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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 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 encoder psychoacoustic model
25  */
26 
27 #include "libavutil/attributes.h"
28 #include "libavutil/internal.h"
29 #include "libavutil/libm.h"
30 
31 #include "avcodec.h"
32 #include "aactab.h"
33 #include "psymodel.h"
34 
35 /***********************************
36  * TODOs:
37  * try other bitrate controlling mechanism (maybe use ratecontrol.c?)
38  * control quality for quality-based output
39  **********************************/
40 
41 /**
42  * constants for 3GPP AAC psychoacoustic model
43  * @{
44  */
45 #define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark)
46 #define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark)
47 /* spreading factor for low-to-hi energy spreading, long block, > 22kbps/channel (20dB/Bark) */
48 #define PSY_3GPP_EN_SPREAD_HI_L1 2.0f
49 /* spreading factor for low-to-hi energy spreading, long block, <= 22kbps/channel (15dB/Bark) */
50 #define PSY_3GPP_EN_SPREAD_HI_L2 1.5f
51 /* spreading factor for low-to-hi energy spreading, short block (15 dB/Bark) */
52 #define PSY_3GPP_EN_SPREAD_HI_S 1.5f
53 /* spreading factor for hi-to-low energy spreading, long block (30dB/Bark) */
54 #define PSY_3GPP_EN_SPREAD_LOW_L 3.0f
55 /* spreading factor for hi-to-low energy spreading, short block (20dB/Bark) */
56 #define PSY_3GPP_EN_SPREAD_LOW_S 2.0f
57 
58 #define PSY_3GPP_RPEMIN 0.01f
59 #define PSY_3GPP_RPELEV 2.0f
60 
61 #define PSY_3GPP_C1 3.0f /* log2(8) */
62 #define PSY_3GPP_C2 1.3219281f /* log2(2.5) */
63 #define PSY_3GPP_C3 0.55935729f /* 1 - C2 / C1 */
64 
65 #define PSY_SNR_1DB 7.9432821e-1f /* -1dB */
66 #define PSY_SNR_25DB 3.1622776e-3f /* -25dB */
67 
68 #define PSY_3GPP_SAVE_SLOPE_L -0.46666667f
69 #define PSY_3GPP_SAVE_SLOPE_S -0.36363637f
70 #define PSY_3GPP_SAVE_ADD_L -0.84285712f
71 #define PSY_3GPP_SAVE_ADD_S -0.75f
72 #define PSY_3GPP_SPEND_SLOPE_L 0.66666669f
73 #define PSY_3GPP_SPEND_SLOPE_S 0.81818181f
74 #define PSY_3GPP_SPEND_ADD_L -0.35f
75 #define PSY_3GPP_SPEND_ADD_S -0.26111111f
76 #define PSY_3GPP_CLIP_LO_L 0.2f
77 #define PSY_3GPP_CLIP_LO_S 0.2f
78 #define PSY_3GPP_CLIP_HI_L 0.95f
79 #define PSY_3GPP_CLIP_HI_S 0.75f
80 
81 #define PSY_3GPP_AH_THR_LONG 0.5f
82 #define PSY_3GPP_AH_THR_SHORT 0.63f
83 
84 #define PSY_PE_FORGET_SLOPE 511
85 
86 enum {
90 };
91 
92 #define PSY_3GPP_BITS_TO_PE(bits) ((bits) * 1.18f)
93 #define PSY_3GPP_PE_TO_BITS(bits) ((bits) / 1.18f)
94 
95 /* LAME psy model constants */
96 #define PSY_LAME_FIR_LEN 21 ///< LAME psy model FIR order
97 #define AAC_BLOCK_SIZE_LONG 1024 ///< long block size
98 #define AAC_BLOCK_SIZE_SHORT 128 ///< short block size
99 #define AAC_NUM_BLOCKS_SHORT 8 ///< number of blocks in a short sequence
100 #define PSY_LAME_NUM_SUBBLOCKS 3 ///< Number of sub-blocks in each short block
101 
102 /**
103  * @}
104  */
105 
106 /**
107  * information for single band used by 3GPP TS26.403-inspired psychoacoustic model
108  */
109 typedef struct AacPsyBand{
110  float energy; ///< band energy
111  float thr; ///< energy threshold
112  float thr_quiet; ///< threshold in quiet
113  float nz_lines; ///< number of non-zero spectral lines
114  float active_lines; ///< number of active spectral lines
115  float pe; ///< perceptual entropy
116  float pe_const; ///< constant part of the PE calculation
117  float norm_fac; ///< normalization factor for linearization
118  int avoid_holes; ///< hole avoidance flag
119 }AacPsyBand;
120 
121 /**
122  * single/pair channel context for psychoacoustic model
123  */
124 typedef struct AacPsyChannel{
125  AacPsyBand band[128]; ///< bands information
126  AacPsyBand prev_band[128]; ///< bands information from the previous frame
127 
128  float win_energy; ///< sliding average of channel energy
129  float iir_state[2]; ///< hi-pass IIR filter state
130  uint8_t next_grouping; ///< stored grouping scheme for the next frame (in case of 8 short window sequence)
131  enum WindowSequence next_window_seq; ///< window sequence to be used in the next frame
132  /* LAME psy model specific members */
133  float attack_threshold; ///< attack threshold for this channel
135  int prev_attack; ///< attack value for the last short block in the previous sequence
137 
138 /**
139  * psychoacoustic model frame type-dependent coefficients
140  */
141 typedef struct AacPsyCoeffs{
142  float ath; ///< absolute threshold of hearing per bands
143  float barks; ///< Bark value for each spectral band in long frame
144  float spread_low[2]; ///< spreading factor for low-to-high threshold spreading in long frame
145  float spread_hi [2]; ///< spreading factor for high-to-low threshold spreading in long frame
146  float min_snr; ///< minimal SNR
147 }AacPsyCoeffs;
148 
149 /**
150  * 3GPP TS26.403-inspired psychoacoustic model specific data
151  */
152 typedef struct AacPsyContext{
153  int chan_bitrate; ///< bitrate per channel
154  int frame_bits; ///< average bits per frame
155  int fill_level; ///< bit reservoir fill level
156  struct {
157  float min; ///< minimum allowed PE for bit factor calculation
158  float max; ///< maximum allowed PE for bit factor calculation
159  float previous; ///< allowed PE of the previous frame
160  float correction; ///< PE correction factor
161  } pe;
164  float global_quality; ///< normalized global quality taken from avctx
166 
167 /**
168  * LAME psy model preset struct
169  */
170 typedef struct PsyLamePreset {
171  int quality; ///< Quality to map the rest of the vaules to.
172  /* This is overloaded to be both kbps per channel in ABR mode, and
173  * requested quality in constant quality mode.
