blob: 2f5b7eb8dc14aa6ec34f776d42eb9dc069b495bd
1 | /* |
2 | * AAC encoder intensity stereo |
3 | * Copyright (C) 2015 Rostislav Pehlivanov |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
7 | * FFmpeg is free software; you can redistribute it and/or |
8 | * modify it under the terms of the GNU Lesser General Public |
9 | * License as published by the Free Software Foundation; either |
10 | * version 2.1 of the License, or (at your option) any later version. |
11 | * |
12 | * FFmpeg is distributed in the hope that it will be useful, |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | * Lesser General Public License for more details. |
16 | * |
17 | * You should have received a copy of the GNU Lesser General Public |
18 | * License along with FFmpeg; if not, write to the Free Software |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
20 | */ |
21 | |
22 | /** |
23 | * @file |
24 | * AAC encoder Intensity Stereo |
25 | * @author Rostislav Pehlivanov ( atomnuker gmail com ) |
26 | */ |
27 | |
28 | #include "aacenc.h" |
29 | #include "aacenc_utils.h" |
30 | #include "aacenc_is.h" |
31 | #include "aacenc_quantization.h" |
32 | |
33 | struct AACISError ff_aac_is_encoding_err(AACEncContext *s, ChannelElement *cpe, |
34 | int start, int w, int g, float ener0, |
35 | float ener1, float ener01, |
36 | int use_pcoeffs, int phase) |
37 | { |
38 | int i, w2; |
39 | SingleChannelElement *sce0 = &cpe->ch[0]; |
40 | SingleChannelElement *sce1 = &cpe->ch[1]; |
41 | float *L = use_pcoeffs ? sce0->pcoeffs : sce0->coeffs; |
42 | float *R = use_pcoeffs ? sce1->pcoeffs : sce1->coeffs; |
43 | float *L34 = &s->scoefs[256*0], *R34 = &s->scoefs[256*1]; |
44 | float *IS = &s->scoefs[256*2], *I34 = &s->scoefs[256*3]; |
45 | float dist1 = 0.0f, dist2 = 0.0f; |
46 | struct AACISError is_error = {0}; |
47 | |
48 | if (ener01 <= 0 || ener0 <= 0) { |
49 | is_error.pass = 0; |
50 | return is_error; |
51 | } |
52 | |
53 | for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) { |
54 | FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g]; |
55 | FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g]; |
56 | int is_band_type, is_sf_idx = FFMAX(1, sce0->sf_idx[w*16+g]-4); |
57 | float e01_34 = phase*pos_pow34(ener1/ener0); |
58 | float maxval, dist_spec_err = 0.0f; |
59 | float minthr = FFMIN(band0->threshold, band1->threshold); |
60 | for (i = 0; i < sce0->ics.swb_sizes[g]; i++) |
61 | IS[i] = (L[start+(w+w2)*128+i] + phase*R[start+(w+w2)*128+i])*sqrt(ener0/ener01); |
62 | s->abs_pow34(L34, &L[start+(w+w2)*128], sce0->ics.swb_sizes[g]); |
63 | s->abs_pow34(R34, &R[start+(w+w2)*128], sce0->ics.swb_sizes[g]); |
64 | s->abs_pow34(I34, IS, sce0->ics.swb_sizes[g]); |
65 | maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34); |
66 | is_band_type = find_min_book(maxval, is_sf_idx); |
67 | dist1 += quantize_band_cost(s, &L[start + (w+w2)*128], L34, |
68 | sce0->ics.swb_sizes[g], |
69 | sce0->sf_idx[w*16+g], |
70 | sce0->band_type[w*16+g], |
71 | s->lambda / band0->threshold, INFINITY, NULL, NULL, 0); |
72 | dist1 += quantize_band_cost(s, &R[start + (w+w2)*128], R34, |
73 | sce1->ics.swb_sizes[g], |
74 | sce1->sf_idx[w*16+g], |
75 | sce1->band_type[w*16+g], |
76 | s->lambda / band1->threshold, INFINITY, NULL, NULL, 0); |
77 | dist2 += quantize_band_cost(s, IS, I34, sce0->ics.swb_sizes[g], |
78 | is_sf_idx, is_band_type, |
