| /* |
| * 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 <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" |
| #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; |
| |
| s->abs_pow34(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; |
| int prevscaler_n = -255, prevscaler_i = 0; |
| int bands = 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]) |
| continue; |
| 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); |
| 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); |
| if (prevscaler_n == -255) |
| prevscaler_n = sce->sf_idx[w*16+g]; |
| bands++; |
| } |
| } |
| } |
| |
| 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->zeroes[w*16+g]) |
| continue; |
| if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) { |
| sce->sf_idx[w*16+g] = prevscaler_i = av_clip(sce->sf_idx[w*16+g], prevscaler_i - SCALE_MAX_DIFF, prevscaler_i + SCALE_MAX_DIFF); |
| } else if (sce->band_type[w*16+g] == NOISE_BT) { |
| sce->sf_idx[w*16+g] = prevscaler_n = av_clip(sce->sf_idx[w*16+g], prevscaler_n - SCALE_MAX_DIFF, prevscaler_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; |
| s->abs_pow34(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_fast(AVCodecContext *avctx, AACEncContext *s, |
| SingleChannelElement *sce, |
| const float lambda) |
| { |
| int start = 0, i, w, w2, g; |
| int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / avctx->channels * (lambda / 120.f); |
| float dists[128] = { 0 }, uplims[128] = { 0 }; |
| float maxvals[128]; |
| int fflag, minscaler; |
| int its = 0; |
| int allz = 0; |
| float minthr = INFINITY; |
| |
| // 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); |
| //some heuristic to determine initial quantizers will reduce search time |
| //determine zero bands and upper limits |
| 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++) { |
| int nz = 0; |
| float uplim = 0.0f, energy = 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]; |
| uplim += band->threshold; |
| energy += band->energy; |
| if (band->energy <= band->threshold || band->threshold == 0.0f) { |
| sce->zeroes[(w+w2)*16+g] = 1; |
| continue; |
| } |
| nz = 1; |
| } |
| uplims[w*16+g] = uplim *512; |
| sce->band_type[w*16+g] = 0; |
| sce->zeroes[w*16+g] = !nz; |
| if (nz) |
| minthr = FFMIN(minthr, uplim); |
| allz |= nz; |
| start += sce->ics.swb_sizes[g]; |
| } |
| } |
| 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; |
| } |
| sce->sf_idx[w*16+g] = SCALE_ONE_POS + FFMIN(log2f(uplims[w*16+g]/minthr)*4,59); |
| } |
| } |
| |
| if (!allz) |
| return; |
| s->abs_pow34(s->scoefs, sce->coeffs, 1024); |
| ff_quantize_band_cost_cache_init(s); |
| |
| 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; |
| maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled); |
| start += sce->ics.swb_sizes[g]; |
| } |
| } |
| |
| //perform two-loop search |
| //outer loop - improve quality |
| do { |
| int tbits, qstep; |
| minscaler = sce->sf_idx[0]; |
| //inner loop - quantize spectrum to fit into given number of bits |
| qstep = its ? 1 : 32; |
| do { |
| int 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; |
| |
| if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) { |
| start += sce->ics.swb_sizes[g]; |
| continue; |
| } |
| minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]); |
| 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; |
| 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, NULL, 0); |
| bits += b; |
| } |
| dists[w*16+g] = dist - bits; |
| if (prev != -1) { |
| bits += ff_aac_scalefactor_bits[sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO]; |
| } |
| tbits += bits; |
| start += sce->ics.swb_sizes[g]; |
| prev = sce->sf_idx[w*16+g]; |
| } |
| } |
| if (tbits > destbits) { |
| for (i = 0; i < 128; i++) |
| if (sce->sf_idx[i] < 218 - qstep) |
| sce->sf_idx[i] += qstep; |
| } else { |
| for (i = 0; i < 128; i++) |
| if (sce->sf_idx[i] > 60 - qstep) |
| sce->sf_idx[i] -= qstep; |
| } |
| qstep >>= 1; |
| if (!qstep && tbits > destbits*1.02 && sce->sf_idx[0] < 217) |
| qstep = 1; |
| } while (qstep); |
| |
| fflag = 0; |
| minscaler = av_clip(minscaler, 60, 255 - SCALE_MAX_DIFF); |
| |
| for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) { |
| for (g = 0; g < sce->ics.num_swb; g++) { |
| int prevsc = sce->sf_idx[w*16+g]; |
| if (dists[w*16+g] > uplims[w*16+g] && sce->sf_idx[w*16+g] > 60) { |
| if (find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1)) |
| sce->sf_idx[w*16+g]--; |
| else //Try to make sure there is some energy in every band |
| sce->sf_idx[w*16+g]-=2; |
| } |
| sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF); |
| sce->sf_idx[w*16+g] = FFMIN(sce->sf_idx[w*16+g], 219); |
| if (sce->sf_idx[w*16+g] != prevsc) |
| fflag = 1; |
| sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]); |
| } |
| } |
| its++; |
| } while (fflag && its < 10); |
| } |
| |
| 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 & AV_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 & AV_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) { |
| 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++) { |
| 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++) { |
| s->random_state = lcg_random(s->random_state); |
| PNS[i] = s->random_state; |
| } |
| 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; |
| s->abs_pow34(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]); |
| s->abs_pow34(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; |
| } else { |
| 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 & AV_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 & AV_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 = s->scoefs + 128*0, *S = s->scoefs + 128*1; |
| float *L34 = s->scoefs + 128*2, *R34 = s->scoefs + 128*3; |
| float *M34 = s->scoefs + 128*4, *S34 = s->scoefs + 128*5; |
| 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; |
| if (!cpe->is_mask[w*16+g]) |
| cpe->ms_mask[w*16+g] = 0; |
| if (!sce0->zeroes[w*16+g] && !sce1->zeroes[w*16+g] && !cpe->is_mask[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]; |
| } |
| s->abs_pow34(M34, M, sce0->ics.swb_sizes[g]); |
| s->abs_pow34(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 (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]; |
| } |
| |
| s->abs_pow34(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]); |
| s->abs_pow34(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]); |
| s->abs_pow34(M34, M, sce0->ics.swb_sizes[g]); |
| s->abs_pow34(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*16+g], |
| sce0->band_type[w*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*16+g], |
| sce1->band_type[w*16+g], |
| lambda / band1->threshold, INFINITY, &b2, NULL, 0); |
| dist2 += quantize_band_cost(s, M, |
| M34, |
| sce0->ics.swb_sizes[g], |
| mididx, |
| midcb, |
| lambda / minthr, INFINITY, &b3, NULL, 0); |
| dist2 += quantize_band_cost(s, S, |
| S34, |
| sce1->ics.swb_sizes[g], |
| sididx, |
| sidcb, |
| mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0); |
| B0 += b1+b2; |
| B1 += b3+b4; |
| dist1 -= b1+b2; |
| dist2 -= b3+b4; |
| } |
| cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0; |
| if (cpe->ms_mask[w*16+g]) { |
| if (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; |
| } else if ((sce0->band_type[w*16+g] != NOISE_BT) ^ (sce1->band_type[w*16+g] != NOISE_BT)) { |
| /* ms_mask unneeded, and it confuses some decoders */ |
| cpe->ms_mask[w*16+g] = 0; |
| } |
| 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]; |
| } |
| } |
| } |
| |
| const AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB] = { |
| [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, |
| 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, |
| }, |
| }; |
