-3 frame header to the output bitstream.
1325  */
1326 static void ac3_output_frame_header(AC3EncodeContext *s)
1327 {
1328  AC3EncOptions *opt = &s->options;
1329 
1330  put_bits(&s->pb, 16, 0x0b77); /* frame header */
1331  put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
1332  put_bits(&s->pb, 2, s->bit_alloc.sr_code);
1333  put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1334  put_bits(&s->pb, 5, s->bitstream_id);
1335  put_bits(&s->pb, 3, s->bitstream_mode);
1336  put_bits(&s->pb, 3, s->channel_mode);
1337  if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1338  put_bits(&s->pb, 2, s->center_mix_level);
1339  if (s->channel_mode & 0x04)
1340  put_bits(&s->pb, 2, s->surround_mix_level);
1341  if (s->channel_mode == AC3_CHMODE_STEREO)
1342  put_bits(&s->pb, 2, opt->dolby_surround_mode);
1343  put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1344  put_bits(&s->pb, 5, -opt->dialogue_level);
1345  put_bits(&s->pb, 1, 0); /* no compression control word */
1346  put_bits(&s->pb, 1, 0); /* no lang code */
1347  put_bits(&s->pb, 1, opt->audio_production_info);
1348  if (opt->audio_production_info) {
1349  put_bits(&s->pb, 5, opt->mixing_level - 80);
1350  put_bits(&s->pb, 2, opt->room_type);
1351  }
1352  put_bits(&s->pb, 1, opt->copyright);
1353  put_bits(&s->pb, 1, opt->original);
1354  if (s->bitstream_id == 6) {
1355  /* alternate bit stream syntax */
1356  put_bits(&s->pb, 1, opt->extended_bsi_1);
1357  if (opt->extended_bsi_1) {
1358  put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1359  put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1360  put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1361  put_bits(&s->pb, 3, s->loro_center_mix_level);
1362  put_bits(&s->pb, 3, s->loro_surround_mix_level);
1363  }
1364  put_bits(&s->pb, 1, opt->extended_bsi_2);
1365  if (opt->extended_bsi_2) {
1366  put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1367  put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1368  put_bits(&s->pb, 1, opt->ad_converter_type);
1369  put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
1370  }
1371  } else {
1372  put_bits(&s->pb, 1, 0); /* no time code 1 */
1373  put_bits(&s->pb, 1, 0); /* no time code 2 */
1374  }
1375  put_bits(&s->pb, 1, 0); /* no additional bit stream info */
1376 }
1377 
1378 
1379 /*
1380  * Write one audio block to the output bitstream.
1381  */
1382 static void output_audio_block(AC3EncodeContext *s, int blk)
1383 {
1384  int ch, i, baie, bnd, got_cpl, ch0;
1385  AC3Block *block = &s->blocks[blk];
1386 
1387  /* block switching */
1388  if (!s->eac3) {
1389  for (ch = 0; ch < s->fbw_channels; ch++)
1390  put_bits(&s->pb, 1, 0);
1391  }
1392 
1393  /* dither flags */
1394  if (!s->eac3) {
1395  for (ch = 0; ch < s->fbw_channels; ch++)
1396  put_bits(&s->pb, 1, 1);
1397  }
1398 
1399  /* dynamic range codes */
1400  put_bits(&s->pb, 1, 0);
1401 
1402  /* spectral extension */
1403  if (s->eac3)
1404  put_bits(&s->pb, 1, 0);
1405 
1406  /* channel coupling */
1407  if (!s->eac3)
1408  put_bits(&s->pb, 1, block->new_cpl_strategy);
1409  if (block->new_cpl_strategy) {
1410  if (!s->eac3)
1411  put_bits(&s->pb, 1, block->cpl_in_use);
1412  if (block->cpl_in_use) {
1413  int start_sub, end_sub;
1414  if (s->eac3)
1415  put_bits(&s->pb, 1, 0); /* enhanced coupling */
1416  if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1417  for (ch = 1; ch <= s->fbw_channels; ch++)
1418  put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1419  }
1420  if (s->channel_mode == AC3_CHMODE_STEREO)
1421  put_bits(&s->pb, 1, 0); /* phase flags in use */
1422  start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1423  end_sub = (s->cpl_end_freq - 37) / 12;
1424  put_bits(&s->pb, 4, start_sub);
1425  put_bits(&s->pb, 4, end_sub - 3);
1426  /* coupling band structure */
1427  if (s->eac3) {
1428  put_bits(&s->pb, 1, 0); /* use default */
1429  } else {
1430  for (bnd = start_sub+1; bnd < end_sub; bnd++)
1431  put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
1432  }
1433  }
1434  }
1435 
1436  /* coupling coordinates */
1437  if (block->cpl_in_use) {
1438  for (ch = 1; ch <= s->fbw_channels; ch++) {
1439  if (block->channel_in_cpl[ch]) {
1440  if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1441  put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1442  if (block->new_cpl_coords[ch]) {
1443  put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1444  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1445  put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1446  put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1447  }
