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audio_mix_matrix.c
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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 
61 static av_always_inline int even(uint64_t layout)
62 {
63  return (!layout || !!(layout & (layout - 1)));
64 }
65 
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 
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 }
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