ac3enc_template.c
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1 /*
2  * AC-3 encoder float/fixed template
3  * Copyright (c) 2000 Fabrice Bellard
4  * Copyright (c) 2006-2011 Justin Ruggles <justin.ruggles@gmail.com>
5  * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6  *
7  * This file is part of Libav.
8  *
9  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
29 #include <stdint.h>
30 
31 
32 /* prototypes for static functions in ac3enc_fixed.c and ac3enc_float.c */
33 
34 static void scale_coefficients(AC3EncodeContext *s);
35 
36 static void apply_window(DSPContext *dsp, SampleType *output,
37  const SampleType *input, const SampleType *window,
38  unsigned int len);
39 
40 static int normalize_samples(AC3EncodeContext *s);
41 
42 static void clip_coefficients(DSPContext *dsp, CoefType *coef, unsigned int len);
43 
44 static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl);
45 
46 
48 {
49  int ch;
50 
51  FF_ALLOC_OR_GOTO(s->avctx, s->windowed_samples, AC3_WINDOW_SIZE *
52  sizeof(*s->windowed_samples), alloc_fail);
53  FF_ALLOC_OR_GOTO(s->avctx, s->planar_samples, s->channels * sizeof(*s->planar_samples),
54  alloc_fail);
55  for (ch = 0; ch < s->channels; ch++) {
56  FF_ALLOCZ_OR_GOTO(s->avctx, s->planar_samples[ch],
57  (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
58  alloc_fail);
59  }
60 
61  return 0;
62 alloc_fail:
63  return AVERROR(ENOMEM);
64 }
65 
66 
67 /*
68  * Deinterleave input samples.
69  * Channels are reordered from Libav's default order to AC-3 order.
70  */
72  const SampleType *samples)
73 {
74  int ch, i;
75 
76  /* deinterleave and remap input samples */
77  for (ch = 0; ch < s->channels; ch++) {
78  const SampleType *sptr;
79  int sinc;
80 
81  /* copy last 256 samples of previous frame to the start of the current frame */
82  memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_BLOCK_SIZE * s->num_blocks],
83  AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
84 
85  /* deinterleave */
86  sinc = s->channels;
87  sptr = samples + s->channel_map[ch];
88  for (i = AC3_BLOCK_SIZE; i < AC3_BLOCK_SIZE * (s->num_blocks + 1); i++) {
89  s->planar_samples[ch][i] = *sptr;
90  sptr += sinc;
91  }
92  }
93 }
94 
95 
96 /*
97  * Apply the MDCT to input samples to generate frequency coefficients.
98  * This applies the KBD window and normalizes the input to reduce precision
99  * loss due to fixed-point calculations.
100  */
102 {
103  int blk, ch;
104 
105  for (ch = 0; ch < s->channels; ch++) {
106  for (blk = 0; blk < s->num_blocks; blk++) {
107  AC3Block *block = &s->blocks[blk];
108  const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
109 
110  apply_window(&s->dsp, s->windowed_samples, input_samples,
112 
113  if (s->fixed_point)
114  block->coeff_shift[ch+1] = normalize_samples(s);
115 
116  s->mdct.mdct_calcw(&s->mdct, block->mdct_coef[ch+1],
117  s->windowed_samples);
118  }
119  }
120 }
121 
122 
123 /*
124  * Calculate coupling channel and coupling coordinates.
125  */
127 {
129 #if CONFIG_AC3ENC_FLOAT
130  LOCAL_ALIGNED_16(int32_t, fixed_cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
131 #else
132  int32_t (*fixed_cpl_coords)[AC3_MAX_CHANNELS][16] = cpl_coords;
133 #endif
134  int blk, ch, bnd, i, j;
135  CoefSumType energy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][16] = {{{0}}};
136  int cpl_start, num_cpl_coefs;
137 
138  memset(cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
139 #if CONFIG_AC3ENC_FLOAT
140  memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
141 #endif
142 
143  /* align start to 16-byte boundary. align length to multiple of 32.
