aacpsy.c
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1 /*
2  * AAC encoder psychoacoustic model
3  * Copyright (C) 2008 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "aactab.h"
29 #include "psymodel.h"
30 
31 /***********************************
32  * TODOs:
33  * try other bitrate controlling mechanism (maybe use ratecontrol.c?)
34  * control quality for quality-based output
35  **********************************/
36 
41 #define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark)
42 #define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark)
43 /* spreading factor for low-to-hi energy spreading, long block, > 22kbps/channel (20dB/Bark) */
44 #define PSY_3GPP_EN_SPREAD_HI_L1 2.0f
45 /* spreading factor for low-to-hi energy spreading, long block, <= 22kbps/channel (15dB/Bark) */
46 #define PSY_3GPP_EN_SPREAD_HI_L2 1.5f
47 /* spreading factor for low-to-hi energy spreading, short block (15 dB/Bark) */
48 #define PSY_3GPP_EN_SPREAD_HI_S 1.5f
49 /* spreading factor for hi-to-low energy spreading, long block (30dB/Bark) */
50 #define PSY_3GPP_EN_SPREAD_LOW_L 3.0f
51 /* spreading factor for hi-to-low energy spreading, short block (20dB/Bark) */
52 #define PSY_3GPP_EN_SPREAD_LOW_S 2.0f
53 
54 #define PSY_3GPP_RPEMIN 0.01f
55 #define PSY_3GPP_RPELEV 2.0f
56 
57 #define PSY_3GPP_C1 3.0f /* log2(8) */
58 #define PSY_3GPP_C2 1.3219281f /* log2(2.5) */
59 #define PSY_3GPP_C3 0.55935729f /* 1 - C2 / C1 */
60 
61 #define PSY_SNR_1DB 7.9432821e-1f /* -1dB */
62 #define PSY_SNR_25DB 3.1622776e-3f /* -25dB */
63 
64 #define PSY_3GPP_SAVE_SLOPE_L -0.46666667f
65 #define PSY_3GPP_SAVE_SLOPE_S -0.36363637f
66 #define PSY_3GPP_SAVE_ADD_L -0.84285712f
67 #define PSY_3GPP_SAVE_ADD_S -0.75f
68 #define PSY_3GPP_SPEND_SLOPE_L 0.66666669f
69 #define PSY_3GPP_SPEND_SLOPE_S 0.81818181f
70 #define PSY_3GPP_SPEND_ADD_L -0.35f
71 #define PSY_3GPP_SPEND_ADD_S -0.26111111f
72 #define PSY_3GPP_CLIP_LO_L 0.2f
73 #define PSY_3GPP_CLIP_LO_S 0.2f
74 #define PSY_3GPP_CLIP_HI_L 0.95f
75 #define PSY_3GPP_CLIP_HI_S 0.75f
76 
77 #define PSY_3GPP_AH_THR_LONG 0.5f
78 #define PSY_3GPP_AH_THR_SHORT 0.63f
79 
80 enum {
84 };
85 
86 #define PSY_3GPP_BITS_TO_PE(bits) ((bits) * 1.18f)
87 
88 /* LAME psy model constants */
89 #define PSY_LAME_FIR_LEN 21
90 #define AAC_BLOCK_SIZE_LONG 1024
91 #define AAC_BLOCK_SIZE_SHORT 128
92 #define AAC_NUM_BLOCKS_SHORT 8
93 #define PSY_LAME_NUM_SUBBLOCKS 3
94 
95 
102 typedef struct AacPsyBand{
103  float energy;
104  float thr;
105  float thr_quiet;
106  float nz_lines;
107  float active_lines;
108  float pe;
109  float pe_const;
110  float norm_fac;
112 }AacPsyBand;
113 
117 typedef struct AacPsyChannel{
120 
121  float win_energy;
122  float iir_state[2];
125  /* LAME psy model specific members */
130 
134 typedef struct AacPsyCoeffs{
135  float ath;
136  float barks;
137  float spread_low[2];
138  float spread_hi [2];
139  float min_snr;
140 }AacPsyCoeffs;
141 
145 typedef struct AacPsyContext{
149  struct {
150  float min;
151  float max;
152  float previous;
153  float correction;
154  } pe;
158 
162 typedef struct {
163  int quality;
164  /* This is overloaded to be both kbps per channel in ABR mode, and
165  * requested quality in constant quality mode.
166  */
167  float st_lrm;
168 } PsyLamePreset;
169 
173 static const PsyLamePreset psy_abr_map[] = {
174 /* TODO: Tuning. These were taken from LAME. */
175 /* kbps/ch st_lrm */
176  { 8, 6.60},
177  { 16, 6.60},
178  { 24, 6.60},
179  { 32, 6.60},
180  { 40, 6.60},
181  { 48, 6.60},
182  { 56, 6.60},
183  { 64, 6.40},
184  { 80, 6.00},
185  { 96, 5.60},
186  {112, 5.20},
187  {128, 5.20},
188  {160, 5.20}
189 };
190 
194 static const PsyLamePreset psy_vbr_map[] = {
195 /* vbr_q st_lrm */
196  { 0, 4.20},
197  { 1, 4.20},
198  { 2, 4.20},
199  { 3, 4.20},
200  { 4, 4.20},
201  { 5, 4.20},
202  { 6, 4.20},
203  { 7, 4.20},
204  { 8, 4.20},
205  { 9, 4.20},
206  {10, 4.20}
207 };
208 
212 static const float psy_fir_coeffs[] = {
213  -8.65163e-18 * 2, -0.00851586 * 2, -6.74764e-18 * 2, 0.0209036 * 2,
214  -3.36639e-17 * 2, -0.0438162 * 2, -1.54175e-17 * 2, 0.0931738 * 2,
215  -5.52212e-17 * 2, -0.313819 * 2
216 };
217 
221 static float lame_calc_attack_threshold(int bitrate)
222 {
223  /* Assume max bitrate to start with */
224  int lower_range = 12, upper_range = 12;
225  int lower_range_kbps = psy_abr_map[12].quality;
226  int upper_range_kbps = psy_abr_map[12].quality;
227  int i;
228 
229  /* Determine which bitrates the value specified falls between.
