FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
audio_mix_matrix.c
Go to the documentation of this file.
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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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  matrix[FRONT_LEFT ][FRONT_CENTER] += M_SQRT1_2;
130  matrix[FRONT_RIGHT][FRONT_CENTER] += M_SQRT1_2;
131  } else
132  return AVERROR_PATCHWELCOME;
133  }
134  /* mix front left/right to center */
135  if (unaccounted & AV_CH_LAYOUT_STEREO) {
136  if (out_layout & AV_CH_FRONT_CENTER) {
137  matrix[FRONT_CENTER][FRONT_LEFT ] += M_SQRT1_2;
138  matrix[FRONT_CENTER][FRONT_RIGHT] += M_SQRT1_2;
139  /* mix left/right/center to center */
140  if (in_layout & AV_CH_FRONT_CENTER)
141  matrix[FRONT_CENTER][FRONT_CENTER] = center_mix_level * M_SQRT2;
142  } else
143  return AVERROR_PATCHWELCOME;
144  }
145  /* mix back center to back, side, or front */
146  if (unaccounted & AV_CH_BACK_CENTER) {
147  if (out_layout & AV_CH_BACK_LEFT) {
148  matrix[BACK_LEFT ][BACK_CENTER] += M_SQRT1_2;
149  matrix[BACK_RIGHT][BACK_CENTER] += M_SQRT1_2;
150  } else if (out_layout & AV_CH_SIDE_LEFT) {
151  matrix[SIDE_LEFT ][BACK_CENTER] += M_SQRT1_2;
152  matrix[SIDE_RIGHT][BACK_CENTER] += M_SQRT1_2;
153  } else if (out_layout & AV_CH_FRONT_LEFT) {
154  if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY ||
155  matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
156  if (unaccounted & (AV_CH_BACK_LEFT | AV_CH_SIDE_LEFT)) {
157  matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level * M_SQRT1_2;
158  matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
159  } else {
160  matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level;
161  matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level;
162  }
163  } else {
164  matrix[FRONT_LEFT ][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
165  matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
166  }
167  } else if (out_layout & AV_CH_FRONT_CENTER) {
168  matrix[FRONT_CENTER][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
169  } else
170  return AVERROR_PATCHWELCOME;
171  }
172  /* mix back left/right to back center, side, or front */
173  if (unaccounted & AV_CH_BACK_LEFT) {
174  if (out_layout & AV_CH_BACK_CENTER) {
175  matrix[BACK_CENTER][BACK_LEFT ] += M_SQRT1_2;
176  matrix[BACK_CENTER][BACK_RIGHT] += M_SQRT1_2;
177  } else if (out_layout & AV_CH_SIDE_LEFT) {
178  /* if side channels do not exist in the input, just copy back
179  channels to side channels, otherwise mix back into side */
180  if (in_layout & AV_CH_SIDE_LEFT) {
181  matrix[SIDE_LEFT ][BACK_LEFT ] += M_SQRT1_2;
182  matrix[SIDE_RIGHT][BACK_RIGHT] += M_SQRT1_2;
183  } else {
184  matrix[SIDE_LEFT ][BACK_LEFT ] += 1.0;
185  matrix[SIDE_RIGHT][BACK_RIGHT] += 1.0;
186  }
187  } else if (out_layout & AV_CH_FRONT_LEFT) {
188  if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
189  matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * M_SQRT1_2;
190  matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2;
191  matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
192  matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
193  } else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
194  matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * SQRT3_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 * SQRT3_2;
198  } else {
199  matrix[FRONT_LEFT ][BACK_LEFT ] += surround_mix_level;
200  matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level;
201  }
202  } else if (out_layout & AV_CH_FRONT_CENTER) {
