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1 /*
2  * Copyright (C) 2011 Michael Niedermayer (michaelni@gmx.at)
3  * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
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 #include <stdint.h>
23 
24 #include "libavutil/common.h"
25 #include "libavutil/libm.h"
26 #include "libavutil/samplefmt.h"
27 #include "avresample.h"
28 #include "internal.h"
29 #include "audio_data.h"
30 #include "audio_mix.h"
31 
32 /* channel positions */
33 #define FRONT_LEFT              0
34 #define FRONT_RIGHT             1
35 #define FRONT_CENTER            2
36 #define LOW_FREQUENCY           3
37 #define BACK_LEFT               4
38 #define BACK_RIGHT              5
39 #define FRONT_LEFT_OF_CENTER    6
40 #define FRONT_RIGHT_OF_CENTER   7
41 #define BACK_CENTER             8
42 #define SIDE_LEFT               9
43 #define SIDE_RIGHT             10
44 #define TOP_CENTER             11
45 #define TOP_FRONT_LEFT         12
46 #define TOP_FRONT_CENTER       13
47 #define TOP_FRONT_RIGHT        14
48 #define TOP_BACK_LEFT          15
49 #define TOP_BACK_CENTER        16
50 #define TOP_BACK_RIGHT         17
51 #define STEREO_LEFT            29
52 #define STEREO_RIGHT           30
53 #define WIDE_LEFT              31
54 #define WIDE_RIGHT             32
55 #define SURROUND_DIRECT_LEFT   33
56 #define SURROUND_DIRECT_RIGHT  34
57 #define LOW_FREQUENCY_2        35
58 
59 #define SQRT3_2      1.22474487139158904909  /* sqrt(3/2) */
60 
even(uint64_t layout)61 static av_always_inline int even(uint64_t layout)
62 {
63     return (!layout || !!(layout & (layout - 1)));
64 }
65 
sane_layout(uint64_t layout)66 static int sane_layout(uint64_t layout)
67 {
68     /* check that there is at least 1 front speaker */
69     if (!(layout & AV_CH_LAYOUT_SURROUND))
70         return 0;
71 
72     /* check for left/right symmetry */
73     if (!even(layout & (AV_CH_FRONT_LEFT           | AV_CH_FRONT_RIGHT))           ||
74         !even(layout & (AV_CH_SIDE_LEFT            | AV_CH_SIDE_RIGHT))            ||
75         !even(layout & (AV_CH_BACK_LEFT            | AV_CH_BACK_RIGHT))            ||
76         !even(layout & (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)) ||
77         !even(layout & (AV_CH_TOP_FRONT_LEFT       | AV_CH_TOP_FRONT_RIGHT))       ||
78         !even(layout & (AV_CH_TOP_BACK_LEFT        | AV_CH_TOP_BACK_RIGHT))        ||
79         !even(layout & (AV_CH_STEREO_LEFT          | AV_CH_STEREO_RIGHT))          ||
80         !even(layout & (AV_CH_WIDE_LEFT            | AV_CH_WIDE_RIGHT))            ||
81         !even(layout & (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)))
82         return 0;
83 
84     return 1;
85 }
86 
avresample_build_matrix(uint64_t in_layout,uint64_t out_layout,double center_mix_level,double surround_mix_level,double lfe_mix_level,int normalize,double * matrix_out,int stride,enum AVMatrixEncoding matrix_encoding)87 int avresample_build_matrix(uint64_t in_layout, uint64_t out_layout,
88                             double center_mix_level, double surround_mix_level,
89                             double lfe_mix_level, int normalize,
90                             double *matrix_out, int stride,
91                             enum AVMatrixEncoding matrix_encoding)
92 {
93     int i, j, out_i, out_j;
94     double matrix[64][64] = {{0}};
95     int64_t unaccounted;
96     double maxcoef = 0;
97     int in_channels, out_channels;
98 
99     if ((out_layout & AV_CH_LAYOUT_STEREO_DOWNMIX) == AV_CH_LAYOUT_STEREO_DOWNMIX) {
100         out_layout = AV_CH_LAYOUT_STEREO;
101     }
102 
103     unaccounted = in_layout & ~out_layout;
104 
105     in_channels  = av_get_channel_layout_nb_channels( in_layout);
106     out_channels = av_get_channel_layout_nb_channels(out_layout);
107 
108     memset(matrix_out, 0, out_channels * stride * sizeof(*matrix_out));
109 
110     /* check if layouts are supported */
111     if (!in_layout || in_channels > AVRESAMPLE_MAX_CHANNELS)
112         return AVERROR(EINVAL);
113     if (!out_layout || out_channels > AVRESAMPLE_MAX_CHANNELS)
114         return AVERROR(EINVAL);
115 
116     /* check if layouts are unbalanced or abnormal */
117     if (!sane_layout(in_layout) || !sane_layout(out_layout))
118         return AVERROR_PATCHWELCOME;
119 
120     /* route matching input/output channels */
121     for (i = 0; i < 64; i++) {
122         if (in_layout & out_layout & (1ULL << i))
123             matrix[i][i] = 1.0;
124     }
125 
126     /* mix front center to front left/right */
127     if (unaccounted & AV_CH_FRONT_CENTER) {