144  note: coupling start bin % 4 will always be 1 */
145  cpl_start = s->start_freq[CPL_CH] - 1;
146  num_cpl_coefs = FFALIGN(s->num_cpl_subbands * 12 + 1, 32);
147  cpl_start = FFMIN(256, cpl_start + num_cpl_coefs) - num_cpl_coefs;
148 
149  /* calculate coupling channel from fbw channels */
150  for (blk = 0; blk < s->num_blocks; blk++) {
151  AC3Block *block = &s->blocks[blk];
152  CoefType *cpl_coef = &block->mdct_coef[CPL_CH][cpl_start];
153  if (!block->cpl_in_use)
154  continue;
155  memset(cpl_coef, 0, num_cpl_coefs * sizeof(*cpl_coef));
156  for (ch = 1; ch <= s->fbw_channels; ch++) {
157  CoefType *ch_coef = &block->mdct_coef[ch][cpl_start];
158  if (!block->channel_in_cpl[ch])
159  continue;
160  for (i = 0; i < num_cpl_coefs; i++)
161  cpl_coef[i] += ch_coef[i];
162  }
163 
164  /* coefficients must be clipped in order to be encoded */
165  clip_coefficients(&s->dsp, cpl_coef, num_cpl_coefs);
166  }
167 
168  /* calculate energy in each band in coupling channel and each fbw channel */
169  /* TODO: possibly use SIMD to speed up energy calculation */
170  bnd = 0;
171  i = s->start_freq[CPL_CH];
172  while (i < s->cpl_end_freq) {
173  int band_size = s->cpl_band_sizes[bnd];
174  for (ch = CPL_CH; ch <= s->fbw_channels; ch++) {
175  for (blk = 0; blk < s->num_blocks; blk++) {
176  AC3Block *block = &s->blocks[blk];
177  if (!block->cpl_in_use || (ch > CPL_CH && !block->channel_in_cpl[ch]))
178  continue;
179  for (j = 0; j < band_size; j++) {
180  CoefType v = block->mdct_coef[ch][i+j];
181  MAC_COEF(energy[blk][ch][bnd], v, v);
182  }
183  }
184  }
185  i += band_size;
186  bnd++;
187  }
188 
189  /* calculate coupling coordinates for all blocks for all channels */
190  for (blk = 0; blk < s->num_blocks; blk++) {
191  AC3Block *block = &s->blocks[blk];
192  if (!block->cpl_in_use)
193  continue;
194  for (ch = 1; ch <= s->fbw_channels; ch++) {
195  if (!block->channel_in_cpl[ch])
196  continue;
197  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
198  cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
199  energy[blk][CPL_CH][bnd]);
200  }
201  }
202  }
203 
204  /* determine which blocks to send new coupling coordinates for */
205  for (blk = 0; blk < s->num_blocks; blk++) {
206  AC3Block *block = &s->blocks[blk];
207  AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
208 
209  memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
210 
211  if (block->cpl_in_use) {
212  /* send new coordinates if this is the first block, if previous
213  * block did not use coupling but this block does, the channels
214  * using coupling has changed from the previous block, or the
215  * coordinate difference from the last block for any channel is
216  * greater than a threshold value. */
217  if (blk == 0 || !block0->cpl_in_use) {
218  for (ch = 1; ch <= s->fbw_channels; ch++)
219  block->new_cpl_coords[ch] = 1;
220  } else {
221  for (ch = 1; ch <= s->fbw_channels; ch++) {
222  if (!block->channel_in_cpl[ch])
223  continue;
224  if (!block0->channel_in_cpl[ch]) {
225  block->new_cpl_coords[ch] = 1;
226  } else {
227  CoefSumType coord_diff = 0;
228  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
229  coord_diff += FFABS(cpl_coords[blk-1][ch][bnd] -
230  cpl_coords[blk ][ch][bnd]);
231  }
232  coord_diff /= s->num_cpl_bands;
233  if (coord_diff > NEW_CPL_COORD_THRESHOLD)
234  block->new_cpl_coords[ch] = 1;
235  }
236  }
237  }
238  }
239  }
240 
241  /* calculate final coupling coordinates, taking into account reusing of
242  coordinates in successive blocks */
243  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
244  blk = 0;
245  while (blk < s->num_blocks) {
246  int av_uninit(blk1);
247  AC3Block *block = &s->blocks[blk];
248 
249  if (!block->cpl_in_use) {
250  blk++;
251  continue;
252  }
253 
254  for (ch = 1; ch <= s->fbw_channels; ch++) {
255  CoefSumType energy_ch, energy_cpl;
256  if (!block->channel_in_cpl[ch])
257  continue;
258  energy_cpl = energy[blk][CPL_CH][bnd];
259  energy_ch = energy[blk][ch][bnd];
260  blk1 = blk+1;
261  while (!s->blocks[blk1].new_cpl_coords[ch] && blk1 < s->num_blocks) {
262  if (s->blocks[blk1].cpl_in_use) {
263  energy_cpl += energy[blk1][CPL_CH][bnd];
264  energy_ch += energy[blk1][ch][bnd];
265  }
266  blk1++;
267  }
268  cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy_ch, energy_cpl);
269  }
270  blk = blk1;
271  }
272  }
273 
274  /* calculate exponents/mantissas for coupling coordinates */
275  for (blk = 0; blk < s->num_blocks; blk++) {
276  AC3Block *block = &s->blocks[blk];