174  */
175  float st_lrm; ///< short threshold for L, R, and M channels
176 } PsyLamePreset;
177 
178 /**
179  * LAME psy model preset table for ABR
180  */
181 static const PsyLamePreset psy_abr_map[] = {
182 /* TODO: Tuning. These were taken from LAME. */
183 /* kbps/ch st_lrm */
184  { 8, 6.60},
185  { 16, 6.60},
186  { 24, 6.60},
187  { 32, 6.60},
188  { 40, 6.60},
189  { 48, 6.60},
190  { 56, 6.60},
191  { 64, 6.40},
192  { 80, 6.00},
193  { 96, 5.60},
194  {112, 5.20},
195  {128, 5.20},
196  {160, 5.20}
197 };
198 
199 /**
200 * LAME psy model preset table for constant quality
201 */
202 static const PsyLamePreset psy_vbr_map[] = {
203 /* vbr_q st_lrm */
204  { 0, 4.20},
205  { 1, 4.20},
206  { 2, 4.20},
207  { 3, 4.20},
208  { 4, 4.20},
209  { 5, 4.20},
210  { 6, 4.20},
211  { 7, 4.20},
212  { 8, 4.20},
213  { 9, 4.20},
214  {10, 4.20}
215 };
216 
217 /**
218  * LAME psy model FIR coefficient table
219  */
220 static const float psy_fir_coeffs[] = {
221  -8.65163e-18 * 2, -0.00851586 * 2, -6.74764e-18 * 2, 0.0209036 * 2,
222  -3.36639e-17 * 2, -0.0438162 * 2, -1.54175e-17 * 2, 0.0931738 * 2,
223  -5.52212e-17 * 2, -0.313819 * 2
224 };
225 
226 #if ARCH_MIPS
227 # include "mips/aacpsy_mips.h"
228 #endif /* ARCH_MIPS */
229 
230 /**
231  * Calculate the ABR attack threshold from the above LAME psymodel table.
232  */
233 static float lame_calc_attack_threshold(int bitrate)
234 {
235  /* Assume max bitrate to start with */
236  int lower_range = 12, upper_range = 12;
237  int lower_range_kbps = psy_abr_map[12].quality;
238  int upper_range_kbps = psy_abr_map[12].quality;
239  int i;
240 
241  /* Determine which bitrates the value specified falls between.
242  * If the loop ends without breaking our above assumption of 320kbps was correct.
243  */
244  for (i = 1; i < 13; i++) {
245  if (FFMAX(bitrate, psy_abr_map[i].quality) != bitrate) {
246  upper_range = i;
247  upper_range_kbps = psy_abr_map[i ].quality;
248  lower_range = i - 1;
249  lower_range_kbps = psy_abr_map[i - 1].quality;
250  break; /* Upper range found */
251  }
252  }
253 
254  /* Determine which range the value specified is closer to */
255  if ((upper_range_kbps - bitrate) > (bitrate - lower_range_kbps))
256  return psy_abr_map[lower_range].st_lrm;
257  return psy_abr_map[upper_range].st_lrm;
258 }
259 
260 /**
261  * LAME psy model specific initialization
262  */
264 {
265  int i, j;
266 
267  for (i = 0; i < avctx->channels; i++) {
268  AacPsyChannel *pch = &ctx->ch[i];
269 
270  if (avctx->flags & AV_CODEC_FLAG_QSCALE)
271  pch->attack_threshold = psy_vbr_map[avctx->global_quality / FF_QP2LAMBDA].st_lrm;
272  else
273  pch->attack_threshold = lame_calc_attack_threshold(avctx->bit_rate / avctx->channels / 1000);
274 
275  for (j = 0; j < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; j++)
276  pch->prev_energy_subshort[j] = 10.0f;
277  }
278 }
279 
280 /**
281  * Calculate Bark value for given line.
282  */
283 static av_cold float calc_bark(float f)
284 {
285  return 13.3f * atanf(0.00076f * f) + 3.5f * atanf((f / 7500.0f) * (f / 7500.0f));
286 }
287 
288 #define ATH_ADD 4
289 /**
290  * Calculate ATH value for given frequency.
291  * Borrowed from Lame.
292  */
293 static av_cold float ath(float f, float add)
294 {
295  f /= 1000.0f;
296  return 3.64 * pow(f, -0.8)
297  - 6.8 * exp(-0.6 * (f - 3.4) * (f - 3.4))
298  + 6.0 * exp(-0.15 * (f - 8.7) * (f - 8.7))
299  + (0.6 + 0.04 * add) * 0.001 * f * f * f * f;
300 }
301 
303  AacPsyContext *pctx;
304  float bark;
305  int i, j, g, start;
306  float prev, minscale, minath, minsnr, pe_min;
307  int chan_bitrate = ctx->avctx->bit_rate / ((ctx->avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : ctx->avctx->channels);
308 
309  const int bandwidth = ctx->cutoff ? ctx->cutoff : AAC_CUTOFF(ctx->avctx);
310  const float num_bark = calc_bark((float)bandwidth);
311 
312  ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext));
313  if (!ctx->model_priv_data)
314  return AVERROR(ENOMEM);
315  pctx = (AacPsyContext*) ctx->model_priv_data;
316  pctx->global_quality = (ctx->avctx->global_quality ? ctx->avctx->global_quality : 120) * 0.01f;
317 
318  if (ctx->avctx->flags & CODEC_FLAG_QSCALE) {
319  /* Use the target average bitrate to compute spread parameters */
320  chan_bitrate = (int)(chan_bitrate / 120.0 * (ctx->avctx->global_quality ? ctx->avctx->global_quality : 120));
321  }
322 
323  pctx->chan_bitrate = chan_bitrate;
324  pctx->frame_bits = FFMIN(2560, chan_bitrate * AAC_BLOCK_SIZE_LONG / ctx->avctx->sample_rate);
325  pctx->pe.min = 8.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
326  pctx->pe.max = 12.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f);
327  ctx->bitres.size = 6144 - pctx->frame_bits;
328  ctx->bitres.size -= ctx->bitres.size % 8;
329  pctx->fill_level = ctx->bitres.size;
330  minath = ath(3410 - 0.733 * ATH_ADD, ATH_ADD);
331  for (j = 0; j < 2; j++) {
332  AacPsyCoeffs *coeffs = pctx->psy_coef[j];
333  const uint8_t *band_sizes = ctx->bands[j];
334  float line_to_frequency = ctx->avctx->sample_rate / (j ? 256.f : 2048.0f);
335  float avg_chan_bits = chan_bitrate * (j ? 128.0f : 1024.0f) / ctx->avctx->sample_rate;
336  /* reference encoder uses 2.4% here instead of 60% like the spec says */
337  float bark_pe = 0.024f * PSY_3GPP_BITS_TO_PE(avg_chan_bits) / num_bark;
338  float en_spread_low = j ? PSY_3GPP_EN_SPREAD_LOW_S : PSY_3GPP_EN_SPREAD_LOW_L;
339  /* High energy spreading for long blocks <= 22kbps/channel and short blocks are the same. */
340  float en_spread_hi = (j || (chan_bitrate <= 22.0f)) ? PSY_3GPP_EN_SPREAD_HI_S : PSY_3GPP_EN_SPREAD_HI_L1;
341 
342  i = 0;
343  prev = 0.0;
344  for (g = 0; g < ctx->num_bands[j]; g++) {
