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Diffstat (limited to 'libavcodec/aaccoder_twoloop.h')
| -rw-r--r-- | libavcodec/aaccoder_twoloop.h | 763 |
1 files changed, 763 insertions, 0 deletions
diff --git a/libavcodec/aaccoder_twoloop.h b/libavcodec/aaccoder_twoloop.h new file mode 100644 index 0000000..8e1bc88 --- /dev/null +++ b/libavcodec/aaccoder_twoloop.h @@ -0,0 +1,763 @@ +/* + * AAC encoder twoloop coder + * Copyright (C) 2008-2009 Konstantin Shishkov + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * AAC encoder twoloop coder + * @author Konstantin Shishkov, Claudio Freire + */ + +/** + * This file contains a template for the twoloop coder function. + * It needs to be provided, externally, as an already included declaration, + * the following functions from aacenc_quantization/util.h. They're not included + * explicitly here to make it possible to provide alternative implementations: + * - quantize_band_cost + * - abs_pow34_v + * - find_max_val + * - find_min_book + * - find_form_factor + */ + +#ifndef AVCODEC_AACCODER_TWOLOOP_H +#define AVCODEC_AACCODER_TWOLOOP_H + +#include <float.h> +#include "libavutil/mathematics.h" +#include "mathops.h" +#include "avcodec.h" +#include "put_bits.h" +#include "aac.h" +#include "aacenc.h" +#include "aactab.h" +#include "aacenctab.h" + +/** Frequency in Hz for lower limit of noise substitution **/ +#define NOISE_LOW_LIMIT 4000 + +#define sclip(x) av_clip(x,60,218) + +/* Reflects the cost to change codebooks */ +static inline int ff_pns_bits(SingleChannelElement *sce, int w, int g) +{ + return (!g || !sce->zeroes[w*16+g-1] || !sce->can_pns[w*16+g-1]) ? 9 : 5; +} + +/** + * two-loop quantizers search taken from ISO 13818-7 Appendix C + */ +static void search_for_quantizers_twoloop(AVCodecContext *avctx, + AACEncContext *s, + SingleChannelElement *sce, + const float lambda) +{ + int start = 0, i, w, w2, g, recomprd; + int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate + / ((avctx->flags & AV_CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels) + * (lambda / 120.f); + int refbits = destbits; + int toomanybits, toofewbits; + char nzs[128]; + uint8_t nextband[128]; + int maxsf[128], minsf[128]; + float dists[128] = { 0 }, qenergies[128] = { 0 }, uplims[128], euplims[128], energies[128]; + float maxvals[128], spread_thr_r[128]; + float min_spread_thr_r, max_spread_thr_r; + + /** + * rdlambda controls the maximum tolerated distortion. Twoloop + * will keep iterating until it fails to lower it or it reaches + * ulimit * rdlambda. Keeping it low increases quality on difficult + * signals, but lower it too much, and bits will be taken from weak + * signals, creating "holes". A balance is necessary. + * rdmax and rdmin specify the relative deviation from rdlambda + * allowed for tonality compensation + */ + float rdlambda = av_clipf(2.0f * 120.f / lambda, 0.0625f, 16.0f); + const float nzslope = 1.5f; + float rdmin = 0.03125f; + float rdmax = 1.0f; + + /** + * sfoffs controls an offset of optmium allocation that will be + * applied based on lambda. Keep it real and modest, the loop + * will take care of the rest, this just accelerates convergence + */ + float sfoffs = av_clipf(log2f(120.0f / lambda) * 4.0f, -5, 10); + + int fflag, minscaler, maxscaler, nminscaler; + int its = 0; + int maxits = 30; + int allz = 0; + int tbits; + int cutoff = 1024; + int pns_start_pos; + int prev; + + /** + * zeroscale