Libav
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 "libavutil/attributes.h"
28 #include "avcodec.h"
29 #include "aactab.h"
30 #include "psymodel.h"
31 
32 /***********************************
33  * TODOs:
34  * try other bitrate controlling mechanism (maybe use ratecontrol.c?)
35  * control quality for quality-based output
36  **********************************/
37 
42 #define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark)
43 #define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark)
44 /* spreading factor for low-to-hi energy spreading, long block, > 22kbps/channel (20dB/Bark) */
45 #define PSY_3GPP_EN_SPREAD_HI_L1 2.0f
46 /* spreading factor for low-to-hi energy spreading, long block, <= 22kbps/channel (15dB/Bark) */
47 #define PSY_3GPP_EN_SPREAD_HI_L2 1.5f
48 /* spreading factor for low-to-hi energy spreading, short block (15 dB/Bark) */
49 #define PSY_3GPP_EN_SPREAD_HI_S 1.5f
50 /* spreading factor for hi-to-low energy spreading, long block (30dB/Bark) */
51 #define PSY_3GPP_EN_SPREAD_LOW_L 3.0f
52 /* spreading factor for hi-to-low energy spreading, short block (20dB/Bark) */
53 #define PSY_3GPP_EN_SPREAD_LOW_S 2.0f
54 
55 #define PSY_3GPP_RPEMIN 0.01f
56 #define PSY_3GPP_RPELEV 2.0f
57 
58 #define PSY_3GPP_C1 3.0f /* log2(8) */
59 #define PSY_3GPP_C2 1.3219281f /* log2(2.5) */
60 #define PSY_3GPP_C3 0.55935729f /* 1 - C2 / C1 */
61 
62 #define PSY_SNR_1DB 7.9432821e-1f /* -1dB */
63 #define PSY_SNR_25DB 3.1622776e-3f /* -25dB */
64 
65 #define PSY_3GPP_SAVE_SLOPE_L -0.46666667f
66 #define PSY_3GPP_SAVE_SLOPE_S -0.36363637f
67 #define PSY_3GPP_SAVE_ADD_L -0.84285712f
68 #define PSY_3GPP_SAVE_ADD_S -0.75f
69 #define PSY_3GPP_SPEND_SLOPE_L 0.66666669f
70 #define PSY_3GPP_SPEND_SLOPE_S 0.81818181f
71 #define PSY_3GPP_SPEND_ADD_L -0.35f
72 #define PSY_3GPP_SPEND_ADD_S -0.26111111f
73 #define PSY_3GPP_CLIP_LO_L 0.2f
74 #define PSY_3GPP_CLIP_LO_S 0.2f
75 #define PSY_3GPP_CLIP_HI_L 0.95f
76 #define PSY_3GPP_CLIP_HI_S 0.75f
77 
78 #define PSY_3GPP_AH_THR_LONG 0.5f
79 #define PSY_3GPP_AH_THR_SHORT 0.63f
80 
81 enum {
85 };
86 
87 #define PSY_3GPP_BITS_TO_PE(bits) ((bits) * 1.18f)
88 
89 /* LAME psy model constants */
90 #define PSY_LAME_FIR_LEN 21
91 #define AAC_BLOCK_SIZE_LONG 1024
92 #define AAC_BLOCK_SIZE_SHORT 128
93 #define AAC_NUM_BLOCKS_SHORT 8
94 #define PSY_LAME_NUM_SUBBLOCKS 3
95 
96 
103 typedef struct AacPsyBand{
104  float energy;
105  float thr;
106  float thr_quiet;
107  float nz_lines;
108  float active_lines;
109  float pe;
110  float pe_const;
111  float norm_fac;
113 }AacPsyBand;
114 
118 typedef struct AacPsyChannel{
121 
122  float win_energy;
123  float iir_state[2];
126  /* LAME psy model specific members */
131 
135 typedef struct AacPsyCoeffs{
136  float ath;
137  float barks;
138  float spread_low[2];
139  float spread_hi [2];
140  float min_snr;
141 }AacPsyCoeffs;
142 
146 typedef struct AacPsyContext{
150  struct {
151  float min;
152  float max;
153  float previous;
154  float correction;
155  } pe;
159 
163 typedef struct {
164  int quality;
165  /* This is overloaded to be both kbps per channel in ABR mode, and
166  * requested quality in constant quality mode.
167  */
168  float st_lrm;
169 } PsyLamePreset;
170 
174 static const PsyLamePreset psy_abr_map[] = {
175 /* TODO: Tuning. These were taken from LAME. */
176 /* kbps/ch st_lrm */
177  { 8, 6.60},
178  { 16, 6.60},
179  { 24, 6.60},
180  { 32, 6.60},
181  { 40, 6.60},
182  { 48, 6.60},
183  { 56, 6.60},
184  { 64, 6.40},
185  { 80, 6.00},
186  { 96, 5.60},
187  {112, 5.20},
188  {128, 5.20},
189  {160, 5.20}
190 };
191 
195 static const PsyLamePreset psy_vbr_map[] = {
196 /* vbr_q st_lrm */
197  { 0, 4.20},
198  { 1, 4.20},
199  { 2, 4.20},
200  { 3, 4.20},
201  { 4, 4.20},
202  { 5, 4.20},
203  { 6, 4.20},
204  { 7, 4.20},
205  { 8, 4.20},
206  { 9, 4.20},
207  {10, 4.20}
208 };
209 
213 static const float psy_fir_coeffs[] = {
214  -8.65163e-18 * 2, -0.00851586 * 2, -6.74764e-18 * 2, 0.0209036 * 2,
215  -3.36639e-17 * 2, -0.0438162 * 2, -1.54175e-17 * 2, 0.0931738 * 2,
216  -5.52212e-17 * 2, -0.313819 * 2
217 };
218 
222 static float lame_calc_attack_threshold(int bitrate)
223 {
224  /* Assume max bitrate to start with */
225  int lower_range = 12, upper_range = 12;
226  int lower_range_kbps = psy_abr_map[12].quality;
227  int upper_range_kbps = psy_abr_map[12].quality;
228  int i;
229 
230  /* Determine which bitrates the value specified falls between.