277  if (!block->cpl_in_use)
278  continue;
279 
280 #if CONFIG_AC3ENC_FLOAT
281  s->ac3dsp.float_to_fixed24(fixed_cpl_coords[blk][1],
282  cpl_coords[blk][1],
283  s->fbw_channels * 16);
284 #endif
286  fixed_cpl_coords[blk][1],
287  s->fbw_channels * 16);
288 
289  for (ch = 1; ch <= s->fbw_channels; ch++) {
290  int bnd, min_exp, max_exp, master_exp;
291 
292  if (!block->new_cpl_coords[ch])
293  continue;
294 
295  /* determine master exponent */
296  min_exp = max_exp = block->cpl_coord_exp[ch][0];
297  for (bnd = 1; bnd < s->num_cpl_bands; bnd++) {
298  int exp = block->cpl_coord_exp[ch][bnd];
299  min_exp = FFMIN(exp, min_exp);
300  max_exp = FFMAX(exp, max_exp);
301  }
302  master_exp = ((max_exp - 15) + 2) / 3;
303  master_exp = FFMAX(master_exp, 0);
304  while (min_exp < master_exp * 3)
305  master_exp--;
306  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
307  block->cpl_coord_exp[ch][bnd] = av_clip(block->cpl_coord_exp[ch][bnd] -
308  master_exp * 3, 0, 15);
309  }
310  block->cpl_master_exp[ch] = master_exp;
311 
312  /* quantize mantissas */
313  for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
314  int cpl_exp = block->cpl_coord_exp[ch][bnd];
315  int cpl_mant = (fixed_cpl_coords[blk][ch][bnd] << (5 + cpl_exp + master_exp * 3)) >> 24;
316  if (cpl_exp == 15)
317  cpl_mant >>= 1;
318  else
319  cpl_mant -= 16;
320 
321  block->cpl_coord_mant[ch][bnd] = cpl_mant;
322  }
323  }
324  }
325 
326  if (CONFIG_EAC3_ENCODER && s->eac3)
328 }
329 
330 
331 /*
332  * Determine rematrixing flags for each block and band.
333  */
335 {
336  int nb_coefs;
337  int blk, bnd, i;
338  AC3Block *block, *av_uninit(block0);
339 
341  return;
342 
343  for (blk = 0; blk < s->num_blocks; blk++) {
344  block = &s->blocks[blk];
345  block->new_rematrixing_strategy = !blk;
346 
347  block->num_rematrixing_bands = 4;
348  if (block->cpl_in_use) {
349  block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
350  block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);
351  if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)
352  block->new_rematrixing_strategy = 1;
353  }
354  nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
355 
356  if (!s->rematrixing_enabled) {
357  block0 = block;
358  continue;
359  }
360 
361  for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
362  /* calculate calculate sum of squared coeffs for one band in one block */
363  int start = ff_ac3_rematrix_band_tab[bnd];
364  int end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
365  CoefSumType sum[4] = {0,};
366  for (i = start; i < end; i++) {
367  CoefType lt = block->mdct_coef[1][i];
368  CoefType rt = block->mdct_coef[2][i];
369  CoefType md = lt + rt;
370  CoefType sd = lt - rt;
371  MAC_COEF(sum[0], lt, lt);
372  MAC_COEF(sum[1], rt, rt);
373  MAC_COEF(sum[2], md, md);
374  MAC_COEF(sum[3], sd, sd);
375  }
376 
377  /* compare sums to determine if rematrixing will be used for this band */
378  if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
379  block->rematrixing_flags[bnd] = 1;
380  else
381  block->rematrixing_flags[bnd] = 0;
382 
383  /* determine if new rematrixing flags will be sent */
384  if (blk &&
385  block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
386  block->new_rematrixing_strategy = 1;
387  }
388  }
389  block0 = block;
390  }
391 }
392 
393 
394 int AC3_NAME(encode_frame)(AVCodecContext *avctx, unsigned char *frame,
395  int buf_size, void *data)
396 {
398  const SampleType *samples = data;
399  int ret;
400 
402  ret = ff_ac3_validate_metadata(s);
403  if (ret)
404  return ret;
405  }
406 
407  if (s->bit_alloc.sr_code == 1 || s->eac3)
409 
410  deinterleave_input_samples(s, samples);
411 
412  apply_mdct(s);
413 
414  if (s->fixed_point)
416 
417  clip_coefficients(&s->dsp, s->blocks[0].mdct_coef[1],
418  AC3_MAX_COEFS * s->num_blocks * s->channels);
419 
420  s->cpl_on = s->cpl_enabled;
422 
423  if (s->cpl_on)
425 
427 
428  if (!s->fixed_point)
430 
432 
434 
436  if (ret) {
437  av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
438  return ret;
439  }
440 
442 
444 
445  ff_ac3_output_frame(s, frame);
446 
447  return s->frame_size;
448 }
static void scale_coefficients(AC3EncodeContext *s)
uint8_t new_rematrixing_strategy
send new rematrixing flags in this block
Definition: ac3enc.h:138
static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
void(* float_to_fixed24)(int32_t *dst, const float *src, unsigned int len)
Convert an array of float in range [-1.0,1.0] to int32_t with range [-(1<<24),(1<<24)].