230  * If the loop ends without breaking our above assumption of 320kbps was correct.
231  */
232  for (i = 1; i < 13; i++) {
233  if (FFMAX(bitrate, psy_abr_map[i].quality) != bitrate) {
234  upper_range = i;
235  upper_range_kbps = psy_abr_map[i ].quality;
236  lower_range = i - 1;
237  lower_range_kbps = psy_abr_map[i - 1].quality;
238  break; /* Upper range found */
239  }
240  }
241 
242  /* Determine which range the value specified is closer to */
243  if ((upper_range_kbps - bitrate) > (bitrate - lower_range_kbps))
244  return psy_abr_map[lower_range].st_lrm;
245  return psy_abr_map[upper_range].st_lrm;
246 }
247 
251 static void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx) {
252  int i, j;
253 
254  for (i = 0; i < avctx->channels; i++) {
255  AacPsyChannel *pch = &ctx->ch[i];
256 
257  if (avctx->flags & CODEC_FLAG_QSCALE)
258  pch->attack_threshold = psy_vbr_map[avctx->global_quality / FF_QP2LAMBDA].st_lrm;
259  else
260  pch->attack_threshold = lame_calc_attack_threshold(avctx->bit_rate / avctx->channels / 1000);
261 
262  for (j = 0; j < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; j++)
263  pch->prev_energy_subshort[j] = 10.0f;
264  }
265 }
266 
270 static av_cold float calc_bark(float f)
271 {
272  return 13.3f * atanf(0.00076f * f) + 3.5f * atanf((f / 7500.0f) * (f / 7500.0f));
273 }
274 
275 #define ATH_ADD 4
276 
280 static av_cold float ath(float f, float add)
281 {
282  f /= 1000.0f;
283  return 3.64 * pow(f, -0.8)
284  - 6.8 * exp(-0.6 * (f - 3.4) * (f - 3.4))
285  + 6.0 * exp(-0.15 * (f - 8.7) * (f - 8.7))
286  + (0.6 + 0.04 * add) * 0.001 * f * f * f * f;
287 }
288 
290  AacPsyContext *pctx;
291  float bark;
292  int i, j, g, start;
293  float prev, minscale, minath, minsnr, pe_min;
294  const int chan_bitrate = ctx->avctx->bit_rate / ctx->avctx->channels;
295  const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : ctx->avctx->sample_rate / 2;
296  const float num_bark = calc_bark((float)bandwidth);
297 
298  ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext));
299  pctx = (AacPsyContext*) ctx->model_priv_data;
300 
301  pctx->chan_bitrate = chan_bitrate;
302  pctx->frame_bits = chan_bitrate * AAC_BLOCK_SIZE_LONG / ctx->avctx->sample_rate;
303  pctx->pe.min = 8.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
304  pctx->pe.max = 12.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
305  ctx->bitres.size = 6144 - pctx->frame_bits;
306  ctx->bitres.size -= ctx->bitres.size % 8;
307  pctx->fill_level = ctx->bitres.size;
308  minath = ath(3410, ATH_ADD);
309  for (j = 0; j < 2; j++) {
310  AacPsyCoeffs *coeffs = pctx->psy_coef[j];
311  const uint8_t *band_sizes = ctx->bands[j];
312  float line_to_frequency = ctx->avctx->sample_rate / (j ? 256.f : 2048.0f);
313  float avg_chan_bits = chan_bitrate / ctx->avctx->sample_rate * (j ? 128.0f : 1024.0f);
314  /* reference encoder uses 2.4% here instead of 60% like the spec says */
315  float bark_pe = 0.024f * PSY_3GPP_BITS_TO_PE(avg_chan_bits) / num_bark;
316  float en_spread_low = j ? PSY_3GPP_EN_SPREAD_LOW_S : PSY_3GPP_EN_SPREAD_LOW_L;
317  /* High energy spreading for long blocks <= 22kbps/channel and short blocks are the same. */
318  float en_spread_hi = (j || (chan_bitrate <= 22.0f)) ? PSY_3GPP_EN_SPREAD_HI_S : PSY_3GPP_EN_SPREAD_HI_L1;
319 
320  i = 0;
321  prev = 0.0;
322  for (g = 0; g < ctx->num_bands[j]; g++) {
323  i += band_sizes[g];
324  bark = calc_bark((i-1) * line_to_frequency);
325  coeffs[g].barks = (bark + prev) / 2.0;
326  prev = bark;
327  }
328  for (g = 0; g < ctx->num_bands[j] - 1; g++) {
329  AacPsyCoeffs *coeff = &coeffs[g];
330  float bark_width = coeffs[g+1].barks - coeffs->barks;
331  coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_LOW);
332  coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_HI);
333  coeff->spread_low[1] = pow(10.0, -bark_width * en_spread_low);
334  coeff->spread_hi [1] = pow(10.0, -bark_width * en_spread_hi);
335  pe_min = bark_pe * bark_width;
336  minsnr = pow(2.0f, pe_min / band_sizes[g]) - 1.5f;
337  coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB);
338  }
339  start = 0;
340  for (g = 0; g < ctx->num_bands[j]; g++) {
341  minscale = ath(start * line_to_frequency, ATH_ADD);
342  for (i = 1; i < band_sizes[g]; i++)
343  minscale = FFMIN(minscale, ath((start + i) * line_to_frequency, ATH_ADD));