1448  }
1449  }
1450  }
1451  }
1452 
1453  /* stereo rematrixing */
1454  if (s->channel_mode == AC3_CHMODE_STEREO) {
1455  if (!s->eac3 || blk > 0)
1456  put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1457  if (block->new_rematrixing_strategy) {
1458  /* rematrixing flags */
1459  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1460  put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1461  }
1462  }
1463 
1464  /* exponent strategy */
1465  if (!s->eac3) {
1466  for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1467  put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1468  if (s->lfe_on)
1469  put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1470  }
1471 
1472  /* bandwidth */
1473  for (ch = 1; ch <= s->fbw_channels; ch++) {
1474  if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1475  put_bits(&s->pb, 6, s->bandwidth_code);
1476  }
1477 
1478  /* exponents */
1479  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1480  int nb_groups;
1481  int cpl = (ch == CPL_CH);
1482 
1483  if (s->exp_strategy[ch][blk] == EXP_REUSE)
1484  continue;
1485 
1486  /* DC exponent */
1487  put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1488 
1489  /* exponent groups */
1490  nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1491  for (i = 1; i <= nb_groups; i++)
1492  put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1493 
1494  /* gain range info */
1495  if (ch != s->lfe_channel && !cpl)
1496  put_bits(&s->pb, 2, 0);
1497  }
1498 
1499  /* bit allocation info */
1500  if (!s->eac3) {
1501  baie = (blk == 0);
1502  put_bits(&s->pb, 1, baie);
1503  if (baie) {
1504  put_bits(&s->pb, 2, s->slow_decay_code);
1505  put_bits(&s->pb, 2, s->fast_decay_code);
1506  put_bits(&s->pb, 2, s->slow_gain_code);
1507  put_bits(&s->pb, 2, s->db_per_bit_code);
1508  put_bits(&s->pb, 3, s->floor_code);
1509  }
1510  }
1511 
1512  /* snr offset */
1513  if (!s->eac3) {
1514  put_bits(&s->pb, 1, block->new_snr_offsets);
1515  if (block->new_snr_offsets) {
1516  put_bits(&s->pb, 6, s->coarse_snr_offset);
1517  for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1518  put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1519  put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1520  }
1521  }
1522  } else {
1523  put_bits(&s->pb, 1, 0); /* no converter snr offset */
1524  }
1525 
1526  /* coupling leak */
1527  if (block->cpl_in_use) {
1528  if (!s->eac3 || block->new_cpl_leak != 2)
1529  put_bits(&s->pb, 1, block->new_cpl_leak);
1530  if (block->new_cpl_leak) {
1531  put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1532  put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1533  }
1534  }
1535 
1536  if (!s->eac3) {
1537  put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1538  put_bits(&s->pb, 1, 0); /* no data to skip */
1539  }
1540 
1541  /* mantissas */
1542  got_cpl = !block->cpl_in_use;
1543  for (ch = 1; ch <= s->channels; ch++) {
1544  int b, q;
1545 
1546  if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1547  ch0 = ch - 1;
1548  ch = CPL_CH;
1549  got_cpl = 1;
1550  }
1551  for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1552  q = block->qmant[ch][i];
1553  b = s->ref_bap[ch][blk][i];
1554  switch (b) {
1555  case 0: break;
1556  case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
1557  case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
1558  case 3: put_sbits(&s->pb, 3, q); break;
1559  case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
1560  case 14: put_sbits(&s->pb, 14, q); break;
1561  case 15: put_sbits(&s->pb, 16, q); break;
1562  default: put_sbits(&s->pb, b-1, q); break;
1563  }
1564  }
1565  if (ch == CPL_CH)
1566  ch = ch0;
1567  }
1568 }
1569 
1570 
1571 /** CRC-16 Polynomial */
1572 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1573 
1574 
1575 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1576 {
1577  unsigned int c;
1578 
1579  c = 0;
1580  while (a) {
1581  if (a & 1)
1582  c ^= b;
1583  a = a >> 1;
1584  b = b << 1;
1585  if (b & (1 << 16))
1586  b ^= poly;
1587  }
1588  return c;
1589 }
1590 
1591 
1592 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1593 {
1594  unsigned int r;
1595  r = 1;
1596  while (n) {
1597  if (n & 1)
1598  r = mul_poly(r, a, poly);
1599  a = mul_poly(a, a, poly);
1600  n >>= 1;
1601  }
1602  return r;
1603 }
1604 
1605 
1606 /*
1607  * Fill the end of the frame with 0's and compute the two CRCs.
