| /* |
| * 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 "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 "aac_tablegen_decl.h" |
| |
| #include "aacenc_is.h" |
| #include "aacenc_tns.h" |
| #include "aacenc_pred.h" |
| |
| /** Frequency in Hz for lower limit of noise substitution **/ |
| #define NOISE_LOW_LIMIT 4500 |
| |
| /* Energy spread threshold value below which no PNS is used, this corresponds to |
| * typically around 17Khz, after which PNS usage decays ending at 19Khz */ |
| #define NOISE_SPREAD_THRESHOLD 0.5f |
| |
| /* This constant gets divided by lambda to return ~1.65 which when multiplied |
| * by the band->threshold and compared to band->energy is the boundary between |
| * excessive PNS and little PNS usage. */ |
| #define NOISE_LAMBDA_NUMERATOR 252.1f |
| |
| /** |
| * 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, 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); |
| } |
| } |
| |
| static void codebook_trellis_rate(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_minbits = 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 = run_bits+4; |
| 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]) { |
| float cost_stay_here = path[swb][0].cost; |
| float cost_get_here = next_minbits + run_bits + 4; |
| if ( run_value_bits[sce->ics.num_windows == 8][path[swb][0].run] |
| != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1]) |
| cost_stay_here += run_bits; |
| if (cost_get_here < cost_stay_here) { |
| path[swb+1][0].prev_idx = next_mincb; |
| path[swb+1][0].cost = cost_get_here; |
| path[swb+1][0].run = 1; |
| } else { |
| path[swb+1][0].prev_idx = 0; |
| path[swb+1][0].cost = cost_stay_here; |
| path[swb+1][0].run = path[swb][0].run + 1; |
| } |
| next_minbits = path[swb+1][0].cost; |
| next_mincb = 0; |
| for (cb = 1; cb < CB_TOT_ALL; cb++) { |
| path[swb+1][cb].cost = 61450; |
| path[swb+1][cb].prev_idx = -1; |
| path[swb+1][cb].run = 0; |
| } |
| } else { |
| float minbits = next_minbits; |
| int mincb = next_mincb; |
| int startcb = sce->band_type[win*16+swb]; |
| startcb = aac_cb_in_map[startcb]; |
| next_minbits = INFINITY; |
| next_mincb = 0; |
| for (cb = 0; cb < startcb; cb++) { |
| path[swb+1][cb].cost = 61450; |
| path[swb+1][cb].prev_idx = -1; |
| path[swb+1][cb].run = 0; |
| } |
| for (cb = startcb; cb < CB_TOT_ALL; cb++) { |
| float cost_stay_here, cost_get_here; |
| float bits = 0.0f; |
| if (cb >= 12 && sce->band_type[win*16+swb] != aac_cb_out_map[cb]) { |
| path[swb+1][cb].cost = 61450; |
| path[swb+1][cb].prev_idx = -1; |
| path[swb+1][cb].run = 0; |
| continue; |
| } |
| for (w = 0; w < group_len; w++) { |
| bits += quantize_band_cost(s, &sce->coeffs[start + w*128], |
| &s->scoefs[start + w*128], size, |
| sce->sf_idx[win*16+swb], |
| aac_cb_out_map[cb], |
| 0, INFINITY, NULL, 0); |
| } |
| cost_stay_here = path[swb][cb].cost + bits; |
| cost_get_here = minbits + bits + 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_minbits) { |
| next_minbits = 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(ceilf(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(4+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 = coef2minsf(q0f); |
| //maximum scalefactor index is when maximum coefficient after quantizing is still not zero |
| q1 = coef2maxsf(q1f); |
| 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; |
| } |
| } |
| |
| 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); |
| 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, 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 = paths[idx][minq].prev; |
| 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]; |
| } |
| |
| /** |
| * 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; |
| 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); |
| //XXX: 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]) { |
| 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->zeroes[w*16+g] = !nz; |
| if (nz) |
| minthr = FFMIN(minthr, uplim); |
| allz |= nz; |
| } |
| } |
| 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; |
| 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 *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(s, coefs + w2*128, |
| scaled + w2*128, |
| sce->ics.swb_sizes[g], |
| sce->sf_idx[w*16+g], |
| cb, |
| 1.0f, |
| INFINITY, |
| &b, |
| 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_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, |
| 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) |
| { |
| int start = 0, w, w2, g; |
| const float lambda = s->lambda; |
| const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f; |
| const float spread_threshold = NOISE_SPREAD_THRESHOLD*(lambda/120.f); |
| const float thr_mult = NOISE_LAMBDA_NUMERATOR/lambda; |
| |
| 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 (start*freq_mult > NOISE_LOW_LIMIT*(lambda/170.0f)) { |
| float energy = 0.0f, threshold = 0.0f, spread = 0.0f; |
| for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) { |
| FFPsyBand *band = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g]; |
| energy += band->energy; |
| threshold += band->threshold; |
| spread += band->spread; |
| } |
| if (spread > spread_threshold*sce->ics.group_len[w] && |
| ((sce->zeroes[w*16+g] && energy >= threshold) || |
| energy < threshold*thr_mult*sce->ics.group_len[w])) { |
| sce->band_type[w*16+g] = NOISE_BT; |
| sce->pns_ener[w*16+g] = energy / sce->ics.group_len[w]; |
| sce->zeroes[w*16+g] = 0; |
| } |
| } |
| start += sce->ics.swb_sizes[g]; |
| } |
| } |
| } |
| |
| static void search_for_ms(AACEncContext *s, ChannelElement *cpe) |
| { |
| int start = 0, i, w, w2, g; |
| 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; |
| SingleChannelElement *sce0 = &cpe->ch[0]; |
| SingleChannelElement *sce1 = &cpe->ch[1]; |
| if (!cpe->common_window) |
| return; |
| 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++) { |
| if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g]) { |
| float dist1 = 0.0f, dist2 = 0.0f; |
| 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); |
| float maxthr = FFMAX(band0->threshold, band1->threshold); |
| 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, 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, 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 / maxthr, INFINITY, 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], |
| lambda / minthr, INFINITY, NULL, 0); |
| } |
| cpe->ms_mask[w*16+g] = dist2 < dist1; |
| } |
| 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_main_pred, |
| ff_aac_adjust_common_prediction, |
| ff_aac_apply_main_pred, |
| ff_aac_apply_tns, |
| set_special_band_scalefactors, |
| search_for_pns, |
| ff_aac_search_for_tns, |
| 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_main_pred, |
| ff_aac_adjust_common_prediction, |
| ff_aac_apply_main_pred, |
| ff_aac_apply_tns, |
| set_special_band_scalefactors, |
| search_for_pns, |
| ff_aac_search_for_tns, |
| 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_main_pred, |
| ff_aac_adjust_common_prediction, |
| ff_aac_apply_main_pred, |
| ff_aac_apply_tns, |
| set_special_band_scalefactors, |
| search_for_pns, |
| ff_aac_search_for_tns, |
| 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_main_pred, |
| ff_aac_adjust_common_prediction, |
| ff_aac_apply_main_pred, |
| ff_aac_apply_tns, |
| set_special_band_scalefactors, |
| search_for_pns, |
| ff_aac_search_for_tns, |
| search_for_ms, |
| ff_aac_search_for_is, |
| ff_aac_search_for_pred, |
| }, |
| }; |