controls a multiplier of the threshold, if band energy + * is below this, a zero is forced. Keep it lower than 1, unless + * low lambda is used, because energy < threshold doesn't mean there's + * no audible signal outright, it's just energy. Also make it rise + * slower than rdlambda, as rdscale has due compensation with + * noisy band depriorization below, whereas zeroing logic is rather dumb + */ + float zeroscale; + if (lambda > 120.f) { + zeroscale = av_clipf(powf(120.f / lambda, 0.25f), 0.0625f, 1.0f); + } else { + zeroscale = 1.f; + } + + if (s->psy.bitres.alloc >= 0) { + /** + * Psy granted us extra bits to use, from the reservoire + * adjust for lambda except what psy already did + */ + destbits = s->psy.bitres.alloc + * (lambda / (avctx->global_quality ? avctx->global_quality : 120)); + } + + if (avctx->flags & AV_CODEC_FLAG_QSCALE) { + /** + * Constant Q-scale doesn't compensate MS coding on its own + * No need to be overly precise, this only controls RD + * adjustment CB limits when going overboard + */ + if (s->options.mid_side && s->cur_type == TYPE_CPE) + destbits *= 2; + + /** + * When using a constant Q-scale, don't adjust bits, just use RD + * Don't let it go overboard, though... 8x psy target is enough + */ + toomanybits = 5800; + toofewbits = destbits / 16; + + /** Don't offset scalers, just RD */ + sfoffs = sce->ics.num_windows - 1; + rdlambda = sqrtf(rdlambda); + + /** search further */ + maxits *= 2; + } else { + /* When using ABR, be strict, but a reasonable leeway is + * critical to allow RC to smoothly track desired bitrate + * without sudden quality drops that cause audible artifacts. + * Symmetry is also desirable, to avoid systematic bias. + */ + toomanybits = destbits + destbits/8; + toofewbits = destbits - destbits/8; + + sfoffs = 0; + rdlambda = sqrtf(rdlambda); + } + + /** and zero out above cutoff frequency */ + { + int wlen = 1024 / sce->ics.num_windows; + int bandwidth; + + /** + * Scale, psy gives us constant quality, this LP only scales + * bitrate by lambda, so we save bits on subjectively unimportant HF + * rather than increase quantization noise. Adjust nominal bitrate + * to effective bitrate according to encoding parameters, + * AAC_CUTOFF_FROM_BITRATE is calibrated for effective bitrate. + */ + float rate_bandwidth_multiplier = 1.5f; + int frame_bit_rate = (avctx->flags & AV_CODEC_FLAG_QSCALE) + ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024) + : (avctx->bit_rate / avctx->channels); + + /** Compensate for extensions that increase efficiency */ + if (s->options.pns || s->options.intensity_stereo) + frame_bit_rate *= 1.15f; + + if (avctx->cutoff > 0) { + bandwidth = avctx->cutoff; + } else { + bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate)); + s->psy.cutoff = bandwidth; + } + + cutoff = bandwidth * 2 * wlen / avctx->sample_rate; + pns_start_pos = NOISE_LOW_LIMIT * 2 * wlen / avctx->sample_rate; + } + + /** + * for values above this the decoder might end up in an endless loop + * due to always having more bits than what can be encoded. + */ + destbits = FFMIN(destbits, 5800); + toomanybits = FFMIN(toomanybits, 5800); + toofewbits = FFMIN(toofewbits, 5800); + /** + * XXX: some heuristic to determine initial quantizers will reduce search time + * determine zero bands and upper distortion limits + */ + min_spread_thr_r = -1; + max_spread_thr_r = -1; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { + int nz = 0; + float uplim = 0.0f, energy = 0.0f, spread = 0.0f; + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; + if (start >= cutoff || band->energy <= (band->threshold * zeroscale) || band->threshold == 0.0f) { + sce->zeroes[(w+w2)*16+g] = 1; + continue; + } + nz = 1; + } + if (!nz) { + uplim = 0.0f; + } else { + nz = 0; + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; + if (band->energy <= (band->threshold * zeroscale) || band->threshold == 0.0f) + continue; + uplim += band->threshold; + energy += band->energy; + spread += band->spread; + nz++; + } + } + uplims[w*16+g] = uplim; + energies[w*16+g] = energy; + nzs[w*16+g] = nz; + sce->zeroes[w*16+g] = !nz; + allz |= nz; + if (nz && sce->can_pns[w*16+g]) { + spread_thr_r[w*16+g] = energy * nz / (uplim * spread); + if (min_spread_thr_r < 0) { + min_spread_thr_r = max_spread_thr_r = spread_thr_r[w*16+g]; + } else { + min_spread_thr_r = FFMIN(min_spread_thr_r, spread_thr_r[w*16+g]); + max_spread_thr_r = FFMAX(max_spread_thr_r, spread_thr_r[w*16+g]); + } + } + } + } + + /** Compute initial scalers */ + minscaler = 65535; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = 0; g < sce->ics.num_swb; g++) { + if (sce->zeroes[w*16+g]) { + sce->sf_idx[w*16+g] = SCALE_ONE_POS; + continue; + } + /** + * log2f-to-distortion ratio is, technically, 2 (1.5db = 4, but it's power vs level so it's 2). + * But, as offsets are applied, low-frequency signals are too sensitive to the induced distortion, + * so we make scaling more conservative by choosing a lower log2f-to-distortion ratio, and thus + * more robust. + */ + sce->sf_idx[w*16+g] = av_clip( + SCALE_ONE_POS + + 1.75*log2f(FFMAX(0.00125f,uplims[w*16+g]) / sce->ics.swb_sizes[g]) + + sfoffs, + 60, SCALE_MAX_POS); + minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]); + } + } + + /** Clip */ + minscaler = av_clip(minscaler, SCALE_ONE_POS - SCALE_DIV_512, SCALE_MAX_POS - SCALE_DIV_512); + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) + for (g = 0; g < sce->ics.num_swb; g++) + if (!sce->zeroes[w*16+g]) + sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF - 1); + + if (!allz) + return; + s->abs_pow34(s->scoefs, sce->coeffs, 1024); + ff_quantize_band_cost_cache_init(s); + + for (i = 0; i < sizeof(minsf) / sizeof(minsf[0]); ++i) + minsf[i] = 0; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + start = w*128; + for (g = 0; g < sce->ics.num_swb; g++) { + const float *scaled = s->scoefs + start; + int minsfidx; + maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled); + if (maxvals[w*16+g] > 0) { + minsfidx = coef2minsf(maxvals[w*16+g]); + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) + minsf[(w+w2)*16+g] = minsfidx; + } + start += sce->ics.swb_sizes[g]; + } + } + + /** + * Scale uplims to match rate distortion to quality + * bu applying noisy band depriorization and tonal band priorization. + * Maxval-energy ratio gives us an idea of how noisy/tonal the band is. + * If maxval^2 ~ energy, then that band is mostly noise, and we can relax + * rate distortion requirements. + */ + memcpy(euplims, uplims, sizeof(euplims)); + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + /** psy already priorizes transients to some extent */ + float de_psy_factor = (sce->ics.num_windows > 1) ? 