1/* 2 * AAC encoder twoloop coder 3 * Copyright (C) 2008-2009 Konstantin Shishkov 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * AAC encoder twoloop coder 25 * @author Konstantin Shishkov, Claudio Freire 26 */ 27 28/** 29 * This file contains a template for the twoloop coder function. 30 * It needs to be provided, externally, as an already included declaration, 31 * the following functions from aacenc_quantization/util.h. They're not included 32 * explicitly here to make it possible to provide alternative implementations: 33 * - quantize_band_cost 34 * - abs_pow34_v 35 * - find_max_val 36 * - find_min_book 37 * - find_form_factor 38 */ 39 40#ifndef AVCODEC_AACCODER_TWOLOOP_H 41#define AVCODEC_AACCODER_TWOLOOP_H 42 43#include <float.h> 44#include "libavutil/mathematics.h" 45#include "mathops.h" 46#include "avcodec.h" 47#include "put_bits.h" 48#include "aac.h" 49#include "aacenc.h" 50#include "aactab.h" 51#include "aacenctab.h" 52 53/** Frequency in Hz for lower limit of noise substitution **/ 54#define NOISE_LOW_LIMIT 4000 55 56#define sclip(x) av_clip(x,60,218) 57 58/* Reflects the cost to change codebooks */ 59static inline int ff_pns_bits(SingleChannelElement *sce, int w, int g) 60{ 61 return (!g || !sce->zeroes[w*16+g-1] || !sce->can_pns[w*16+g-1]) ? 9 : 5; 62} 63 64/** 65 * two-loop quantizers search taken from ISO 13818-7 Appendix C 66 */ 67static void search_for_quantizers_twoloop(AVCodecContext *avctx, 68 AACEncContext *s, 69 SingleChannelElement *sce, 70 const float lambda) 71{ 72 int start = 0, i, w, w2, g, recomprd; 73 int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate 74 / ((avctx->flags & AV_CODEC_FLAG_QSCALE) ? 2.0f : avctx->ch_layout.nb_channels) 75 * (lambda / 120.f); 76 int refbits = destbits; 77 int toomanybits, toofewbits; 78 char nzs[128]; 79 uint8_t nextband[128]; 80 int maxsf[128], minsf[128]; 81 float dists[128] = { 0 }, qenergies[128] = { 0 }, uplims[128], euplims[128], energies[128]; 82 float maxvals[128], spread_thr_r[128]; 83 float min_spread_thr_r, max_spread_thr_r; 84 85 /** 86 * rdlambda controls the maximum tolerated distortion. Twoloop 87 * will keep iterating until it fails to lower it or it reaches 88 * ulimit * rdlambda. Keeping it low increases quality on difficult 89 * signals, but lower it too much, and bits will be taken from weak 90 * signals, creating "holes". A balance is necessary. 91 * rdmax and rdmin specify the relative deviation from rdlambda 92 * allowed for tonality compensation 93 */ 94 float rdlambda = av_clipf(2.0f * 120.f / lambda, 0.0625f, 16.0f); 95 const float nzslope = 1.5f; 96 float rdmin = 0.03125f; 97 float rdmax = 1.0f; 98 99 /** 100 * sfoffs controls an offset of optmium allocation that will be 101 * applied based on lambda. Keep it real and modest, the loop 102 * will take care of the rest, this just accelerates convergence 103 */ 104 float sfoffs = av_clipf(log2f(120.0f / lambda) * 4.0f, -5, 10); 105 106 int fflag, minscaler, maxscaler, nminscaler; 107 int its = 0; 108 int maxits = 30; 109 int allz = 0; 110 int tbits; 111 int cutoff = 1024; 112 int pns_start_pos; 113 int prev; 114 115 /** 116 * zeroscale controls a multiplier of the threshold, if band energy 117 * is below this, a zero is forced. Keep it lower than 1, unless 118 * low lambda is used, because energy < threshold doesn't mean there's 119 * no audible signal outright, it's just energy. Also make it rise 120 * slower than rdlambda, as rdscale has due compensation with 121 * noisy band depriorization below, whereas zeroing logic is rather dumb 122 */ 123 float zeroscale; 124 if (lambda > 120.f) { 125 zeroscale = av_clipf(powf(120.f / lambda, 0.25f), 0.0625f, 1.0f); 126 } else { 127 zeroscale = 1.f; 128 } 129 130 if (s->psy.bitres.alloc >= 0) { 131 /** 132 * Psy granted us extra bits to use, from the reservoire 133 * adjust for lambda except what psy already did 134 */ 135 destbits = s->psy.bitres.alloc 136 * (lambda / (avctx->global_quality ? avctx->global_quality : 120)); 137 } 138 139 if (avctx->flags & AV_CODEC_FLAG_QSCALE) { 140 /** 141 * Constant Q-scale doesn't compensate MS coding on its own 142 * No need to be overly precise, this only controls RD 143 * adjustment CB limits when going overboard 144 */ 145 if (s->options.mid_side && s->cur_type == TYPE_CPE) 146 destbits *= 2; 147 148 /** 149 * When using a constant Q-scale, don't adjust bits, just use RD 150 * Don't let it go overboard, though... 8x psy target is enough 151 */ 152 toomanybits = 5800; 153 toofewbits = destbits / 16; 154 155 /** Don't offset scalers, just RD */ 156 sfoffs = sce->ics.num_windows - 1; 157 rdlambda = sqrtf(rdlambda); 158 159 /** search further */ 160 maxits *= 2; 161 } else { 162 /* When using ABR, be strict, but a reasonable leeway is 163 * critical to allow RC to smoothly track desired bitrate 164 * without sudden quality drops that cause audible artifacts. 165 * Symmetry is also desirable, to avoid systematic bias. 166 */ 167 toomanybits = destbits + destbits/8; 168 toofewbits = destbits - destbits/8; 169 170 sfoffs = 0; 171 rdlambda = sqrtf(rdlambda); 172 } 173 174 /** and zero out above cutoff frequency */ 175 { 176 int wlen = 1024 / sce->ics.num_windows; 177 int bandwidth; 178 179 /** 180 * Scale, psy gives us constant quality, this LP only scales 181 * bitrate by lambda, so we save bits on subjectively unimportant HF 182 * rather than increase quantization noise. Adjust nominal bitrate 183 * to effective bitrate according to encoding parameters, 184 * AAC_CUTOFF_FROM_BITRATE is calibrated for effective bitrate. 185 */ 186 float rate_bandwidth_multiplier = 1.5f; 187 int frame_bit_rate = (avctx->flags & AV_CODEC_FLAG_QSCALE) 188 ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024) 189 : (avctx->bit_rate / avctx->ch_layout.nb_channels); 190 191 /** Compensate for extensions that increase efficiency */ 192 if (s->options.pns || s->options.intensity_stereo) 193 frame_bit_rate *= 1.15f; 194 195 if (avctx->cutoff > 0) { 196 bandwidth = avctx->cutoff; 197 } else { 198 bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate)); 199 s->psy.cutoff = bandwidth; 200 } 201 202 cutoff = bandwidth * 2 * wlen / avctx->sample_rate; 203 pns_start_pos = NOISE_LOW_LIMIT * 2 * wlen / avctx->sample_rate; 204 } 205 206 /** 207 * for values above this the decoder might end up in an endless loop 208 * due to always having more bits than what can be encoded. 209 */ 210 destbits = FFMIN(destbits, 5800); 211 toomanybits = FFMIN(toomanybits, 5800); 212 toofewbits = FFMIN(toofewbits, 5800); 213 /** 214 * XXX: some heuristic to determine initial quantizers will reduce search time 215 * determine zero bands and upper distortion limits 216 */ 217 min_spread_thr_r = -1; 218 max_spread_thr_r = -1; 219 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 220 for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { 221 int nz = 0; 222 float uplim = 0.0f, energy = 0.0f, spread = 0.0f; 223 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 224 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; 225 if (start >= cutoff || band->energy <= (band->threshold * zeroscale) || band->threshold == 0.0f) { 226 sce->zeroes[(w+w2)*16+g] = 1; 227 continue; 228 } 229 nz = 1; 230 } 231 if (!nz) { 232 uplim = 0.0f; 233 } else { 234 nz = 0; 235 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 236 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; 237 if (band->energy <= (band->threshold * zeroscale) || band->threshold == 0.0f) 238 continue; 239 uplim += band->threshold; 240 energy += band->energy; 241 spread += band->spread; 242 nz++; 243 } 244 } 245 uplims[w*16+g] = uplim; 246 energies[w*16+g] = energy; 247 nzs[w*16+g] = nz; 248 sce->zeroes[w*16+g] = !nz; 249 allz |= nz; 250 if (nz && sce->can_pns[w*16+g]) { 251 spread_thr_r[w*16+g] = energy * nz / (uplim * spread); 252 if (min_spread_thr_r < 0) { 253 min_spread_thr_r = max_spread_thr_r = spread_thr_r[w*16+g]; 254 } else { 255 min_spread_thr_r = FFMIN(min_spread_thr_r, spread_thr_r[w*16+g]); 256 max_spread_thr_r = FFMAX(max_spread_thr_r, spread_thr_r[w*16+g]); 257 } 258 } 259 } 260 } 261 262 /** Compute initial scalers */ 263 minscaler = 65535; 264 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 265 for (g = 0; g < sce->ics.num_swb; g++) { 266 if (sce->zeroes[w*16+g]) { 267 sce->sf_idx[w*16+g] = SCALE_ONE_POS; 268 continue; 269 } 270 /** 271 * log2f-to-distortion ratio is, technically, 2 (1.5db = 4, but it's power vs level so it's 2). 272 * But, as offsets are applied, low-frequency signals are too sensitive to the induced distortion, 273 * so we make scaling more conservative by choosing a lower log2f-to-distortion ratio, and thus 274 * more robust. 275 */ 276 sce->sf_idx[w*16+g] = av_clip( 277 SCALE_ONE_POS 278 + 1.75*log2f(FFMAX(0.00125f,uplims[w*16+g]) / sce->ics.swb_sizes[g]) 279 + sfoffs, 280 60, SCALE_MAX_POS); 281 minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]); 282 } 283 } 284 285 /** Clip */ 286 minscaler = av_clip(minscaler, SCALE_ONE_POS - SCALE_DIV_512, SCALE_MAX_POS - SCALE_DIV_512); 287 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) 288 for (g = 0; g < sce->ics.num_swb; g++) 289 if (!sce->zeroes[w*16+g]) 290 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF - 1); 291 292 if (!allz) 293 return; 294 s->abs_pow34(s->scoefs, sce->coeffs, 1024); 295 ff_quantize_band_cost_cache_init(s); 296 297 for (i = 0; i < sizeof(minsf) / sizeof(minsf[0]); ++i) 298 minsf[i] = 0; 299 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 300 start = w*128; 301 for (g = 0; g < sce->ics.num_swb; g++) { 302 const float *scaled = s->scoefs + start; 303 int minsfidx; 304 maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled); 305 if (maxvals[w*16+g] > 0) { 306 minsfidx = coef2minsf(maxvals[w*16+g]); 307 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) 308 minsf[(w+w2)*16+g] = minsfidx; 309 } 310 start += sce->ics.swb_sizes[g]; 311 } 312 } 313 314 /** 315 * Scale uplims to match rate distortion to quality 316 * bu applying noisy band depriorization and tonal band priorization. 317 * Maxval-energy ratio gives us an idea of how noisy/tonal the band is. 318 * If maxval^2 ~ energy, then that band is mostly noise, and we can relax 319 * rate distortion requirements. 320 */ 321 memcpy(euplims, uplims, sizeof(euplims)); 322 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 323 /** psy already priorizes transients to some extent */ 324 float de_psy_factor = (sce->ics.num_windows > 1) ? 8.0f / sce->ics.group_len[w] : 1.0f; 325 start = w*128; 326 for (g = 0; g < sce->ics.num_swb; g++) { 327 if (nzs[g] > 0) { 328 float cleanup_factor = ff_sqrf(av_clipf(start / (cutoff * 0.75f), 1.0f, 2.0f)); 329 float energy2uplim = find_form_factor( 330 sce->ics.group_len[w], sce->ics.swb_sizes[g], 331 uplims[w*16+g] / (nzs[g] * sce->ics.swb_sizes[w]), 332 sce->coeffs + start, 333 nzslope * cleanup_factor); 334 energy2uplim *= de_psy_factor; 335 if (!