231  * If the loop ends without breaking our above assumption of 320kbps was correct.
232  */
233  for (i = 1; i < 13; i++) {
234  if (FFMAX(bitrate, psy_abr_map[i].quality) != bitrate) {
235  upper_range = i;
236  upper_range_kbps = psy_abr_map[i ].quality;
237  lower_range = i - 1;
238  lower_range_kbps = psy_abr_map[i - 1].quality;
239  break; /* Upper range found */
240  }
241  }
242 
243  /* Determine which range the value specified is closer to */
244  if ((upper_range_kbps - bitrate) > (bitrate - lower_range_kbps))
245  return psy_abr_map[lower_range].st_lrm;
246  return psy_abr_map[upper_range].st_lrm;
247 }
248 
253 {
254  int i, j;
255 
256  for (i = 0; i < avctx->channels; i++) {
257  AacPsyChannel *pch = &ctx->ch[i];
258 
259  if (avctx->flags & CODEC_FLAG_QSCALE)
260  pch->attack_threshold = psy_vbr_map[avctx->global_quality / FF_QP2LAMBDA].st_lrm;
261  else
262  pch->attack_threshold = lame_calc_attack_threshold(avctx->bit_rate / avctx->channels / 1000);
263 
264  for (j = 0; j < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; j++)
265  pch->prev_energy_subshort[j] = 10.0f;
266  }
267 }
268 
272 static av_cold float calc_bark(float f)
273 {
274  return 13.3f * atanf(0.00076f * f) + 3.5f * atanf((f / 7500.0f) * (f / 7500.0f));
275 }
276 
277 #define ATH_ADD 4
278 
282 static av_cold float ath(float f, float add)
283 {
284  f /= 1000.0f;
285  return 3.64 * pow(f, -0.8)
286  - 6.8 * exp(-0.6 * (f - 3.4) * (f - 3.4))
287  + 6.0 * exp(-0.15 * (f - 8.7) * (f - 8.7))
288  + (0.6 + 0.04 * add) * 0.001 * f * f * f * f;
289 }
290 
292  AacPsyContext *pctx;
293  float bark;
294  int i, j, g, start;
295  float prev, minscale, minath, minsnr, pe_min;
296  const int chan_bitrate = ctx->avctx->bit_rate / ctx->avctx->channels;
297  const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : ctx->avctx->sample_rate / 2;
298  const float num_bark = calc_bark((float)bandwidth);
299 
300  ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext));
301  pctx = (AacPsyContext*) ctx->model_priv_data;
302 
303  pctx->chan_bitrate = chan_bitrate;
304  pctx->frame_bits = chan_bitrate * AAC_BLOCK_SIZE_LONG / ctx->avctx->sample_rate;
305  pctx->pe.min = 8.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
306  pctx->pe.max = 12.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
307  ctx->bitres.size = 6144 - pctx->frame_bits;
308  ctx->bitres.size -= ctx->bitres.size % 8;
309  pctx->fill_level = ctx->bitres.size;
310  minath = ath(3410, ATH_ADD);
311  for (j = 0; j < 2; j++) {
312  AacPsyCoeffs *coeffs = pctx->psy_coef[j];
313  const uint8_t *band_sizes = ctx->bands[j];
314  float line_to_frequency = ctx->avctx->sample_rate / (j ? 256.f : 2048.0f);
315  float avg_chan_bits = chan_bitrate * (j ? 128.0f : 1024.0f) / ctx->avctx->sample_rate;
316  /* reference encoder uses 2.4% here instead of 60% like the spec says */
317  float bark_pe = 0.024f * PSY_3GPP_BITS_TO_PE(avg_chan_bits) / num_bark;
318  float en_spread_low = j ? PSY_3GPP_EN_SPREAD_LOW_S : PSY_3GPP_EN_SPREAD_LOW_L;
319  /* High energy spreading for long blocks <= 22kbps/channel and short blocks are the same. */
320  float en_spread_hi = (j || (chan_bitrate <= 22.0f)) ? PSY_3GPP_EN_SPREAD_HI_S : PSY_3GPP_EN_SPREAD_HI_L1;
321 
322  i = 0;
323  prev = 0.0;
324  for (g = 0; g < ctx->num_bands[j]; g++) {
325  i += band_sizes[g];
326  bark = calc_bark((i-1) * line_to_frequency);
327  coeffs[g].barks = (bark + prev) / 2.0;
328  prev = bark;
329  }
330  for (g = 0; g < ctx->num_bands[j] - 1; g++) {
331  AacPsyCoeffs *coeff = &coeffs[g];
332  float bark_width = coeffs[g+1].barks - coeffs->barks;
333  coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_LOW);
334  coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_HI);
335  coeff->spread_low[1] = pow(10.0, -bark_width * en_spread_low);
336  coeff->spread_hi [1] = pow(10.0, -bark_width * en_spread_hi);
337  pe_min = bark_pe * bark_width;
338  minsnr = pow(2.0f, pe_min / band_sizes[g]) - 1.5f;
339  coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB);
340  }
341  start = 0;
342  for (g = 0; g < ctx->num_bands[j]; g++) {
343  minscale = ath(start * line_to_frequency, ATH_ADD);
344  for (i = 1; i < band_sizes[g]; i++)
345  minscale = FFMIN(minscale, ath((start + i) * line_to_frequency, ATH_ADD));