8.0f / sce->ics.group_len[w] : 1.0f; + start = w*128; + for (g = 0; g < sce->ics.num_swb; g++) { + if (nzs[g] > 0) { + float cleanup_factor = ff_sqrf(av_clipf(start / (cutoff * 0.75f), 1.0f, 2.0f)); + float energy2uplim = find_form_factor( + sce->ics.group_len[w], sce->ics.swb_sizes[g], + uplims[w*16+g] / (nzs[g] * sce->ics.swb_sizes[w]), + sce->coeffs + start, + nzslope * cleanup_factor); + energy2uplim *= de_psy_factor; + if (!(avctx->flags & AV_CODEC_FLAG_QSCALE)) { + /** In ABR, we need to priorize less and let rate control do its thing */ + energy2uplim = sqrtf(energy2uplim); + } + energy2uplim = FFMAX(0.015625f, FFMIN(1.0f, energy2uplim)); + uplims[w*16+g] *= av_clipf(rdlambda * energy2uplim, rdmin, rdmax) + * sce->ics.group_len[w]; + + energy2uplim = find_form_factor( + sce->ics.group_len[w], sce->ics.swb_sizes[g], + uplims[w*16+g] / (nzs[g] * sce->ics.swb_sizes[w]), + sce->coeffs + start, + 2.0f); + energy2uplim *= de_psy_factor; + if (!(avctx->flags & AV_CODEC_FLAG_QSCALE)) { + /** In ABR, we need to priorize less and let rate control do its thing */ + energy2uplim = sqrtf(energy2uplim); + } + energy2uplim = FFMAX(0.015625f, FFMIN(1.0f, energy2uplim)); + euplims[w*16+g] *= av_clipf(rdlambda * energy2uplim * sce->ics.group_len[w], + 0.5f, 1.0f); + } + start += sce->ics.swb_sizes[g]; + } + } + + for (i = 0; i < sizeof(maxsf) / sizeof(maxsf[0]); ++i) + maxsf[i] = SCALE_MAX_POS; + + //perform two-loop search + //outer loop - improve quality + do { + //inner loop - quantize spectrum to fit into given number of bits + int overdist; + int qstep = its ? 1 : 32; + do { + int changed = 0; + prev = -1; + recomprd = 0; + tbits = 0; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + start = w*128; + for (g = 0; g < sce->ics.num_swb; g++) { + const float *coefs = &sce->coeffs[start]; + const float *scaled = &s->scoefs[start]; + int bits = 0; + int cb; + float dist = 0.0f; + float qenergy = 0.0f; + + if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) { + start += sce->ics.swb_sizes[g]; + if (sce->can_pns[w*16+g]) { + /** PNS isn't free */ + tbits += ff_pns_bits(sce, w, g); + } + continue; + } + cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + int b; + float sqenergy; + dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, + scaled + w2*128, + sce->ics.swb_sizes[g], + sce->sf_idx[w*16+g], + cb, + 1.0f, + INFINITY, + &b, &sqenergy, + 0); + bits += b; + qenergy += sqenergy; + } + dists[w*16+g] = dist - bits; + qenergies[w*16+g] = qenergy; + if (prev != -1) { + int sfdiff = av_clip(sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF); + bits += ff_aac_scalefactor_bits[sfdiff]; + } + tbits += bits; + start += sce->ics.swb_sizes[g]; + prev = sce->sf_idx[w*16+g]; + } + } + if (tbits > toomanybits) { + recomprd = 1; + for (i = 0; i < 128; i++) { + if (sce->sf_idx[i] < (SCALE_MAX_POS - SCALE_DIV_512)) { + int maxsf_i = (tbits > 5800) ? SCALE_MAX_POS : maxsf[i]; + int new_sf = FFMIN(maxsf_i, sce->sf_idx[i] + qstep); + if (new_sf != sce->sf_idx[i]) { + sce->sf_idx[i] = new_sf; + changed = 1; + } + } + } + } else if (tbits < toofewbits) { + recomprd = 1; + for (i = 0; i < 128; i++) { + if (sce->sf_idx[i] > SCALE_ONE_POS) { + int new_sf = FFMAX3(minsf[i], SCALE_ONE_POS, sce->sf_idx[i] - qstep); + if (new_sf != sce->sf_idx[i]) { + sce->sf_idx[i] = new_sf; + changed = 1; + } + } + } + } + qstep >>= 1; + if (!qstep && tbits > toomanybits && sce->sf_idx[0] < 217 && changed) + qstep = 1; + } while (qstep); + + overdist = 1; + fflag = tbits < toofewbits; + for (i = 0; i < 2 && (overdist || recomprd); ++i) { + if (recomprd) { + /** Must recompute distortion */ + prev = -1; + tbits = 0; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + start = w*128; + for (g = 0; g < sce->ics.num_swb; g++) { + const float *coefs = sce->coeffs + start; + const float *scaled = s->scoefs + start; + int bits = 0; + int cb; + float dist = 0.0f; + float qenergy = 0.0f; + + if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) { + start += sce->ics.swb_sizes[g]; + if (sce->can_pns[w*16+g]) { + /** PNS isn't free */ + tbits += ff_pns_bits(sce, w, g); + } + continue; + } + cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + int b; + float sqenergy; + dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, + scaled + w2*128, + sce->ics.swb_sizes[g], + sce->sf_idx[w*16+g], + cb, + 1.0f, + INFINITY, + &b, &sqenergy, + 0); + bits += b; + qenergy += sqenergy; + } + dists[w*16+g] = dist - bits; + qenergies[w*16+g] = qenergy; + if (prev != -1) { + int sfdiff = av_clip(sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO, 0, 2*SCALE_MAX_DIFF); + bits += ff_aac_scalefactor_bits[sfdiff]; + } + tbits += bits; + start += sce->ics.swb_sizes[g]; + prev = sce->sf_idx[w*16+g]; + } + } + } + if (!i && s->options.pns && its > maxits/2 && tbits > toofewbits) { + float maxoverdist = 0.0f; + float ovrfactor = 1.f+(maxits-its)*16.f/maxits; + overdist = recomprd = 0; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { + if (!sce->zeroes[w*16+g] && sce->sf_idx[w*16+g] > SCALE_ONE_POS && dists[w*16+g] > uplims[w*16+g]*ovrfactor) { + float ovrdist = dists[w*16+g] / FFMAX(uplims[w*16+g],euplims[w*16+g]); + maxoverdist = FFMAX(maxoverdist, ovrdist); + overdist++; + } + } + } + if (overdist) { + /* We have overdistorted bands, trade for zeroes (that can be noise) + * Zero the bands in the lowest 1.25% spread-energy-threshold ranking + */ + float minspread = max_spread_thr_r; + float maxspread = min_spread_thr_r; + float zspread; + int zeroable = 0; + int zeroed = 0; + int maxzeroed, zloop; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = start = 0; g < sce->ics.num_swb; start += sce->ics.swb_sizes[g++]) { + if (start >= pns_start_pos && !sce->zeroes[w*16+g] && sce->can_pns[w*16+g]) { + minspread = FFMIN(minspread, spread_thr_r[w*16+g]); + maxspread = FFMAX(maxspread, spread_thr_r[w*16+g]); + zeroable++; + } + } + } + zspread = (maxspread-minspread) * 0.0125f + minspread; + /* Don't PNS everything even if allowed. It suppresses bit starvation signals from RC, + * and forced the hand of the later search_for_pns step. + * Instead, PNS a fraction of the spread_thr_r range depending on how starved for bits we are, + * and leave further PNSing to search_for_pns if worthwhile. + */ + zspread = FFMIN3(min_spread_thr_r * 8.f, zspread, + ((toomanybits - tbits) * min_spread_thr_r + (tbits - toofewbits) * max_spread_thr_r) / (toomanybits - toofewbits + 1)); + maxzeroed = FFMIN(zeroable, FFMAX(1, (zeroable * its + maxits - 1) / (2 * maxits))); + for (zloop = 0; zloop < 2; zloop++) { + /* Two passes: first distorted stuff - two birds in one shot and all that, + * then anything viable. Viable means not zero, but either CB=zero-able + * (too high SF), not SF <= 1 (that means we'd be operating at very high + * quality, we don't want PNS when doing VHQ), PNS allowed, and within + * the lowest ranking percentile. + */ + float loopovrfactor = (zloop) ? 