1608  */
1609 static void output_frame_end(AC3EncodeContext *s)
1610 {
1611  const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1612  int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1613  uint8_t *frame;
1614 
1615  frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1616 
1617  /* pad the remainder of the frame with zeros */
1618  av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1619  flush_put_bits(&s->pb);
1620  frame = s->pb.buf;
1621  pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1622  av_assert2(pad_bytes >= 0);
1623  if (pad_bytes > 0)
1624  memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1625 
1626  if (s->eac3) {
1627  /* compute crc2 */
1628  crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1629  } else {
1630  /* compute crc1 */
1631  /* this is not so easy because it is at the beginning of the data... */
1632  crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1633  crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1634  crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
1635  AV_WB16(frame + 2, crc1);
1636 
1637  /* compute crc2 */
1638  crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1639  s->frame_size - frame_size_58 - 3);
1640  }
1641  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1642  /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1643  if (crc2 == 0x770B) {
1644  frame[s->frame_size - 3] ^= 0x1;
1645  crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1646  }
1647  crc2 = av_bswap16(crc2);
1648  AV_WB16(frame + s->frame_size - 2, crc2);
1649 }
1650 
1651 
1652 /**
1653  * Write the frame to the output bitstream.
1654  *
1655  * @param s AC-3 encoder private context
1656  * @param frame output data buffer
1657  */
1658 void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
1659 {
1660  int blk;
1661 
1662  init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
1663 
1664  s->output_frame_header(s);
1665 
1666  for (blk = 0; blk < s->num_blocks; blk++)
1667  output_audio_block(s, blk);
1668 
1669  output_frame_end(s);
1670 }
1671 
1672 
1673 static void dprint_options(AC3EncodeContext *s)
1674 {
1675 #ifdef DEBUG
1676  AVCodecContext *avctx = s->avctx;
1677  AC3EncOptions *opt = &s->options;
1678  char strbuf[32];
1679 
1680  switch (s->bitstream_id) {
1681  case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
1682  case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
1683  case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
1684  case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1685  case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
1686  default: snprintf(strbuf, 32, "ERROR");
1687  }
1688  av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1689  av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1690  av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1691  av_dlog(avctx, "channel_layout: %s\n", strbuf);
1692  av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1693  av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1694  av_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1695  if (s->cutoff)
1696  av_dlog(avctx, "cutoff: %d\n", s->cutoff);
1697 
1698  av_dlog(avctx, "per_frame_metadata: %s\n",
1699  opt->allow_per_frame_metadata?"on":"off");
1700  if (s->has_center)
1701  av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1702  s->center_mix_level);
1703  else
1704  av_dlog(avctx, "center_mixlev: {not written}\n");
1705  if (s->has_surround)
1706  av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1707  s->surround_mix_level);
1708  else
1709  av_dlog(avctx, "surround_mixlev: {not written}\n");
1710  if (opt->audio_production_info) {
1711  av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1712  switch (opt->room_type) {
1713  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1714  case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
1715  case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
1716  default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1717  }
1718  av_dlog(avctx, "room_type: %s\n", strbuf);
1719  } else {
1720  av_dlog(avctx, "mixing_level: {not written}\n");
1721  av_dlog(avctx, "room_type: {not written}\n");
1722  }
1723  av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1724  av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1725  if (s->channel_mode == AC3_CHMODE_STEREO) {
1726  switch (opt->dolby_surround_mode) {
1727  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1728  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1729  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1730  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1731  }
1732  av_dlog(avctx, "dsur_mode: %s\n", strbuf);
1733  } else {
1734  av_dlog(avctx, "dsur_mode: {not written}\n");
1735  }
1736  av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1737 
1738  if (s->bitstream_id == 6) {
1739  if (opt->extended_bsi_1) {
1740  switch (opt->preferred_stereo_downmix) {
1741  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1742  case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
1743  case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
1744  default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1745  }
1746  av_dlog(avctx, "dmix_mode: %s\n", strbuf);
1747  av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1748  opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1749  av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1750  opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1751  av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1752  opt->loro_center_mix_level, s->loro_center_mix_level);
1753  av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1754  opt->loro_surround_mix_level, s->loro_surround_mix_level);
1755  } else {
1756  av_dlog(avctx, "extended bitstream info 1: {not written}\n");
1757  }
1758  if (opt->extended_bsi_2) {
1759  switch (opt->dolby_surround_ex_mode) {
1760  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1761  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1762  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1763  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1764  }
1765  av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1766  switch (opt->dolby_headphone_mode) {
1767  case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1768  case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
1769  case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
1770  default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1771  }
1772  av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1773 
1774  switch (opt->ad_converter_type) {
1775  case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1776  case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
1777  default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1778  }
1779  av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1780  } else {
1781  av_dlog(avctx, "extended bitstream info 2: {not written}\n");
1782  }
1783  }
1784 #endif
1785 }
1786 
1787 
1788 #define FLT_OPTION_THRESHOLD 0.01
1789 
1790 static int validate_float_option(float v, const float *v_list, int v_list_size)
1791 {
1792  int i;
1793 
1794  for (i = 0; i < v_list_size; i++) {
1795  if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1796  v > (v_list[i] - FLT_OPTION_THRESHOLD))
1797  break;
1798  }
1799  if (i == v_list_size)
1800  return -1;
1801 
1802  return i;
1803 }
1804 
1805 
1806 static void validate_mix_level(void *log_ctx, const char *opt_name,
1807  float *opt_param, const float *list,
1808  int list_size, int default_value, int min_value,
1809  int *ctx_param)
1810 {
1811  int mixlev = validate_float_option(*opt_param, list, list_size);
1812  if (mixlev < min_value) {
1813  mixlev = default_value;
1814  if (*opt_param >= 0.0) {
1815  av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1816  "default value: %0.3f\n", opt_name, list[mixlev]);
1817  }
1818  }
1819  *opt_param = list[mixlev];
1820  *ctx_param = mixlev;
1821 }
1822 
1823 
1824 /**
1825  * Validate metadata options as set by AVOption system.