346  coeffs[g].ath = minscale - minath;
347  start += band_sizes[g];
348  }
349  }
350 
351  pctx->ch = av_mallocz(sizeof(AacPsyChannel) * ctx->avctx->channels);
352 
353  lame_window_init(pctx, ctx->avctx);
354 
355  return 0;
356 }
357 
361 static float iir_filter(int in, float state[2])
362 {
363  float ret;
364 
365  ret = 0.7548f * (in - state[0]) + 0.5095f * state[1];
366  state[0] = in;
367  state[1] = ret;
368  return ret;
369 }
370 
374 static const uint8_t window_grouping[9] = {
375  0xB6, 0x6C, 0xD8, 0xB2, 0x66, 0xC6, 0x96, 0x36, 0x36
376 };
377 
383  const int16_t *audio,
384  const int16_t *la,
385  int channel, int prev_type)
386 {
387  int i, j;
388  int br = ctx->avctx->bit_rate / ctx->avctx->channels;
389  int attack_ratio = br <= 16000 ? 18 : 10;
391  AacPsyChannel *pch = &pctx->ch[channel];
392  uint8_t grouping = 0;
393  int next_type = pch->next_window_seq;
394  FFPsyWindowInfo wi = { { 0 } };
395 
396  if (la) {
397  float s[8], v;
398  int switch_to_eight = 0;
399  float sum = 0.0, sum2 = 0.0;
400  int attack_n = 0;
401  int stay_short = 0;
402  for (i = 0; i < 8; i++) {
403  for (j = 0; j < 128; j++) {
404  v = iir_filter(la[i*128+j], pch->iir_state);
405  sum += v*v;
406  }
407  s[i] = sum;
408  sum2 += sum;
409  }
410  for (i = 0; i < 8; i++) {
411  if (s[i] > pch->win_energy * attack_ratio) {
412  attack_n = i + 1;
413  switch_to_eight = 1;
414  break;
415  }
416  }
417  pch->win_energy = pch->win_energy*7/8 + sum2/64;
418 
419  wi.window_type[1] = prev_type;
420  switch (prev_type) {
421  case ONLY_LONG_SEQUENCE:
422  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
423  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
424  break;
425  case LONG_START_SEQUENCE:
426  wi.window_type[0] = EIGHT_SHORT_SEQUENCE;
427  grouping = pch->next_grouping;
428  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
429  break;
430  case LONG_STOP_SEQUENCE:
431  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
432  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
433  break;
435  stay_short = next_type == EIGHT_SHORT_SEQUENCE || switch_to_eight;
436  wi.window_type[0] = stay_short ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
437  grouping = next_type == EIGHT_SHORT_SEQUENCE ? pch->next_grouping : 0;
438  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
439  break;
440  }
441 
442  pch->next_grouping = window_grouping[attack_n];
443  pch->next_window_seq = next_type;
444  } else {
445  for (i = 0; i < 3; i++)
446  wi.window_type[i] = prev_type;
447  grouping = (prev_type == EIGHT_SHORT_SEQUENCE) ? window_grouping[0] : 0;
448  }
449 
450  wi.window_shape = 1;
451  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
452  wi.num_windows = 1;
453  wi.grouping[0] = 1;
454  } else {
455  int lastgrp = 0;
456  wi.num_windows = 8;
457  for (i = 0; i < 8; i++) {
458  if (!((grouping >> i) & 1))
459  lastgrp = i;
460  wi.grouping[lastgrp]++;
461  }
462  }
463 
464  return wi;
465 }
466 
467 /* 5.6.1.2 "Calculation of Bit Demand" */
468 static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size,
469  int short_window)
470 {
471  const float bitsave_slope = short_window ? PSY_3GPP_SAVE_SLOPE_S : PSY_3GPP_SAVE_SLOPE_L;
472  const float bitsave_add = short_window ? PSY_3GPP_SAVE_ADD_S : PSY_3GPP_SAVE_ADD_L;
473  const float bitspend_slope = short_window ? PSY_3GPP_SPEND_SLOPE_S : PSY_3GPP_SPEND_SLOPE_L;
474  const float bitspend_add = short_window ? PSY_3GPP_SPEND_ADD_S : PSY_3GPP_SPEND_ADD_L;
475  const float clip_low = short_window ? PSY_3GPP_CLIP_LO_S : PSY_3GPP_CLIP_LO_L;
476  const float clip_high = short_window ? PSY_3GPP_CLIP_HI_S : PSY_3GPP_CLIP_HI_L;
477  float clipped_pe, bit_save, bit_spend, bit_factor, fill_level;
478 
479  ctx->fill_level += ctx->frame_bits - bits;
480  ctx->fill_level = av_clip(ctx->fill_level, 0, size);
481  fill_level = av_clipf((float)ctx->fill_level / size, clip_low, clip_high);
482  clipped_pe = av_clipf(pe, ctx->pe.min, ctx->pe.max);
483  bit_save = (fill_level + bitsave_add) * bitsave_slope;
484  assert(bit_save <= 0.3f && bit_save >= -0.05000001f);
485  bit_spend = (fill_level + bitspend_add) * bitspend_slope;
486  assert(bit_spend <= 0.5f && bit_spend >= -0.1f);
487  /* The bit factor graph in the spec is obviously incorrect.
