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aaccoder.c
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1 /*
2  * AAC coefficients encoder
3  * Copyright (C) 2008-2009 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * AAC coefficients encoder
25  */
26 
27 /***********************************
28  * TODOs:
29  * speedup quantizer selection
30  * add sane pulse detection
31  ***********************************/
32 
33 #include "libavutil/libm.h" // brought forward to work around cygwin header breakage
34 
35 #include <float.h>
36 
37 #include "libavutil/mathematics.h"
38 #include "mathops.h"
39 #include "avcodec.h"
40 #include "put_bits.h"
41 #include "aac.h"
42 #include "aacenc.h"
43 #include "aactab.h"
44 #include "aacenctab.h"
45 #include "aacenc_utils.h"
46 #include "aacenc_quantization.h"
47 
48 #include "aacenc_is.h"
49 #include "aacenc_tns.h"
50 #include "aacenc_ltp.h"
51 #include "aacenc_pred.h"
52 
54 
55 /* Parameter of f(x) = a*(lambda/100), defines the maximum fourier spread
56  * beyond which no PNS is used (since the SFBs contain tone rather than noise) */
57 #define NOISE_SPREAD_THRESHOLD 0.9f
58 
59 /* Parameter of f(x) = a*(100/lambda), defines how much PNS is allowed to
60  * replace low energy non zero bands */
61 #define NOISE_LAMBDA_REPLACE 1.948f
62 
64 
65 /**
66  * structure used in optimal codebook search
67  */
68 typedef struct BandCodingPath {
69  int prev_idx; ///< pointer to the previous path point
70  float cost; ///< path cost
71  int run;
73 
74 /**
75  * Encode band info for single window group bands.
76  */
78  int win, int group_len, const float lambda)
79 {
80  BandCodingPath path[120][CB_TOT_ALL];
81  int w, swb, cb, start, size;
82  int i, j;
83  const int max_sfb = sce->ics.max_sfb;
84  const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
85  const int run_esc = (1 << run_bits) - 1;
86  int idx, ppos, count;
87  int stackrun[120], stackcb[120], stack_len;
88  float next_minrd = INFINITY;
89  int next_mincb = 0;
90 
91  abs_pow34_v(s->scoefs, sce->coeffs, 1024);
92  start = win*128;
93  for (cb = 0; cb < CB_TOT_ALL; cb++) {
94  path[0][cb].cost = 0.0f;
95  path[0][cb].prev_idx = -1;
96  path[0][cb].run = 0;
97  }
98  for (swb = 0; swb < max_sfb; swb++) {
99  size = sce->ics.swb_sizes[swb];
100  if (sce->zeroes[win*16 + swb]) {
101  for (cb = 0; cb < CB_TOT_ALL; cb++) {
102  path[swb+1][cb].prev_idx = cb;
103  path[swb+1][cb].cost = path[swb][cb].cost;
104  path[swb+1][cb].run = path[swb][cb].run + 1;
105  }
106  } else {
107  float minrd = next_minrd;
108  int mincb = next_mincb;
109  next_minrd = INFINITY;
110  next_mincb = 0;
111  for (cb = 0; cb < CB_TOT_ALL; cb++) {
112  float cost_stay_here, cost_get_here;
113  float rd = 0.0f;
114  if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] ||
115  cb < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) {
116  path[swb+1][cb].prev_idx = -1;
117  path[swb+1][cb].cost = INFINITY;
118  path[swb+1][cb].run = path[swb][cb].run + 1;
119  continue;
120  }
121  for (w = 0; w < group_len; w++) {
122  FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb];
123  rd += quantize_band_cost(s, &sce->coeffs[start + w*128],
124  &s->scoefs[start + w*128], size,
125  sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb],
126  lambda / band->threshold, INFINITY, NULL, NULL, 0);
127  }
128  cost_stay_here = path[swb][cb].cost + rd;
129  cost_get_here = minrd + rd + run_bits + 4;
130  if ( run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
131  != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
132  cost_stay_here += run_bits;
133  if (cost_get_here < cost_stay_here) {
134  path[swb+1][cb].prev_idx = mincb;
135  path[swb+1][cb].cost = cost_get_here;
136  path[swb+1][cb].run = 1;
137  } else {
138  path[swb+1][cb].prev_idx = cb;
139  path[swb+1][cb].cost = cost_stay_here;
140  path[swb+1][cb].run = path[swb][cb].run + 1;
141  }
142  if (path[swb+1][cb].cost < next_minrd) {
143  next_minrd = path[swb+1][cb].cost;
144  next_mincb = cb;
145  }
146  }
147  }
148  start += sce->ics.swb_sizes[swb];
149  }
150 
151  //convert resulting path from backward-linked list
152  stack_len = 0;
153  idx = 0;
154  for (cb = 1; cb < CB_TOT_ALL; cb++)
155  if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
156  idx = cb;
157  ppos = max_sfb;
158  while (ppos > 0) {
159  av_assert1(idx >= 0);
160  cb = idx;
161  stackrun[stack_len] = path[ppos][cb].run;
162  stackcb [stack_len] = cb;
163  idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
164  ppos -= path[ppos][cb].run;
165  stack_len++;
166  }
167  //perform actual band info encoding
168  start = 0;