(avctx->flags & AV_CODEC_FLAG_QSCALE)) { 336 /** In ABR, we need to priorize less and let rate control do its thing */ 337 energy2uplim = sqrtf(energy2uplim); 338 } 339 energy2uplim = FFMAX(0.015625f, FFMIN(1.0f, energy2uplim)); 340 uplims[w*16+g] *= av_clipf(rdlambda * energy2uplim, rdmin, rdmax) 341 * sce->ics.group_len[w]; 342 343 energy2uplim = find_form_factor( 344 sce->ics.group_len[w], sce->ics.swb_sizes[g], 345 uplims[w*16+g] / (nzs[g] * sce->ics.swb_sizes[w]), 346 sce->coeffs + start, 347 2.0f); 348 energy2uplim *= de_psy_factor; 349 if (!(avctx->flags & AV_CODEC_FLAG_QSCALE)) { 350 /** In ABR, we need to priorize less and let rate control do its thing */ 351 energy2uplim = sqrtf(energy2uplim); 352 } 353 energy2uplim = FFMAX(0.015625f, FFMIN(1.0f, energy2uplim)); 354 euplims[w*16+g] *= av_clipf(rdlambda * energy2uplim * sce->ics.group_len[w], 355 0.5f, 1.0f); 356 } 357 start += sce->ics.swb_sizes[g]; 358 } 359 } 360 361 for (i = 0; i < sizeof(maxsf) / sizeof(maxsf[0]); ++i) 362 maxsf[i] = SCALE_MAX_POS; 363 364 //perform two-loop search 365 //outer loop - improve quality 366 do { 367 //inner loop - quantize spectrum to fit into given number of bits 368 int overdist; 369 int qstep = its ? 1 : 32; 370 do { 371 int changed = 0; 372 prev = -1; 373 recomprd = 0; 374 tbits = 0; 375 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 376 start = w*128; 377 for (g = 0; g < sce->ics.num_swb; g++) { 378 const float *coefs = &sce->coeffs[start]; 379 const float *scaled = &s->scoefs[start]; 380 int bits = 0; 381 int cb; 382 float dist = 0.0f; 383 float qenergy = 0.0f; 384 385 if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) { 386 start += sce->ics.swb_sizes[g]; 387 if (sce->can_pns[w*16+g]) { 388 /** PNS isn't free */ 389 tbits += ff_pns_bits(sce, w, g); 390 } 391 continue; 392 } 393 cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 394 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 395 int b; 396 float sqenergy; 397 dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, 398 scaled + w2*128, 399 sce->ics.swb_sizes[g], 400 sce->sf_idx[w*16+g], 401 cb, 402 1.0f, 403 INFINITY, 404 &b, &sqenergy, 405 0); 406 bits += b; 407 qenergy += sqenergy; 408 } 409 dists[w*16+g] = dist - bits; 410 qenergies[w*16+g] = qenergy; 411 if (prev != -1) { 412 int sfdiff = av_clip(sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF); 413 bits += ff_aac_scalefactor_bits[sfdiff]; 414 } 415 tbits += bits; 416 start += sce->ics.swb_sizes[g]; 417 prev = sce->sf_idx[w*16+g]; 418 } 419 } 420 if (tbits > toomanybits) { 421 recomprd = 1; 422 for (i = 0; i < 128; i++) { 423 if (sce->sf_idx[i] < (SCALE_MAX_POS - SCALE_DIV_512)) { 424 int maxsf_i = (tbits > 5800) ? SCALE_MAX_POS : maxsf[i]; 425 int new_sf = FFMIN(maxsf_i, sce->sf_idx[i] + qstep); 426 if (new_sf != sce->sf_idx[i]) { 427 sce->sf_idx[i] = new_sf; 428 changed = 1; 429 } 430 } 431 } 432 } else if (tbits < toofewbits) { 433 recomprd = 1; 434 for (i = 0; i < 128; i++) { 435 if (sce->sf_idx[i] > SCALE_ONE_POS) { 436 int new_sf = FFMAX3(minsf[i], SCALE_ONE_POS, sce->sf_idx[i] - qstep); 437 if (new_sf != sce->sf_idx[i]) { 438 sce->sf_idx[i] = new_sf; 439 changed = 1; 440 } 441 } 442 } 443 } 444 qstep >>= 1; 445 if (!qstep && tbits > toomanybits && sce->sf_idx[0] < 217 && changed) 446 qstep = 1; 447 } while (qstep); 448 449 overdist = 1; 450 fflag = tbits < toofewbits; 451 for (i = 0; i < 2 && (overdist || recomprd); ++i) { 452 if (recomprd) { 453 /** Must recompute distortion */ 454 prev = -1; 455 tbits = 0; 456 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 