488  * bit_spend + ((bit_spend - bit_spend))...
489  * The reference encoder subtracts everything from 1, but also seems incorrect.
490  * 1 - bit_save + ((bit_spend + bit_save))...
491  * Hopefully below is correct.
492  */
493  bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min);
494  /* NOTE: The reference encoder attempts to center pe max/min around the current pe. */
495  ctx->pe.max = FFMAX(pe, ctx->pe.max);
496  ctx->pe.min = FFMIN(pe, ctx->pe.min);
497 
498  return FFMIN(ctx->frame_bits * bit_factor, ctx->frame_bits + size - bits);
499 }
500 
501 static float calc_pe_3gpp(AacPsyBand *band)
502 {
503  float pe, a;
504 
505  band->pe = 0.0f;
506  band->pe_const = 0.0f;
507  band->active_lines = 0.0f;
508  if (band->energy > band->thr) {
509  a = log2f(band->energy);
510  pe = a - log2f(band->thr);
511  band->active_lines = band->nz_lines;
512  if (pe < PSY_3GPP_C1) {
513  pe = pe * PSY_3GPP_C3 + PSY_3GPP_C2;
514  a = a * PSY_3GPP_C3 + PSY_3GPP_C2;
515  band->active_lines *= PSY_3GPP_C3;
516  }
517  band->pe = pe * band->nz_lines;
518  band->pe_const = a * band->nz_lines;
519  }
520 
521  return band->pe;
522 }
523 
524 static float calc_reduction_3gpp(float a, float desired_pe, float pe,
525  float active_lines)
526 {
527  float thr_avg, reduction;
528 
529  thr_avg = powf(2.0f, (a - pe) / (4.0f * active_lines));
530  reduction = powf(2.0f, (a - desired_pe) / (4.0f * active_lines)) - thr_avg;
531 
532  return FFMAX(reduction, 0.0f);
533 }
534 
535 static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr,
536  float reduction)
537 {
538  float thr = band->thr;
539 
540  if (band->energy > thr) {
541  thr = powf(thr, 0.25f) + reduction;
542  thr = powf(thr, 4.0f);
543 
544  /* This deviates from the 3GPP spec to match the reference encoder.
545  * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands
546  * that have hole avoidance on (active or inactive). It always reduces the
547  * threshold of bands with hole avoidance off.
548  */
549  if (thr > band->energy * min_snr && band->avoid_holes != PSY_3GPP_AH_NONE) {
550  thr = FFMAX(band->thr, band->energy * min_snr);
552  }
553  }
554 
555  return thr;
556 }
557 
561 static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel,
562  const float *coefs, const FFPsyWindowInfo *wi)
563 {
565  AacPsyChannel *pch = &pctx->ch[channel];
566  int start = 0;
567  int i, w, g;
568  float desired_bits, desired_pe, delta_pe, reduction, spread_en[128] = {0};
569  float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f;
570  float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f);
571  const int num_bands = ctx->num_bands[wi->num_windows == 8];
572  const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8];
573  AacPsyCoeffs *coeffs = pctx->psy_coef[wi->num_windows == 8];
574  const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG;
575 
576  //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation"
577  for (w = 0; w < wi->num_windows*16; w += 16) {
578  for (g = 0; g < num_bands; g++) {
579  AacPsyBand *band = &pch->band[w+g];
580 
581  float form_factor = 0.0f;
582  band->energy = 0.0f;
583  for (i = 0; i < band_sizes[g]; i++) {
584  band->energy += coefs[start+i] * coefs[start+i];
585  form_factor += sqrtf(fabs(coefs[start+i]));
586  }
587  band->thr = band->energy * 0.001258925f;
588  band->nz_lines = form_factor / powf(band->energy / band_sizes[g], 0.25f);
589 
590  start += band_sizes[g];
591  }
592  }
593  //modify thresholds and energies - spread, threshold in quiet, pre-echo control
594  for (w = 0; w < wi->num_windows*16; w += 16) {
595  AacPsyBand *bands = &pch->band[w];
596 
597  /* 5.4.2.3 "Spreading" & 5.4.3 "Spread Energy Calculation" */
598  spread_en[0] = bands[0].energy;
599  for (g = 1; g < num_bands; g++) {
600  bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]);
601  spread_en[w+g] = FFMAX(bands[g].energy, spread_en[w+g-1] * coeffs[g].spread_hi[1]);
602  }
603  for (g = num_bands - 2; g >= 0; g--) {
604  bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]);
605  spread_en[w+g] = FFMAX(spread_en[w+g], spread_en[w+g+1] * coeffs[g].spread_low[1]);
606  }
607  //5.4.2.4 "Threshold in quiet"
608  for (g = 0; g < num_bands; g++) {
609  AacPsyBand *band = &bands[g];
610 
611  band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath);
612  //5.4.2.5 "Pre-echo control"
613  if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w)))
614  band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr,
615  PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet));
616 
617  /* 5.6.1.3.1 "Preparatory steps of the perceptual entropy calculation" */
618  pe += calc_pe_3gpp(band);
619  a += band->pe_const;
620  active_lines += band->active_lines;
621 
622  /* 5.6.1.3.3 "Selection of the bands for avoidance of holes" */
623  if (spread_en[w+g] * avoid_hole_thr > band->energy || coeffs[g].min_snr > 1.0f)
625  else
627  }
628  }
629 
630  /* 5.6.1.3.2 "Calculation of the desired perceptual entropy" */
631  ctx->ch[channel].entropy = pe;
632  desired_bits = calc_bit_demand(pctx, pe, ctx->bitres.bits, ctx->bitres.size, wi->num_windows == 8);
633  desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits);
634  /* NOTE: PE correction is kept simple. During initial testing it had very
635  * little effect on the final bitrate. Probably a good idea to come
636  * back and do more testing later.