1826  * These values can optionally be changed per-frame.
1827  *
1828  * @param s AC-3 encoder private context
1829  */
1830 int ff_ac3_validate_metadata(AC3EncodeContext *s)
1831 {
1832  AVCodecContext *avctx = s->avctx;
1833  AC3EncOptions *opt = &s->options;
1834 
1835  opt->audio_production_info = 0;
1836  opt->extended_bsi_1 = 0;
1837  opt->extended_bsi_2 = 0;
1838  opt->eac3_mixing_metadata = 0;
1839  opt->eac3_info_metadata = 0;
1840 
1841  /* determine mixing metadata / xbsi1 use */
1842  if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
1843  opt->extended_bsi_1 = 1;
1844  opt->eac3_mixing_metadata = 1;
1845  }
1846  if (s->has_center &&
1847  (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
1848  opt->extended_bsi_1 = 1;
1849  opt->eac3_mixing_metadata = 1;
1850  }
1851  if (s->has_surround &&
1852  (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
1853  opt->extended_bsi_1 = 1;
1854  opt->eac3_mixing_metadata = 1;
1855  }
1856 
1857  if (s->eac3) {
1858  /* determine info metadata use */
1859  if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
1860  opt->eac3_info_metadata = 1;
1861  if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
1862  opt->eac3_info_metadata = 1;
1863  if (s->channel_mode == AC3_CHMODE_STEREO &&
1864  (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
1865  opt->eac3_info_metadata = 1;
1866  if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1867  opt->eac3_info_metadata = 1;
1868  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
1869  opt->ad_converter_type != AC3ENC_OPT_NONE) {
1870  opt->audio_production_info = 1;
1871  opt->eac3_info_metadata = 1;
1872  }
1873  } else {
1874  /* determine audio production info use */
1875  if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
1876  opt->audio_production_info = 1;
1877 
1878  /* determine xbsi2 use */
1879  if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1880  opt->extended_bsi_2 = 1;
1881  if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
1882  opt->extended_bsi_2 = 1;
1883  if (opt->ad_converter_type != AC3ENC_OPT_NONE)
1884  opt->extended_bsi_2 = 1;
1885  }
1886 
1887  /* validate AC-3 mixing levels */
1888  if (!s->eac3) {
1889  if (s->has_center) {
1890  validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1891  cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
1892  &s->center_mix_level);
1893  }
1894  if (s->has_surround) {
1895  validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1896  surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
1897  &s->surround_mix_level);
1898  }
1899  }
1900 
1901  /* validate extended bsi 1 / mixing metadata */
1902  if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
1903  /* default preferred stereo downmix */
1904  if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
1905  opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
1906  if (!s->eac3 || s->has_center) {
1907  /* validate Lt/Rt center mix level */
1908  validate_mix_level(avctx, "ltrt_center_mix_level",
1909  &opt->ltrt_center_mix_level, extmixlev_options,
1910  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1911  &s->ltrt_center_mix_level);
1912  /* validate Lo/Ro center mix level */
1913  validate_mix_level(avctx, "loro_center_mix_level",
1914  &opt->loro_center_mix_level, extmixlev_options,
1915  EXTMIXLEV_NUM_OPTIONS, 5, 0,
1916  &s->loro_center_mix_level);
1917  }
1918  if (!s->eac3 || s->has_surround) {
1919  /* validate Lt/Rt surround mix level */
1920  validate_mix_level(avctx, "ltrt_surround_mix_level",
1921  &opt->ltrt_surround_mix_level, extmixlev_options,