345  i += band_sizes[g];
346  bark = calc_bark((i-1) * line_to_frequency);
347  coeffs[g].barks = (bark + prev) / 2.0;
348  prev = bark;
349  }
350  for (g = 0; g < ctx->num_bands[j] - 1; g++) {
351  AacPsyCoeffs *coeff = &coeffs[g];
352  float bark_width = coeffs[g+1].barks - coeffs->barks;
353  coeff->spread_low[0] = ff_exp10(-bark_width * PSY_3GPP_THR_SPREAD_LOW);
354  coeff->spread_hi [0] = ff_exp10(-bark_width * PSY_3GPP_THR_SPREAD_HI);
355  coeff->spread_low[1] = ff_exp10(-bark_width * en_spread_low);
356  coeff->spread_hi [1] = ff_exp10(-bark_width * en_spread_hi);
357  pe_min = bark_pe * bark_width;
358  minsnr = exp2(pe_min / band_sizes[g]) - 1.5f;
359  coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB);
360  }
361  start = 0;
362  for (g = 0; g < ctx->num_bands[j]; g++) {
363  minscale = ath(start * line_to_frequency, ATH_ADD);
364  for (i = 1; i < band_sizes[g]; i++)
365  minscale = FFMIN(minscale, ath((start + i) * line_to_frequency, ATH_ADD));
366  coeffs[g].ath = minscale - minath;
367  start += band_sizes[g];
368  }
369  }
370 
371  pctx->ch = av_mallocz_array(ctx->avctx->channels, sizeof(AacPsyChannel));
372  if (!pctx->ch) {
373  av_freep(&ctx->model_priv_data);
374  return AVERROR(ENOMEM);
375  }
376 
377  lame_window_init(pctx, ctx->avctx);
378 
379  return 0;
380 }
381 
382 /**
383  * IIR filter used in block switching decision
384  */
385 static float iir_filter(int in, float state[2])
386 {
387  float ret;
388 
389  ret = 0.7548f * (in - state[0]) + 0.5095f * state[1];
390  state[0] = in;
391  state[1] = ret;
392  return ret;
393 }
394 
395 /**
396  * window grouping information stored as bits (0 - new group, 1 - group continues)
397  */
398 static const uint8_t window_grouping[9] = {
399  0xB6, 0x6C, 0xD8, 0xB2, 0x66, 0xC6, 0x96, 0x36, 0x36
400 };
401 
402 /**
403  * Tell encoder which window types to use.
404  * @see 3GPP TS26.403 5.4.1 "Blockswitching"
405  */
407  const int16_t *audio,
408  const int16_t *la,
409  int channel, int prev_type)
410 {
411  int i, j;
412  int br = ((AacPsyContext*)ctx->model_priv_data)->chan_bitrate;
413  int attack_ratio = br <= 16000 ? 18 : 10;
415  AacPsyChannel *pch = &pctx->ch[channel];
416  uint8_t grouping = 0;
417  int next_type = pch->next_window_seq;
418  FFPsyWindowInfo wi = { { 0 } };
419 
420  if (la) {
421  float s[8], v;
422  int switch_to_eight = 0;
423  float sum = 0.0, sum2 = 0.0;
424  int attack_n = 0;
425  int stay_short = 0;
426  for (i = 0; i < 8; i++) {
427  for (j = 0; j < 128; j++) {
428  v = iir_filter(la[i*128+j], pch->iir_state);
429  sum += v*v;
430  }
431  s[i] = sum;
432  sum2 += sum;
433  }
434  for (i = 0; i < 8; i++) {
435  if (s[i] > pch->win_energy * attack_ratio) {
436  attack_n = i + 1;
437  switch_to_eight = 1;
438  break;
439  }
440  }
441  pch->win_energy = pch->win_energy*7/8 + sum2/64;
442 
443  wi.window_type[1] = prev_type;
444  switch (prev_type) {
445  case ONLY_LONG_SEQUENCE:
446  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
447  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
448  break;
449  case LONG_START_SEQUENCE:
450  wi.window_type[0] = EIGHT_SHORT_SEQUENCE;
451  grouping = pch->next_grouping;
452  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
453  break;
454  case LONG_STOP_SEQUENCE:
455  wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE;
456  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE;
457  break;
459  stay_short = next_type == EIGHT_SHORT_SEQUENCE || switch_to_eight;
460  wi.window_type[0] = stay_short ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
461  grouping = next_type == EIGHT_SHORT_SEQUENCE ? pch->next_grouping : 0;
462  next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE;
463  break;
464  }
465 
466  pch->next_grouping = window_grouping[attack_n];
467  pch->next_window_seq = next_type;
468  } else {
469  for (i = 0; i < 3; i++)
470  wi.window_type[i] = prev_type;
471  grouping = (prev_type == EIGHT_SHORT_SEQUENCE) ? window_grouping[0] : 0;
472  }
473 
474  wi.window_shape = 1;
475  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
476  wi.num_windows = 1;
477  wi.grouping[0] = 1;
478  } else {
479  int lastgrp = 0;
480  wi.num_windows = 8;
481  for (i = 0; i < 8; i++) {
482  if (!((grouping >> i) & 1))
483  lastgrp = i;
484  wi.grouping[lastgrp]++;
485  }
486  }
487 
488  return wi;
489 }
490 
491 /* 5.6.1.2 "Calculation of Bit Demand" */
492 static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size,
493  int short_window)
494 {
495  const float bitsave_slope = short_window ? PSY_3GPP_SAVE_SLOPE_S : PSY_3GPP_SAVE_SLOPE_L;
496  const float bitsave_add = short_window ? PSY_3GPP_SAVE_ADD_S : PSY_3GPP_SAVE_ADD_L;
497  const float bitspend_slope = short_window ? PSY_3GPP_SPEND_SLOPE_S : PSY_3GPP_SPEND_SLOPE_L;
498  const float bitspend_add = short_window ? PSY_3GPP_SPEND_ADD_S : PSY_3GPP_SPEND_ADD_L;
499  const float clip_low = short_window ? PSY_3GPP_CLIP_LO_S : PSY_3GPP_CLIP_LO_L;
500  const float clip_high = short_window ? PSY_3GPP_CLIP_HI_S : PSY_3GPP_CLIP_HI_L;
501  float clipped_pe, bit_save, bit_spend, bit_factor, fill_level, forgetful_min_pe;
502 
503  ctx->fill_level += ctx->frame_bits - bits;
504  ctx->fill_level = av_clip(ctx->fill_level, 0, size);
505  fill_level = av_clipf((float)ctx->fill_level / size, clip_low, clip_high);
506  clipped_pe = av_clipf(pe, ctx->pe.min, ctx->pe.max);
507  bit_save = (fill_level + bitsave_add) * bitsave_slope;
508  assert(bit_save <= 0.3f && bit_save >= -0.05000001f);
509  bit_spend = (fill_level + bitspend_add) * bitspend_slope;
510  assert(bit_spend <= 0.5f && bit_spend >= -0.1f);
511  /* The bit factor graph in the spec is obviously incorrect.