457 start = w*128; 458 for (g = 0; g < sce->ics.num_swb; g++) { 459 const float *coefs = sce->coeffs + start; 460 const float *scaled = s->scoefs + start; 461 int bits = 0; 462 int cb; 463 float dist = 0.0f; 464 float qenergy = 0.0f; 465 466 if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) { 467 start += sce->ics.swb_sizes[g]; 468 if (sce->can_pns[w*16+g]) { 469 /** PNS isn't free */ 470 tbits += ff_pns_bits(sce, w, g); 471 } 472 continue; 473 } 474 cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 475 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 476 int b; 477 float sqenergy; 478 dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, 479 scaled + w2*128, 480 sce->ics.swb_sizes[g], 481 sce->sf_idx[w*16+g], 482 cb, 483 1.0f, 484 INFINITY, 485 &b, &sqenergy, 486 0); 487 bits += b; 488 qenergy += sqenergy; 489 } 490 dists[w*16+g] = dist - bits; 491 qenergies[w*16+g] = qenergy; 492 if (prev != -1) { 493 int sfdiff = av_clip(sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF); 494 bits += ff_aac_scalefactor_bits[sfdiff]; 495 } 496 tbits += bits; 497 start += sce->ics.swb_sizes[g]; 498 prev = sce->sf_idx[w*16+g]; 499 } 500 } 501 } 502 if (!i && s->options.pns && its > maxits/2 && tbits > toofewbits) { 503 float maxoverdist = 0.0f; 504 float ovrfactor = 1.f+(maxits-its)*16.f/maxits; 505 overdist = recomprd = 0; 506 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 507 for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { 508 if (!sce->zeroes[w*16+g] && sce->sf_idx[w*16+g] > SCALE_ONE_POS && dists[w*16+g] > uplims[w*16+g]*ovrfactor) { 509 float ovrdist = dists[w*16+g] / FFMAX(uplims[w*16+g],euplims[w*16+g]); 510 maxoverdist = FFMAX(maxoverdist, ovrdist); 511 overdist++; 512 } 513 } 514 } 515 if (overdist) { 516 /* We have overdistorted bands, trade for zeroes (that can be noise) 517 * Zero the bands in the lowest 1.25% spread-energy-threshold ranking 518 */ 519 float minspread = max_spread_thr_r; 520 float maxspread = min_spread_thr_r; 521 float zspread; 522 int zeroable = 0; 523 int zeroed = 0; 524 int maxzeroed, zloop; 525 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 526 for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { 527 if (start >= pns_start_pos && !sce->zeroes[w*16+g] && sce->can_pns[w*16+g]) { 528 minspread = FFMIN(minspread, spread_thr_r[w*16+g]); 529 maxspread = FFMAX(maxspread, spread_thr_r[w*16+g]); 530 zeroable++; 531 } 532 } 533 } 534 zspread = (maxspread-minspread) * 0.0125f + minspread; 535 /* Don't PNS everything even if allowed. It suppresses bit starvation signals from RC, 536 * and forced the hand of the later search_for_pns step. 537 * Instead, PNS a fraction of the spread_thr_r range depending on how starved for bits we are, 538 * and leave further PNSing to search_for_pns if worthwhile. 539 */ 540 zspread = FFMIN3(min_spread_thr_r * 8.f, zspread, 541 ((toomanybits - tbits) * min_spread_thr_r + (tbits - toofewbits) * max_spread_thr_r) / (toomanybits - toofewbits + 1)); 542 maxzeroed = FFMIN(zeroable, FFMAX(1, (zeroable * its + maxits - 1) / (2 * maxits))); 543 for (zloop = 0; zloop < 2; zloop++) { 544 /* Two passes: first distorted stuff - two birds in one shot and all that, 545 * then anything viable. Viable means not zero, but either CB=zero-able 546 * (too high SF), not SF <= 1 (that means we'd be operating at very high 547 * quality, we don't want PNS when doing VHQ), PNS allowed, and within 548 * the lowest ranking percentile. 549 */ 550 float loopovrfactor = (zloop) ? 