/* * AAC coefficients encoder * 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 coefficients encoder */ /*********************************** * TODOs: * speedup quantizer selection * add sane pulse detection ***********************************/ #include "libavutil/libm.h" // brought forward to work around cygwin header breakage #include #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" #include "aacenc_utils.h" #include "aacenc_quantization.h" #include "aacenc_is.h" #include "aacenc_tns.h" #include "aacenc_ltp.h" #include "aacenc_pred.h" #include "libavcodec/aaccoder_twoloop.h" /* Parameter of f(x) = a*(lambda/100), defines the maximum fourier spread * beyond which no PNS is used (since the SFBs contain tone rather than noise) */ #define NOISE_SPREAD_THRESHOLD 0.9f /* Parameter of f(x) = a*(100/lambda), defines how much PNS is allowed to * replace low energy non zero bands */ #define NOISE_LAMBDA_REPLACE 1.948f #include "libavcodec/aaccoder_trellis.h" /** * structure used in optimal codebook search */ typedef struct BandCodingPath { int prev_idx; ///< pointer to the previous path point float cost; ///< path cost int run; } BandCodingPath; /** * Encode band info for single window group bands. */ static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce, int win, int group_len, const float lambda) { BandCodingPath path[120][CB_TOT_ALL]; int w, swb, cb, start, size; int i, j; const int max_sfb = sce->ics.max_sfb; const int run_bits = sce->ics.num_windows == 1 ? 5 : 3; const int run_esc = (1 << run_bits) - 1; int idx, ppos, count; int stackrun[120], stackcb[120], stack_len; float next_minrd = INFINITY; int next_mincb = 0; abs_pow34_v(s->scoefs, sce->coeffs, 1024); start = win*128; for (cb = 0; cb < CB_TOT_ALL; cb++) { path[0][cb].cost = 0.0f; path[0][cb].prev_idx = -1; path[0][cb].run = 0; } for (swb = 0; swb < max_sfb; swb++) { size = sce->ics.swb_sizes[swb]; if (sce->zeroes[win*16 + swb]) { for (cb = 0; cb < CB_TOT_ALL; cb++) { path[swb+1][cb].prev_idx = cb; path[swb+1][cb].cost = path[swb][cb].cost; path[swb+1][cb].run = path[swb][cb].run + 1; } } else { float minrd = next_minrd; int mincb = next_mincb; next_minrd = INFINITY; next_mincb = 0; for (cb = 0; cb < CB_TOT_ALL; cb++) { float cost_stay_here, cost_get_here; float rd = 0.0f; if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] || cb < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) { path[swb+1][cb].prev_idx = -1; path[swb+1][cb].cost = INFINITY; path[swb+1][cb].run = path[swb][cb].run + 1; continue; } for (w = 0; w < group_len; w++) { FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb]; rd += quantize_band_cost(s, &sce->coeffs[start + w*128], &s->scoefs[start + w*128], size, sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb], lambda / band->threshold, INFINITY, NULL, NULL, 0); } cost_stay_here = path[swb][cb].cost + rd; cost_get_here = minrd + rd + run_bits + 4; if ( run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run] != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1]) cost_stay_here += run_bits; if (cost_get_here < cost_stay_here) { path[swb+1][cb].prev_idx = mincb; path[swb+1][cb].cost = cost_get_here; path[swb+1][cb].run = 1; } else { path[swb+1][cb].prev_idx = cb; path[swb+1][cb].cost = cost_stay_here; path[swb+1][cb].run = path[swb][cb].run + 1; } if (path[swb+1][cb].cost < next_minrd) { next_minrd = path[swb+1][cb].cost; next_mincb = cb; } } } start += sce->ics.swb_sizes[swb]; } //convert resulting path from backward-linked list stack_len = 0; idx = 0; for (cb = 1; cb < CB_TOT_ALL; cb++) if (path[max_sfb][cb].cost < path[max_sfb][idx].cost) idx = cb; ppos = max_sfb; while (ppos > 0) { av_assert1(idx >= 0); cb = idx; stackrun[stack_len] = path[ppos][cb].run; stackcb [stack_len] = cb; idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx; ppos -= path[ppos][cb].run; stack_len++; } //perform actual band info encoding start = 0; for (i = stack_len - 1; i >= 0; i--) { cb = aac_cb_out_map[stackcb[i]]; put_bits(&s->pb, 4, cb); count = stackrun[i]; memset(sce->zeroes + win*16 + start, !cb, count); //XXX: memset when band_type is also uint8_t for (j = 0; j < count; j++) { sce->band_type[win*16 + start] = cb; start++; } while (count >= run_esc) { put_bits(&s->pb, run_bits, run_esc); count -= run_esc; } put_bits(&s->pb, run_bits, count); } } typedef struct TrellisPath { float cost; int prev; } TrellisPath; #define TRELLIS_STAGES 121 #define TRELLIS_STATES (SCALE_MAX_DIFF+1) static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce) { int w, g, start = 0; int minscaler_n = sce->sf_idx[0], minscaler_i = sce->sf_idx[0]; int bands = 0; for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { start = 0; for (g = 0; g < sce->ics.num_swb; g++) { if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) { sce->sf_idx[w*16+g] = av_clip(roundf(log2f(sce->is_ener[w*16+g])*2), -155, 100); minscaler_i = FFMIN(minscaler_i, sce->sf_idx[w*16+g]); bands++; } else if (sce->band_type[w*16+g] == NOISE_BT) { sce->sf_idx[w*16+g] = av_clip(3+ceilf(log2f(sce->pns_ener[w*16+g])*2), -100, 155); minscaler_n = FFMIN(minscaler_n, sce->sf_idx[w*16+g]); bands++; } start += sce->ics.swb_sizes[g]; } } if (!bands) return; /* Clip the scalefactor indices */ 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->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) { sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_i, minscaler_i + SCALE_MAX_DIFF); } else if (sce->band_type[w*16+g] == NOISE_BT) { sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_n, minscaler_n + SCALE_MAX_DIFF); } } } } static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda) { int q, w, w2, g, start = 0; int i, j; int idx; TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES]; int bandaddr[TRELLIS_STAGES]; int minq; float mincost; float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f; int q0, q1, qcnt = 0; for (i = 0; i < 1024; i++) { float t = fabsf(sce->coeffs[i]); if (t > 0.0f) { q0f = FFMIN(q0f, t); q1f = FFMAX(q1f, t); qnrgf += t*t; qcnt++; } } if (!qcnt) { memset(sce->sf_idx, 0, sizeof(sce->sf_idx)); memset(sce->zeroes, 1, sizeof(sce->zeroes)); return; } //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped q0 = av_clip(coef2minsf(q0f), 0, SCALE_MAX_POS-1); //maximum scalefactor index is when maximum coefficient after quantizing is still not zero q1 = av_clip(coef2maxsf(q1f), 1, SCALE_MAX_POS); if (q1 - q0 > 60) { int q0low = q0; int q1high = q1; //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512); q1 = qnrg + 30; q0 = qnrg - 30; if (q0 < q0low) { q1 += q0low - q0; q0 = q0low; } else if (q1 > q1high) { q0 -= q1 - q1high; q1 = q1high; } } // q0 == q1 isn't really a legal situation if (q0 == q1) { // the following is indirect but guarantees q1 != q0 && q1 near q0 q1 = av_clip(q0+1, 1, SCALE_MAX_POS); q0 = av_clip(q1-1, 0, SCALE_MAX_POS - 1); } for (i = 0; i < TRELLIS_STATES; i++) { paths[0][i].cost = 0.0f; paths[0][i].prev = -1; } for (j = 1; j < TRELLIS_STAGES; j++) { for (i = 0; i < TRELLIS_STATES; i++) { paths[j][i].cost = INFINITY; paths[j][i].prev = -2; } } idx = 1; abs_pow34_v(s->scoefs, sce->coeffs, 1024); 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]; float qmin, qmax; int nz = 0; bandaddr[idx] = w * 16 + g; qmin = INT_MAX; qmax = 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 (band->energy <= band->threshold || band->threshold == 0.0f) { sce->zeroes[(w+w2)*16+g] = 1; continue; } sce->zeroes[(w+w2)*16+g] = 0; nz = 1; for (i = 0; i < sce->ics.swb_sizes[g]; i++) { float t = fabsf(coefs[w2*128+i]); if (t > 0.0f) qmin = FFMIN(qmin, t); qmax = FFMAX(qmax, t); } } if (nz) { int minscale, maxscale; float minrd = INFINITY; float maxval; //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped minscale = coef2minsf(qmin); //maximum scalefactor index is when maximum coefficient after quantizing is still not zero maxscale = coef2maxsf(qmax); minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1); maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES); if (minscale == maxscale) { maxscale = av_clip(minscale+1, 1, TRELLIS_STATES); minscale = av_clip(maxscale-1, 0, TRELLIS_STATES - 1); } maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start); for (q = minscale; q < maxscale; q++) { float dist = 0; int cb = find_min_book(maxval, sce->sf_idx[w*16+g]); for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g], q + q0, cb, lambda / band->threshold, INFINITY, NULL, NULL, 0); } minrd = FFMIN(minrd, dist); for (i = 0; i < q1 - q0; i++) { float cost; cost = paths[idx - 1][i].cost + dist + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO]; if (cost < paths[idx][q].cost) { paths[idx][q].cost = cost; paths[idx][q].prev = i; } } } } else { for (q = 0; q < q1 - q0; q++) { paths[idx][q].cost = paths[idx - 1][q].cost + 1; paths[idx][q].prev = q; } } sce->zeroes[w*16+g] = !nz; start += sce->ics.swb_sizes[g]; idx++; } } idx--; mincost = paths[idx][0].cost; minq = 0; for (i = 1; i < TRELLIS_STATES; i++) { if (paths[idx][i].cost < mincost) { mincost = paths[idx][i].cost; minq = i; } } while (idx) { sce->sf_idx[bandaddr[idx]] = minq + q0; minq = FFMAX(paths[idx][minq].prev, 0); idx--; } //set the same quantizers inside window groups for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) for (g = 0; g < sce->ics.num_swb; g++) for (w2 = 1; w2 < sce->ics.group_len[w]; w2++) sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g]; } static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda) { int start = 0, i, w, w2, g; float uplim[128], maxq[128]; int minq, maxsf; float distfact = ((sce->ics.num_windows > 1) ? 85.80 : 147.84) / lambda; int last = 0, lastband = 0, curband = 0; float avg_energy = 0.0; if (sce->ics.num_windows == 1) { start = 0; for (i = 0; i < 1024; i++) { if (i - start >= sce->ics.swb_sizes[curband]) { start += sce->ics.swb_sizes[curband]; curband++; } if (sce->coeffs[i]) { avg_energy += sce->coeffs[i] * sce->coeffs[i]; last = i; lastband = curband; } } } else { for (w = 0; w < 8; w++) { const float *coeffs = &sce->coeffs[w*128]; curband = start = 0; for (i = 0; i < 128; i++) { if (i - start >= sce->ics.swb_sizes[curband]) { start += sce->ics.swb_sizes[curband]; curband++; } if (coeffs[i]) { avg_energy += coeffs[i] * coeffs[i]; last = FFMAX(last, i); lastband = FFMAX(lastband, curband); } } } } last++; avg_energy /= last; if (avg_energy == 0.0f) { for (i = 0; i < FF_ARRAY_ELEMS(sce->sf_idx); i++) sce->sf_idx[i] = SCALE_ONE_POS; return; } 