344  coeffs[g].ath = minscale - minath;
345  start += band_sizes[g];
346  }
347  }
348 
349  pctx->ch = av_mallocz(sizeof(AacPsyChannel) * ctx->avctx->channels);
350 
351  lame_window_init(pctx, ctx->avctx);
352 
353  return 0;
354 }
355 
359 static float iir_filter(int in, float state[2])
360 {
361  float ret;
362 
363  ret = 0.7548f * (in - state[0]) + 0.5095f * state[1];
364  state[0] = in;
365  state[1] = ret;
366  return ret;
367 }
368 
372 static const uint8_t window_grouping[9] = {
373  0xB6, 0x6C, 0xD8, 0xB2, 0x66, 0xC6, 0x96, 0x36, 0x36
374 };
375 
381  const int16_t *audio,
382  const int16_t *la,
383  int channel, int prev_type)
384 {
385  int i, j;
386  int br = ctx->avctx->bit_rate / ctx->avctx->channels;
387  int attack_ratio = br <= 16000 ? 18 : 10;
389  AacPsyChannel *pch = &pctx->ch[channel];
390  uint8_t grouping = 0;
391  int next_type = pch->next_window_seq;
392  FFPsyWindowInfo wi = { { 0 } };
393 
394  if (la) {
395  float s[8], v;
396  int switch_to_eight = 0;
397  float sum = 0.0, sum2 = 0.0;
398  int attack_n = 0;
399  int stay_short = 0;
400  for (i = 0; i < 8; i++) {
401  for (j = 0; j < 128; j++) {
402  v = iir_filter(la[i*128+j], pch->iir_state);
403  sum += v*v;
404  }
405  s[i] = sum;
406  sum2 += sum;
407  }
408  for (i = 0; i < 8; i++) {
409  if (s[i] > pch->win_energy * attack_ratio) {
410  attack_n = i + 1;
411  switch_to_eight = 1;
412  break;
413  }
414  }
415  pch->win_energy = pch->win_energy*7/8 + sum2/64;
416 
417  wi.window_type[1] = prev_type;
418  switch (prev_type) {
419  case ONLY_LONG_SEQUENCE:
420  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
421  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
422  break;
423  case LONG_START_SEQUENCE:
424  wi.window_type[0] = EIGHT_SHORT_SEQUENCE;
425  grouping = pch->next_grouping;
426  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
427  break;
428  case LONG_STOP_SEQUENCE:
429  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
430  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
431  break;
433  stay_short = next_type == EIGHT_SHORT_SEQUENCE || switch_to_eight;
434  wi.window_type[0] = stay_short ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
435  grouping = next_type == EIGHT_SHORT_SEQUENCE ? pch->next_grouping : 0;
436  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
437  break;
438  }
439 
440  pch->next_grouping = window_grouping[attack_n];
441  pch->next_window_seq = next_type;
442  } else {
443  for (i = 0; i < 3; i++)
444  wi.window_type[i] = prev_type;
445  grouping = (prev_type == EIGHT_SHORT_SEQUENCE) ? window_grouping[0] : 0;
446  }
447 
448  wi.window_shape = 1;
449  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
450  wi.num_windows = 1;
451  wi.grouping[0] = 1;
452  } else {
453  int lastgrp = 0;
454  wi.num_windows = 8;
455  for (i = 0; i < 8; i++) {
456  if (!((grouping >> i) & 1))
457  lastgrp = i;
458  wi.grouping[lastgrp]++;
459  }
460  }
461 
462  return wi;
463 }
464 
465 /* 5.6.1.2 "Calculation of Bit Demand" */
466 static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size,
467  int short_window)
468 {
469  const float bitsave_slope = short_window ? PSY_3GPP_SAVE_SLOPE_S : PSY_3GPP_SAVE_SLOPE_L;
470  const float bitsave_add = short_window ? PSY_3GPP_SAVE_ADD_S : PSY_3GPP_SAVE_ADD_L;
471  const float bitspend_slope = short_window ? PSY_3GPP_SPEND_SLOPE_S : PSY_3GPP_SPEND_SLOPE_L;
472  const float bitspend_add = short_window ? PSY_3GPP_SPEND_ADD_S : PSY_3GPP_SPEND_ADD_L;
473  const float clip_low = short_window ? PSY_3GPP_CLIP_LO_S : PSY_3GPP_CLIP_LO_L;
474  const float clip_high = short_window ? PSY_3GPP_CLIP_HI_S : PSY_3GPP_CLIP_HI_L;
475  float clipped_pe, bit_save, bit_spend, bit_factor, fill_level;
476 
477  ctx->fill_level += ctx->frame_bits - bits;
478  ctx->fill_level = av_clip(ctx->fill_level, 0, size);
479  fill_level = av_clipf((float)ctx->fill_level / size, clip_low, clip_high);
480  clipped_pe = av_clipf(pe, ctx->pe.min, ctx->pe.max);
481  bit_save = (fill_level + bitsave_add) * bitsave_slope;
482  assert(bit_save <= 0.3f && bit_save >= -0.05000001f);
483  bit_spend = (fill_level + bitspend_add) * bitspend_slope;
484  assert(bit_spend <= 0.5f && bit_spend >= -0.1f);
485  /* The bit factor graph in the spec is obviously incorrect.