637  */
638  if (ctx->bitres.bits > 0)
639  desired_pe *= av_clipf(pctx->pe.previous / PSY_3GPP_BITS_TO_PE(ctx->bitres.bits),
640  0.85f, 1.15f);
641  pctx->pe.previous = PSY_3GPP_BITS_TO_PE(desired_bits);
642 
643  if (desired_pe < pe) {
644  /* 5.6.1.3.4 "First Estimation of the reduction value" */
645  for (w = 0; w < wi->num_windows*16; w += 16) {
646  reduction = calc_reduction_3gpp(a, desired_pe, pe, active_lines);
647  pe = 0.0f;
648  a = 0.0f;
649  active_lines = 0.0f;
650  for (g = 0; g < num_bands; g++) {
651  AacPsyBand *band = &pch->band[w+g];
652 
653  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
654  /* recalculate PE */
655  pe += calc_pe_3gpp(band);
656  a += band->pe_const;
657  active_lines += band->active_lines;
658  }
659  }
660 
661  /* 5.6.1.3.5 "Second Estimation of the reduction value" */
662  for (i = 0; i < 2; i++) {
663  float pe_no_ah = 0.0f, desired_pe_no_ah;
664  active_lines = a = 0.0f;
665  for (w = 0; w < wi->num_windows*16; w += 16) {
666  for (g = 0; g < num_bands; g++) {
667  AacPsyBand *band = &pch->band[w+g];
668 
669  if (band->avoid_holes != PSY_3GPP_AH_ACTIVE) {
670  pe_no_ah += band->pe;
671  a += band->pe_const;
672  active_lines += band->active_lines;
673  }
674  }
675  }
676  desired_pe_no_ah = FFMAX(desired_pe - (pe - pe_no_ah), 0.0f);
677  if (active_lines > 0.0f)
678  reduction += calc_reduction_3gpp(a, desired_pe_no_ah, pe_no_ah, active_lines);
679 
680  pe = 0.0f;
681  for (w = 0; w < wi->num_windows*16; w += 16) {
682  for (g = 0; g < num_bands; g++) {
683  AacPsyBand *band = &pch->band[w+g];
684 
685  if (active_lines > 0.0f)
686  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
687  pe += calc_pe_3gpp(band);
688  band->norm_fac = band->active_lines / band->thr;
689  norm_fac += band->norm_fac;
690  }
691  }
692  delta_pe = desired_pe - pe;
693  if (fabs(delta_pe) > 0.05f * desired_pe)
694  break;
695  }
696 
697  if (pe < 1.15f * desired_pe) {
698  /* 6.6.1.3.6 "Final threshold modification by linearization" */
699  norm_fac = 1.0f / norm_fac;
700  for (w = 0; w < wi->num_windows*16; w += 16) {
701  for (g = 0; g < num_bands; g++) {
702  AacPsyBand *band = &pch->band[w+g];
703 
704  if (band->active_lines > 0.5f) {
705  float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe;
706  float thr = band->thr;
707 
708  thr *= powf(2.0f, delta_sfb_pe / band->active_lines);
709  if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE)
710  thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy);
711  band->thr = thr;
712  }
713  }
714  }
715  } else {
716  /* 5.6.1.3.7 "Further perceptual entropy reduction" */
717  g = num_bands;
718  while (pe > desired_pe && g--) {
719  for (w = 0; w < wi->num_windows*16; w+= 16) {
720  AacPsyBand *band = &pch->band[w+g];
721  if (band->avoid_holes != PSY_3GPP_AH_NONE && coeffs[g].min_snr < PSY_SNR_1DB) {
722  coeffs[g].min_snr = PSY_SNR_1DB;
723  band->thr = band->energy * PSY_SNR_1DB;
724  pe += band->active_lines * 1.5f - band->pe;
725  }
726  }
727  }
728  /* TODO: allow more holes (unused without mid/side) */
729  }
730  }
731 
732  for (w = 0; w < wi->num_windows*16; w += 16) {
733  for (g = 0; g < num_bands; g++) {
734  AacPsyBand *band = &pch->band[w+g];
735  FFPsyBand *psy_band = &ctx->ch[channel].psy_bands[w+g];
736 
737  psy_band->threshold = band->thr;
738  psy_band->energy = band->energy;
739  }
740  }
741 
742  memcpy(pch->prev_band, pch->band, sizeof(pch->band));
743 }
744 
745 static void psy_3gpp_analyze(FFPsyContext *ctx, int channel,
746  const float **coeffs, const FFPsyWindowInfo *wi)
747 {
748  int ch;
749  FFPsyChannelGroup *group = ff_psy_find_group(ctx, channel);
750 
751  for (ch = 0; ch < group->num_ch; ch++)
752  psy_3gpp_analyze_channel(ctx, channel + ch, coeffs[ch], &wi[ch]);
753 }
754 
756 {
758  av_freep(&pctx->ch);
759  av_freep(&apc->model_priv_data);
760 }
761 
762 static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
763 {
764  int blocktype = ONLY_LONG_SEQUENCE;
765  if (uselongblock) {
767  blocktype = LONG_STOP_SEQUENCE;
768  } else {
769  blocktype = EIGHT_SHORT_SEQUENCE;
774  }
775 
776  wi->window_type[0] = ctx->next_window_seq;
777  ctx->next_window_seq = blocktype;
778 }
779 
780 static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio,
781  const float *la, int channel, int prev_type)
782 {
784  AacPsyChannel *pch = &pctx->ch[channel];
785  int grouping = 0;
786  int uselongblock = 1;
787  int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
788  int i;
789  FFPsyWindowInfo wi = { { 0 } };
790 
791  if (la) {