169  for (i = stack_len - 1; i >= 0; i--) {
170  cb = aac_cb_out_map[stackcb[i]];
171  put_bits(&s->pb, 4, cb);
172  count = stackrun[i];
173  memset(sce->zeroes + win*16 + start, !cb, count);
174  //XXX: memset when band_type is also uint8_t
175  for (j = 0; j < count; j++) {
176  sce->band_type[win*16 + start] = cb;
177  start++;
178  }
179  while (count >= run_esc) {
180  put_bits(&s->pb, run_bits, run_esc);
181  count -= run_esc;
182  }
183  put_bits(&s->pb, run_bits, count);
184  }
185 }
186 
187 
188 typedef struct TrellisPath {
189  float cost;
190  int prev;
191 } TrellisPath;
192 
193 #define TRELLIS_STAGES 121
194 #define TRELLIS_STATES (SCALE_MAX_DIFF+1)
195 
197 {
198  int w, g;
199  int prevscaler_n = -255, prevscaler_i = 0;
200  int bands = 0;
201 
202  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
203  for (g = 0; g < sce->ics.num_swb; g++) {
204  if (sce->zeroes[w*16+g])
205  continue;
206  if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
207  sce->sf_idx[w*16+g] = av_clip(roundf(log2f(sce->is_ener[w*16+g])*2), -155, 100);
208  bands++;
209  } else if (sce->band_type[w*16+g] == NOISE_BT) {
210  sce->sf_idx[w*16+g] = av_clip(3+ceilf(log2f(sce->pns_ener[w*16+g])*2), -100, 155);
211  if (prevscaler_n == -255)
212  prevscaler_n = sce->sf_idx[w*16+g];
213  bands++;
214  }
215  }
216  }
217 
218  if (!bands)
219  return;
220 
221  /* Clip the scalefactor indices */
222  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
223  for (g = 0; g < sce->ics.num_swb; g++) {
224  if (sce->zeroes[w*16+g])
225  continue;
226  if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
227  sce->sf_idx[w*16+g] = prevscaler_i = av_clip(sce->sf_idx[w*16+g], prevscaler_i - SCALE_MAX_DIFF, prevscaler_i + SCALE_MAX_DIFF);
228  } else if (sce->band_type[w*16+g] == NOISE_BT) {
229  sce->sf_idx[w*16+g] = prevscaler_n = av_clip(sce->sf_idx[w*16+g], prevscaler_n - SCALE_MAX_DIFF, prevscaler_n + SCALE_MAX_DIFF);
230  }
231  }
232  }
233 }
234 
237  const float lambda)
238 {
239  int q, w, w2, g, start = 0;
240  int i, j;
241  int idx;
243  int bandaddr[TRELLIS_STAGES];
244  int minq;
245  float mincost;
246  float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f;
247  int q0, q1, qcnt = 0;
248 
249  for (i = 0; i < 1024; i++) {
250  float t = fabsf(sce->coeffs[i]);
251  if (t > 0.0f) {
252  q0f = FFMIN(q0f, t);
253  q1f = FFMAX(q1f, t);
254  qnrgf += t*t;
255  qcnt++;
256  }
257  }
258 
259  if (!qcnt) {
260  memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
261  memset(sce->zeroes, 1, sizeof(sce->zeroes));
262  return;
263  }
264 
265  //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
266  q0 = av_clip(coef2minsf(q0f), 0, SCALE_MAX_POS-1);
267  //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
268  q1 = av_clip(coef2maxsf(q1f), 1, SCALE_MAX_POS);
269  if (q1 - q0 > 60) {
270  int q0low = q0;
271  int q1high = q1;
272  //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped
273  int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512);
274  q1 = qnrg + 30;
275  q0 = qnrg - 30;
276  if (q0 < q0low) {
277  q1 += q0low - q0;
278  q0 = q0low;
279  } else if (q1 > q1high) {
280  q0 -= q1 - q1high;
281  q1 = q1high;
282  }
283  }
284  // q0 == q1 isn't really a legal situation
285  if (q0 == q1) {
286  // the following is indirect but guarantees q1 != q0 && q1 near q0
287  q1 = av_clip(q0+1, 1, SCALE_MAX_POS);
288  q0 = av_clip(q1-1, 0, SCALE_MAX_POS - 1);
289  }
290 
291  for (i = 0; i < TRELLIS_STATES; i++) {
292  paths[0][i].cost = 0.0f;
293  paths[0][i].prev = -1;
294  }
295  for (j = 1; j < TRELLIS_STAGES; j++) {
296  for (i = 0; i < TRELLIS_STATES; i++) {
297  paths[j][i].cost = INFINITY;
298  paths[j][i].prev = -2;
299  }
300  }
301  idx = 1;
302  abs_pow34_v(s->scoefs, sce->coeffs, 1024);
303  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
304  start = w*128;
305  for (g = 0; g < sce->ics.num_swb; g++) {
306  const float *coefs = &sce->coeffs[start];
307  float qmin, qmax;
308  int nz = 0;
309 
310  bandaddr[idx] = w * 16 + g;
311  qmin = INT_MAX;
312  qmax = 0.0f;
313  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
314  FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
315  if (band->energy <= band->threshold || band->threshold == 0.0f) {
316  sce->zeroes[(w+w2)*16+g] = 1;
317  continue;
318  }
319  sce->zeroes[(w+w2)*16+g] = 0;
320  nz = 1;
321  for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
322  float t = fabsf(coefs[w2*128+i]);
323  if (t > 0.0f)
324  qmin = FFMIN(qmin, t);
325  qmax = FFMAX(qmax, t);
326  }
327  }
328  if (nz) {
329  int minscale, maxscale;
330  float minrd = INFINITY;