486  * bit_spend + ((bit_spend - bit_spend))...
487  * The reference encoder subtracts everything from 1, but also seems incorrect.
488  * 1 - bit_save + ((bit_spend + bit_save))...
489  * Hopefully below is correct.
490  */
491  bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min);
492  /* NOTE: The reference encoder attempts to center pe max/min around the current pe. */
493  ctx->pe.max = FFMAX(pe, ctx->pe.max);
494  ctx->pe.min = FFMIN(pe, ctx->pe.min);
495 
496  return FFMIN(ctx->frame_bits * bit_factor, ctx->frame_bits + size - bits);
497 }
498 
499 static float calc_pe_3gpp(AacPsyBand *band)
500 {
501  float pe, a;
502 
503  band->pe = 0.0f;
504  band->pe_const = 0.0f;
505  band->active_lines = 0.0f;
506  if (band->energy > band->thr) {
507  a = log2f(band->energy);
508  pe = a - log2f(band->thr);
509  band->active_lines = band->nz_lines;
510  if (pe < PSY_3GPP_C1) {
511  pe = pe * PSY_3GPP_C3 + PSY_3GPP_C2;
512  a = a * PSY_3GPP_C3 + PSY_3GPP_C2;
513  band->active_lines *= PSY_3GPP_C3;
514  }
515  band->pe = pe * band->nz_lines;
516  band->pe_const = a * band->nz_lines;
517  }
518 
519  return band->pe;
520 }
521 
522 static float calc_reduction_3gpp(float a, float desired_pe, float pe,
523  float active_lines)
524 {
525  float thr_avg, reduction;
526 
527  thr_avg = powf(2.0f, (a - pe) / (4.0f * active_lines));
528  reduction = powf(2.0f, (a - desired_pe) / (4.0f * active_lines)) - thr_avg;
529 
530  return FFMAX(reduction, 0.0f);
531 }
532 
533 static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr,
534  float reduction)
535 {
536  float thr = band->thr;
537 
538  if (band->energy > thr) {
539  thr = powf(thr, 0.25f) + reduction;
540  thr = powf(thr, 4.0f);
541 
542  /* This deviates from the 3GPP spec to match the reference encoder.
543  * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands
544  * that have hole avoidance on (active or inactive). It always reduces the
545  * threshold of bands with hole avoidance off.
546  */
547  if (thr > band->energy * min_snr && band->avoid_holes != PSY_3GPP_AH_NONE) {
548  thr = FFMAX(band->thr, band->energy * min_snr);
550  }
551  }
552 
553  return thr;
554 }
555 
559 static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel,
560  const float *coefs, const FFPsyWindowInfo *wi)
561 {
563  AacPsyChannel *pch = &pctx->ch[channel];
564  int start = 0;
565  int i, w, g;
566  float desired_bits, desired_pe, delta_pe, reduction, spread_en[128] = {0};
567  float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f;
568  float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f);
569  const int num_bands = ctx->num_bands[wi->num_windows == 8];
570  const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8];
571  AacPsyCoeffs *coeffs = pctx->psy_coef[wi->num_windows == 8];
572  const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG;
573 
574  //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation"
575  for (w = 0; w < wi->num_windows*16; w += 16) {
576  for (g = 0; g < num_bands; g++) {
577  AacPsyBand *band = &pch->band[w+g];
578 
579  float form_factor = 0.0f;
580  band->energy = 0.0f;
581  for (i = 0; i < band_sizes[g]; i++) {
582  band->energy += coefs[start+i] * coefs[start+i];
583  form_factor += sqrtf(fabs(coefs[start+i]));
584  }
585  band->thr = band->energy * 0.001258925f;
586  band->nz_lines = form_factor / powf(band->energy / band_sizes[g], 0.25f);
587 
588  start += band_sizes[g];
589  }
590  }
591  //modify thresholds and energies - spread, threshold in quiet, pre-echo control
592  for (w = 0; w < wi->num_windows*16; w += 16) {
593  AacPsyBand *bands = &pch->band[w];
594 
595  /* 5.4.2.3 "Spreading" & 5.4.3 "Spread Energy Calculation" */
596  spread_en[0] = bands[0].energy;
597  for (g = 1; g < num_bands; g++) {
598  bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]);
599  spread_en[w+g] = FFMAX(bands[g].energy, spread_en[w+g-1] * coeffs[g].spread_hi[1]);
600  }
601  for (g = num_bands - 2; g >= 0; g--) {
602  bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]);
603  spread_en[w+g] = FFMAX(spread_en[w+g], spread_en[w+g+1] * coeffs[g].spread_low[1]);
604  }
605  //5.4.2.4 "Threshold in quiet"
606  for (g = 0; g < num_bands; g++) {
607  AacPsyBand *band = &bands[g];
608 
609  band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath);
610  //5.4.2.5 "Pre-echo control"
611  if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w)))
612  band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr,
613  PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet));
614 
615  /* 5.6.1.3.1 "Preparatory steps of the perceptual entropy calculation" */
616  pe += calc_pe_3gpp(band);
617  a += band->pe_const;
618  active_lines += band->active_lines;
619 
620  /* 5.6.1.3.3 "Selection of the bands for avoidance of holes" */
621  if (spread_en[w+g] * avoid_hole_thr > band->energy || coeffs[g].min_snr > 1.0f)
623  else
625  }
626  }
627 
628  /* 5.6.1.3.2 "Calculation of the desired perceptual entropy" */
629  ctx->ch[channel].entropy = pe;
630  desired_bits = calc_bit_demand(pctx, pe, ctx->bitres.bits, ctx->bitres.size, wi->num_windows == 8);
631  desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits);
632  /* NOTE: PE correction is kept simple. During initial testing it had very
633  * little effect on the final bitrate. Probably a good idea to come
634  * back and do more testing later.