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++) { float *coefs = &sce->coeffs[start]; const int size = sce->ics.swb_sizes[g]; int start2 = start, end2 = start + size, peakpos = start; float maxval = -1, thr = 0.0f, t; maxq[w*16+g] = 0.0f; if (g > lastband) { maxq[w*16+g] = 0.0f; start += size; for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) memset(coefs + w2*128, 0, sizeof(coefs[0])*size); continue; } for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { for (i = 0; i < size; i++) { float t = coefs[w2*128+i]*coefs[w2*128+i]; maxq[w*16+g] = FFMAX(maxq[w*16+g], fabsf(coefs[w2*128 + i])); thr += t; if (sce->ics.num_windows == 1 && maxval < t) { maxval = t; peakpos = start+i; } } } if (sce->ics.num_windows == 1) { start2 = FFMAX(peakpos - 2, start2); end2 = FFMIN(peakpos + 3, end2); } else { start2 -= start; end2 -= start; } start += size; thr = pow(thr / (avg_energy * (end2 - start2)), 0.3 + 0.1*(lastband - g) / lastband); t = 1.0 - (1.0 * start2 / last); uplim[w*16+g] = distfact / (1.4 * thr + t*t*t + 0.075); } } memset(sce->sf_idx, 0, sizeof(sce->sf_idx)); abs_pow34_v(s->scoefs, sce->coeffs, 1024); 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]; const int size = sce->ics.swb_sizes[g]; int scf, prev_scf, step; int min_scf = -1, max_scf = 256; float curdiff; if (maxq[w*16+g] < 21.544) { sce->zeroes[w*16+g] = 1; start += size; continue; } sce->zeroes[w*16+g] = 0; scf = prev_scf = av_clip(SCALE_ONE_POS - SCALE_DIV_512 - log2f(1/maxq[w*16+g])*16/3, 60, 218); for (;;) { float dist = 0.0f; int quant_max; for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { int b; dist += quantize_band_cost(s, coefs + w2*128, scaled + w2*128, sce->ics.swb_sizes[g], scf, ESC_BT, lambda, INFINITY, &b, NULL, 0); dist -= b; } dist *= 1.0f / 512.0f / lambda; quant_max = quant(maxq[w*16+g], ff_aac_pow2sf_tab[POW_SF2_ZERO - scf + SCALE_ONE_POS - SCALE_DIV_512], ROUND_STANDARD); if (quant_max >= 8191) { // too much, return to the previous quantizer sce->sf_idx[w*16+g] = prev_scf; break; } prev_scf = scf; curdiff = fabsf(dist - uplim[w*16+g]); if (curdiff <= 1.0f) step = 0; else step = log2f(curdiff); if (dist > uplim[w*16+g]) step = -step; scf += step; scf = av_clip_uint8(scf); step = scf - prev_scf; if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) { sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf); break; } if (step > 0) min_scf = prev_scf; else max_scf = prev_scf; } start += size; } } minq = sce->sf_idx[0] ? sce->sf_idx[0] : INT_MAX; for (i = 1; i < 128; i++) { if (!sce->sf_idx[i]) sce->sf_idx[i] = sce->sf_idx[i-1]; else minq = FFMIN(minq, sce->sf_idx[i]); } if (minq == INT_MAX) minq = 0; minq = FFMIN(minq, SCALE_MAX_POS); maxsf = FFMIN(minq + SCALE_MAX_DIFF, SCALE_MAX_POS); for (i = 126; i >= 0; i--) { if (!sce->sf_idx[i]) sce->sf_idx[i] = sce->sf_idx[i+1]; sce->sf_idx[i] = av_clip(sce->sf_idx[i], minq, maxsf); } } static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s, SingleChannelElement *sce, const float lambda) { int i, w, w2, g; int minq = 255; memset(sce->sf_idx, 0, sizeof(sce->sf_idx)); for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { for (g = 0; g < sce->ics.num_swb; g++) { 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) { sce->sf_idx[(w+w2)*16+g] = 218; sce->zeroes[(w+w2)*16+g] = 1; } else { sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218); sce->zeroes[(w+w2)*16+g] = 0; } minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]); } } } for (i = 0; i < 128; i++) { sce->sf_idx[i] = 