1.0f : ovrfactor; + int loopminsf = (zloop) ? (SCALE_ONE_POS - SCALE_DIV_512) : SCALE_ONE_POS; + int mcb; + for (g = sce->ics.num_swb-1; g > 0 && zeroed < maxzeroed; g--) { + if (sce->ics.swb_offset[g] < pns_start_pos) + continue; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + if (!sce->zeroes[w*16+g] && sce->can_pns[w*16+g] && spread_thr_r[w*16+g] <= zspread + && sce->sf_idx[w*16+g] > loopminsf + && (dists[w*16+g] > loopovrfactor*uplims[w*16+g] || !(mcb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g])) + || (mcb <= 1 && dists[w*16+g] > FFMIN(uplims[w*16+g], euplims[w*16+g]))) ) { + sce->zeroes[w*16+g] = 1; + sce->band_type[w*16+g] = 0; + zeroed++; + } + } + } + } + if (zeroed) + recomprd = fflag = 1; + } else { + overdist = 0; + } + } + } + + minscaler = SCALE_MAX_POS; + maxscaler = 0; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = 0; g < sce->ics.num_swb; g++) { + if (!sce->zeroes[w*16+g]) { + minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]); + maxscaler = FFMAX(maxscaler, sce->sf_idx[w*16+g]); + } + } + } + + minscaler = nminscaler = av_clip(minscaler, SCALE_ONE_POS - SCALE_DIV_512, SCALE_MAX_POS - SCALE_DIV_512); + prev = -1; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + /** Start with big steps, end up fine-tunning */ + int depth = (its > maxits/2) ? ((its > maxits*2/3) ? 1 : 3) : 10; + int edepth = depth+2; + float uplmax = its / (maxits*0.25f) + 1.0f; + uplmax *= (tbits > destbits) ? FFMIN(2.0f, tbits / (float)FFMAX(1,destbits)) : 1.0f; + start = w * 128; + for (g = 0; g < sce->ics.num_swb; g++) { + int prevsc = sce->sf_idx[w*16+g]; + if (prev < 0 && !sce->zeroes[w*16+g]) + prev = sce->sf_idx[0]; + if (!sce->zeroes[w*16+g]) { + const float *coefs = sce->coeffs + start; + const float *scaled = s->scoefs + start; + int cmb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + int mindeltasf = FFMAX(0, prev - SCALE_MAX_DIFF); + int maxdeltasf = FFMIN(SCALE_MAX_POS - SCALE_DIV_512, prev + SCALE_MAX_DIFF); + if ((!cmb || dists[w*16+g] > uplims[w*16+g]) && sce->sf_idx[w*16+g] > FFMAX(mindeltasf, minsf[w*16+g])) { + /* Try to make sure there is some energy in every nonzero band + * NOTE: This algorithm must be forcibly imbalanced, pushing harder + * on holes or more distorted bands at first, otherwise there's + * no net gain (since the next iteration will offset all bands + * on the opposite direction to compensate for extra bits) + */ + for (i = 0; i < edepth && sce->sf_idx[w*16+g] > mindeltasf; ++i) { + int cb, bits; + float dist, qenergy; + int mb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1); + cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + dist = qenergy = 0.f; + bits = 0; + if (!cb) { + maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g]-1, maxsf[w*16+g]); + } else if (i >= depth && dists[w*16+g] < euplims[w*16+g]) { + break; + } + /* !g is the DC band, it's important, since quantization error here + * applies to less than a cycle, it creates horrible intermodulation + * distortion if it doesn't stick to what psy requests + */ + if (!g && sce->ics.num_windows > 1 && dists[w*16+g] >= euplims[w*16+g]) + maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g], maxsf[w*16+g]); + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + int b; + float sqenergy; + dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, + scaled + w2*128, + sce->ics.swb_sizes[g], + sce->sf_idx[w*16+g]-1, + cb, + 1.0f, + INFINITY, + &b, &sqenergy, + 