331  float maxval;
332  //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
333  minscale = coef2minsf(qmin);
334  //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
335  maxscale = coef2maxsf(qmax);
336  minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
337  maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
338  if (minscale == maxscale) {
339  maxscale = av_clip(minscale+1, 1, TRELLIS_STATES);
340  minscale = av_clip(maxscale-1, 0, TRELLIS_STATES - 1);
341  }
342  maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
343  for (q = minscale; q < maxscale; q++) {
344  float dist = 0;
345  int cb = find_min_book(maxval, sce->sf_idx[w*16+g]);
346  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
347  FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
348  dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
349  q + q0, cb, lambda / band->threshold, INFINITY, NULL, NULL, 0);
350  }
351  minrd = FFMIN(minrd, dist);
352 
353  for (i = 0; i < q1 - q0; i++) {
354  float cost;
355  cost = paths[idx - 1][i].cost + dist
357  if (cost < paths[idx][q].cost) {
358  paths[idx][q].cost = cost;
359  paths[idx][q].prev = i;
360  }
361  }
362  }
363  } else {
364  for (q = 0; q < q1 - q0; q++) {
365  paths[idx][q].cost = paths[idx - 1][q].cost + 1;
366  paths[idx][q].prev = q;
367  }
368  }
369  sce->zeroes[w*16+g] = !nz;
370  start += sce->ics.swb_sizes[g];
371  idx++;
372  }
373  }
374  idx--;
375  mincost = paths[idx][0].cost;
376  minq = 0;
377  for (i = 1; i < TRELLIS_STATES; i++) {
378  if (paths[idx][i].cost < mincost) {
379  mincost = paths[idx][i].cost;
380  minq = i;
381  }
382  }
383  while (idx) {
384  sce->sf_idx[bandaddr[idx]] = minq + q0;
385  minq = FFMAX(paths[idx][minq].prev, 0);
386  idx--;
387  }
388  //set the same quantizers inside window groups
389  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
390  for (g = 0; g < sce->ics.num_swb; g++)
391  for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
392  sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
393 }
394 
397  const float lambda)
398 {
399  int i, w, w2, g;
400  int minq = 255;
401 
402  memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
403  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
404  for (g = 0; g < sce->ics.num_swb; g++) {
405  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
406  FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
407  if (band->energy <= band->threshold) {
408  sce->sf_idx[(w+w2)*16+g] = 218;
409  sce->zeroes[(w+w2)*16+g] = 1;
410  } else {
411  sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218);
412  sce->zeroes[(w+w2)*16+g] = 0;
413  }
414  minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]);
415  }
416  }
417  }
418  for (i = 0; i < 128; i++) {
419  sce->sf_idx[i] = 140;
420  //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1);
421  }
422  //set the same quantizers inside window groups
423  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
424  for (g = 0; g < sce->ics.num_swb; g++)
425  for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
426  sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
427 }
428 
430 {
431  FFPsyBand *band;
432  int w, g, w2, i;
433  int wlen = 1024 / sce->ics.num_windows;
434  int bandwidth, cutoff;
435  float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128];
436  float *NOR34 = &s->scoefs[3*128];
437  uint8_t nextband[128];
438  const float lambda = s->lambda;
439  const float freq_mult = avctx->sample_rate*0.5f/wlen;
440  const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda);
441  const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f));
442  const float dist_bias = av_clipf(4.f * 120 / lambda, 0.25f, 4.0f);
443  const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f);
444 
445  int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate
446  / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels)
447  * (lambda / 120.f);
448 
449  /** Keep this in sync with twoloop's cutoff selection */
450  float rate_bandwidth_multiplier = 1.5f;
451  int prev = -1000, prev_sf = -1;
452  int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE)
453  ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024)
454  : (avctx->bit_rate / avctx->channels);
455 
456  frame_bit_rate *= 1.15f;
457 
458  if (avctx->cutoff > 0) {
459  bandwidth = avctx->cutoff;
460  } else {
461  bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate));
462  }
463 
464  cutoff = bandwidth * 2 * wlen / avctx->sample_rate;
465 
466  memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type));
467  ff_init_nextband_map(sce, nextband);