140; //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1); } //set the same quantizers inside window groups for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) for (g = 0; g < sce->ics.num_swb; g++) for (w2 = 1; w2 < sce->ics.group_len[w]; w2++) sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g]; } static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce) { FFPsyBand *band; int w, g, w2, i; int wlen = 1024 / sce->ics.num_windows; int bandwidth, cutoff; float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128]; float *NOR34 = &s->scoefs[3*128]; uint8_t nextband[128]; const float lambda = s->lambda; const float freq_mult = avctx->sample_rate*0.5f/wlen; const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda); const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f)); const float dist_bias = av_clipf(4.f * 120 / lambda, 0.25f, 4.0f); const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f); int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels) * (lambda / 120.f); /** Keep this in sync with twoloop's cutoff selection */ float rate_bandwidth_multiplier = 1.5f; int prev = -1000, prev_sf = -1; int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE) ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024) : (avctx->bit_rate / avctx->channels); 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)); } cutoff = bandwidth * 2 * wlen / avctx->sample_rate; memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type)); ff_init_nextband_map(sce, nextband); for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { int wstart = w*128; for (g = 0; g < sce->ics.num_swb; g++) { int noise_sfi; float dist1 = 0.0f, dist2 = 0.0f, noise_amp; float pns_energy = 0.0f, pns_tgt_energy, energy_ratio, dist_thresh; float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f; float min_energy = -1.0f, max_energy = 0.0f; const int start = wstart+sce->ics.swb_offset[g]; const float freq = (start-wstart)*freq_mult; const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f); if (freq < NOISE_LOW_LIMIT || (start-wstart) >= cutoff) continue; for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; sfb_energy += band->energy; spread = FFMIN(spread, band->spread); threshold += band->threshold; if (!w2) { min_energy = max_energy = band->energy; } else { min_energy = FFMIN(min_energy, band->energy); max_energy = FFMAX(max_energy, band->energy); } } /* Ramps down at ~8000Hz and loosens the dist threshold */ dist_thresh = av_clipf(2.5f*NOISE_LOW_LIMIT/freq, 0.5f, 2.5f) * dist_bias; /* PNS is acceptable when all of these are true: * 1. high spread energy (noise-like band) * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed) * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS) * * At this stage, point 2 is relaxed for zeroed bands near the noise threshold (hole avoidance is more important) */ if ((!sce->zeroes[w*16+g] && !ff_sfdelta_can_remove_band(sce, nextband, prev_sf, w*16+g)) || ((sce->zeroes[w*16+g] || !sce->band_alt[w*16+g]) && sfb_energy < threshold*sqrtf(1.0f/freq_boost)) || spread < spread_threshold || (!sce->zeroes[w*16+g] && sce->band_alt[w*16+g] && sfb_energy > threshold*thr_mult*freq_boost) || min_energy < pns_transient_energy_r * max_energy ) { sce->pns_ener[w*16+g] = sfb_energy; if (!sce->zeroes[w*16+g]) prev_sf = sce->sf_idx[w*16+g]; continue; } pns_tgt_energy = sfb_energy*FFMIN(1.0f, spread*spread); noise_sfi = av_clip(roundf(log2f(pns_tgt_energy)*2), -100, 155); /* Quantize */ noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO]; /* Dequantize */ if (prev != -1000) { int noise_sfdiff = noise_sfi - prev + SCALE_DIFF_ZERO; if (noise_sfdiff < 0 || noise_sfdiff > 2*SCALE_MAX_DIFF) { if (!sce->zeroes[w*16+g]) prev_sf = sce->sf_idx[w*16+g]; continue; } } for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { float band_energy, scale, pns_senergy; const int start_c = (w+w2)*128+sce->ics.swb_offset[g]; band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; for (i = 0; i < sce->ics.swb_sizes[g]; i+=2) { double rnd[2]; av_bmg_get(&s->lfg, rnd); PNS[i+0] = (float)rnd[0]; PNS[i+1] = (float)rnd[1]; } band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]); scale = noise_amp/sqrtf(band_energy); s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]); pns_senergy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]); pns_energy += pns_senergy; abs_pow34_v(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]); abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]); dist1 += quantize_band_cost(s, &sce->coeffs[start_c], NOR34, sce->ics.swb_sizes[g], sce->sf_idx[(w+w2)*16+g], sce->band_alt[(w+w2)*16+g], lambda/band->threshold, INFINITY, NULL, NULL, 0); /* Estimate rd on average as 5 bits for SF, 4 for the CB, plus spread energy * lambda/thr */ dist2 += band->energy/(band->spread*band->spread)*lambda*dist_thresh/band->threshold; } if (g && sce->band_type[w*16+g-1] == NOISE_BT) { dist2 += 5; } else { dist2 += 9; } energy_ratio = pns_tgt_energy/pns_energy; /* Compensates for quantization error */ sce->pns_ener[w*16+g] = energy_ratio*pns_tgt_energy; if (sce->zeroes[w*16+g] || !sce->band_alt[w*16+g] || (energy_ratio > 0.85f && energy_ratio < 1.25f && dist2 < dist1)) { sce->band_type[w*16+g] = NOISE_BT; sce->zeroes[w*16+g] = 0; prev = noise_sfi; } if (!sce->zeroes[w*16+g]) prev_sf = sce->sf_idx[w*16+g]; } } } static void mark_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce) { FFPsyBand *band; int w, g, w2; int wlen = 1024 / sce->ics.num_windows; int bandwidth, cutoff; const float lambda = s->lambda; const float freq_mult = avctx->sample_rate*0.5f/wlen; const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f)); const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f); int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels) * (lambda / 120.f); /** Keep this in sync with twoloop's cutoff selection */ float rate_bandwidth_multiplier = 1.5f; int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE) ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024) : (avctx->bit_rate / avctx->channels); 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)); } cutoff = bandwidth * 2 * wlen / avctx->sample_rate; memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type)); for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { for (g = 0; g < sce->ics.num_swb; g++) { float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f; float min_energy = -1.0f, max_energy = 0.0f; const int start = sce->ics.swb_offset[g]; const float freq = start*freq_mult; const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f); if (freq < NOISE_LOW_LIMIT || start >= cutoff) { sce->can_pns[w*16+g] = 0; continue; } for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g]; sfb_energy += band->energy; spread = FFMIN(spread, band->spread); threshold += band->threshold; if (!w2) { min_energy = max_energy = band->energy; } else { min_energy = FFMIN(min_energy, band->energy); max_energy = FFMAX(max_energy, band->energy); } } /* PNS