79 | s->lambda / minthr, INFINITY, NULL, NULL, 0); |
80 | for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { |
81 | dist_spec_err += (L34[i] - I34[i])*(L34[i] - I34[i]); |
82 | dist_spec_err += (R34[i] - I34[i]*e01_34)*(R34[i] - I34[i]*e01_34); |
83 | } |
84 | dist_spec_err *= s->lambda / minthr; |
85 | dist2 += dist_spec_err; |
86 | } |
87 | |
88 | is_error.pass = dist2 <= dist1; |
89 | is_error.phase = phase; |
90 | is_error.error = dist2 - dist1; |
91 | is_error.dist1 = dist1; |
92 | is_error.dist2 = dist2; |
93 | is_error.ener01 = ener01; |
94 | |
95 | return is_error; |
96 | } |
97 | |
98 | void ff_aac_search_for_is(AACEncContext *s, AVCodecContext *avctx, ChannelElement *cpe) |
99 | { |
100 | SingleChannelElement *sce0 = &cpe->ch[0]; |
101 | SingleChannelElement *sce1 = &cpe->ch[1]; |
102 | int start = 0, count = 0, w, w2, g, i, prev_sf1 = -1, prev_bt = -1, prev_is = 0; |
103 | const float freq_mult = avctx->sample_rate/(1024.0f/sce0->ics.num_windows)/2.0f; |
104 | uint8_t nextband1[128]; |
105 | |
106 | if (!cpe->common_window) |
107 | return; |
108 | |
109 | /** Scout out next nonzero bands */ |
110 | ff_init_nextband_map(sce1, nextband1); |
111 | |
112 | for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) { |
113 | start = 0; |
114 | for (g = 0; g < sce0->ics.num_swb; g++) { |
115 | if (start*freq_mult > INT_STEREO_LOW_LIMIT*(s->lambda/170.0f) && |
116 | cpe->ch[0].band_type[w*16+g] != NOISE_BT && !cpe->ch[0].zeroes[w*16+g] && |
117 | cpe->ch[1].band_type[w*16+g] != NOISE_BT && !cpe->ch[1].zeroes[w*16+g] && |
118 | ff_sfdelta_can_remove_band(sce1, nextband1, prev_sf1, w*16+g)) { |
119 | float ener0 = 0.0f, ener1 = 0.0f, ener01 = 0.0f, ener01p = 0.0f; |
120 | struct AACISError ph_err1, ph_err2, *best; |
121 | for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) { |
122 | for (i = 0; i < sce0->ics.swb_sizes[g]; i++) { |
123 | float coef0 = sce0->coeffs[start+(w+w2)*128+i]; |
124 | float coef1 = sce1->coeffs[start+(w+w2)*128+i]; |
125 | ener0 += coef0*coef0; |
126 | ener1 += coef1*coef1; |
127 | ener01 += (coef0 + coef1)*(coef0 + coef1); |
128 | ener01p += (coef0 - coef1)*(coef0 - coef1); |
129 | } |
130 | } |
131 | ph_err1 = ff_aac_is_encoding_err(s, cpe, start, w, g, |
132 | ener0, ener1, ener01p, 0, -1); |
133 | ph_err2 = ff_aac_is_encoding_err(s, cpe, start, w, g, |
134 | ener0, ener1, ener01, 0, +1); |
135 | best = (ph_err1.pass && ph_err1.error < ph_err2.error) ? &ph_err1 : &ph_err2; |
136 | if (best->pass) { |
137 | cpe->is_mask[w*16+g] = 1; |
138 | cpe->ms_mask[w*16+g] = 0; |
139 | cpe->ch[0].is_ener[w*16+g] = sqrt(ener0 / best->ener01); |
140 | cpe->ch[1].is_ener[w*16+g] = ener0/ener1; |
141 | cpe->ch[1].band_type[w*16+g] = (best->phase > 0) ? INTENSITY_BT : INTENSITY_BT2; |
142 | if (prev_is && prev_bt != cpe->ch[1].band_type[w*16+g]) { |
143 | /** Flip M/S mask and pick the other CB, since it encodes more efficiently */ |
144 | cpe->ms_mask[w*16+g] = 1; |
145 | cpe->ch[1].band_type[w*16+g] = (best->phase > 0) ? INTENSITY_BT2 : INTENSITY_BT; |
146 | } |
147 | prev_bt = cpe->ch[1].band_type[w*16+g]; |
148 | count++; |
149 | } |
150 | } |
151 | if (!sce1->zeroes[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT) |
152 | prev_sf1 = sce1->sf_idx[w*16+g]; |
153 | prev_is = cpe->is_mask[w*16+g]; |
154 | start += sce0->ics.swb_sizes[g]; |
155 | } |
156 | } |
157 | cpe->is_mode = !!count; |
158 | } |
159 |