1.0f : ovrfactor; 551 int loopminsf = (zloop) ? (SCALE_ONE_POS - SCALE_DIV_512) : SCALE_ONE_POS; 552 int mcb; 553 for (g = sce->ics.num_swb-1; g > 0 && zeroed < maxzeroed; g--) { 554 if (sce->ics.swb_offset[g] < pns_start_pos) 555 continue; 556 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 557 if (!sce->zeroes[w*16+g] && sce->can_pns[w*16+g] && spread_thr_r[w*16+g] <= zspread 558 && sce->sf_idx[w*16+g] > loopminsf 559 && (dists[w*16+g] > loopovrfactor*uplims[w*16+g] || !(mcb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g])) 560 || (mcb <= 1 && dists[w*16+g] > FFMIN(uplims[w*16+g], euplims[w*16+g]))) ) { 561 sce->zeroes[w*16+g] = 1; 562 sce->band_type[w*16+g] = 0; 563 zeroed++; 564 } 565 } 566 } 567 } 568 if (zeroed) 569 recomprd = fflag = 1; 570 } else { 571 overdist = 0; 572 } 573 } 574 } 575 576 minscaler = SCALE_MAX_POS; 577 maxscaler = 0; 578 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 579 for (g = 0; g < sce->ics.num_swb; g++) { 580 if (!sce->zeroes[w*16+g]) { 581 minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]); 582 maxscaler = FFMAX(maxscaler, sce->sf_idx[w*16+g]); 583 } 584 } 585 } 586 587 minscaler = nminscaler = av_clip(minscaler, SCALE_ONE_POS - SCALE_DIV_512, SCALE_MAX_POS - SCALE_DIV_512); 588 prev = -1; 589 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 590 /** Start with big steps, end up fine-tunning */ 591 int depth = (its > maxits/2) ? ((its > maxits*2/3) ? 1 : 3) : 10; 592 int edepth = depth+2; 593 float uplmax = its / (maxits*0.25f) + 1.0f; 594 uplmax *= (tbits > destbits) ? FFMIN(2.0f, tbits / (float)FFMAX(1,destbits)) : 1.0f; 595 start = w * 128; 596 for (g = 0; g < sce->ics.num_swb; g++) { 597 int prevsc = sce->sf_idx[w*16+g]; 598 if (prev < 0 && !sce->zeroes[w*16+g]) 599 prev = sce->sf_idx[0]; 600 if (!sce->zeroes[w*16+g]) { 601 const float *coefs = sce->coeffs + start; 602 const float *scaled = s->scoefs + start; 603 int cmb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 604 int mindeltasf = FFMAX(0, prev - SCALE_MAX_DIFF); 605 int maxdeltasf = FFMIN(SCALE_MAX_POS - SCALE_DIV_512, prev + SCALE_MAX_DIFF); 606 if ((!cmb || dists[w*16+g] > uplims[w*16+g]) && sce->sf_idx[w*16+g] > FFMAX(mindeltasf, minsf[w*16+g])) { 607 /* Try to make sure there is some energy in every nonzero band 608 * NOTE: This algorithm must be forcibly imbalanced, pushing harder 609 * on holes or more distorted bands at first, otherwise there's 610 * no net gain (since the next iteration will offset all bands 611 * on the opposite direction to compensate for extra bits) 612 */ 613 for (i = 0; i < edepth && sce->sf_idx[w*16+g] > mindeltasf; ++i) { 614 int cb, bits; 615 float dist, qenergy; 616 int mb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1); 617 cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 618 dist = qenergy = 0.f; 619 bits = 0; 620 if (!cb) { 621 maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g]-1, maxsf[w*16+g]); 622 } else if (i >= depth && dists[w*16+g] < euplims[w*16+g]) { 623 break; 624 } 625 /* !g is the DC band, it's important, since quantization error here 626 * applies to less than a cycle, it creates horrible intermodulation 627 * distortion if it doesn't stick to what psy requests 628 */ 629 if (!g && sce->ics.num_windows > 1 && dists[w*16+g] >= euplims[w*16+g]) 630 maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g], maxsf[w*16+g]); 631 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 632 int b; 633 float sqenergy; 634 dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, 635 scaled + w2*128, 636 sce->ics.swb_sizes[g], 637 sce->sf_idx[w*16+g]-1, 638 cb, 639 1.0f, 640 INFINITY, 641 &b, &sqenergy, 642 0); 643 bits += b; 644 qenergy += sqenergy; 