is acceptable when all of these are true: * 1. high spread energy (noise-like band) * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed) * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS) */ sce->pns_ener[w*16+g] = sfb_energy; if (sfb_energy < threshold*sqrtf(1.5f/freq_boost) || spread < spread_threshold || min_energy < pns_transient_energy_r * max_energy) { sce->can_pns[w*16+g] = 0; } else { sce->can_pns[w*16+g] = 1; } } } } static void search_for_ms(AACEncContext *s, ChannelElement *cpe) { int start = 0, i, w, w2, g, sid_sf_boost, prev_mid, prev_side; uint8_t nextband0[128], nextband1[128]; float M[128], S[128]; float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3; const float lambda = s->lambda; const float mslambda = FFMIN(1.0f, lambda / 120.f); SingleChannelElement *sce0 = &cpe->ch[0]; SingleChannelElement *sce1 = &cpe->ch[1]; if (!cpe->common_window) return; /** Scout out next nonzero bands */ ff_init_nextband_map(sce0, nextband0); ff_init_nextband_map(sce1, nextband1); prev_mid = sce0->sf_idx[0]; prev_side = sce1->sf_idx[0]; for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) { start = 0; for (g = 0; g < sce0->ics.num_swb; g++) { float bmax = bval2bmax(g * 17.0f / sce0->ics.num_swb) / 0.0045f; cpe->ms_mask[w*16+g] = 0; if (!sce0->zeroes[w*16+g] && !sce1->zeroes[w*16+g]) { float Mmax = 0.0f, Smax = 0.0f; /* Must compute mid/side SF and book for the whole window group */ for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) { for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { M[i] = (sce0->coeffs[start+(w+w2)*128+i] + sce1->coeffs[start+(w+w2)*128+i]) * 0.5; S[i] = M[i] - sce1->coeffs[start+(w+w2)*128+i]; } abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]); abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]); for (i = 0; i < sce0->ics.swb_sizes[g]; i++ ) { Mmax = FFMAX(Mmax, M34[i]); Smax = FFMAX(Smax, S34[i]); } } for (sid_sf_boost = 0; sid_sf_boost < 4; sid_sf_boost++) { float dist1 = 0.0f, dist2 = 0.0f; int B0 = 0, B1 = 0; int minidx; int mididx, sididx; int midcb, sidcb; minidx = FFMIN(sce0->sf_idx[w*16+g], sce1->sf_idx[w*16+g]); mididx = av_clip(minidx, 0, SCALE_MAX_POS - SCALE_DIV_512); sididx = av_clip(minidx - sid_sf_boost * 3, 0, SCALE_MAX_POS - SCALE_DIV_512); if (!cpe->is_mask[w*16+g] && sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT && ( !ff_sfdelta_can_replace(sce0, nextband0, prev_mid, mididx, w*16+g) || !ff_sfdelta_can_replace(sce1, nextband1, prev_side, sididx, w*16+g))) { /* scalefactor range violation, bad stuff, will decrease quality unacceptably */ continue; } midcb = find_min_book(Mmax, mididx); sidcb = find_min_book(Smax, sididx); /* No CB can be zero */ midcb = FFMAX(1,midcb); sidcb = FFMAX(1,sidcb); for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) { FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g]; FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g]; float minthr = FFMIN(band0->threshold, band1->threshold); int b1,b2,b3,b4; for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { M[i] = (sce0->coeffs[start+(w+w2)*128+i] + sce1->coeffs[start+(w+w2)*128+i]) * 0.5; S[i] = M[i] - sce1->coeffs[start+(w+w2)*128+i]; } abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]); abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]); abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]); abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]); dist1 += quantize_band_cost(s, &sce0->coeffs[start + (w+w2)*128], L34, sce0->ics.swb_sizes[g], sce0->sf_idx[(w+w2)*16+g], sce0->band_type[(w+w2)*16+g], lambda / band0->threshold, INFINITY, &b1, NULL, 0); dist1 += quantize_band_cost(s, &sce1->coeffs[start + (w+w2)*128], R34, sce1->ics.swb_sizes[g], sce1->sf_idx[(w+w2)*16+g], sce1->band_type[(w+w2)*16+g], lambda / band1->threshold, INFINITY, &b2, NULL, 0); dist2 += quantize_band_cost(s, M, M34, sce0->ics.swb_sizes[g], sce0->sf_idx[(w+w2)*16+g], sce0->band_type[(w+w2)*16+g], lambda / minthr, INFINITY, &b3, NULL, 0); dist2 += quantize_band_cost(s, S, S34, sce1->ics.swb_sizes[g], sce1->sf_idx[(w+w2)*16+g], sce1->band_type[(w+w2)*16+g], mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0); B0 += b1+b2; B1 += b3+b4; dist1 -= B0; dist2 -= B1; } cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0; if (cpe->ms_mask[w*16+g]) { /* Setting the M/S mask is useful with I/S or PNS, but only the flag */ if (!cpe->is_mask[w*16+g] && sce0->band_type[w*16+g] != NOISE_BT && sce1->band_type[w*16+g] != NOISE_BT) { sce0->sf_idx[w*16+g] = mididx; sce1->sf_idx[w*16+g] = sididx; sce0->band_type[w*16+g] = midcb; sce1->band_type[w*16+g] = sidcb; } break; } else if (B1 > B0) { /* More boost won't fix this */ break; } } } if (!sce0->zeroes[w*16+g] && sce0->band_type[w*16+g] < RESERVED_BT) prev_mid = sce0->sf_idx[w*16+g]; if (!sce1->zeroes[w*16+g] && !cpe->is_mask[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT) prev_side = sce1->sf_idx[w*16+g]; start += sce0->ics.swb_sizes[g]; } } } AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB] = { [AAC_CODER_FAAC] = { search_for_quantizers_faac, encode_window_bands_info, quantize_and_encode_band, ff_aac_encode_tns_info, ff_aac_encode_ltp_info, ff_aac_encode_main_pred, ff_aac_adjust_common_pred, ff_aac_adjust_common_ltp, ff_aac_apply_main_pred, ff_aac_apply_tns, ff_aac_update_ltp, ff_aac_ltp_insert_new_frame, set_special_band_scalefactors, search_for_pns, mark_pns, ff_aac_search_for_tns, ff_aac_search_for_ltp, search_for_ms, ff_aac_search_for_is, ff_aac_search_for_pred, }, [AAC_CODER_ANMR] = { search_for_quantizers_anmr, encode_window_bands_info, quantize_and_encode_band, ff_aac_encode_tns_info, ff_aac_encode_ltp_info, ff_aac_encode_main_pred, ff_aac_adjust_common_pred, ff_aac_adjust_common_ltp, ff_aac_apply_main_pred, ff_aac_apply_tns, ff_aac_update_ltp, ff_aac_ltp_insert_new_frame, set_special_band_scalefactors, search_for_pns, mark_pns, ff_aac_search_for_tns, ff_aac_search_for_ltp, search_for_ms, ff_aac_search_for_is, ff_aac_search_for_pred, }, [AAC_CODER_TWOLOOP] = { search_for_quantizers_twoloop, codebook_trellis_rate, quantize_and_encode_band, ff_aac_encode_tns_info, ff_aac_encode_ltp_info, ff_aac_encode_main_pred, ff_aac_adjust_common_pred, ff_aac_adjust_common_ltp, ff_aac_apply_main_pred, ff_aac_apply_tns, ff_aac_update_ltp, ff_aac_ltp_insert_new_frame, set_special_band_scalefactors, search_for_pns, mark_pns, ff_aac_search_for_tns, ff_aac_search_for_ltp, search_for_ms, ff_aac_search_for_is, ff_aac_search_for_pred, }, [AAC_CODER_FAST] = { search_for_quantizers_fast, encode_window_bands_info, quantize_and_encode_band, ff_aac_encode_tns_info, ff_aac_encode_ltp_info, ff_aac_encode_main_pred, ff_aac_adjust_common_pred, ff_aac_adjust_common_ltp, ff_aac_apply_main_pred, ff_aac_apply_tns, ff_aac_update_ltp, ff_aac_ltp_insert_new_frame, set_special_band_scalefactors, search_for_pns, mark_pns, ff_aac_search_for_tns, ff_aac_search_for_ltp, search_for_ms, ff_aac_search_for_is, ff_aac_search_for_pred, }, };