1922  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1923  &s->ltrt_surround_mix_level);
1924  /* validate Lo/Ro surround mix level */
1925  validate_mix_level(avctx, "loro_surround_mix_level",
1926  &opt->loro_surround_mix_level, extmixlev_options,
1927  EXTMIXLEV_NUM_OPTIONS, 6, 3,
1928  &s->loro_surround_mix_level);
1929  }
1930  }
1931 
1932  /* validate audio service type / channels combination */
1933  if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
1934  avctx->channels == 1) ||
1935  ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
1936  avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY ||
1937  avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
1938  && avctx->channels > 1)) {
1939  av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
1940  "specified number of channels\n");
1941  return AVERROR(EINVAL);
1942  }
1943 
1944  /* validate extended bsi 2 / info metadata */
1945  if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
1946  /* default dolby headphone mode */
1947  if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
1948  opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
1949  /* default dolby surround ex mode */
1950  if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
1951  opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
1952  /* default A/D converter type */
1953  if (opt->ad_converter_type == AC3ENC_OPT_NONE)
1954  opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
1955  }
1956 
1957  /* copyright & original defaults */
1958  if (!s->eac3 || opt->eac3_info_metadata) {
1959  /* default copyright */
1960  if (opt->copyright == AC3ENC_OPT_NONE)
1961  opt->copyright = AC3ENC_OPT_OFF;
1962  /* default original */
1963  if (opt->original == AC3ENC_OPT_NONE)
1964  opt->original = AC3ENC_OPT_ON;
1965  }
1966 
1967  /* dolby surround mode default */
1968  if (!s->eac3 || opt->eac3_info_metadata) {
1969  if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
1970  opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
1971  }
1972 
1973  /* validate audio production info */
1974  if (opt->audio_production_info) {
1975  if (opt->mixing_level == AC3ENC_OPT_NONE) {
1976  av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
1977  "room_type is set\n");
1978  return AVERROR(EINVAL);
1979  }
1980  if (opt->mixing_level < 80) {
1981  av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
1982  "80dB and 111dB\n");
1983  return AVERROR(EINVAL);
1984  }
1985  /* default room type */
1986  if (opt->room_type == AC3ENC_OPT_NONE)
1987  opt->room_type = AC3ENC_OPT_NOT_INDICATED;
1988  }
1989 
1990  /* set bitstream id for alternate bitstream syntax */
1991  if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
1992  if (s->bitstream_id > 8 && s->bitstream_id < 11) {
1993  static int warn_once = 1;
1994  if (warn_once) {
1995  av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
1996  "not compatible with reduced samplerates. writing of "
1997  "extended bitstream information will be disabled.\n");
1998  warn_once = 0;
1999  }
2000  } else {
2001  s->bitstream_id = 6;
2002  }
2003  }
2004 
2005  return 0;
2006 }
2007 
2008 
2009 /**
2010  * Finalize encoding and free any memory allocated by the encoder.
2011  *
2012  * @param avctx Codec context
2013  */
2014 av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
2015 {
2016  int blk, ch;
2017  AC3EncodeContext *s = avctx->priv_data;
2018 
2019  av_freep(&s->windowed_samples);
2020  if (s->planar_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  return 0;
2053 }
2054 
2055 
2056 /*
2057  * Set channel information during initialization.
