| /* |
| * AAC encoder intensity stereo |
| * Copyright (C) 2015 Rostislav Pehlivanov |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * AAC encoder Intensity Stereo |
| * @author Rostislav Pehlivanov ( atomnuker gmail com ) |
| */ |
| |
| #include "aacenc.h" |
| #include "aacenc_utils.h" |
| #include "aacenc_is.h" |
| #include "aacenc_quantization.h" |
| |
| struct AACISError ff_aac_is_encoding_err(AACEncContext *s, ChannelElement *cpe, |
| int start, int w, int g, float ener0, |
| float ener1, float ener01, |
| int use_pcoeffs, int phase) |
| { |
| int i, w2; |
| SingleChannelElement *sce0 = &cpe->ch[0]; |
| SingleChannelElement *sce1 = &cpe->ch[1]; |
| float *L = use_pcoeffs ? sce0->pcoeffs : sce0->coeffs; |
| float *R = use_pcoeffs ? sce1->pcoeffs : sce1->coeffs; |
| float *L34 = &s->scoefs[256*0], *R34 = &s->scoefs[256*1]; |
| float *IS = &s->scoefs[256*2], *I34 = &s->scoefs[256*3]; |
| float dist1 = 0.0f, dist2 = 0.0f; |
| struct AACISError is_error = {0}; |
| |
| if (ener01 <= 0 || ener0 <= 0) { |
| is_error.pass = 0; |
| return is_error; |
| } |
| |
| 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]; |
| int is_band_type, is_sf_idx = FFMAX(1, sce0->sf_idx[w*16+g]-4); |
| float e01_34 = phase*pos_pow34(ener1/ener0); |
| float maxval, dist_spec_err = 0.0f; |
| float minthr = FFMIN(band0->threshold, band1->threshold); |
| for (i = 0; i < sce0->ics.swb_sizes[g]; i++) |
| IS[i] = (L[start+(w+w2)*128+i] + phase*R[start+(w+w2)*128+i])*sqrt(ener0/ener01); |
| s->abs_pow34(L34, &L[start+(w+w2)*128], sce0->ics.swb_sizes[g]); |
| s->abs_pow34(R34, &R[start+(w+w2)*128], sce0->ics.swb_sizes[g]); |
| s->abs_pow34(I34, IS, sce0->ics.swb_sizes[g]); |
| maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34); |
| is_band_type = find_min_book(maxval, is_sf_idx); |
| dist1 += quantize_band_cost(s, &L[start + (w+w2)*128], L34, |
| sce0->ics.swb_sizes[g], |
| sce0->sf_idx[w*16+g], |
| sce0->band_type[w*16+g], |
| s->lambda / band0->threshold, INFINITY, NULL, NULL, 0); |
| dist1 += quantize_band_cost(s, &R[start + (w+w2)*128], R34, |
| sce1->ics.swb_sizes[g], |
| sce1->sf_idx[w*16+g], |
| sce1->band_type[w*16+g], |
| s->lambda / band1->threshold, INFINITY, NULL, NULL, 0); |
| dist2 += quantize_band_cost(s, IS, I34, sce0->ics.swb_sizes[g], |
| is_sf_idx, is_band_type, |
| s->lambda / minthr, INFINITY, NULL, NULL, 0); |
| for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { |
| dist_spec_err += (L34[i] - I34[i])*(L34[i] - I34[i]); |
| dist_spec_err += (R34[i] - I34[i]*e01_34)*(R34[i] - I34[i]*e01_34); |
| } |
| dist_spec_err *= s->lambda / minthr; |
| dist2 += dist_spec_err; |
| } |
| |
| is_error.pass = dist2 <= dist1; |
| is_error.phase = phase; |
| is_error.error = dist2 - dist1; |
| is_error.dist1 = dist1; |
| is_error.dist2 = dist2; |
| is_error.ener01 = ener01; |
| |
| return is_error; |
| } |
| |
| void ff_aac_search_for_is(AACEncContext *s, AVCodecContext *avctx, ChannelElement *cpe) |
| { |
| SingleChannelElement *sce0 = &cpe->ch[0]; |
| SingleChannelElement *sce1 = &cpe->ch[1]; |
| int start = 0, count = 0, w, w2, g, i, prev_sf1 = -1, prev_bt = -1, prev_is = 0; |
| const float freq_mult = avctx->sample_rate/(1024.0f/sce0->ics.num_windows)/2.0f; |
| uint8_t nextband1[128]; |
| |
| if (!cpe->common_window) |
| return; |
| |
| /** Scout out next nonzero bands */ |
| ff_init_nextband_map(sce1, nextband1); |
| |
| 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 (start*freq_mult > INT_STEREO_LOW_LIMIT*(s->lambda/170.0f) && |
| cpe->ch[0].band_type[w*16+g] != NOISE_BT && !cpe->ch[0].zeroes[w*16+g] && |
| cpe->ch[1].band_type[w*16+g] != NOISE_BT && !cpe->ch[1].zeroes[w*16+g] && |
| ff_sfdelta_can_remove_band(sce1, nextband1, prev_sf1, w*16+g)) { |
| float ener0 = 0.0f, ener1 = 0.0f, ener01 = 0.0f, ener01p = 0.0f; |
| struct AACISError ph_err1, ph_err2, *best; |
| for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) { |
| for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { |
| float coef0 = sce0->coeffs[start+(w+w2)*128+i]; |
| float coef1 = sce1->coeffs[start+(w+w2)*128+i]; |
| ener0 += coef0*coef0; |
| ener1 += coef1*coef1; |
| ener01 += (coef0 + coef1)*(coef0 + coef1); |
| ener01p += (coef0 - coef1)*(coef0 - coef1); |
| } |
| } |
| ph_err1 = ff_aac_is_encoding_err(s, cpe, start, w, g, |
| ener0, ener1, ener01p, 0, -1); |
| ph_err2 = ff_aac_is_encoding_err(s, cpe, start, w, g, |
| ener0, ener1, ener01, 0, +1); |
| best = (ph_err1.pass && ph_err1.error < ph_err2.error) ? &ph_err1 : &ph_err2; |
| if (best->pass) { |
| cpe->is_mask[w*16+g] = 1; |
| cpe->ms_mask[w*16+g] = 0; |
| cpe->ch[0].is_ener[w*16+g] = sqrt(ener0 / best->ener01); |
| cpe->ch[1].is_ener[w*16+g] = ener0/ener1; |
| cpe->ch[1].band_type[w*16+g] = (best->phase > 0) ? INTENSITY_BT : INTENSITY_BT2; |
| if (prev_is && prev_bt != cpe->ch[1].band_type[w*16+g]) { |
| /** Flip M/S mask and pick the other CB, since it encodes more efficiently */ |
| cpe->ms_mask[w*16+g] = 1; |
| cpe->ch[1].band_type[w*16+g] = (best->phase > 0) ? INTENSITY_BT2 : INTENSITY_BT; |
| } |
| prev_bt = cpe->ch[1].band_type[w*16+g]; |
| count++; |
| } |
| } |
| if (!sce1->zeroes[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT) |
| prev_sf1 = sce1->sf_idx[w*16+g]; |
| prev_is = cpe->is_mask[w*16+g]; |
| start += sce0->ics.swb_sizes[g]; |
| } |
| } |
| cpe->is_mode = !!count; |
| } |