0); + bits += b; + qenergy += sqenergy; + } + sce->sf_idx[w*16+g]--; + dists[w*16+g] = dist - bits; + qenergies[w*16+g] = qenergy; + if (mb && (sce->sf_idx[w*16+g] < mindeltasf || ( + (dists[w*16+g] < FFMIN(uplmax*uplims[w*16+g], euplims[w*16+g])) + && (fabsf(qenergies[w*16+g]-energies[w*16+g]) < euplims[w*16+g]) + ) )) { + break; + } + } + } else if (tbits > toofewbits && sce->sf_idx[w*16+g] < FFMIN(maxdeltasf, maxsf[w*16+g]) + && (dists[w*16+g] < FFMIN(euplims[w*16+g], uplims[w*16+g])) + && (fabsf(qenergies[w*16+g]-energies[w*16+g]) < euplims[w*16+g]) + ) { + /** Um... over target. Save bits for more important stuff. */ + for (i = 0; i < depth && sce->sf_idx[w*16+g] < maxdeltasf; ++i) { + int cb, bits; + float dist, qenergy; + cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]+1); + if (cb > 0) { + dist = qenergy = 0.f; + bits = 0; + for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { + int b; + float sqenergy; + dist += quantize_band_cost_cached(s, w + w2, g, coefs + w2*128, + scaled + w2*128, + sce->ics.swb_sizes[g], + sce->sf_idx[w*16+g]+1, + cb, + 1.0f, + INFINITY, + &b, &sqenergy, + 0); + bits += b; + qenergy += sqenergy; + } + dist -= bits; + if (dist < FFMIN(euplims[w*16+g], uplims[w*16+g])) { + sce->sf_idx[w*16+g]++; + dists[w*16+g] = dist; + qenergies[w*16+g] = qenergy; + } else { + break; + } + } else { + maxsf[w*16+g] = FFMIN(sce->sf_idx[w*16+g], maxsf[w*16+g]); + break; + } + } + } + prev = sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], mindeltasf, maxdeltasf); + if (sce->sf_idx[w*16+g] != prevsc) + fflag = 1; + nminscaler = FFMIN(nminscaler, sce->sf_idx[w*16+g]); + sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + } + start += sce->ics.swb_sizes[g]; + } + } + + /** SF difference limit violation risk. Must re-clamp. */ + prev = -1; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + for (g = 0; g < sce->ics.num_swb; g++) { + if (!sce->zeroes[w*16+g]) { + int prevsf = sce->sf_idx[w*16+g]; + if (prev < 0) + prev = prevsf; + sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], prev - SCALE_MAX_DIFF, prev + SCALE_MAX_DIFF); + sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + prev = sce->sf_idx[w*16+g]; + if (!fflag && prevsf != sce->sf_idx[w*16+g]) + fflag = 1; + } + } + } + + its++; + } while (fflag && its < maxits); + + /** Scout out next nonzero bands */ + ff_init_nextband_map(sce, nextband); + + prev = -1; + for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { + /** Make sure proper codebooks are set */ + for (g = 0; g < sce->ics.num_swb; g++) { + if (!sce->zeroes[w*16+g]) { + sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); + if (sce->band_type[w*16+g] <= 0) { + if (!ff_sfdelta_can_remove_band(sce, nextband, prev, w*16+g)) { + /** Cannot zero out, make sure it's not attempted */ + sce->band_type[w*16+g] = 1; + } else { + sce->zeroes[w*16+g] = 1; + sce->band_type[w*16+g] = 0; + } + } + } else { + sce->band_type[w*16+g] = 0; + } + /** Check that there's no SF delta range violations */ + if (!sce->zeroes[w*16+g]) { + if (prev != -1) { + av_unused int sfdiff = sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO; + av_assert1(sfdiff >= 0 && sfdiff <= 2*SCALE_MAX_DIFF); + } else if (sce->zeroes[0]) { + /** Set global gain to something useful */ + sce->sf_idx[0] = sce->sf_idx[w*16+g]; + } + prev = sce->sf_idx[w*16+g]; + } + } + } +} + +#endif /* AVCODEC_AACCODER_TWOLOOP_H */ |