128         if ((out_layout & AV_CH_LAYOUT_STEREO) == AV_CH_LAYOUT_STEREO) {
129             if ((in_layout & AV_CH_LAYOUT_STEREO) == AV_CH_LAYOUT_STEREO) {
130                 matrix[FRONT_LEFT ][FRONT_CENTER] += center_mix_level;
131                 matrix[FRONT_RIGHT][FRONT_CENTER] += center_mix_level;
132             } else {
133                 matrix[FRONT_LEFT ][FRONT_CENTER] += M_SQRT1_2;
134                 matrix[FRONT_RIGHT][FRONT_CENTER] += M_SQRT1_2;
135             }
136         } else
137             return AVERROR_PATCHWELCOME;
138     }
139     /* mix front left/right to center */
140     if (unaccounted & AV_CH_LAYOUT_STEREO) {
141         if (out_layout & AV_CH_FRONT_CENTER) {
142             matrix[FRONT_CENTER][FRONT_LEFT ] += M_SQRT1_2;
143             matrix[FRONT_CENTER][FRONT_RIGHT] += M_SQRT1_2;
144             /* mix left/right/center to center */
145             if (in_layout & AV_CH_FRONT_CENTER)
146                 matrix[FRONT_CENTER][FRONT_CENTER] = center_mix_level * M_SQRT2;
147         } else
148             return AVERROR_PATCHWELCOME;
149     }
150     /* mix back center to back, side, or front */
151     if (unaccounted & AV_CH_BACK_CENTER) {
152         if (out_layout & AV_CH_BACK_LEFT) {
153             matrix[BACK_LEFT ][BACK_CENTER] += M_SQRT1_2;
154             matrix[BACK_RIGHT][BACK_CENTER] += M_SQRT1_2;
155         } else if (out_layout & AV_CH_SIDE_LEFT) {
156             matrix[SIDE_LEFT ][BACK_CENTER] += M_SQRT1_2;
157             matrix[SIDE_RIGHT][BACK_CENTER] += M_SQRT1_2;
158         } else if (out_layout & AV_CH_FRONT_LEFT) {
159             if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY ||
160                 matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
161                 if (unaccounted & (AV_CH_BACK_LEFT | AV_CH_SIDE_LEFT)) {
162                     matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level * M_SQRT1_2;
163                     matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
164                 } else {
165                     matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level;
166                     matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level;
167                 }
168             } else {
169                 matrix[FRONT_LEFT ][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
170                 matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
171             }
172         } else if (out_layout & AV_CH_FRONT_CENTER) {
173             matrix[FRONT_CENTER][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
174         } else
175             return AVERROR_PATCHWELCOME;
176     }
177     /* mix back left/right to back center, side, or front */
178     if (unaccounted & AV_CH_BACK_LEFT) {
179         if (out_layout & AV_CH_BACK_CENTER) {
180             matrix[BACK_CENTER][BACK_LEFT ] += M_SQRT1_2;
181             matrix[BACK_CENTER][BACK_RIGHT] += M_SQRT1_2;
182         } else if (out_layout & AV_CH_SIDE_LEFT) {
183             /* if side channels do not exist in the input, just copy back
184                channels to side channels, otherwise mix back into side */
185             if (in_layout & AV_CH_SIDE_LEFT) {
186                 matrix[SIDE_LEFT ][BACK_LEFT ] += M_SQRT1_2;
187                 matrix[SIDE_RIGHT][BACK_RIGHT] += M_SQRT1_2;
188             } else {
189                 matrix[SIDE_LEFT ][BACK_LEFT ] += 1.0;
190                 matrix[SIDE_RIGHT][BACK_RIGHT] += 1.0;
191             }
192         } else if (out_layout & AV_CH_FRONT_LEFT) {
193             if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
194                 matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * M_SQRT1_2;
195                 matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2;
196                 matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
197                 matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
198             } else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
199                 matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * SQRT3_2;
200                 matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2;
201                 matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
202                 matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level * SQRT3_2;
203             } else {
204                 matrix[FRONT_LEFT ][BACK_LEFT ] += surround_mix_level;
205                 matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level;