512  * bit_spend + ((bit_spend - bit_spend))...
513  * The reference encoder subtracts everything from 1, but also seems incorrect.
514  * 1 - bit_save + ((bit_spend + bit_save))...
515  * Hopefully below is correct.
516  */
517  bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min);
518  /* NOTE: The reference encoder attempts to center pe max/min around the current pe.
519  * Here we do that by slowly forgetting pe.min when pe stays in a range that makes
520  * it unlikely (ie: above the mean)
521  */
522  ctx->pe.max = FFMAX(pe, ctx->pe.max);
523  forgetful_min_pe = ((ctx->pe.min * PSY_PE_FORGET_SLOPE)
524  + FFMAX(ctx->pe.min, pe * (pe / ctx->pe.max))) / (PSY_PE_FORGET_SLOPE + 1);
525  ctx->pe.min = FFMIN(pe, forgetful_min_pe);
526 
527  /* NOTE: allocate a minimum of 1/8th average frame bits, to avoid
528  * reservoir starvation from producing zero-bit frames
529  */
530  return FFMIN(
531  ctx->frame_bits * bit_factor,
532  FFMAX(ctx->frame_bits + size - bits, ctx->frame_bits / 8));
533 }
534 
536 {
537  float pe, a;
538 
539  band->pe = 0.0f;
540  band->pe_const = 0.0f;
541  band->active_lines = 0.0f;
542  if (band->energy > band->thr) {
543  a = log2f(band->energy);
544  pe = a - log2f(band->thr);
545  band->active_lines = band->nz_lines;
546  if (pe < PSY_3GPP_C1) {
547  pe = pe * PSY_3GPP_C3 + PSY_3GPP_C2;
548  a = a * PSY_3GPP_C3 + PSY_3GPP_C2;
549  band->active_lines *= PSY_3GPP_C3;
550  }
551  band->pe = pe * band->nz_lines;
552  band->pe_const = a * band->nz_lines;
553  }
554 
555  return band->pe;
556 }
557 
558 static float calc_reduction_3gpp(float a, float desired_pe, float pe,
559  float active_lines)
560 {
561  float thr_avg, reduction;
562 
563  if(active_lines == 0.0)
564  return 0;
565 
566  thr_avg = exp2f((a - pe) / (4.0f * active_lines));
567  reduction = exp2f((a - desired_pe) / (4.0f * active_lines)) - thr_avg;
568 
569  return FFMAX(reduction, 0.0f);
570 }
571 
572 static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr,
573  float reduction)
574 {
575  float thr = band->thr;
576 
577  if (band->energy > thr) {
578  thr = sqrtf(thr);
579  thr = sqrtf(thr) + reduction;
580  thr *= thr;
581  thr *= thr;
582 
583  /* This deviates from the 3GPP spec to match the reference encoder.
584  * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands
585  * that have hole avoidance on (active or inactive). It always reduces the
586  * threshold of bands with hole avoidance off.
587  */
588  if (thr > band->energy * min_snr && band->avoid_holes != PSY_3GPP_AH_NONE) {
589  thr = FFMAX(band->thr, band->energy * min_snr);
591  }
592  }
593 
594  return thr;
595 }
596 
597 #ifndef calc_thr_3gpp
598 static void calc_thr_3gpp(const FFPsyWindowInfo *wi, const int num_bands, AacPsyChannel *pch,
599  const uint8_t *band_sizes, const float *coefs, const int cutoff)
600 {
601  int i, w, g;
602  int start = 0, wstart = 0;
603  for (w = 0; w < wi->num_windows*16; w += 16) {
604  wstart = 0;
605  for (g = 0; g < num_bands; g++) {
606  AacPsyBand *band = &pch->band[w+g];
607 
608  float form_factor = 0.0f;
609  float Temp;
610  band->energy = 0.0f;
611  if (wstart < cutoff) {
612  for (i = 0; i < band_sizes[g]; i++) {
613  band->energy += coefs[start+i] * coefs[start+i];
614  form_factor += sqrtf(fabs(coefs[start+i]));
615  }
616  }
617  Temp = band->energy > 0 ? sqrtf((float)band_sizes[g] / band->energy) : 0;
618  band->thr = band->energy * 0.001258925f;
619  band->nz_lines = form_factor * sqrtf(Temp);
620 
621  start += band_sizes[g];
622  wstart += band_sizes[g];
623  }
624  }
625 }
626 #endif /* calc_thr_3gpp */
627 
628 #ifndef psy_hp_filter
629 static void psy_hp_filter(const float *firbuf, float *hpfsmpl, const float *psy_fir_coeffs)
630 {
631  int i, j;
632  for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) {
633  float sum1, sum2;
634  sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2];
635  sum2 = 0.0;
636  for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) {
637  sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]);
638  sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]);
639  }
640  /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768.