792  float hpfsmpl[AAC_BLOCK_SIZE_LONG];
793  float const *pf = hpfsmpl;
794  float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
795  float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
796  float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
797  const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN);
798  int j, att_sum = 0;
799 
800  /* LAME comment: apply high pass filter of fs/4 */
801  for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) {
802  float sum1, sum2;
803  sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2];
804  sum2 = 0.0;
805  for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) {
806  sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]);
807  sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]);
808  }
809  /* NOTE: The LAME psymodel expects its input in the range -32768 to
810  * 32768. Tuning this for normalized floats would be difficult. */
811  hpfsmpl[i] = (sum1 + sum2) * 32768.0f;
812  }
813 
814  /* Calculate the energies of each sub-shortblock */
815  for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) {
816  energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)];
817  assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0);
818  attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)];
819  energy_short[0] += energy_subshort[i];
820  }
821 
822  for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) {
823  float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS);
824  float p = 1.0f;
825  for (; pf < pfe; pf++)
826  p = FFMAX(p, fabsf(*pf));
827  pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p;
828  energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p;
829  /* NOTE: The indexes below are [i + 3 - 2] in the LAME source.
830  * Obviously the 3 and 2 have some significance, or this would be just [i + 1]
831  * (which is what we use here). What the 3 stands for is ambiguous, as it is both
832  * number of short blocks, and the number of sub-short blocks.
833  * It seems that LAME is comparing each sub-block to sub-block + 1 in the
834  * previous block.
835  */
836  if (p > energy_subshort[i + 1])
837  p = p / energy_subshort[i + 1];
838  else if (energy_subshort[i + 1] > p * 10.0f)
839  p = energy_subshort[i + 1] / (p * 10.0f);
840  else
841  p = 0.0;
842  attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p;
843  }
844 
845  /* compare energy between sub-short blocks */
846  for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++)
847  if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS])
848  if (attack_intensity[i] > pch->attack_threshold)
849  attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1;
850 
851  /* should have energy change between short blocks, in order to avoid periodic signals */
852  /* Good samples to show the effect are Trumpet test songs */
853  /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */
854  /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */
855  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) {
856  float const u = energy_short[i - 1];
857  float const v = energy_short[i];
858  float const m = FFMAX(u, v);
859  if (m < 40000) { /* (2) */
860  if (u < 1.7f * v && v < 1.7f * u) { /* (1) */
861  if (i == 1 && attacks[0] < attacks[i])
862  attacks[0] = 0;
863  attacks[i] = 0;
864  }
865  }
866  att_sum += attacks[i];
867  }
868 
869  if (attacks[0] <= pch->prev_attack)
870  attacks[0] = 0;
871 
872  att_sum += attacks[0];
873  /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */
874  if (pch->prev_attack == 3 || att_sum) {
875  uselongblock = 0;
876 
877  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++)
878  if (attacks[i] && attacks[i-1])
879  attacks[i] = 0;
880  }
881  } else {
882  /* We have no lookahead info, so just use same type as the previous sequence. */
883  uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE);
884  }
885 
886  lame_apply_block_type(pch, &wi, uselongblock);
887 
888  wi.window_type[1] = prev_type;
889  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
890  wi.num_windows = 1;
891  wi.grouping[0] = 1;
892  if (wi.window_type[0] == LONG_START_SEQUENCE)
893  wi.window_shape = 0;
894  else
895  wi.window_shape = 1;
896  } else {
897  int lastgrp = 0;
898 
899  wi.num_windows = 8;
900  wi.window_shape = 0;
901  for (i = 0; i < 8; i++) {
902  if (!((pch->next_grouping >> i) & 1))
903  lastgrp = i;
904  wi.grouping[lastgrp]++;
905  }
906  }
907 
908  /* Determine grouping, based on the location of the first attack, and save for
909  * the next frame.
