/*
* Copyright (C) 2011 Michael Niedermayer (michaelni@gmx.at)
* Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
*
* 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
*/
#include <stdint.h>
#include "libavutil/common.h"
#include "libavutil/libm.h"
#include "libavutil/samplefmt.h"
#include "avresample.h"
#include "internal.h"
#include "audio_data.h"
#include "audio_mix.h"
/* channel positions */
#define FRONT_LEFT 0
#define FRONT_RIGHT 1
#define FRONT_CENTER 2
#define LOW_FREQUENCY 3
#define BACK_LEFT 4
#define BACK_RIGHT 5
#define FRONT_LEFT_OF_CENTER 6
#define FRONT_RIGHT_OF_CENTER 7
#define BACK_CENTER 8
#define SIDE_LEFT 9
#define SIDE_RIGHT 10
#define TOP_CENTER 11
#define TOP_FRONT_LEFT 12
#define TOP_FRONT_CENTER 13
#define TOP_FRONT_RIGHT 14
#define TOP_BACK_LEFT 15
#define TOP_BACK_CENTER 16
#define TOP_BACK_RIGHT 17
#define STEREO_LEFT 29
#define STEREO_RIGHT 30
#define WIDE_LEFT 31
#define WIDE_RIGHT 32
#define SURROUND_DIRECT_LEFT 33
#define SURROUND_DIRECT_RIGHT 34
#define LOW_FREQUENCY_2 35
#define SQRT3_2 1.22474487139158904909 /* sqrt(3/2) */
static av_always_inline int even(uint64_t layout)
{
return (!layout || !!(layout & (layout - 1)));
}
static int sane_layout(uint64_t layout)
{
/* check that there is at least 1 front speaker */
if (!(layout & AV_CH_LAYOUT_SURROUND))
return 0;
/* check for left/right symmetry */
if (!even(layout & (AV_CH_FRONT_LEFT | AV_CH_FRONT_RIGHT)) ||
!even(layout & (AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT)) ||
!even(layout & (AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT)) ||
!even(layout & (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)) ||
!even(layout & (AV_CH_TOP_FRONT_LEFT | AV_CH_TOP_FRONT_RIGHT)) ||
!even(layout & (AV_CH_TOP_BACK_LEFT | AV_CH_TOP_BACK_RIGHT)) ||
!even(layout & (AV_CH_STEREO_LEFT | AV_CH_STEREO_RIGHT)) ||
!even(layout & (AV_CH_WIDE_LEFT | AV_CH_WIDE_RIGHT)) ||
!even(layout & (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)))
return 0;
return 1;
}
int 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)
{
int i, j, out_i, out_j;
double matrix[64][64] = {{0}};
int64_t unaccounted;
double maxcoef = 0;
int in_channels, out_channels;
if ((out_layout & AV_CH_LAYOUT_STEREO_DOWNMIX) == AV_CH_LAYOUT_STEREO_DOWNMIX) {
out_layout = AV_CH_LAYOUT_STEREO;
}
unaccounted = in_layout & ~out_layout;
in_channels = av_get_channel_layout_nb_channels( in_layout);
out_channels = av_get_channel_layout_nb_channels(out_layout);
memset(matrix_out, 0, out_channels * stride * sizeof(*matrix_out));
/* check if layouts are supported */
if (!in_layout || in_channels > AVRESAMPLE_MAX_CHANNELS)
return AVERROR(EINVAL);
if (!out_layout || out_channels > AVRESAMPLE_MAX_CHANNELS)
return AVERROR(EINVAL);
/* check if layouts are unbalanced or abnormal */
if (!sane_layout(in_layout) || !sane_layout(out_layout))
return AVERROR_PATCHWELCOME;
/* route matching input/output channels */
for (i = 0; i < 64; i++) {
if (in_layout & out_layout & (1ULL << i))
matrix[i][i] = 1.0;
}
/* mix front center to front left/right */
if (unaccounted & AV_CH_FRONT_CENTER) {
if ((out_layout & AV_CH_LAYOUT_STEREO) == AV_CH_LAYOUT_STEREO) {
if ((in_layout & AV_CH_LAYOUT_STEREO) == AV_CH_LAYOUT_STEREO) {
matrix[FRONT_LEFT ][FRONT_CENTER] += center_mix_level;
matrix[FRONT_RIGHT][FRONT_CENTER] += center_mix_level;
} else {
matrix[FRONT_LEFT ][FRONT_CENTER] += M_SQRT1_2;