641  * Tuning this for normalized floats would be difficult. */
642  hpfsmpl[i] = (sum1 + sum2) * 32768.0f;
643  }
644 }
645 #endif /* psy_hp_filter */
646 
647 /**
648  * Calculate band thresholds as suggested in 3GPP TS26.403
649  */
650 static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel,
651  const float *coefs, const FFPsyWindowInfo *wi)
652 {
654  AacPsyChannel *pch = &pctx->ch[channel];
655  int i, w, g;
656  float desired_bits, desired_pe, delta_pe, reduction= NAN, spread_en[128] = {0};
657  float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f;
658  float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f);
659  const int num_bands = ctx->num_bands[wi->num_windows == 8];
660  const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8];
661  AacPsyCoeffs *coeffs = pctx->psy_coef[wi->num_windows == 8];
662  const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG;
663  const int bandwidth = ctx->cutoff ? ctx->cutoff : AAC_CUTOFF(ctx->avctx);
664  const int cutoff = bandwidth * 2048 / wi->num_windows / ctx->avctx->sample_rate;
665 
666  //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation"
667  calc_thr_3gpp(wi, num_bands, pch, band_sizes, coefs, cutoff);
668 
669  //modify thresholds and energies - spread, threshold in quiet, pre-echo control
670  for (w = 0; w < wi->num_windows*16; w += 16) {
671  AacPsyBand *bands = &pch->band[w];
672 
673  /* 5.4.2.3 "Spreading" & 5.4.3 "Spread Energy Calculation" */
674  spread_en[0] = bands[0].energy;
675  for (g = 1; g < num_bands; g++) {
676  bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]);
677  spread_en[w+g] = FFMAX(bands[g].energy, spread_en[w+g-1] * coeffs[g].spread_hi[1]);
678  }
679  for (g = num_bands - 2; g >= 0; g--) {
680  bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]);
681  spread_en[w+g] = FFMAX(spread_en[w+g], spread_en[w+g+1] * coeffs[g].spread_low[1]);
682  }
683  //5.4.2.4 "Threshold in quiet"
684  for (g = 0; g < num_bands; g++) {
685  AacPsyBand *band = &bands[g];
686 
687  band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath);
688  //5.4.2.5 "Pre-echo control"
689  if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w)))
690  band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr,
691  PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet));
692 
693  /* 5.6.1.3.1 "Preparatory steps of the perceptual entropy calculation" */
694  pe += calc_pe_3gpp(band);
695  a += band->pe_const;
696  active_lines += band->active_lines;
697 
698  /* 5.6.1.3.3 "Selection of the bands for avoidance of holes" */
699  if (spread_en[w+g] * avoid_hole_thr > band->energy || coeffs[g].min_snr > 1.0f)
701  else
703  }
704  }
705 
706  /* 5.6.1.3.2 "Calculation of the desired perceptual entropy" */
707  ctx->ch[channel].entropy = pe;
708  if (ctx->avctx->flags & CODEC_FLAG_QSCALE) {
709  /* (2.5 * 120) achieves almost transparent rate, and we want to give
710  * ample room downwards, so we make that equivalent to QSCALE=2.4
711  */
712  desired_pe = pe * (ctx->avctx->global_quality ? ctx->avctx->global_quality : 120) / (2 * 2.5f * 120.0f);
713  desired_bits = FFMIN(2560, PSY_3GPP_PE_TO_BITS(desired_pe));
714  desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits); // reflect clipping
715 
716  /* PE slope smoothing */
717  if (ctx->bitres.bits > 0) {
718  desired_bits = FFMIN(2560, PSY_3GPP_PE_TO_BITS(desired_pe));
719  desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits); // reflect clipping
720  }
721 
722  pctx->pe.max = FFMAX(pe, pctx->pe.max);
723  pctx->pe.min = FFMIN(pe, pctx->pe.min);
724  } else {
725  desired_bits = calc_bit_demand(pctx, pe, ctx->bitres.bits, ctx->bitres.size, wi->num_windows == 8);
726  desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits);
727 
728  /* NOTE: PE correction is kept simple. During initial testing it had very
729  * little effect on the final bitrate. Probably a good idea to come
730  * back and do more testing later.
731  */
732  if (ctx->bitres.bits > 0)
733  desired_pe *= av_clipf(pctx->pe.previous / PSY_3GPP_BITS_TO_PE(ctx->bitres.bits),
734  0.85f, 1.15f);
735  }
736  pctx->pe.previous = PSY_3GPP_BITS_TO_PE(desired_bits);
737  ctx->bitres.alloc = desired_bits;
738 
739  if (desired_pe < pe) {
740  /* 5.6.1.3.4 "First Estimation of the reduction value" */
741  for (w = 0; w < wi->num_windows*16; w += 16) {
742  reduction = calc_reduction_3gpp(a, desired_pe, pe, active_lines);
743  pe = 0.0f;
744  a = 0.0f;
745  active_lines = 0.0f;
746  for (g = 0; g < num_bands; g++) {
747  AacPsyBand *band = &pch->band[w+g];
748 
749  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
750  /* recalculate PE */
751  pe += calc_pe_3gpp(band);
752  a += band->pe_const;
753  active_lines += band->active_lines;
754  }
755  }
756 
757  /* 5.6.1.3.5 "Second Estimation of the reduction value" */
758  for (i = 0; i < 2; i++) {
759  float pe_no_ah = 0.0f, desired_pe_no_ah;
760  active_lines = a = 0.0f;
761  for (w = 0; w < wi->num_windows*16; w += 16) {
762  for (g = 0; g < num_bands; g++) {
763  AacPsyBand *band = &pch->band[w+g];
764 
765  if (band->avoid_holes != PSY_3GPP_AH_ACTIVE) {
766  pe_no_ah += band->pe;
767  a += band->pe_const;
768  active_lines += band->active_lines;
769  }
770  }
771  }
772  desired_pe_no_ah = FFMAX(desired_pe - (pe - pe_no_ah), 0.0f);
773  if (active_lines > 0.0f)
774  reduction = calc_reduction_3gpp(a, desired_pe_no_ah, pe_no_ah, active_lines);
775 
776  pe = 0.0f;
777  for (w = 0; w < wi->num_windows*16; w += 16) {
778  for (g = 0; g < num_bands; g++) {
779  AacPsyBand *band = &pch->band[w+g];
780 
781  if (active_lines > 0.0f)
782  band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction);
783  pe += calc_pe_3gpp(band);
784  if (band->thr > 0.0f)
785  band->norm_fac = band->active_lines / band->thr;
786  else
787  band->norm_fac = 0.0f;
788  norm_fac += band->norm_fac;
789  }
790  }
791  delta_pe = desired_pe - pe;
792  if (fabs(delta_pe) > 0.05f * desired_pe)
793  break;
794  }
795 
796  if (pe < 1.15f * desired_pe) {
797  /* 6.6.1.3.6 "Final threshold modification by linearization" */
798  norm_fac = 1.0f / norm_fac;
799  for (w = 0; w < wi->num_windows*16; w += 16) {
800  for (g = 0; g < num_bands; g++) {
801  AacPsyBand *band = &pch->band[w+g];
802 
803  if (band->active_lines > 0.5f) {
804  float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe;
805  float thr = band->thr;
806 
807  thr *= exp2f(delta_sfb_pe / band->active_lines);
808  if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE)
809  thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy);
810  band->thr = thr;
811  }
812  }
813  }
814  } else {
815  /* 5.6.1.3.7 "Further perceptual entropy reduction" */
816  g = num_bands;
817  while (pe > desired_pe && g--) {
818  for (w = 0; w < wi->num_windows*16; w+= 16) {
819  AacPsyBand *band = &pch->band[w+g];