910  * FIXME: Move this to analysis.
911  * TODO: Tune groupings depending on attack location
912  * TODO: Handle more than one attack in a group
913  */
914  for (i = 0; i < 9; i++) {
915  if (attacks[i]) {
916  grouping = i;
917  break;
918  }
919  }
920  pch->next_grouping = window_grouping[grouping];
921 
922  pch->prev_attack = attacks[8];
923 
924  return wi;
925 }
926 
928 {
929  .name = "3GPP TS 26.403-inspired model",
930  .init = psy_3gpp_init,
931  .window = psy_lame_window,
932  .analyze = psy_3gpp_analyze,
933  .end = psy_3gpp_end,
934 };
#define FFMAX(a, b)
Definition: common.h:55
int quality
Quality to map the rest of the vaules to.
Definition: aacpsy.c:164
int size
static const uint8_t window_grouping[9]
window grouping information stored as bits (0 - new group, 1 - group continues)
Definition: aacpsy.c:374
int grouping[8]
window grouping (for e.g. AAC)
Definition: psymodel.h:67
#define AAC_BLOCK_SIZE_SHORT
short block size
Definition: aacpsy.c:92
static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size, int short_window)
Definition: aacpsy.c:468
uint8_t ** bands
scalefactor band sizes for possible frame sizes
Definition: psymodel.h:82
#define PSY_3GPP_AH_THR_SHORT
Definition: aacpsy.c:79
float iir_state[2]
hi-pass IIR filter state
Definition: aacpsy.c:123
static const PsyLamePreset psy_vbr_map[]
LAME psy model preset table for constant quality.
Definition: aacpsy.c:195
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:524
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt)>2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);returnNULL;}returnac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_dlog(ac->avr,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> in
float ath
absolute threshold of hearing per bands
Definition: aacpsy.c:136
#define PSY_3GPP_EN_SPREAD_HI_L1
Definition: aacpsy.c:45
static av_cold float ath(float f, float add)
Calculate ATH value for given frequency.
Definition: aacpsy.c:282
float prev_energy_subshort[AAC_NUM_BLOCKS_SHORT *PSY_LAME_NUM_SUBBLOCKS]
Definition: aacpsy.c:128
enum WindowSequence next_window_seq
window sequence to be used in the next frame
Definition: aacpsy.c:125
#define PSY_SNR_25DB
Definition: aacpsy.c:63
#define AAC_BLOCK_SIZE_LONG
long block size
Definition: aacpsy.c:91
int * num_bands
number of scalefactor bands for possible frame sizes
Definition: psymodel.h:83
LAME psy model preset struct.
Definition: aacpsy.c:163
void av_freep(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:198
float thr
energy threshold
Definition: aacpsy.c:105
float correction
PE correction factor.
Definition: aacpsy.c:154
static av_cold void psy_3gpp_end(FFPsyContext *apc)
Definition: aacpsy.c:755
float attack_threshold
attack threshold for this channel
Definition: aacpsy.c:127
#define PSY_3GPP_EN_SPREAD_LOW_L
Definition: aacpsy.c:51
float nz_lines
number of non-zero spectral lines
Definition: aacpsy.c:107
uint8_t bits
Definition: crc.c:251
uint8_t
psychoacoustic model frame type-dependent coefficients
Definition: aacpsy.c:135
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:535
#define PSY_3GPP_C2
Definition: aacpsy.c:59
#define PSY_LAME_FIR_LEN
LAME psy model FIR order.
Definition: aacpsy.c:90
#define PSY_3GPP_CLIP_LO_L
Definition: aacpsy.c:73
#define PSY_3GPP_SPEND_SLOPE_S
Definition: aacpsy.c:70
#define PSY_3GPP_THR_SPREAD_LOW
Definition: aacpsy.c:43
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:222
struct FFPsyContext::@59 bitres
uint8_t next_grouping
stored grouping scheme for the next frame (in case of 8 short window sequence)
Definition: aacpsy.c:124
#define PSY_3GPP_SAVE_ADD_L
Definition: aacpsy.c:67
static av_cold float calc_bark(float f)
Calculate Bark value for given line.
Definition: aacpsy.c:272
#define PSY_3GPP_SPEND_ADD_S
Definition: aacpsy.c:72
#define PSY_SNR_1DB
Definition: aacpsy.c:62
AacPsyBand prev_band[128]
bands information from the previous frame
Definition: aacpsy.c:120
g
Definition: yuv2rgb.c:535
3GPP TS26.403-inspired psychoacoustic model specific data
Definition: aacpsy.c:146
single/pair channel context for psychoacoustic model
Definition: aacpsy.c:118
static const float psy_fir_coeffs[]
LAME psy model FIR coefficient table.
Definition: aacpsy.c:213
float barks
Bark value for each spectral band in long frame.
Definition: aacpsy.c:137
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1144
#define CODEC_FLAG_QSCALE
Use fixed qscale.