203  matrix[FRONT_CENTER][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
204  matrix[FRONT_CENTER][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
205  } else
206  return AVERROR_PATCHWELCOME;
207  }
208  /* mix side left/right into back or front */
209  if (unaccounted & AV_CH_SIDE_LEFT) {
210  if (out_layout & AV_CH_BACK_LEFT) {
211  /* if back channels do not exist in the input, just copy side
212  channels to back channels, otherwise mix side into back */
213  if (in_layout & AV_CH_BACK_LEFT) {
214  matrix[BACK_LEFT ][SIDE_LEFT ] += M_SQRT1_2;
215  matrix[BACK_RIGHT][SIDE_RIGHT] += M_SQRT1_2;
216  } else {
217  matrix[BACK_LEFT ][SIDE_LEFT ] += 1.0;
218  matrix[BACK_RIGHT][SIDE_RIGHT] += 1.0;
219  }
220  } else if (out_layout & AV_CH_BACK_CENTER) {
221  matrix[BACK_CENTER][SIDE_LEFT ] += M_SQRT1_2;
222  matrix[BACK_CENTER][SIDE_RIGHT] += M_SQRT1_2;
223  } else if (out_layout & AV_CH_FRONT_LEFT) {
224  if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
225  matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * M_SQRT1_2;
226  matrix[FRONT_LEFT ][SIDE_RIGHT] -= surround_mix_level * M_SQRT1_2;
227  matrix[FRONT_RIGHT][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
228  matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
229  } else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
230  matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * SQRT3_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 * SQRT3_2;
234  } else {
235  matrix[FRONT_LEFT ][SIDE_LEFT ] += surround_mix_level;
236  matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level;
237  }
238  } else if (out_layout & AV_CH_FRONT_CENTER) {
239  matrix[FRONT_CENTER][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
240  matrix[FRONT_CENTER][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
241  } else
242  return AVERROR_PATCHWELCOME;
243  }
244  /* mix left-of-center/right-of-center into front left/right or center */
245  if (unaccounted & AV_CH_FRONT_LEFT_OF_CENTER) {
246  if (out_layout & AV_CH_FRONT_LEFT) {
247  matrix[FRONT_LEFT ][FRONT_LEFT_OF_CENTER ] += 1.0;
248  matrix[FRONT_RIGHT][FRONT_RIGHT_OF_CENTER] += 1.0;
249  } else if (out_layout & AV_CH_FRONT_CENTER) {
250  matrix[FRONT_CENTER][FRONT_LEFT_OF_CENTER ] += M_SQRT1_2;
251  matrix[FRONT_CENTER][FRONT_RIGHT_OF_CENTER] += M_SQRT1_2;
252  } else
253  return AVERROR_PATCHWELCOME;
254  }
255  /* mix LFE into front left/right or center */
256  if (unaccounted & AV_CH_LOW_FREQUENCY) {
257  if (out_layout & AV_CH_FRONT_CENTER) {
258  matrix[FRONT_CENTER][LOW_FREQUENCY] += lfe_mix_level;
259  } else if (out_layout & AV_CH_FRONT_LEFT) {
260  matrix[FRONT_LEFT ][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
261  matrix[FRONT_RIGHT][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
262  } else
263  return AVERROR_PATCHWELCOME;
264  }
265 
266  /* transfer internal matrix to output matrix and calculate maximum
267  per-channel coefficient sum */
268  for (out_i = i = 0; out_i < out_channels && i < 64; i++) {
269  double sum = 0;
270  for (out_j = j = 0; out_j < in_channels && j < 64; j++) {
271  matrix_out[out_i * stride + out_j] = matrix[i][j];
272  sum += fabs(matrix[i][j]);
273  if (in_layout & (1ULL << j))
274  out_j++;
275  }
276  maxcoef = FFMAX(maxcoef, sum);
277  if (out_layout & (1ULL << i))
278  out_i++;
279  }
280 
281  /* normalize */
282  if (normalize && maxcoef > 1.0) {
283  for (i = 0; i < out_channels; i++)
284  for (j = 0; j < in_channels; j++)
285  matrix_out[i * stride + j] /= maxcoef;
286  }
287 
288  return 0;
289 }
Generated on Sat May 25 2013 03:58:49 for FFmpeg by   doxygen 1.8.2