820  if (band->avoid_holes != PSY_3GPP_AH_NONE && coeffs[g].min_snr < PSY_SNR_1DB) {
821  coeffs[g].min_snr = PSY_SNR_1DB;
822  band->thr = band->energy * PSY_SNR_1DB;
823  pe += band->active_lines * 1.5f - band->pe;
824  }
825  }
826  }
827  /* TODO: allow more holes (unused without mid/side) */
828  }
829  }
830 
831  for (w = 0; w < wi->num_windows*16; w += 16) {
832  for (g = 0; g < num_bands; g++) {
833  AacPsyBand *band = &pch->band[w+g];
834  FFPsyBand *psy_band = &ctx->ch[channel].psy_bands[w+g];
835 
836  psy_band->threshold = band->thr;
837  psy_band->energy = band->energy;
838  psy_band->spread = band->active_lines * 2.0f / band_sizes[g];
839  psy_band->bits = PSY_3GPP_PE_TO_BITS(band->pe);
840  }
841  }
842 
843  memcpy(pch->prev_band, pch->band, sizeof(pch->band));
844 }
845 
846 static void psy_3gpp_analyze(FFPsyContext *ctx, int channel,
847  const float **coeffs, const FFPsyWindowInfo *wi)
848 {
849  int ch;
850  FFPsyChannelGroup *group = ff_psy_find_group(ctx, channel);
851 
852  for (ch = 0; ch < group->num_ch; ch++)
853  psy_3gpp_analyze_channel(ctx, channel + ch, coeffs[ch], &wi[ch]);
854 }
855 
857 {
859  av_freep(&pctx->ch);
860  av_freep(&apc->model_priv_data);
861 }
862 
863 static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
864 {
865  int blocktype = ONLY_LONG_SEQUENCE;
866  if (uselongblock) {
868  blocktype = LONG_STOP_SEQUENCE;
869  } else {
870  blocktype = EIGHT_SHORT_SEQUENCE;
875  }
876 
877  wi->window_type[0] = ctx->next_window_seq;
878  ctx->next_window_seq = blocktype;
879 }
880 
881 static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio,
882  const float *la, int channel, int prev_type)
883 {
885  AacPsyChannel *pch = &pctx->ch[channel];
886  int grouping = 0;
887  int uselongblock = 1;
888  int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
889  float clippings[AAC_NUM_BLOCKS_SHORT];
890  int i;
891  FFPsyWindowInfo wi = { { 0 } };
892 
893  if (la) {
894  float hpfsmpl[AAC_BLOCK_SIZE_LONG];
895  float const *pf = hpfsmpl;
896  float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
897  float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
898  float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
899  const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN);
900  int att_sum = 0;
901 
902  /* LAME comment: apply high pass filter of fs/4 */
903  psy_hp_filter(firbuf, hpfsmpl, psy_fir_coeffs);
904 
905  /* Calculate the energies of each sub-shortblock */
906  for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) {
907  energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)];
908  assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0);
909  attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)];
910  energy_short[0] += energy_subshort[i];
911  }
912 
913  for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) {
914  float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS);
915  float p = 1.0f;
916  for (; pf < pfe; pf++)
917  p = FFMAX(p, fabsf(*pf));
918  pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p;
919  energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p;
920  /* NOTE: The indexes below are [i + 3 - 2] in the LAME source.
921  * Obviously the 3 and 2 have some significance, or this would be just [i + 1]
922  * (which is what we use here). What the 3 stands for is ambiguous, as it is both
923  * number of short blocks, and the number of sub-short blocks.
924  * It seems that LAME is comparing each sub-block to sub-block + 1 in the
925  * previous block.
926  */
927  if (p > energy_subshort[i + 1])
928  p = p / energy_subshort[i + 1];
929  else if (energy_subshort[i + 1] > p * 10.0f)
930  p = energy_subshort[i + 1] / (p * 10.0f);
931  else
932  p = 0.0;
933  attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p;
934  }
935 
936  /* compare energy between sub-short blocks */
937  for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++)
938  if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS])
939  if (attack_intensity[i] > pch->attack_threshold)
940  attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1;
941 
942  /* should have energy change between short blocks, in order to avoid periodic signals */
943  /* Good samples to show the effect are Trumpet test songs */
944  /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */
945  /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */
946  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) {
947  float const u = energy_short[i - 1];
948  float const v = energy_short[i];
949  float const m = FFMAX(u, v);
950  if (m < 40000) { /* (2) */
951  if (u < 1.7f * v && v < 1.7f * u) { /* (1) */
952  if (i == 1 && attacks[0] < attacks[i])
953  attacks[0] = 0;
954  attacks[i] = 0;
955  }
956  }
957  att_sum += attacks[i];
958  }
959 
960  if (attacks[0] <= pch->prev_attack)
961  attacks[0] = 0;
962 
963  att_sum += attacks[0];
964  /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */
965  if (pch->prev_attack == 3 || att_sum) {
966  uselongblock = 0;
967 
968  for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++)
969  if (attacks[i] && attacks[i-1])
970  attacks[i] = 0;
971  }
972  } else {
973  /* We have no lookahead info, so just use same type as the previous sequence. */
974  uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE);
975  }
976 
977  lame_apply_block_type(pch, &wi, uselongblock);
978 
979  /* Calculate input sample maximums and evaluate clipping risk */
980  if (audio) {
981  for (i = 0; i < AAC_NUM_BLOCKS_SHORT; i++) {
982  const float *wbuf = audio + i * AAC_BLOCK_SIZE_SHORT;
983  float max = 0;
984  int j;
985  for (j = 0; j < AAC_BLOCK_SIZE_SHORT; j++)
986  max = FFMAX(max, fabsf(wbuf[j]));
987  clippings[i] = max;
988  }
989  } else {
990  for (i = 0; i < 8; i++)
991  clippings[i] = 0;
992  }
993 
994  wi.window_type[1] = prev_type;
995  if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
996  float clipping = 0.0f;
997 
998  wi.num_windows = 1;
999  wi.grouping[0] = 1;
1000  if (wi.window_type[0] == LONG_START_SEQUENCE)
1001  wi.window_shape = 0;
1002  else
1003  wi.window_shape = 1;
1004 
1005  for (i = 0; i < 8; i++)
1006  clipping = FFMAX(clipping, clippings[i]);
1007  wi.clipping[0] = clipping;
1008  } else {
1009  int lastgrp = 0;
1010 
1011  wi.num_windows = 8;
1012  wi.window_shape = 0;
1013  for (i = 0; i < 8; i++) {
1014  if (!((pch->next_grouping >> i) & 1))
1015  lastgrp = i;
1016  wi.grouping[lastgrp]++;
1017  }
1018 
1019  for (i = 0; i < 8; i += wi.grouping[i]) {
1020  int w;
1021  float clipping = 0.0f;
1022  for (w = 0; w < wi.grouping[i] && !clipping; w++)
1023  clipping = FFMAX(clipping, clippings[i+w]);
1024  wi.clipping[i] = clipping;
1025  }
1026  }
1027 
1028  /* Determine grouping, based on the location of the first attack, and save for
1029  * the next frame.