635  */
636  if (ctx->bitres.bits > 0)
637  desired_pe *= av_clipf(pctx->pe.previous / PSY_3GPP_BITS_TO_PE(ctx->bitres.bits),
638  0.85f, 1.15f);
639  pctx->pe.previous = PSY_3GPP_BITS_TO_PE(desired_bits);
640 
641  if (desired_pe < pe) {
642  /* 5.6.1.3.4 "First Estimation of the reduction value" */
643  for (w = 0; w < wi->num_windows*16; w += 16) {
644  reduction = calc_reduction_3gpp(a, desired_pe, pe, active_lines);
645  pe = 0.0f;
646  a = 0.0f;
647  active_lines = 0.0f;
648  for (g = 0; g < num_bands; g++) {
649  AacPsyBand *band = &pch->band[w+g];
650 
651  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
652  /* recalculate PE */
653  pe += calc_pe_3gpp(band);
654  a += band->pe_const;
655  active_lines += band->active_lines;
656  }
657  }
658 
659  /* 5.6.1.3.5 "Second Estimation of the reduction value" */
660  for (i = 0; i < 2; i++) {
661  float pe_no_ah = 0.0f, desired_pe_no_ah;
662  active_lines = a = 0.0f;
663  for (w = 0; w < wi->num_windows*16; w += 16) {
664  for (g = 0; g < num_bands; g++) {
665  AacPsyBand *band = &pch->band[w+g];
666 
667  if (band->avoid_holes != PSY_3GPP_AH_ACTIVE) {
668  pe_no_ah += band->pe;
669  a += band->pe_const;
670  active_lines += band->active_lines;
671  }
672  }
673  }
674  desired_pe_no_ah = FFMAX(desired_pe - (pe - pe_no_ah), 0.0f);
675  if (active_lines > 0.0f)
676  reduction += calc_reduction_3gpp(a, desired_pe_no_ah, pe_no_ah, active_lines);
677 
678  pe = 0.0f;
679  for (w = 0; w < wi->num_windows*16; w += 16) {
680  for (g = 0; g < num_bands; g++) {
681  AacPsyBand *band = &pch->band[w+g];
682 
683  if (active_lines > 0.0f)
684  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
685  pe += calc_pe_3gpp(band);
686  band->norm_fac = band->active_lines / band->thr;
687  norm_fac += band->norm_fac;
688  }
689  }
690  delta_pe = desired_pe - pe;
691  if (fabs(delta_pe) > 0.05f * desired_pe)
692  break;
693  }
694 
695  if (pe < 1.15f * desired_pe) {
696  /* 6.6.1.3.6 "Final threshold modification by linearization" */
697  norm_fac = 1.0f / norm_fac;
698  for (w = 0; w < wi->num_windows*16; w += 16) {
699  for (g = 0; g < num_bands; g++) {
700  AacPsyBand *band = &pch->band[w+g];
701 
702  if (band->active_lines > 0.5f) {
703  float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe;
704  float thr = band->thr;
705 
706  thr *= powf(2.0f, delta_sfb_pe / band->active_lines);
707  if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE)
708  thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy);
709  band->thr = thr;
710  }
711  }
712  }
713  } else {
714  /* 5.6.1.3.7 "Further perceptual entropy reduction" */
715  g = num_bands;
716  while (pe > desired_pe && g--) {
717  for (w = 0; w < wi->num_windows*16; w+= 16) {
718  AacPsyBand *band = &pch->band[w+g];
719  if (band->avoid_holes != PSY_3GPP_AH_NONE && coeffs[g].min_snr < PSY_SNR_1DB) {
720  coeffs[g].min_snr = PSY_SNR_1DB;
721  band->thr = band->energy * PSY_SNR_1DB;
722  pe += band->active_lines * 1.5f - band->pe;
723  }
724  }
725  }
726  /* TODO: allow more holes (unused without mid/side) */
727  }
728  }
729 
730  for (w = 0; w < wi->num_windows*16; w += 16) {
731  for (g = 0; g < num_bands; g++) {
732  AacPsyBand *band = &pch->band[w+g];
733  FFPsyBand *psy_band = &ctx->ch[channel].psy_bands[w+g];
734 
735  psy_band->threshold = band->thr;
736  psy_band->energy = band->energy;
737  }
738  }
739 
740  memcpy(pch->prev_band, pch->band, sizeof(pch->band));
741 }
742 
743 static void psy_3gpp_analyze(FFPsyContext *ctx, int channel,
744  const float **coeffs, const FFPsyWindowInfo *wi)
745 {
746  int ch;
747  FFPsyChannelGroup *group = ff_psy_find_group(ctx, channel);
748 
749  for (ch = 0; ch < group->num_ch; ch++)
750  psy_3gpp_analyze_channel(ctx, channel + ch, coeffs[ch], &wi[ch]);
751 }
752 
754 {
756  av_freep(&pctx->ch);
757  av_freep(&apc->model_priv_data);
758 }
759 
760 static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
761 {
762  int blocktype = ONLY_LONG_SEQUENCE;
763  if (uselongblock) {
765  blocktype = LONG_STOP_SEQUENCE;
766  } else {
767  blocktype = EIGHT_SHORT_SEQUENCE;
772  }
773 
774  wi->window_type[0] = ctx->next_window_seq;
775  ctx->next_window_seq = blocktype;
776 }
777 
778 static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio,
779  const float *la, int channel, int prev_type)
780 {
782  AacPsyChannel *pch = &pctx->ch[channel];
783  int grouping = 0;
784  int uselongblock = 1;
785  int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
786  int i;
787  FFPsyWindowInfo wi = { { 0 } };
788 
789  if (la) {
790  float hpfsmpl[AAC_BLOCK_SIZE_LONG];
791  float const *pf = hpfsmpl;
792  float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
793  float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
794  float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