645 } 646 sce->sf_idx[w*16+g]--; 647 dists[w*16+g] = dist - bits; 648 qenergies[w*16+g] = qenergy; 649 if (mb && (sce->sf_idx[w*16+g] < mindeltasf || ( 650 (dists[w*16+g] < FFMIN(uplmax*uplims[w*16+g], euplims[w*16+g])) 651 && (fabsf(qenergies[w*16+g]-energies[w*16+g]) < euplims[w*16+g]) 652 ) )) { 653 break; 654 } 655 } 656 } else if (tbits > toofewbits && sce->sf_idx[w*16+g] < FFMIN(maxdeltasf, maxsf[w*16+g]) 657 && (dists[w*16+g] < FFMIN(euplims[w*16+g], uplims[w*16+g])) 658 && (fabsf(qenergies[w*16+g]-energies[w*16+g]) < euplims[w*16+g]) 659 ) { 660 /** Um... over target. Save bits for more important stuff. */ 661 for (i = 0; i < depth && sce->sf_idx[w*16+g] < maxdeltasf; ++i) { 662 int cb, bits; 663 float dist, qenergy; 664 cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]+1); 665 if (cb > 0) { 666 dist = qenergy = 0.f; 667 bits = 0; 668 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { 669 int b; 670 float sqenergy; 671 dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, 672 scaled + w2*128, 673 sce->ics.swb_sizes[g], 674 sce->sf_idx[w*16+g]+1, 675 cb, 676 1.0f, 677 INFINITY, 678 &b, &sqenergy, 679 0); 680 bits += b; 681 qenergy += sqenergy; 682 } 683 dist -= bits; 684 if (dist < FFMIN(euplims[w*16+g], uplims[w*16+g])) { 685 sce->sf_idx[w*16+g]++; 686 dists[w*16+g] = dist; 687 qenergies[w*16+g] = qenergy; 688 } else { 689 break; 690 } 691 } else { 692 maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g], maxsf[w*16+g]); 693 break; 694 } 695 } 696 } 697 prev = sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], mindeltasf, maxdeltasf); 698 if (sce->sf_idx[w*16+g] != prevsc) 699 fflag = 1; 700 nminscaler = FFMIN(nminscaler, sce->sf_idx[w*16+g]); 701 sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 702 } 703 start += sce->ics.swb_sizes[g]; 704 } 705 } 706 707 /** SF difference limit violation risk. Must re-clamp. */ 708 prev = -1; 709 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 710 for (g = 0; g < sce->ics.num_swb; g++) { 711 if (!sce->zeroes[w*16+g]) { 712 int prevsf = sce->sf_idx[w*16+g]; 713 if (prev < 0) 714 prev = prevsf; 715 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], prev - SCALE_MAX_DIFF, prev + SCALE_MAX_DIFF); 716 sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 717 prev = sce->sf_idx[w*16+g]; 718 if (!fflag && prevsf != sce->sf_idx[w*16+g]) 719 fflag = 1; 720 } 721 } 722 } 723 724 its++; 725 } while (fflag && its < maxits); 726 727 /** Scout out next nonzero bands */ 728 ff_init_nextband_map(sce, nextband); 729 730 prev = -1; 731 for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { 732 /** Make sure proper codebooks are set */ 733 for (g = 0; g < sce->ics.num_swb; g++) { 734 if (!sce->zeroes[w*16+g]) { 735 sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); 736 if (sce->band_type[w*16+g] <= 0) { 737 if (!ff_sfdelta_can_remove_band(sce, nextband, prev, w*16+g)) { 738 /** Cannot zero out, make sure it's not attempted */ 739 sce->band_type[w*16+g] = 1; 740 } else { 741 sce->zeroes[w*16+g] = 1; 742 sce->band_type[w*16+g] = 0; 743 } 744 } 745 } else { 746 sce->band_type[w*16+g] = 0; 747 } 748 /** Check that there's no SF delta range violations */ 749 if (!sce->zeroes[w*16+g]) { 750 if (prev != -1) { 751 av_unused int sfdiff = sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO; 752 av_assert1(sfdiff >= 0 && sfdiff <= 2*SCALE_MAX_DIFF); 753 } else if (sce->zeroes[0]) { 754 /** Set global gain to something useful */ 755 sce->sf_idx[0] = sce->sf_idx[w*16+g]; 756 } 757 prev = sce->sf_idx[w*16+g]; 758 } 759 } 760 } 761} 762 763#endif /* AVCODEC_AACCODER_TWOLOOP_H */ 764