2058  */
2059 static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
2060  uint64_t *channel_layout)
2061 {
2062  int ch_layout;
2063 
2064  if (channels < 1 || channels > AC3_MAX_CHANNELS)
2065  return AVERROR(EINVAL);
2066  if (*channel_layout > 0x7FF)
2067  return AVERROR(EINVAL);
2068  ch_layout = *channel_layout;
2069  if (!ch_layout)
2070  ch_layout = av_get_default_channel_layout(channels);
2071 
2072  s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
2073  s->channels = channels;
2074  s->fbw_channels = channels - s->lfe_on;
2075  s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
2076  if (s->lfe_on)
2077  ch_layout -= AV_CH_LOW_FREQUENCY;
2078 
2079  switch (ch_layout) {
2080  case AV_CH_LAYOUT_MONO: s->channel_mode = AC3_CHMODE_MONO; break;
2081  case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
2082  case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
2083  case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
2084  case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
2085  case AV_CH_LAYOUT_QUAD:
2086  case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
2087  case AV_CH_LAYOUT_5POINT0:
2088  case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
2089  default:
2090  return AVERROR(EINVAL);
2091  }
2092  s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2093  s->has_surround = s->channel_mode & 0x04;
2094 
2095  s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
2096  *channel_layout = ch_layout;
2097  if (s->lfe_on)
2098  *channel_layout |= AV_CH_LOW_FREQUENCY;
2099 
2100  return 0;
2101 }
2102 
2103 
2104 static av_cold int validate_options(AC3EncodeContext *s)
2105 {
2106  AVCodecContext *avctx = s->avctx;
2107  int i, ret, max_sr;
2108 
2109  /* validate channel layout */
2110  if (!avctx->channel_layout) {
2111  av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2112  "encoder will guess the layout, but it "
2113  "might be incorrect.\n");
2114  }
2115  ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
2116  if (ret) {
2117  av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2118  return ret;
2119  }
2120 
2121  /* validate sample rate */
2122  /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2123  decoder that supports half sample rate so we can validate that
2124  the generated files are correct. */
2125  max_sr = s->eac3 ? 2 : 8;
2126  for (i = 0; i <= max_sr; i++) {
2127  if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2128  break;
2129  }
2130  if (i > max_sr) {
2131  av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2132  return AVERROR(EINVAL);
2133  }
2134  s->sample_rate = avctx->sample_rate;
2135  s->bit_alloc.sr_shift = i / 3;
2136  s->bit_alloc.sr_code = i % 3;
2137  s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2138 
2139  /* select a default bit rate if not set by the user */
2140  if (!avctx->bit_rate) {
2141  switch (s->fbw_channels) {
2142  case 1: avctx->bit_rate = 96000; break;
2143  case 2: avctx->bit_rate = 192000; break;
2144  case 3: avctx->bit_rate = 320000; break;
2145  case 4: avctx->bit_rate = 384000; break;
2146  case 5: avctx->bit_rate = 448000; break;
2147  }
2148  }
2149 
2150  /* validate bit rate */
2151  if (s->eac3) {
2152  int max_br, min_br, wpf, min_br_dist, min_br_code;
2153  int num_blks_code, num_blocks, frame_samples;
2154 
2155  /* calculate min/max bitrate */
2156  /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2157  found use either 6 blocks or 1 block, even though 2 or 3 blocks
2158  would work as far as the bit rate is concerned. */
2159  for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2160  num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2161  frame_samples = AC3_BLOCK_SIZE * num_blocks;
2162  max_br = 2048 * s->sample_rate / frame_samples * 16;
2163  min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2164  if (avctx->bit_rate <= max_br)
2165  break;
2166  }
2167  if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2168  av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2169  "for this sample rate\n", min_br, max_br);
2170  return AVERROR(EINVAL);
2171  }
2172  s->num_blks_code = num_blks_code;
2173  s->num_blocks = num_blocks;
2174 
2175  /* calculate words-per-frame for the selected bitrate */
2176  wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2177  av_assert1(wpf > 0 && wpf <= 2048);
2178 
2179  /* find the closest AC-3 bitrate code to the selected bitrate.
2180  this is needed for lookup tables for bandwidth and coupling
2181  parameter selection */
2182  min_br_code = -1;
2183  min_br_dist = INT_MAX;
2184  for (i = 0; i < 19; i++) {
2185  int br_dist = abs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2186  if (br_dist < min_br_dist) {
2187  min_br_dist = br_dist;
2188  min_br_code = i;
2189  }
2190  }
2191 
2192  /* make sure the minimum frame size is below the average frame size */
2193  s->frame_size_code = min_br_code << 1;
2194  while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2195  wpf--;
2196  s->frame_size_min = 2 * wpf;
2197  } else {
2198  int best_br = 0, best_code = 0, best_diff = INT_MAX;
2199  for (i = 0; i < 19; i++) {
2200  int br = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2201  int diff = abs(br - avctx->bit_rate);
2202  if (diff < best_diff) {
2203  best_br = br;
2204  best_code = i;
2205  best_diff = diff;
2206  }
2207  if (!best_diff)
2208  break;
2209  }
2210  avctx->bit_rate = best_br;
2211  s->frame_size_code = best_code << 1;
2212  s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2213  s->num_blks_code = 0x3;
2214  s->num_blocks = 6;
2215  }
2216  s->bit_rate = avctx->bit_rate;
2217  s->frame_size = s->frame_size_min;
2218 
2219  /* validate cutoff */
2220  if (avctx->cutoff < 0) {
2221  av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2222  return AVERROR(EINVAL);
2223  }
2224  s->cutoff = avctx->cutoff;
2225  if (s->cutoff > (s->sample_rate >> 1))
2226  s->cutoff = s->sample_rate >> 1;
2227 
2228  ret = ff_ac3_validate_metadata(s);
2229  if (ret)
2230  return ret;
2231 
2232  s->rematrixing_enabled = s->options.stereo_rematrixing &&
2233  (s->channel_mode == AC3_CHMODE_STEREO);
2234 
2235  s->cpl_enabled = s->options.channel_coupling &&
2236  s->channel_mode >= AC3_CHMODE_STEREO;
2237 
2238  return 0;
2239 }
2240 
2241 
2242 /*
2243  * Set bandwidth for all channels.