206             }
207         } else if (out_layout & AV_CH_FRONT_CENTER) {
208             matrix[FRONT_CENTER][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
209             matrix[FRONT_CENTER][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
210         } else
211             return AVERROR_PATCHWELCOME;
212     }
213     /* mix side left/right into back or front */
214     if (unaccounted & AV_CH_SIDE_LEFT) {
215         if (out_layout & AV_CH_BACK_LEFT) {
216             /* if back channels do not exist in the input, just copy side
217                channels to back channels, otherwise mix side into back */
218             if (in_layout & AV_CH_BACK_LEFT) {
219                 matrix[BACK_LEFT ][SIDE_LEFT ] += M_SQRT1_2;
220                 matrix[BACK_RIGHT][SIDE_RIGHT] += M_SQRT1_2;
221             } else {
222                 matrix[BACK_LEFT ][SIDE_LEFT ] += 1.0;
223                 matrix[BACK_RIGHT][SIDE_RIGHT] += 1.0;
224             }
225         } else if (out_layout & AV_CH_BACK_CENTER) {
226             matrix[BACK_CENTER][SIDE_LEFT ] += M_SQRT1_2;
227             matrix[BACK_CENTER][SIDE_RIGHT] += M_SQRT1_2;
228         } else if (out_layout & AV_CH_FRONT_LEFT) {
229             if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
230                 matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * M_SQRT1_2;
231                 matrix[FRONT_LEFT ][SIDE_RIGHT] -= surround_mix_level * M_SQRT1_2;
232                 matrix[FRONT_RIGHT][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
233                 matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
234             } else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
235                 matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * SQRT3_2;
236                 matrix[FRONT_LEFT ][SIDE_RIGHT] -= surround_mix_level * M_SQRT1_2;
237                 matrix[FRONT_RIGHT][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
238                 matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level * SQRT3_2;
239             } else {
240                 matrix[FRONT_LEFT ][SIDE_LEFT ] += surround_mix_level;
241                 matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level;
242             }
243         } else if (out_layout & AV_CH_FRONT_CENTER) {
244             matrix[FRONT_CENTER][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
245             matrix[FRONT_CENTER][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
246         } else
247             return AVERROR_PATCHWELCOME;
248     }
249     /* mix left-of-center/right-of-center into front left/right or center */
250     if (unaccounted & AV_CH_FRONT_LEFT_OF_CENTER) {
251         if (out_layout & AV_CH_FRONT_LEFT) {
252             matrix[FRONT_LEFT ][FRONT_LEFT_OF_CENTER ] += 1.0;
253             matrix[FRONT_RIGHT][FRONT_RIGHT_OF_CENTER] += 1.0;
254         } else if (out_layout & AV_CH_FRONT_CENTER) {
255             matrix[FRONT_CENTER][FRONT_LEFT_OF_CENTER ] += M_SQRT1_2;
256             matrix[FRONT_CENTER][FRONT_RIGHT_OF_CENTER] += M_SQRT1_2;
257         } else
258             return AVERROR_PATCHWELCOME;
259     }
260     /* mix LFE into front left/right or center */
261     if (unaccounted & AV_CH_LOW_FREQUENCY) {
262         if (out_layout & AV_CH_FRONT_CENTER) {
263             matrix[FRONT_CENTER][LOW_FREQUENCY] += lfe_mix_level;
264         } else if (out_layout & AV_CH_FRONT_LEFT) {
265             matrix[FRONT_LEFT ][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
266             matrix[FRONT_RIGHT][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
267         } else
268             return AVERROR_PATCHWELCOME;
269     }
270 
271     /* transfer internal matrix to output matrix and calculate maximum
272        per-channel coefficient sum */
273     for (out_i = i = 0; out_i < out_channels && i < 64; i++) {
274         double sum = 0;
275         for (out_j = j = 0; out_j < in_channels && j < 64; j++) {
276             matrix_out[out_i * stride + out_j] = matrix[i][j];
277             sum += fabs(matrix[i][j]);
278             if (in_layout & (1ULL << j))
279                 out_j++;
280         }
281         maxcoef = FFMAX(maxcoef, sum);
282         if (out_layout & (1ULL << i))
283             out_i++;
284     }
285 
286     /* normalize */
287     if (normalize && maxcoef > 1.0) {
288         for (i = 0; i < out_channels; i++)
289             for (j = 0; j < in_channels; j++)
290                 matrix_out[i * stride + j] /= maxcoef;
291     }
292 
293     return 0;
294 }
295