468  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
469  int wstart = w*128;
470  for (g = 0; g < sce->ics.num_swb; g++) {
471  int noise_sfi;
472  float dist1 = 0.0f, dist2 = 0.0f, noise_amp;
473  float pns_energy = 0.0f, pns_tgt_energy, energy_ratio, dist_thresh;
474  float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f;
475  float min_energy = -1.0f, max_energy = 0.0f;
476  const int start = wstart+sce->ics.swb_offset[g];
477  const float freq = (start-wstart)*freq_mult;
478  const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
479  if (freq < NOISE_LOW_LIMIT || (start-wstart) >= cutoff) {
480  if (!sce->zeroes[w*16+g])
481  prev_sf = sce->sf_idx[w*16+g];
482  continue;
483  }
484  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
485  band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
486  sfb_energy += band->energy;
487  spread = FFMIN(spread, band->spread);
488  threshold += band->threshold;
489  if (!w2) {
490  min_energy = max_energy = band->energy;
491  } else {
492  min_energy = FFMIN(min_energy, band->energy);
493  max_energy = FFMAX(max_energy, band->energy);
494  }
495  }
496 
497  /* Ramps down at ~8000Hz and loosens the dist threshold */
498  dist_thresh = av_clipf(2.5f*NOISE_LOW_LIMIT/freq, 0.5f, 2.5f) * dist_bias;
499 
500  /* PNS is acceptable when all of these are true:
501  * 1. high spread energy (noise-like band)
502  * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed)
503  * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS)
504  *
505  * At this stage, point 2 is relaxed for zeroed bands near the noise threshold (hole avoidance is more important)
506  */
507  if ((!sce->zeroes[w*16+g] && !ff_sfdelta_can_remove_band(sce, nextband, prev_sf, w*16+g)) ||
508  ((sce->zeroes[w*16+g] || !sce->band_alt[w*16+g]) && sfb_energy < threshold*sqrtf(1.0f/freq_boost)) || spread < spread_threshold ||
509  (!sce->zeroes[w*16+g] && sce->band_alt[w*16+g] && sfb_energy > threshold*thr_mult*freq_boost) ||
510  min_energy < pns_transient_energy_r * max_energy ) {
511  sce->pns_ener[w*16+g] = sfb_energy;
512  if (!sce->zeroes[w*16+g])
513  prev_sf = sce->sf_idx[w*16+g];
514  continue;
515  }
516 
517  pns_tgt_energy = sfb_energy*FFMIN(1.0f, spread*spread);
518  noise_sfi = av_clip(roundf(log2f(pns_tgt_energy)*2), -100, 155); /* Quantize */
519  noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO]; /* Dequantize */
520  if (prev != -1000) {
521  int noise_sfdiff = noise_sfi - prev + SCALE_DIFF_ZERO;
522  if (noise_sfdiff < 0 || noise_sfdiff > 2*SCALE_MAX_DIFF) {
523  if (!sce->zeroes[w*16+g])
524  prev_sf = sce->sf_idx[w*16+g];
525  continue;
526  }
527  }
528  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
529  float band_energy, scale, pns_senergy;
530  const int start_c = (w+w2)*128+sce->ics.swb_offset[g];
531  band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
532  for (i = 0; i < sce->ics.swb_sizes[g]; i+=2) {
533  double rnd[2];
534  av_bmg_get(&s->lfg, rnd);
535  PNS[i+0] = (float)rnd[0];
536  PNS[i+1] = (float)rnd[1];
537  }
538  band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
539  scale = noise_amp/sqrtf(band_energy);
540  s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]);
541  pns_senergy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
542  pns_energy += pns_senergy;
543  abs_pow34_v(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]);
544  abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]);
545  dist1 += quantize_band_cost(s, &sce->coeffs[start_c],
546  NOR34,
547  sce->ics.swb_sizes[g],
548  sce->sf_idx[(w+w2)*16+g],
549  sce->band_alt[(w+w2)*16+g],
550  lambda/band->threshold, INFINITY, NULL, NULL, 0);
551  /* Estimate rd on average as 5 bits for SF, 4 for the CB, plus spread energy * lambda/thr */
552  dist2 += band->energy/(band->spread*band->spread)*lambda*dist_thresh/band->threshold;
553  }
554  if (g && sce->band_type[w*16+g-1] == NOISE_BT) {
555  dist2 += 5;
556  } else {
557  dist2 += 9;
558  }
559  energy_ratio = pns_tgt_energy/pns_energy; /* Compensates for quantization error */
560  sce->pns_ener[w*16+g] = energy_ratio*pns_tgt_energy;
561  if (sce->zeroes[w*16+g] || !sce->band_alt[w*16+g] || (energy_ratio > 0.85f && energy_ratio < 1.25f && dist2 < dist1)) {
562  sce->band_type[w*16+g] = NOISE_BT;
563  sce->zeroes[w*16+g] = 0;
564  prev = noise_sfi;
565  } else {
566  if (!sce->zeroes[w*16+g])
567  prev_sf = sce->sf_idx[w*16+g];
568  }
569  }
570  }
571 }
572 
574 {
575  FFPsyBand *band;
576  int w, g, w2;
577  int wlen = 1024 / sce->ics.num_windows;
578  int bandwidth, cutoff;
579  const float lambda = s->lambda;