Definition: ac3dsp.h:89
static short * samples
Definition: ffmpeg.c:233
int AC3_NAME() allocate_sample_buffers(AC3EncodeContext *s)
static void apply_mdct(AC3EncodeContext *s)
uint8_t ** cpl_coord_exp
coupling coord exponents (cplcoexp)
Definition: ac3enc.h:135
#define AC3_MAX_COEFS
Definition: ac3.h:34
#define AC3_WINDOW_SIZE
Definition: ac3.h:38
void ff_ac3_process_exponents(AC3EncodeContext *s)
Calculate final exponents from the supplied MDCT coefficients and exponent shift. ...
Definition: ac3enc.c:636
void ff_eac3_set_cpl_states(AC3EncodeContext *s)
Set coupling states.
Definition: eac3enc.c:89
static void deinterleave_input_samples(AC3EncodeContext *s, const SampleType *samples)
uint8_t ** cpl_coord_mant
coupling coord mantissas (cplcomant)
Definition: ac3enc.h:136
int start_freq[AC3_MAX_CHANNELS]
start frequency bin (strtmant)
Definition: ac3enc.h:202
#define blk(i)
Definition: sha.c:163
AC3BitAllocParameters bit_alloc
bit allocation parameters
Definition: ac3enc.h:219
#define v(n)
Definition: regs.h:34
#define FFALIGN(x, a)
Definition: common.h:60
DSPContext dsp
Definition: ac3enc.h:160
int ff_ac3_validate_metadata(AC3EncodeContext *s)
Validate metadata options as set by AVOption system.
Definition: ac3enc.c:1836
int rematrixing_enabled
stereo rematrixing enabled
Definition: ac3enc.h:211
static void apply_channel_coupling(AC3EncodeContext *s)
int channel_mode
channel mode (acmod)
Definition: ac3enc.h:190
int num_cpl_subbands
number of coupling subbands (ncplsubnd)
Definition: ac3enc.h:207
uint8_t rematrixing_flags[4]
rematrixing flags
Definition: ac3enc.h:140
int fbw_channels
number of full-bandwidth channels (nfchans)
Definition: ac3enc.h:184
uint8_t new_cpl_coords[AC3_MAX_CHANNELS]
send new coupling coordinates (cplcoe)
Definition: ac3enc.h:145
const char data[16]
Definition: mxf.c:60
uint8_t cpl_master_exp[AC3_MAX_CHANNELS]
coupling coord master exponents (mstrcplco)
Definition: ac3enc.h:146
int num_rematrixing_bands
number of rematrixing bands
Definition: ac3enc.h:139
#define LOCAL_ALIGNED_16(t, v,...)
Definition: dsputil.h:698
AC3DSPContext ac3dsp
AC-3 optimized functions.
Definition: ac3enc.h:161
int num_cpl_bands
number of coupling bands (ncplbnd)
Definition: ac3enc.h:208
static DSPContext dsp
Definition: atrac3.c:135
int64_t CoefSumType
Definition: ac3enc.h:67
CoefType ** mdct_coef
MDCT coefficients.
Definition: ac3enc.h:127
uint8_t channel_in_cpl[AC3_MAX_CHANNELS]
channel in coupling (chincpl)
Definition: ac3enc.h:143
AC3EncOptions options
encoding options
Definition: ac3enc.h:157
#define AVERROR(e)
Definition: error.h:43
int channels
total number of channels (nchans)
Definition: ac3enc.h:185
#define AC3_MAX_CHANNELS
maximum number of channels, including coupling channel
Definition: ac3.h:31
#define AC3_NAME(x)
Definition: ac3enc.h:60
int cpl_on
coupling turned on for this frame
Definition: ac3enc.h:205
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
int fixed_point
indicates if fixed-point encoder is being used
Definition: ac3enc.h:167
#define FFMAX(a, b)
Definition: common.h:53
int cpl_in_use
coupling in use for this block (cplinu)
Definition: ac3enc.h:142
int cpl_enabled
coupling enabled for all frames
Definition: ac3enc.h:206
#define AC3_BLOCK_SIZE
Definition: ac3.h:35
int16_t SampleType
Definition: ac3enc.h:65
static int normalize_samples(AC3EncodeContext *s)
Data for a single audio block.