1030  * FIXME: Move this to analysis.
1031  * TODO: Tune groupings depending on attack location
1032  * TODO: Handle more than one attack in a group
1033  */
1034  for (i = 0; i < 9; i++) {
1035  if (attacks[i]) {
1036  grouping = i;
1037  break;
1038  }
1039  }
1040  pch->next_grouping = window_grouping[grouping];
1041 
1042  pch->prev_attack = attacks[8];
1043 
1044  return wi;
1045 }
1046 
1048 {
1049  .name = "3GPP TS 26.403-inspired model",
1050  .init = psy_3gpp_init,
1051  .window = psy_lame_window,
1052  .analyze = psy_3gpp_analyze,
1053  .end = psy_3gpp_end,
1054 };
int quality
Quality to map the rest of the vaules to.
Definition: aacpsy.c:171
float global_quality
normalized global quality taken from avctx
Definition: aacpsy.c:164
const char * s
Definition: avisynth_c.h:631
static const uint8_t window_grouping[9]
window grouping information stored as bits (0 - new group, 1 - group continues)
Definition: aacpsy.c:398
int grouping[8]
window grouping (for e.g. AAC)
Definition: psymodel.h:81
#define AAC_BLOCK_SIZE_SHORT
short block size
Definition: aacpsy.c:98
static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size, int short_window)
Definition: aacpsy.c:492
uint8_t ** bands
scalefactor band sizes for possible frame sizes
Definition: psymodel.h:98
AVFormatContext * ctx
Definition: movenc-test.c:48
#define PSY_3GPP_AH_THR_SHORT
Definition: aacpsy.c:82
float iir_state[2]
hi-pass IIR filter state
Definition: aacpsy.c:129
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1597
const char * g
Definition: vf_curves.c:108
static const PsyLamePreset psy_vbr_map[]
LAME psy model preset table for constant quality.
Definition: aacpsy.c:202
psychoacoustic information for an arbitrary group of channels
Definition: psymodel.h:68
static float calc_reduction_3gpp(float a, float desired_pe, float pe, float active_lines)
Definition: aacpsy.c:558
float ath
absolute threshold of hearing per bands
Definition: aacpsy.c:142
#define PSY_3GPP_EN_SPREAD_HI_L1
Definition: aacpsy.c:48
static av_cold float ath(float f, float add)
Calculate ATH value for given frequency.
Definition: aacpsy.c:293
float prev_energy_subshort[AAC_NUM_BLOCKS_SHORT *PSY_LAME_NUM_SUBBLOCKS]
Definition: aacpsy.c:134
enum WindowSequence next_window_seq
window sequence to be used in the next frame
Definition: aacpsy.c:131
#define PSY_SNR_25DB
Definition: aacpsy.c:66
#define AAC_BLOCK_SIZE_LONG
long block size
Definition: aacpsy.c:97
int * num_bands
number of scalefactor bands for possible frame sizes
Definition: psymodel.h:99
Macro definitions for various function/variable attributes.
LAME psy model preset struct.
Definition: aacpsy.c:170
float thr
energy threshold
Definition: aacpsy.c:111
float correction
PE correction factor.
Definition: aacpsy.c:160
static av_cold void psy_3gpp_end(FFPsyContext *apc)
Definition: aacpsy.c:856
float attack_threshold
attack threshold for this channel
Definition: aacpsy.c:133
#define PSY_3GPP_EN_SPREAD_LOW_L
Definition: aacpsy.c:54
float nz_lines
number of non-zero spectral lines
Definition: aacpsy.c:113
uint8_t bits
Definition: crc.c:295
uint8_t
psychoacoustic model frame type-dependent coefficients
Definition: aacpsy.c:141
#define av_cold
Definition: attributes.h:82
int size
size of the bitresevoir in bits
Definition: psymodel.h:103
static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr, float reduction)
Definition: aacpsy.c:572
#define PSY_3GPP_C2
Definition: aacpsy.c:62
#define PSY_LAME_FIR_LEN
LAME psy model FIR order.
Definition: aacpsy.c:96
#define PSY_3GPP_CLIP_LO_L
Definition: aacpsy.c:76
#define PSY_3GPP_SPEND_SLOPE_S
Definition: aacpsy.c:73
#define PSY_3GPP_THR_SPREAD_LOW
Definition: aacpsy.c:46
context used by psychoacoustic model
Definition: psymodel.h:89
#define atanf(x)
Definition: libm.h:40
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1425
#define AAC_CUTOFF(s)
Definition: psymodel.h:41
single band psychoacoustic information
Definition: psymodel.h:50
ptrdiff_t size
Definition: opengl_enc.c:101
static float lame_calc_attack_threshold(int bitrate)
Calculate the ABR attack threshold from the above LAME psymodel table.
Definition: aacpsy.c:233
uint8_t next_grouping
stored grouping scheme for the next frame (in case of 8 short window sequence)
Definition: aacpsy.c:130
unsigned m
Definition: audioconvert.c:187
#define PSY_3GPP_SAVE_ADD_L
Definition: aacpsy.c:70
struct FFPsyContext::@81 bitres
static av_cold float calc_bark(float f)
Calculate Bark value for given line.
Definition: aacpsy.c:283
#define AVERROR(e)
Definition: error.h:43
#define PSY_3GPP_SPEND_ADD_S
Definition: aacpsy.c:75
#define PSY_SNR_1DB
Definition: aacpsy.c:65
AacPsyBand prev_band[128]
bands information from the previous frame
Definition: aacpsy.c:126
3GPP TS26.403-inspired psychoacoustic model specific data
Definition: aacpsy.c:152
single/pair channel context for psychoacoustic model
Definition: aacpsy.c:124
static const float psy_fir_coeffs[]
LAME psy model FIR coefficient table.
Definition: aacpsy.c:220
int bits
Definition: psymodel.h:51
float barks
Bark value for each spectral band in long frame.
Definition: aacpsy.c:143
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1627
#define CODEC_FLAG_QSCALE
Definition: avcodec.h:952
float pe_const
constant part of the PE calculation
Definition: aacpsy.c:116
int num_windows
number of windows in a frame
Definition: psymodel.h:80
static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio, const float *la, int channel, int prev_type)
Definition: aacpsy.c:881
#define PSY_3GPP_SPEND_SLOPE_L
Definition: aacpsy.c:72
#define PSY_3GPP_THR_SPREAD_HI
constants for 3GPP AAC psychoacoustic model
Definition: aacpsy.c:45
float energy
Definition: psymodel.h:52
WindowSequence
Definition: aac.h:75
#define FFMAX(a, b)
Definition: common.h:94
codec-specific psychoacoustic model implementation
Definition: psymodel.h:114
#define PSY_3GPP_RPELEV
Definition: aacpsy.c:59
int8_t exp
Definition: eval.c:63
struct AacPsyContext::@31 pe
float thr_quiet
threshold in quiet
Definition: aacpsy.c:112
common internal API header
static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, const float **coeffs, const FFPsyWindowInfo *wi)
Definition: aacpsy.c:846
#define AV_CODEC_FLAG_QSCALE
Use fixed qscale.