580  const float freq_mult = avctx->sample_rate*0.5f/wlen;
581  const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f));
582  const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f);
583 
584  int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate
585  / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels)
586  * (lambda / 120.f);
587 
588  /** Keep this in sync with twoloop's cutoff selection */
589  float rate_bandwidth_multiplier = 1.5f;
590  int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE)
591  ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024)
592  : (avctx->bit_rate / avctx->channels);
593 
594  frame_bit_rate *= 1.15f;
595 
596  if (avctx->cutoff > 0) {
597  bandwidth = avctx->cutoff;
598  } else {
599  bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate));
600  }
601 
602  cutoff = bandwidth * 2 * wlen / avctx->sample_rate;
603 
604  memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type));
605  for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
606  for (g = 0; g < sce->ics.num_swb; g++) {
607  float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f;
608  float min_energy = -1.0f, max_energy = 0.0f;
609  const int start = sce->ics.swb_offset[g];
610  const float freq = start*freq_mult;
611  const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
612  if (freq < NOISE_LOW_LIMIT || start >= cutoff) {
613  sce->can_pns[w*16+g] = 0;
614  continue;
615  }
616  for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
617  band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
618  sfb_energy += band->energy;
619  spread = FFMIN(spread, band->spread);
620  threshold += band->threshold;
621  if (!w2) {
622  min_energy = max_energy = band->energy;
623  } else {
624  min_energy = FFMIN(min_energy, band->energy);
625  max_energy = FFMAX(max_energy, band->energy);
626  }
627  }
628 
629  /* PNS is acceptable when all of these are true:
630  * 1. high spread energy (noise-like band)
631  * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed)
632  * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS)
633  */
634  sce->pns_ener[w*16+g] = sfb_energy;
635  if (sfb_energy < threshold*sqrtf(1.5f/freq_boost) || spread < spread_threshold || min_energy < pns_transient_energy_r * max_energy) {
636  sce->can_pns[w*16+g] = 0;
637  } else {
638  sce->can_pns[w*16+g] = 1;
639  }
640  }
641  }
642 }
643 
645 {
646  int start = 0, i, w, w2, g, sid_sf_boost, prev_mid, prev_side;
647  uint8_t nextband0[128], nextband1[128];
648  float M[128], S[128];
649  float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
650  const float lambda = s->lambda;
651  const float mslambda = FFMIN(1.0f, lambda / 120.f);
652  SingleChannelElement *sce0 = &cpe->ch[0];
653  SingleChannelElement *sce1 = &cpe->ch[1];
654  if (!cpe->common_window)
655  return;
656 
657  /** Scout out next nonzero bands */
658  ff_init_nextband_map(sce0, nextband0);
659  ff_init_nextband_map(sce1, nextband1);
660 
661  prev_mid = sce0->sf_idx[0];
662  prev_side = sce1->sf_idx[0];
663  for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
664  start = 0;
665  for (g = 0; g < sce0->ics.num_swb; g++) {
666  float bmax = bval2bmax(g * 17.0f / sce0->ics.num_swb) / 0.0045f;
667  if (!cpe->is_mask[w*16+g])
668  cpe->ms_mask[w*16+g] = 0;
669  if (!sce0->zeroes[w*16+g] && !sce1->zeroes[w*16+g] && !cpe->is_mask[w*16+g]) {
670  float Mmax = 0.0f, Smax = 0.0f;
671 
672  /* Must compute mid/side SF and book for the whole window group */
673  for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
674  for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
675  M[i] = (sce0->coeffs[start+(w+w2)*128+i]
676  + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
677  S[i] = M[i]
678  - sce1->coeffs[start+(w+w2)*128+i];
679  }
680  abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
681  abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
682  for (i = 0; i < sce0->ics.swb_sizes[g]; i++ ) {
683  Mmax = FFMAX(Mmax, M34[i]);
684  Smax = FFMAX(Smax, S34[i]);
685  }
686  }
687 
688  for (sid_sf_boost = 0; sid_sf_boost < 4; sid_sf_boost++) {
689  float dist1 = 0.0f, dist2 = 0.0f;
690  int B0 = 0, B1 = 0;
691  int minidx;
692  int mididx, sididx;
693  int midcb, sidcb;
694 
695  minidx = FFMIN(sce0->sf_idx[w*16+g], sce1->sf_idx[w*16+g]);
696  mididx = av_clip(minidx, 0, SCALE_MAX_POS - SCALE_DIV_512);
697  sididx = av_clip(minidx - sid_sf_boost * 3, 0, SCALE_MAX_POS - SCALE_DIV_512);
698  if (sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT
699  && ( !ff_sfdelta_can_replace(sce0, nextband0, prev_mid, mididx, w*16+g)
700  || !ff_sfdelta_can_replace(sce1, nextband1, prev_side, sididx, w*16+g))) {