795  const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN);
796  int j, att_sum = 0;
797 
798  /* LAME comment: apply high pass filter of fs/4 */
799  for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) {
800  float sum1, sum2;
801  sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2];
802  sum2 = 0.0;
803  for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) {
804  sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]);
805  sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]);
806  }
807  /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768. Tuning this for normalized floats would be difficult. */
808  hpfsmpl[i] = (sum1 + sum2) * 32768.0f;
809  }
810 
811  /* Calculate the energies of each sub-shortblock */
812  for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) {
813  energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)];
814  assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0);
815  attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)];
816  energy_short[0] += energy_subshort[i];
817  }
818 
819  for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) {
820  float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS);
821  float p = 1.0f;
822  for (; pf < pfe; pf++)
823  p = FFMAX(p, fabsf(*pf));
824  pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p;
825  energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p;
826  /* NOTE: The indexes below are [i + 3 - 2] in the LAME source.
827  * Obviously the 3 and 2 have some significance, or this would be just [i + 1]
828  * (which is what we use here). What the 3 stands for is ambiguous, as it is both
829  * number of short blocks, and the number of sub-short blocks.
830  * It seems that LAME is comparing each sub-block to sub-block + 1 in the
831  * previous block.
832  */
833  if (p > energy_subshort[i + 1])
834  p = p / energy_subshort[i + 1];
835  else if (energy_subshort[i + 1] > p * 10.0f)
836  p = energy_subshort[i + 1] / (p * 10.0f);
837  else
838  p = 0.0;
839  attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p;
840  }
841 
842  /* compare energy between sub-short blocks */
843  for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++)
844  if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS])
845  if (attack_intensity[i] > pch->attack_threshold)
846  attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1;
847 
848  /* should have energy change between short blocks, in order to avoid periodic signals */
849  /* Good samples to show the effect are Trumpet test songs */
850  /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */
851  /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */
852  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) {
853  float const u = energy_short[i - 1];
854  float const v = energy_short[i];
855  float const m = FFMAX(u, v);
856  if (m < 40000) { /* (2) */
857  if (u < 1.7f * v && v < 1.7f * u) { /* (1) */
858  if (i == 1 && attacks[0] < attacks[i])
859  attacks[0] = 0;
860  attacks[i] = 0;
861  }
862  }
863  att_sum += attacks[i];
864  }
865 
866  if (attacks[0] <= pch->prev_attack)
867  attacks[0] = 0;
868 
869  att_sum += attacks[0];
870  /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */
871  if (pch->prev_attack == 3 || att_sum) {
872  uselongblock = 0;
873 
874  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++)
875  if (attacks[i] && attacks[i-1])
876  attacks[i] = 0;
877  }
878  } else {
879  /* We have no lookahead info, so just use same type as the previous sequence. */
880  uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE);
881  }
882 
883  lame_apply_block_type(pch, &wi, uselongblock);
884 
885  wi.window_type[1] = prev_type;
886  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
887  wi.num_windows = 1;
888  wi.grouping[0] = 1;
889  if (wi.window_type[0] == LONG_START_SEQUENCE)
890  wi.window_shape = 0;
891  else
892  wi.window_shape = 1;
893  } else {
894  int lastgrp = 0;
895 
896  wi.num_windows = 8;
897  wi.window_shape = 0;
898  for (i = 0; i < 8; i++) {
899  if (!((pch->next_grouping >> i) & 1))
900  lastgrp = i;
901  wi.grouping[lastgrp]++;
902  }
903  }
904 
905  /* Determine grouping, based on the location of the first attack, and save for
906  * the next frame.
907  * FIXME: Move this to analysis.
908  * TODO: Tune groupings depending on attack location
909  * TODO: Handle more than one attack in a group
910  */
911  for (i = 0; i < 9; i++) {
912  if (attacks[i]) {
913  grouping = i;
914  break;
915  }
916  }
917  pch->next_grouping = window_grouping[grouping];
918 
919  pch->prev_attack = attacks[8];
920 
921  return wi;
922 }
923 
925 {
926  .name = "3GPP TS 26.403-inspired model",
927  .init = psy_3gpp_init,
928  .window = psy_lame_window,
929  .analyze = psy_3gpp_analyze,
930  .end = psy_3gpp_end,
931 };
int quality
Quality to map the rest of the vaules to.