Definition: avcodec.h:734
#define FFMIN(a, b)
Definition: common.h:96
int prev_attack
attack value for the last short block in the previous sequence
Definition: aacpsy.c:135
#define PSY_3GPP_SAVE_SLOPE_S
Definition: aacpsy.c:69
#define PSY_3GPP_C3
Definition: aacpsy.c:63
uint8_t num_ch
number of channels in this group
Definition: psymodel.h:70
int frame_bits
average bits per frame
Definition: aacpsy.c:154
int fill_level
bit reservoir fill level
Definition: aacpsy.c:155
static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
Definition: aacpsy.c:863
#define PSY_3GPP_SAVE_SLOPE_L
Definition: aacpsy.c:68
Reference: libavcodec/aacpsy.c.
#define PSY_LAME_NUM_SUBBLOCKS
Number of sub-blocks in each short block.
Definition: aacpsy.c:100
static struct @204 state
#define ATH_ADD
Definition: aacpsy.c:288
float energy
band energy
Definition: aacpsy.c:110
const FFPsyModel ff_aac_psy_model
Definition: aacpsy.c:1047
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:650
float st_lrm
short threshold for L, R, and M channels
Definition: aacpsy.c:175
#define PSY_3GPP_EN_SPREAD_LOW_S
Definition: aacpsy.c:56
#define exp2f(x)
Definition: libm.h:293
Libavcodec external API header.
int sample_rate
samples per second
Definition: avcodec.h:2287
FFPsyChannelGroup * ff_psy_find_group(FFPsyContext *ctx, int channel)
Determine what group a channel belongs to.
Definition: psymodel.c:73
main external API structure.
Definition: avcodec.h:1532
float win_energy
sliding average of channel energy
Definition: aacpsy.c:128
void * model_priv_data
psychoacoustic model implementation private data
Definition: psymodel.h:108
float active_lines
number of active spectral lines
Definition: aacpsy.c:114
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_log(ac->avr, AV_LOG_TRACE,"%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
static float iir_filter(int in, float state[2])
IIR filter used in block switching decision.
Definition: aacpsy.c:385
int avoid_holes
hole avoidance flag
Definition: aacpsy.c:118
Replacements for frequently missing libm functions.
AacPsyBand band[128]
bands information
Definition: aacpsy.c:125
#define PSY_3GPP_CLIP_HI_S
Definition: aacpsy.c:79
#define PSY_3GPP_RPEMIN
Definition: aacpsy.c:58
static const PsyLamePreset psy_abr_map[]
LAME psy model preset table for ABR.
Definition: aacpsy.c:181
int window_shape
window shape (sine/KBD/whatever)
Definition: psymodel.h:79
#define PSY_PE_FORGET_SLOPE
Definition: aacpsy.c:84
#define PSY_3GPP_PE_TO_BITS(bits)
Definition: aacpsy.c:93
int cutoff
lowpass frequency cutoff for analysis
Definition: psymodel.h:96
float min_snr
minimal SNR
Definition: aacpsy.c:146
float max
maximum allowed PE for bit factor calculation
Definition: aacpsy.c:158
static void calc_thr_3gpp(const FFPsyWindowInfo *wi, const int num_bands, AacPsyChannel *pch, const uint8_t *band_sizes, const float *coefs, const int cutoff)
Definition: aacpsy.c:598
float previous
allowed PE of the previous frame
Definition: aacpsy.c:159
AacPsyCoeffs psy_coef[2][64]
Definition: aacpsy.c:162
float min
minimum allowed PE for bit factor calculation
Definition: aacpsy.c:157
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1613
static av_cold int psy_3gpp_init(FFPsyContext *ctx)
Definition: aacpsy.c:302
static void psy_hp_filter(const float *firbuf, float *hpfsmpl, const float *psy_fir_coeffs)
Definition: aacpsy.c:629
float spread_hi[2]
spreading factor for high-to-low threshold spreading in long frame
Definition: aacpsy.c:145
const char * name
Definition: psymodel.h:115
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:406
static float calc_pe_3gpp(AacPsyBand *band)
Definition: aacpsy.c:535
#define exp2(x)
Definition: libm.h:288
windowing related information
Definition: psymodel.h:77
#define log2f(x)
Definition: libm.h:409
#define PSY_3GPP_BITS_TO_PE(bits)
Definition: aacpsy.c:92
#define PSY_3GPP_C1
Definition: aacpsy.c:61
float norm_fac
normalization factor for linearization
Definition: aacpsy.c:117
int chan_bitrate
bitrate per channel
Definition: aacpsy.c:153
#define PSY_3GPP_CLIP_LO_S
Definition: aacpsy.c:77
#define PSY_3GPP_AH_THR_LONG
Definition: aacpsy.c:81
#define NAN
Definition: math.h:28
static const int16_t coeffs[]
int channels
number of audio channels
Definition: avcodec.h:2288
float pe
perceptual entropy
Definition: aacpsy.c:115
#define PSY_3GPP_EN_SPREAD_HI_S
Definition: aacpsy.c:52
static const double coeff[2][5]
Definition: vf_owdenoise.c:71
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:219
AacPsyChannel * ch
Definition: aacpsy.c:163
static void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.h:229
#define PSY_3GPP_SAVE_ADD_S
Definition: aacpsy.c:71
#define av_freep(p)
static av_always_inline double ff_exp10(double x)
Compute 10^x for floating point values.
Definition: internal.h:306
void INT64 start
Definition: avisynth_c.h:553
information for single band used by 3GPP TS26.403-inspired psychoacoustic model
Definition: aacpsy.c:109
AVCodecContext * avctx
encoder context
Definition: psymodel.h:90
float threshold
Definition: psymodel.h:53
AAC data declarations.
float spread_low[2]
spreading factor for low-to-high threshold spreading in long frame
Definition: aacpsy.c:144
#define PSY_3GPP_CLIP_HI_L
Definition: aacpsy.c:78
float spread
Definition: psymodel.h:54
int window_type[3]
window type (short/long/transitional, etc.) - current, previous and next
Definition: psymodel.h:78
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:252
#define AAC_NUM_BLOCKS_SHORT
number of blocks in a short sequence
Definition: aacpsy.c:99
#define av_unused
Definition: attributes.h:126
float clipping[8]
maximum absolute normalized intensity in the given window for clip avoidance
Definition: psymodel.h:82
#define PSY_3GPP_SPEND_ADD_L
Definition: aacpsy.c:74
static av_cold void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx)
LAME psy model specific initialization.
Definition: aacpsy.c:263