701  /* scalefactor range violation, bad stuff, will decrease quality unacceptably */
702  continue;
703  }
704 
705  midcb = find_min_book(Mmax, mididx);
706  sidcb = find_min_book(Smax, sididx);
707 
708  /* No CB can be zero */
709  midcb = FFMAX(1,midcb);
710  sidcb = FFMAX(1,sidcb);
711 
712  for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
713  FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
714  FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
715  float minthr = FFMIN(band0->threshold, band1->threshold);
716  int b1,b2,b3,b4;
717  for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
718  M[i] = (sce0->coeffs[start+(w+w2)*128+i]
719  + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
720  S[i] = M[i]
721  - sce1->coeffs[start+(w+w2)*128+i];
722  }
723 
724  abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
725  abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
726  abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
727  abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
728  dist1 += quantize_band_cost(s, &sce0->coeffs[start + (w+w2)*128],
729  L34,
730  sce0->ics.swb_sizes[g],
731  sce0->sf_idx[w*16+g],
732  sce0->band_type[w*16+g],
733  lambda / band0->threshold, INFINITY, &b1, NULL, 0);
734  dist1 += quantize_band_cost(s, &sce1->coeffs[start + (w+w2)*128],
735  R34,
736  sce1->ics.swb_sizes[g],
737  sce1->sf_idx[w*16+g],
738  sce1->band_type[w*16+g],
739  lambda / band1->threshold, INFINITY, &b2, NULL, 0);
740  dist2 += quantize_band_cost(s, M,
741  M34,
742  sce0->ics.swb_sizes[g],
743  mididx,
744  midcb,
745  lambda / minthr, INFINITY, &b3, NULL, 0);
746  dist2 += quantize_band_cost(s, S,
747  S34,
748  sce1->ics.swb_sizes[g],
749  sididx,
750  sidcb,
751  mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0);
752  B0 += b1+b2;
753  B1 += b3+b4;
754  dist1 -= b1+b2;
755  dist2 -= b3+b4;
756  }
757  cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0;
758  if (cpe->ms_mask[w*16+g]) {
759  if (sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT) {
760  sce0->sf_idx[w*16+g] = mididx;
761  sce1->sf_idx[w*16+g] = sididx;
762  sce0->band_type[w*16+g] = midcb;
763  sce1->band_type[w*16+g] = sidcb;
764  } else if ((sce0->band_type[w*16+g] != NOISE_BT) ^ (sce1->band_type[w*16+g] != NOISE_BT)) {
765  /* ms_mask unneeded, and it confuses some decoders */
766  cpe->ms_mask[w*16+g] = 0;
767  }
768  break;
769  } else if (B1 > B0) {
770  /* More boost won't fix this */
771  break;
772  }
773  }
774  }
775  if (!sce0->zeroes[w*16+g] && sce0->band_type[w*16+g] < RESERVED_BT)
776  prev_mid = sce0->sf_idx[w*16+g];
777  if (!sce1->zeroes[w*16+g] && !cpe->is_mask[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT)
778  prev_side = sce1->sf_idx[w*16+g];
779  start += sce0->ics.swb_sizes[g];
780  }
781  }
782 }
783 
785  [AAC_CODER_ANMR] = {
800  mark_pns,
806  },
807  [AAC_CODER_TWOLOOP] = {
822  mark_pns,
828  },
829  [AAC_CODER_FAST] = {
844  mark_pns,
850  },
851 };
AAC encoder long term prediction extension.
static const uint8_t *const run_value_bits[2]
Definition: aacenctab.h:105
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Band types following are encoded differently from others.
Definition: aac.h:86
float pns_ener[128]
Noise energy values (used by encoder)
Definition: aac.h:260
AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB]
Definition: aaccoder.c:784
void ff_aac_encode_ltp_info(AACEncContext *s, SingleChannelElement *sce, int common_window)
Encode LTP data.
Definition: aacenc_ltp.c:35
AAC encoder trellis codebook selector.
static const uint8_t aac_cb_out_map[CB_TOT_ALL]
Map to convert values from BandCodingPath index to a codebook index.
Definition: aacenctab.h:110
void ff_aac_ltp_insert_new_frame(AACEncContext *s)
Definition: aacenc_ltp.c:53
static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce, int win, int group_len, const float lambda)
Encode band info for single window group bands.
Definition: aaccoder.c:77
static void abs_pow34_v(float *out, const float *in, const int size)
Definition: aacenc_utils.h:39
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:168
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1597
#define SCALE_DIFF_ZERO
codebook index corresponding to zero scalefactor indices difference
Definition: aac.h:152
#define AAC_CUTOFF_FROM_BITRATE(bit_rate, channels, sample_rate)
Definition: psymodel.h:35
const char * g
Definition: vf_curves.c:108
FFPsyBand psy_bands[PSY_MAX_BANDS]
channel bands information
Definition: psymodel.h:61
void ff_aac_encode_tns_info(AACEncContext *s, SingleChannelElement *sce)
Encode TNS data.