Definition: avcodec.h:611
float pe_const
constant part of the PE calculation
Definition: aacpsy.c:110
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:780
#define PSY_3GPP_SPEND_SLOPE_L
Definition: aacpsy.c:69
#define PSY_3GPP_THR_SPREAD_HI
constants for 3GPP AAC psychoacoustic model
Definition: aacpsy.c:42
float energy
Definition: psymodel.h:37
WindowSequence
Definition: aac.h:68
Libavcodec external API header.
codec-specific psychoacoustic model implementation
Definition: psymodel.h:97
#define PSY_3GPP_RPELEV
Definition: aacpsy.c:56
#define powf(x, y)
Definition: libm.h:44
float thr_quiet
threshold in quiet
Definition: aacpsy.c:106
static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, const float **coeffs, const FFPsyWindowInfo *wi)
Definition: aacpsy.c:745
int bit_rate
the average bitrate
Definition: avcodec.h:1114
int prev_attack
attack value for the last short block in the previous sequence
Definition: aacpsy.c:129
#define PSY_3GPP_SAVE_SLOPE_S
Definition: aacpsy.c:66
#define PSY_3GPP_C3
Definition: aacpsy.c:60
uint8_t num_ch
number of channels in this group
Definition: psymodel.h:56
int frame_bits
average bits per frame
Definition: aacpsy.c:148
int fill_level
bit reservoir fill level
Definition: aacpsy.c:149
static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
Definition: aacpsy.c:762
#define PSY_3GPP_SAVE_SLOPE_L
Definition: aacpsy.c:65
#define PSY_LAME_NUM_SUBBLOCKS
Number of sub-blocks in each short block.
Definition: aacpsy.c:94
#define ATH_ADD
Definition: aacpsy.c:277
float energy
band energy
Definition: aacpsy.c:104
const FFPsyModel ff_aac_psy_model
Definition: aacpsy.c:927
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:561
float st_lrm
short threshold for L, R, and M channels
Definition: aacpsy.c:168
#define PSY_3GPP_EN_SPREAD_LOW_S
Definition: aacpsy.c:53
#define av_cold
Definition: attributes.h:66
int sample_rate
samples per second
Definition: avcodec.h:1791
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:1050
float win_energy
sliding average of channel energy
Definition: aacpsy.c:122
void * model_priv_data
psychoacoustic model implementation private data
Definition: psymodel.h:91
#define av_unused
Definition: attributes.h:86
float active_lines
number of active spectral lines
Definition: aacpsy.c:108
static float iir_filter(int in, float state[2])
IIR filter used in block switching decision.
Definition: aacpsy.c:361
int avoid_holes
hole avoidance flag
Definition: aacpsy.c:112
AacPsyBand band[128]
bands information
Definition: aacpsy.c:119
#define PSY_3GPP_CLIP_HI_S
Definition: aacpsy.c:76
#define PSY_3GPP_RPEMIN
Definition: aacpsy.c:55
static const PsyLamePreset psy_abr_map[]
LAME psy model preset table for ABR.
Definition: aacpsy.c:174
int window_shape
window shape (sine/KBD/whatever)
Definition: psymodel.h:65
float min_snr
minimal SNR
Definition: aacpsy.c:140
float max
maximum allowed PE for bit factor calculation
Definition: aacpsy.c:152
float previous
allowed PE of the previous frame
Definition: aacpsy.c:153
AacPsyCoeffs psy_coef[2][64]
Definition: aacpsy.c:156
float min
minimum allowed PE for bit factor calculation
Definition: aacpsy.c:151
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1130
static av_cold int psy_3gpp_init(FFPsyContext *ctx)
Definition: aacpsy.c:291
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:139
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:382
static float calc_pe_3gpp(AacPsyBand *band)
Definition: aacpsy.c:501
windowing related information
Definition: psymodel.h:63
#define log2f(x)
Definition: libm.h:116
#define PSY_3GPP_BITS_TO_PE(bits)
Definition: aacpsy.c:87
#define PSY_3GPP_C1
Definition: aacpsy.c:58
float norm_fac
normalization factor for linearization
Definition: aacpsy.c:111
int chan_bitrate
bitrate per channel
Definition: aacpsy.c:147
int cutoff
Audio cutoff bandwidth (0 means "automatic")
Definition: avcodec.h:1835
#define PSY_3GPP_CLIP_LO_S
Definition: aacpsy.c:74
#define PSY_3GPP_AH_THR_LONG
Definition: aacpsy.c:78
int channels
number of audio channels
Definition: avcodec.h:1792
float pe
perceptual entropy
Definition: aacpsy.c:109
#define PSY_3GPP_EN_SPREAD_HI_S
Definition: aacpsy.c:49
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:207
AacPsyChannel * ch
Definition: aacpsy.c:157
#define PSY_3GPP_SAVE_ADD_S
Definition: aacpsy.c:68
information for single band used by 3GPP TS26.403-inspired psychoacoustic model
Definition: aacpsy.c:103
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:138
#define PSY_3GPP_CLIP_HI_L
Definition: aacpsy.c:75
int window_type[3]
window type (short/long/transitional, etc.) - current, previous and next
Definition: psymodel.h:64
#define FFMIN(a, b)
Definition: common.h:57
#define AAC_NUM_BLOCKS_SHORT
number of blocks in a short sequence
Definition: aacpsy.c:93
void * av_mallocz(size_t size) av_malloc_attrib 1(1)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
struct AacPsyContext::@9 pe
#define PSY_3GPP_SPEND_ADD_L
Definition: aacpsy.c:71
static av_cold void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx)
LAME psy model specific initialization.
Definition: aacpsy.c:252