2244  * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2245  * default value will be used.
2246  */
2247 static av_cold void set_bandwidth(AC3EncodeContext *s)
2248 {
2249  int blk, ch, cpl_start;
2250 
2251  if (s->cutoff) {
2252  /* calculate bandwidth based on user-specified cutoff frequency */
2253  int fbw_coeffs;
2254  fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2255  s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2256  } else {
2257  /* use default bandwidth setting */
2258  s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2259  }
2260 
2261  /* set number of coefficients for each channel */
2262  for (ch = 1; ch <= s->fbw_channels; ch++) {
2263  s->start_freq[ch] = 0;
2264  for (blk = 0; blk < s->num_blocks; blk++)
2265  s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2266  }
2267  /* LFE channel always has 7 coefs */
2268  if (s->lfe_on) {
2269  s->start_freq[s->lfe_channel] = 0;
2270  for (blk = 0; blk < s->num_blocks; blk++)
2271  s->blocks[blk].end_freq[ch] = 7;
2272  }
2273 
2274  /* initialize coupling strategy */
2275  if (s->cpl_enabled) {
2276  if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2277  cpl_start = s->options.cpl_start;
2278  } else {
2279  cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2280  if (cpl_start < 0) {
2281  if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
2282  s->cpl_enabled = 0;
2283  else
2284  cpl_start = 15;
2285  }
2286  }
2287  }
2288  if (s->cpl_enabled) {
2289  int i, cpl_start_band, cpl_end_band;
2290  uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2291 
2292  cpl_end_band = s->bandwidth_code / 4 + 3;
2293  cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2294 
2295  s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2296 
2297  s->num_cpl_bands = 1;
2298  *cpl_band_sizes = 12;
2299  for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2300  if (ff_eac3_default_cpl_band_struct[i]) {
2301  *cpl_band_sizes += 12;
2302  } else {
2303  s->num_cpl_bands++;
2304  cpl_band_sizes++;
2305  *cpl_band_sizes = 12;
2306  }
2307  }
2308 
2309  s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2310  s->cpl_end_freq = cpl_end_band * 12 + 37;
2311  for (blk = 0; blk < s->num_blocks; blk++)
2312  s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2313  }
2314 }
2315 
2316 
2317 static av_cold int allocate_buffers(AC3EncodeContext *s)
2318 {
2319  AVCodecContext *avctx = s->avctx;
2320  int blk, ch;
2321  int channels = s->channels + 1; /* includes coupling channel */
2322  int channel_blocks = channels * s->num_blocks;
2323  int total_coefs = AC3_MAX_COEFS * channel_blocks;
2324 
2325  if (s->allocate_sample_buffers(s))
2326  goto alloc_fail;
2327 
2328  FF_ALLOC_OR_GOTO(avctx, s->bap_buffer, total_coefs *
2329  sizeof(*s->bap_buffer), alloc_fail);
2330  FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, total_coefs *
2331  sizeof(*s->bap1_buffer), alloc_fail);
2332  FF_ALLOCZ_OR_GOTO(avctx, s->mdct_coef_buffer, total_coefs *
2333  sizeof(*s->mdct_coef_buffer), alloc_fail);
2334  FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, total_coefs *
2335  sizeof(*s->exp_buffer), alloc_fail);
2336  FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, channel_blocks * 128 *
2337  sizeof(*s->grouped_exp_buffer), alloc_fail);
2338  FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, total_coefs *
2339  sizeof(*s->psd_buffer), alloc_fail);
2340  FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, channel_blocks * 64 *
2341  sizeof(*s->band_psd_buffer), alloc_fail);
2342  FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, channel_blocks * 64 *
2343  sizeof(*s->mask_buffer), alloc_fail);
2344  FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, total_coefs *
2345  sizeof(*s->qmant_buffer), alloc_fail);
2346  if (s->cpl_enabled) {
2347  FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_exp_buffer, channel_blocks * 16 *
2348  sizeof(*s->cpl_coord_exp_buffer), alloc_fail);
2349  FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_mant_buffer, channel_blocks * 16 *
2350  sizeof(*s->cpl_coord_mant_buffer), alloc_fail);
2351  }
2352  for (blk = 0; blk < s->num_blocks; blk++) {
2353  AC3Block *block = &s->blocks[blk];
2354  FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, channels * sizeof(*block->mdct_coef),
2355  alloc_fail);
2356  FF_ALLOCZ_OR_GOTO(avctx, block->exp, channels * sizeof(*block->exp),
2357  alloc_fail);
2358  FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, channels * sizeof(*block->grouped_exp),
2359  alloc_fail);
2360  FF_ALLOCZ_OR_GOTO(avctx, block->psd, channels * sizeof(*block->psd),