Definition: aacpsy.c:163
static const int16_t coeffs[28]
int size
static const uint8_t window_grouping[9]
window grouping information stored as bits (0 - new group, 1 - group continues)
Definition: aacpsy.c:372
int grouping[8]
window grouping (for e.g. AAC)
Definition: psymodel.h:67
#define AAC_BLOCK_SIZE_SHORT
short block size
Definition: aacpsy.c:91
static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size, int short_window)
Definition: aacpsy.c:466
uint8_t ** bands
scalefactor band sizes for possible frame sizes
Definition: psymodel.h:82
struct AacPsyContext::@6 pe
#define PSY_3GPP_AH_THR_SHORT
Definition: aacpsy.c:78
float iir_state[2]
hi-pass IIR filter state
Definition: aacpsy.c:122
static const PsyLamePreset psy_vbr_map[]
LAME psy model preset table for constant quality.
Definition: aacpsy.c:194
psychoacoustic information for an arbitrary group of channels
Definition: psymodel.h:54
static float calc_reduction_3gpp(float a, float desired_pe, float pe, float active_lines)
Definition: aacpsy.c:522
float ath
absolute threshold of hearing per bands
Definition: aacpsy.c:135
#define PSY_3GPP_EN_SPREAD_HI_L1
Definition: aacpsy.c:44
static av_cold float ath(float f, float add)
Calculate ATH value for given frequency.
Definition: aacpsy.c:280
float prev_energy_subshort[AAC_NUM_BLOCKS_SHORT *PSY_LAME_NUM_SUBBLOCKS]
Definition: aacpsy.c:127
enum WindowSequence next_window_seq
window sequence to be used in the next frame
Definition: aacpsy.c:124
#define PSY_SNR_25DB
Definition: aacpsy.c:62
#define AAC_BLOCK_SIZE_LONG
long block size
Definition: aacpsy.c:90
int * num_bands
number of scalefactor bands for possible frame sizes
Definition: psymodel.h:83
LAME psy model preset struct.
Definition: aacpsy.c:162
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:151
float thr
energy threshold
Definition: aacpsy.c:104
float correction
PE correction factor.
Definition: aacpsy.c:153
static av_cold void psy_3gpp_end(FFPsyContext *apc)
Definition: aacpsy.c:753
float attack_threshold
attack threshold for this channel
Definition: aacpsy.c:126
#define PSY_3GPP_EN_SPREAD_LOW_L
Definition: aacpsy.c:50
float nz_lines
number of non-zero spectral lines
Definition: aacpsy.c:106
uint8_t bits
Definition: crc.c:31
uint8_t
psychoacoustic model frame type-dependent coefficients
Definition: aacpsy.c:134
int size
size of the bitresevoir in bits
Definition: psymodel.h:87
static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr, float reduction)
Definition: aacpsy.c:533
#define PSY_3GPP_C2
Definition: aacpsy.c:58
#define PSY_LAME_FIR_LEN
LAME psy model FIR order.
Definition: aacpsy.c:89
#define PSY_3GPP_CLIP_LO_L
Definition: aacpsy.c:72
#define PSY_3GPP_SPEND_SLOPE_S
Definition: aacpsy.c:69
#define PSY_3GPP_THR_SPREAD_LOW
Definition: aacpsy.c:42
context used by psychoacoustic model
Definition: psymodel.h:74
#define atanf(x)
Definition: libm.h:34
single band psychoacoustic information
Definition: psymodel.h:35
static float lame_calc_attack_threshold(int bitrate)
Calculate the ABR attack threshold from the above LAME psymodel table.
Definition: aacpsy.c:221
uint8_t next_grouping
stored grouping scheme for the next frame (in case of 8 short window sequence)
Definition: aacpsy.c:123
#define PSY_3GPP_SAVE_ADD_L
Definition: aacpsy.c:66
static av_cold float calc_bark(float f)
Calculate Bark value for given line.
Definition: aacpsy.c:270
#define PSY_3GPP_SPEND_ADD_S
Definition: aacpsy.c:71
struct AacPsyBand AacPsyBand
information for single band used by 3GPP TS26.403-inspired psychoacoustic model
#define PSY_SNR_1DB
Definition: aacpsy.c:61
AacPsyBand prev_band[128]
bands information from the previous frame
Definition: aacpsy.c:119
g
Definition: yuv2rgb.c:540
3GPP TS26.403-inspired psychoacoustic model specific data
Definition: aacpsy.c:145
single/pair channel context for psychoacoustic model
Definition: aacpsy.c:117
static const float psy_fir_coeffs[]
LAME psy model FIR coefficient table.
Definition: aacpsy.c:212
float barks
Bark value for each spectral band in long frame.
Definition: aacpsy.c:136
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1434
float pe_const
constant part of the PE calculation
Definition: aacpsy.c:109
int num_windows
number of windows in a frame
Definition: psymodel.h:66
static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio, const float *la, int channel, int prev_type)
Definition: aacpsy.c:778
#define PSY_3GPP_SPEND_SLOPE_L
Definition: aacpsy.c:68
#define PSY_3GPP_THR_SPREAD_HI
constants for 3GPP AAC psychoacoustic model
Definition: aacpsy.c:41
float energy
Definition: psymodel.h:37
WindowSequence
Definition: aac.h:69
codec-specific psychoacoustic model implementation
Definition: psymodel.h:97
#define PSY_3GPP_RPELEV
Definition: aacpsy.c:55
#define powf(x, y)
Definition: libm.h:44
static void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx)
LAME psy model specific initialization.