Definition: aacenc_tns.c:70
#define SCALE_MAX_POS
scalefactor index maximum value
Definition: aac.h:150
#define TRELLIS_STATES
Definition: aaccoder.c:194
#define SCALE_MAX_DIFF
maximum scalefactor difference allowed by standard
Definition: aac.h:151
float(* scalarproduct_float)(const float *v1, const float *v2, int len)
Calculate the scalar product of two vectors of floats.
Definition: float_dsp.h:159
static av_always_inline float bval2bmax(float b)
approximates exp10f(-3.0f*(0.5f + 0.5f * cosf(FFMIN(b,15.5f) / 15.5f)))
Definition: aacenc_utils.h:185
static int ff_sfdelta_can_remove_band(const SingleChannelElement *sce, const uint8_t *nextband, int prev_sf, int band)
Definition: aacenc_utils.h:229
int common_window
Set if channels share a common 'IndividualChannelStream' in bitstream.
Definition: aac.h:278
float cost
Definition: aaccoder.c:189
int prev_idx
pointer to the previous path point
Definition: aaccoder.c:69
uint8_t ms_mask[128]
Set if mid/side stereo is used for each scalefactor window band.
Definition: aac.h:281
float lambda
Definition: aacenc.h:119
#define NOISE_LAMBDA_REPLACE
Definition: aaccoder.c:61
static const uint8_t q1[256]
Definition: twofish.c:96
static uint8_t coef2maxsf(float coef)
Return the maximum scalefactor where the quantized coef is not zero.
Definition: aacenc_utils.h:160
static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda)
Definition: aaccoder.c:395
AVLFG lfg
PRNG needed for PNS.
Definition: aacenc.h:103
static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
Definition: aaccoder.c:429
Spectral data are scaled white noise not coded in the bitstream.
Definition: aac.h:87
AAC encoder quantizer.
static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce, int win, int group_len, const float lambda)
#define B1
Definition: faandct.c:41
const uint16_t * swb_offset
table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular wind...
Definition: aac.h:181
static int ff_sfdelta_can_replace(const SingleChannelElement *sce, const uint8_t *nextband, int prev_sf, int new_sf, int band)
Definition: aacenc_utils.h:243
static double cb(void *priv, double x, double y)
Definition: vf_geq.c:97
#define M(a, b)
Definition: vp3dsp.c:44
AAC encoder context.
Definition: aacenc.h:96
uint8_t
SingleChannelElement ch[2]
Definition: aac.h:284
const uint8_t ff_aac_scalefactor_bits[121]
Definition: aactab.c:82
AAC encoder main-type prediction.
static const uint8_t run_bits[7][16]
Definition: h264_cavlc.c:229
void ff_aac_encode_main_pred(AACEncContext *s, SingleChannelElement *sce)
Encoder predictors data.
Definition: aacenc_pred.c:332
Scalefactor data are intensity stereo positions (in phase).
Definition: aac.h:89
single band psychoacoustic information
Definition: psymodel.h:50
ptrdiff_t size
Definition: opengl_enc.c:101
void av_bmg_get(AVLFG *lfg, double out[2])
Get the next two numbers generated by a Box-Muller Gaussian generator using the random numbers issued...
Definition: lfg.c:47
void ff_aac_update_ltp(AACEncContext *s, SingleChannelElement *sce)
Process LTP parameters.
Definition: aacenc_ltp.c:117
static const uint8_t aac_cb_in_map[CB_TOT_ALL+1]
Inverse map to convert from codebooks to BandCodingPath indices.
Definition: aacenctab.h:112
void ff_aac_search_for_tns(AACEncContext *s, SingleChannelElement *sce)
Definition: aacenc_tns.c:161
#define S(s, c, i)
float is_ener[128]
Intensity stereo pos (used by encoder)
Definition: aac.h:259
void ff_aac_apply_tns(AACEncContext *s, SingleChannelElement *sce)
Definition: aacenc_tns.c:102
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1627
#define CODEC_FLAG_QSCALE
Definition: avcodec.h:952
uint8_t max_sfb
number of scalefactor bands per group
Definition: aac.h:175
float energy
Definition: psymodel.h:52
GLsizei count
Definition: opengl_enc.c:109
int num_swb
number of scalefactor window bands
Definition: aac.h:183
#define FFMAX(a, b)
Definition: common.h:94
float cost
path cost
Definition: aaccoder.c:70
static const uint8_t q0[256]
Definition: twofish.c:77
void ff_aac_search_for_pred(AACEncContext *s, SingleChannelElement *sce)
Definition: aacenc_pred.c:233
float ff_aac_pow2sf_tab[428]
Definition: aactab.c:35
#define SCALE_DIV_512
scalefactor difference that corresponds to scale difference in 512 times
Definition: aac.h:148
static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda)
Definition: aaccoder.c:235
enum BandType band_alt[128]
alternative band type (used by encoder)
Definition: aac.h:253
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:53
void ff_aac_adjust_common_pred(AACEncContext *s, ChannelElement *cpe)
Definition: aacenc_pred.c:151
static uint8_t coef2minsf(float coef)
Return the minimum scalefactor where the quantized coef does not clip.