2361  alloc_fail);
2362  FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, channels * sizeof(*block->band_psd),
2363  alloc_fail);
2364  FF_ALLOCZ_OR_GOTO(avctx, block->mask, channels * sizeof(*block->mask),
2365  alloc_fail);
2366  FF_ALLOCZ_OR_GOTO(avctx, block->qmant, channels * sizeof(*block->qmant),
2367  alloc_fail);
2368  if (s->cpl_enabled) {
2369  FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_exp, channels * sizeof(*block->cpl_coord_exp),
2370  alloc_fail);
2371  FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_mant, channels * sizeof(*block->cpl_coord_mant),
2372  alloc_fail);
2373  }
2374 
2375  for (ch = 0; ch < channels; ch++) {
2376  /* arrangement: block, channel, coeff */
2377  block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
2378  block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2379  block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
2380  block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
2381  block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
2382  if (s->cpl_enabled) {
2383  block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
2384  block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
2385  }
2386 
2387  /* arrangement: channel, block, coeff */
2388  block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2389  block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2390  }
2391  }
2392 
2393  if (!s->fixed_point) {
2394  FF_ALLOCZ_OR_GOTO(avctx, s->fixed_coef_buffer, total_coefs *
2395  sizeof(*s->fixed_coef_buffer), alloc_fail);
2396  for (blk = 0; blk < s->num_blocks; blk++) {
2397  AC3Block *block = &s->blocks[blk];
2398  FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2399  sizeof(*block->fixed_coef), alloc_fail);
2400  for (ch = 0; ch < channels; ch++)
2401  block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2402  }
2403  } else {
2404  for (blk = 0; blk < s->num_blocks; blk++) {
2405  AC3Block *block = &s->blocks[blk];
2406  FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2407  sizeof(*block->fixed_coef), alloc_fail);
2408  for (ch = 0; ch < channels; ch++)
2409  block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2410  }
2411  }
2412 
2413  return 0;
2414 alloc_fail:
2415  return AVERROR(ENOMEM);
2416 }
2417 
2418 
2419 av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
2420 {
2421  AC3EncodeContext *s = avctx->priv_data;
2422  int ret, frame_size_58;
2423 
2424  s->avctx = avctx;
2425 
2426  s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2427 
2428  ff_ac3_common_init();
2429 
2430  ret = validate_options(s);
2431  if (ret)
2432  return ret;
2433 
2434  avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2435  avctx->delay = AC3_BLOCK_SIZE;
2436 
2437  s->bitstream_mode = avctx->audio_service_type;
2438  if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2439  s->bitstream_mode = 0x7;
2440 
2441  s->bits_written = 0;
2442  s->samples_written = 0;
2443 
2444  /* calculate crc_inv for both possible frame sizes */
2445  frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
2446  s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2447  if (s->bit_alloc.sr_code == 1) {
2448  frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2449  s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2450  }
2451 
2452  /* set function pointers */
2453  if (CONFIG_AC3_FIXED_ENCODER && s->fixed_point) {
2454  s->mdct_end = ff_ac3_fixed_mdct_end;
2455  s->mdct_init = ff_ac3_fixed_mdct_init;
2456  s->allocate_sample_buffers = ff_ac3_fixed_allocate_sample_buffers;
2457  } else if (CONFIG_AC3_ENCODER || CONFIG_EAC3_ENCODER) {
2458  s->mdct_end = ff_ac3_float_mdct_end;
2459  s->mdct_init = ff_ac3_float_mdct_init;
2460  s->allocate_sample_buffers = ff_ac3_float_allocate_sample_buffers;
2461  }
2462  if (CONFIG_EAC3_ENCODER && s->eac3)
2463  s->output_frame_header = ff_eac3_output_frame_header;
2464  else
2465  s->output_frame_header = ac3_output_frame_header;
2466 
2467  set_bandwidth(s);
2468 
2469  exponent_init(s);
2470 
2471  bit_alloc_init(s);
2472 
2473  ret = s->mdct_init(s);
2474  if (ret)
2475  goto init_fail;
2476 
2477  ret = allocate_buffers(s);
2478  if (ret)
2479  goto init_fail;
2480 
2481  ff_dsputil_init(&s->dsp, avctx);
2482  avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
2483  ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
2484 
2485  dprint_options(s);
2486 
2487  return 0;
2488 init_fail:
2489  ff_ac3_encode_close(avctx);
2490  return ret;
2491 }
Generated on Sat Jan 25 2014 19:51:43 for FFmpeg by   doxygen 1.8.2