Definition: aacpsy.c:251
float thr_quiet
threshold in quiet
Definition: aacpsy.c:105
static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, const float **coeffs, const FFPsyWindowInfo *wi)
Definition: aacpsy.c:743
int bit_rate
the average bitrate
Definition: avcodec.h:1404
struct AacPsyContext AacPsyContext
3GPP TS26.403-inspired psychoacoustic model specific data
int prev_attack
attack value for the last short block in the previous sequence
Definition: aacpsy.c:128
#define PSY_3GPP_SAVE_SLOPE_S
Definition: aacpsy.c:65
#define PSY_3GPP_C3
Definition: aacpsy.c:59
uint8_t num_ch
number of channels in this group
Definition: psymodel.h:56
int frame_bits
average bits per frame
Definition: aacpsy.c:147
int fill_level
bit reservoir fill level
Definition: aacpsy.c:148
static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
Definition: aacpsy.c:760
#define PSY_3GPP_SAVE_SLOPE_L
Definition: aacpsy.c:64
#define PSY_LAME_NUM_SUBBLOCKS
Number of sub-blocks in each short block.
Definition: aacpsy.c:93
#define ATH_ADD
Definition: aacpsy.c:275
float energy
band energy
Definition: aacpsy.c:103
const FFPsyModel ff_aac_psy_model
Definition: aacpsy.c:924
static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, const float *coefs, const FFPsyWindowInfo *wi)
Calculate band thresholds as suggested in 3GPP TS26.403.
Definition: aacpsy.c:559
float st_lrm
short threshold for L, R, and M channels
Definition: aacpsy.c:167
#define PSY_3GPP_EN_SPREAD_LOW_S
Definition: aacpsy.c:52
external API header
int sample_rate
samples per second
Definition: avcodec.h:2104
FFPsyChannelGroup * ff_psy_find_group(FFPsyContext *ctx, int channel)
Determine what group a channel belongs to.
Definition: psymodel.c:66
main external API structure.
Definition: avcodec.h:1339
float win_energy
sliding average of channel energy
Definition: aacpsy.c:121
void * model_priv_data
psychoacoustic model implementation private data
Definition: psymodel.h:91
float active_lines
number of active spectral lines
Definition: aacpsy.c:107
static float iir_filter(int in, float state[2])
IIR filter used in block switching decision.
Definition: aacpsy.c:359
int avoid_holes
hole avoidance flag
Definition: aacpsy.c:111
AacPsyBand band[128]
bands information
Definition: aacpsy.c:118
#define PSY_3GPP_CLIP_HI_S
Definition: aacpsy.c:75
#define PSY_3GPP_RPEMIN
Definition: aacpsy.c:54
static const PsyLamePreset psy_abr_map[]
LAME psy model preset table for ABR.
Definition: aacpsy.c:173
int window_shape
window shape (sine/KBD/whatever)
Definition: psymodel.h:65
float min_snr
minimal SNR
Definition: aacpsy.c:139
float max
maximum allowed PE for bit factor calculation
Definition: aacpsy.c:151
struct FFPsyContext::@51 bitres
float previous
allowed PE of the previous frame
Definition: aacpsy.c:152
AacPsyCoeffs psy_coef[2][64]
Definition: aacpsy.c:155
float min
minimum allowed PE for bit factor calculation
Definition: aacpsy.c:150
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1420
static av_cold int psy_3gpp_init(FFPsyContext *ctx)
Definition: aacpsy.c:289
static uint32_t state
Definition: trasher.c:27
float spread_hi[2]
spreading factor for high-to-low threshold spreading in long frame
Definition: aacpsy.c:138
const char * name
Definition: psymodel.h:98
static av_unused FFPsyWindowInfo psy_3gpp_window(FFPsyContext *ctx, const int16_t *audio, const int16_t *la, int channel, int prev_type)
Tell encoder which window types to use.
Definition: aacpsy.c:380
static float calc_pe_3gpp(AacPsyBand *band)
Definition: aacpsy.c:499
windowing related information
Definition: psymodel.h:63
#define log2f(x)
Definition: libm.h:116
#define PSY_3GPP_BITS_TO_PE(bits)
Definition: aacpsy.c:86
#define PSY_3GPP_C1
Definition: aacpsy.c:57
float norm_fac
normalization factor for linearization
Definition: aacpsy.c:110
int chan_bitrate
bitrate per channel
Definition: aacpsy.c:146
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:2148
#define PSY_3GPP_CLIP_LO_S
Definition: aacpsy.c:73
#define PSY_3GPP_AH_THR_LONG
Definition: aacpsy.c:77
int channels
number of audio channels
Definition: avcodec.h:2105
float pe
perceptual entropy
Definition: aacpsy.c:108
#define PSY_3GPP_EN_SPREAD_HI_S
Definition: aacpsy.c:48
AacPsyChannel * ch
Definition: aacpsy.c:156
#define PSY_3GPP_SAVE_ADD_S
Definition: aacpsy.c:67
struct AacPsyCoeffs AacPsyCoeffs
psychoacoustic model frame type-dependent coefficients
information for single band used by 3GPP TS26.403-inspired psychoacoustic model
Definition: aacpsy.c:102
AVCodecContext * avctx
encoder context
Definition: psymodel.h:75
float threshold
Definition: psymodel.h:38
AAC data declarations.
float spread_low[2]
spreading factor for low-to-high threshold spreading in long frame
Definition: aacpsy.c:137
#define PSY_3GPP_CLIP_HI_L
Definition: aacpsy.c:74
int window_type[3]
window type (short/long/transitional, etc.) - current, previous and next
Definition: psymodel.h:64
struct AacPsyChannel AacPsyChannel
single/pair channel context for psychoacoustic model
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:158
#define AAC_NUM_BLOCKS_SHORT
number of blocks in a short sequence
Definition: aacpsy.c:92
#define PSY_3GPP_SPEND_ADD_L
Definition: aacpsy.c:70