Definition: ac3enc.h:126
int ff_ac3_compute_bit_allocation(AC3EncodeContext *s)
Definition: ac3enc.c:1145
static DCTELEM block[64]
Definition: dct-test.c:189
static void apply_window(DSPContext *dsp, SampleType *output, const SampleType *input, const SampleType *window, unsigned int len)
#define FFMIN(a, b)
Definition: common.h:55
int eac3
indicates if this is E-AC-3 vs. AC-3
Definition: ac3enc.h:168
#define FFABS(a)
Definition: common.h:50
void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
Adjust the frame size to make the average bit rate match the target bit rate.
Definition: ac3enc.c:182
FFTContext mdct
FFT context for MDCT calculation.
Definition: ac3enc.h:162
void(* extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs)
Definition: ac3dsp.h:127
const SampleType * mdct_window
MDCT window function array.
Definition: ac3enc.h:163
SampleType ** planar_samples
Definition: ac3enc.h:228
NULL
Definition: eval.c:50
#define CPL_CH
coupling channel index
Definition: ac3.h:32
int AC3_NAME() encode_frame(AVCodecContext *avctx, unsigned char *frame, int buf_size, void *data)
#define NEW_CPL_COORD_THRESHOLD
Definition: ac3enc.h:64
main external API structure.
Definition: avcodec.h:1329
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
const uint8_t * channel_map
channel map used to reorder channels
Definition: ac3enc.h:191
int end_freq[AC3_MAX_CHANNELS]
end frequency bin (endmant)
Definition: ac3enc.h:149
#define AC3_MAX_BLOCKS
Definition: ac3.h:36
AC-3 encoder private context.
Definition: ac3enc.h:155
void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
Write the frame to the output bitstream.
Definition: ac3enc.c:1664
AC3Block blocks[AC3_MAX_BLOCKS]
per-block info
Definition: ac3enc.h:165
SampleType * windowed_samples
Definition: ac3enc.h:227
void ff_ac3_quantize_mantissas(AC3EncodeContext *s)
Quantize mantissas using coefficients, exponents, and bit allocation pointers.
Definition: ac3enc.c:1302
int num_blocks
number of blocks per frame
Definition: ac3enc.h:176
#define CONFIG_EAC3_ENCODER
Definition: config.h:769
uint8_t coeff_shift[AC3_MAX_CHANNELS]
fixed-point coefficient shift values
Definition: ac3enc.h:137
#define AC3_FRAME_SIZE
Definition: ac3.h:37
int frame_size
current frame size in bytes
Definition: ac3enc.h:178
int cpl_end_freq
coupling channel end frequency bin
Definition: ac3enc.h:203
uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]
number of coeffs in each coupling band
Definition: ac3enc.h:209
#define FF_ALLOC_OR_GOTO(ctx, p, size, label)
Definition: internal.h:163
AVCodecContext * avctx
parent AVCodecContext
Definition: ac3enc.h:158
static void compute_rematrixing_strategy(AC3EncodeContext *s)
void * priv_data
Definition: avcodec.h:1531
int allow_per_frame_metadata
Definition: ac3enc.h:117
int len
#define MAC_COEF(d, a, b)
Definition: ac3enc.h:61
#define av_uninit(x)
Definition: attributes.h:124
void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
Apply stereo rematrixing to coefficients based on rematrixing flags.
Definition: ac3enc.c:271
const uint8_t ff_ac3_rematrix_band_tab[5]
Table of bin locations for rematrixing bands reference: Section 7.5.2 Rematrixing : Frequency Band De...
Definition: ac3tab.c:139
void ff_ac3_group_exponents(AC3EncodeContext *s)
Group exponents.
Definition: ac3enc.c:578
int32_t CoefType
Definition: ac3enc.h:66
void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
Set the initial coupling strategy parameters prior to coupling analysis.
Definition: ac3enc.c:200
#define FF_ALLOCZ_OR_GOTO(ctx, p, size, label)
Definition: internal.h:172
void(* mdct_calcw)(struct FFTContext *s, FFTDouble *output, const FFTSample *input)
Definition: fft.h:84
DSPContext.
Definition: dsputil.h:226
static void clip_coefficients(DSPContext *dsp, CoefType *coef, unsigned int len)