Definition: aacenc_utils.h:154
int cur_channel
current channel for coder context
Definition: aacenc.h:116
#define FFMIN(a, b)
Definition: common.h:96
void ff_aac_apply_main_pred(AACEncContext *s, SingleChannelElement *sce)
Definition: aacenc_pred.c:119
static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce)
Definition: aaccoder.c:196
uint8_t can_pns[128]
band is allowed to PNS (informative)
Definition: aac.h:258
static void ff_init_nextband_map(const SingleChannelElement *sce, uint8_t *nextband)
Definition: aacenc_utils.h:196
static void mark_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
Definition: aaccoder.c:573
void(* vector_fmul_scalar)(float *dst, const float *src, float mul, int len)
Multiply a vector of floats by a scalar float.
Definition: float_dsp.h:69
AAC encoder Intensity Stereo.
AAC definitions and structures.
AAC encoder twoloop coder.
PutBitContext pb
Definition: aacenc.h:99
AVFloatDSPContext * fdsp
Definition: aacenc.h:102
#define TRELLIS_STAGES
Definition: aaccoder.c:193
#define INFINITY
Definition: math.h:27
void ff_aac_search_for_is(AACEncContext *s, AVCodecContext *avctx, ChannelElement *cpe)
Definition: aacenc_is.c:98
Libavcodec external API header.
static int find_min_book(float maxval, int sf)
Definition: aacenc_utils.h:91
int sample_rate
samples per second
Definition: avcodec.h:2287
main external API structure.
Definition: avcodec.h:1532
IndividualChannelStream ics
Definition: aac.h:249
structure used in optimal codebook search
Definition: aaccoder.c:68
uint8_t group_len[8]
Definition: aac.h:179
Replacements for frequently missing libm functions.
const uint8_t * swb_sizes
table of scalefactor band sizes for a particular window
Definition: aac.h:182
FFPsyContext psy
Definition: aacenc.h:113
#define NOISE_SPREAD_THRESHOLD
Definition: aaccoder.c:57
static av_always_inline av_const float roundf(float x)
Definition: libm.h:451
AAC encoder data.
#define CB_TOT_ALL
Total number of codebooks, including special ones.
Definition: aacenctab.h:37
uint8_t zeroes[128]
band is not coded (used by encoder)
Definition: aac.h:257
int sf_idx[128]
scalefactor indices (used by encoder)
Definition: aac.h:256
INTFLOAT coeffs[1024]
coefficients for IMDCT, maybe processed
Definition: aac.h:262
Scalefactor data are intensity stereo positions (out of phase).
Definition: aac.h:88
#define SCALE_ONE_POS
scalefactor index that corresponds to scale=1.0
Definition: aac.h:149
static void search_for_quantizers_twoloop(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda)
two-loop quantizers search taken from ISO 13818-7 Appendix C
AAC encoder utilities.
Single Channel Element - used for both SCE and LFE elements.
Definition: aac.h:248
#define log2f(x)
Definition: libm.h:409
#define rnd()
Definition: checkasm.h:64
channel element - generic struct for SCE/CPE/CCE/LFE
Definition: aac.h:275
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:2331
int channels
number of audio channels
Definition: avcodec.h:2288
FFPsyChannel * ch
single channel information
Definition: psymodel.h:93
enum BandType band_type[128]
band types
Definition: aac.h:252
static void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb, const float *in, float *out, int size, int scale_idx, int cb, const float lambda, int rtz)
AAC encoder temporal noise shaping.
#define POW_SF2_ZERO
ff_aac_pow2sf_tab index corresponding to pow(2, 0);
Definition: aac.h:154
static float find_max_val(int group_len, int swb_size, const float *scaled)
Definition: aacenc_utils.h:79
void ff_aac_adjust_common_ltp(AACEncContext *s, ChannelElement *cpe)
Definition: aacenc_ltp.c:130
void ff_aac_search_for_ltp(AACEncContext *s, SingleChannelElement *sce, int common_window)
Mark LTP sfb's.
Definition: aacenc_ltp.c:159
void INT64 start
Definition: avisynth_c.h:553
static float quantize_band_cost(struct AACEncContext *s, const float *in, const float *scaled, int size, int scale_idx, int cb, const float lambda, const float uplim, int *bits, float *energy, int rtz)
uint8_t is_mask[128]
Set if intensity stereo is used (used by encoder)
Definition: aac.h:282
float threshold
Definition: psymodel.h:53
AAC data declarations.
float scoefs[1024]
scaled coefficients
Definition: aacenc.h:127
static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
Definition: aaccoder.c:644
float spread
Definition: psymodel.h:54
#define B0
Definition: faandct.c:40
#define NOISE_LOW_LIMIT
This file contains a template for the twoloop coder function.
bitstream writer API