matrix[FRONT_RIGHT][FRONT_CENTER] += M_SQRT1_2;
}
} else
return AVERROR_PATCHWELCOME;
}
/* mix front left/right to center */
if (unaccounted & AV_CH_LAYOUT_STEREO) {
if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][FRONT_LEFT ] += M_SQRT1_2;
matrix[FRONT_CENTER][FRONT_RIGHT] += M_SQRT1_2;
/* mix left/right/center to center */
if (in_layout & AV_CH_FRONT_CENTER)
matrix[FRONT_CENTER][FRONT_CENTER] = center_mix_level * M_SQRT2;
} else
return AVERROR_PATCHWELCOME;
}
/* mix back center to back, side, or front */
if (unaccounted & AV_CH_BACK_CENTER) {
if (out_layout & AV_CH_BACK_LEFT) {
matrix[BACK_LEFT ][BACK_CENTER] += M_SQRT1_2;
matrix[BACK_RIGHT][BACK_CENTER] += M_SQRT1_2;
} else if (out_layout & AV_CH_SIDE_LEFT) {
matrix[SIDE_LEFT ][BACK_CENTER] += M_SQRT1_2;
matrix[SIDE_RIGHT][BACK_CENTER] += M_SQRT1_2;
} else if (out_layout & AV_CH_FRONT_LEFT) {
if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY ||
matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
if (unaccounted & (AV_CH_BACK_LEFT | AV_CH_SIDE_LEFT)) {
matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
} else {
matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level;
matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level;
}
} else {
matrix[FRONT_LEFT ][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
}
} else if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][BACK_CENTER] += surround_mix_level * M_SQRT1_2;
} else
return AVERROR_PATCHWELCOME;
}
/* mix back left/right to back center, side, or front */
if (unaccounted & AV_CH_BACK_LEFT) {
if (out_layout & AV_CH_BACK_CENTER) {
matrix[BACK_CENTER][BACK_LEFT ] += M_SQRT1_2;
matrix[BACK_CENTER][BACK_RIGHT] += M_SQRT1_2;
} else if (out_layout & AV_CH_SIDE_LEFT) {
/* if side channels do not exist in the input, just copy back
channels to side channels, otherwise mix back into side */
if (in_layout & AV_CH_SIDE_LEFT) {
matrix[SIDE_LEFT ][BACK_LEFT ] += M_SQRT1_2;
matrix[SIDE_RIGHT][BACK_RIGHT] += M_SQRT1_2;
} else {
matrix[SIDE_LEFT ][BACK_LEFT ] += 1.0;
matrix[SIDE_RIGHT][BACK_RIGHT] += 1.0;
}
} else if (out_layout & AV_CH_FRONT_LEFT) {
if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
} else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * SQRT3_2;
matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level * SQRT3_2;
} else {
matrix[FRONT_LEFT ][BACK_LEFT ] += surround_mix_level;
matrix[FRONT_RIGHT][BACK_RIGHT] += surround_mix_level;
}
} else if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_CENTER][BACK_RIGHT] += surround_mix_level * M_SQRT1_2;
} else
return AVERROR_PATCHWELCOME;
}
/* mix side left/right into back or front */
if (unaccounted & AV_CH_SIDE_LEFT) {
if (out_layout & AV_CH_BACK_LEFT) {
/* if back channels do not exist in the input, just copy side
channels to back channels, otherwise mix side into back */
if (in_layout & AV_CH_BACK_LEFT) {
matrix[BACK_LEFT ][SIDE_LEFT ] += M_SQRT1_2;
matrix[BACK_RIGHT][SIDE_RIGHT] += M_SQRT1_2;
} else {
matrix[BACK_LEFT ][SIDE_LEFT ] += 1.0;
matrix[BACK_RIGHT][SIDE_RIGHT] += 1.0;
}
} else if (out_layout & AV_CH_BACK_CENTER) {
matrix[BACK_CENTER][SIDE_LEFT ] += M_SQRT1_2;
matrix[BACK_CENTER][SIDE_RIGHT] += M_SQRT1_2;
} else if (out_layout & AV_CH_FRONT_LEFT) {
if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) {
matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_LEFT ][SIDE_RIGHT] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
} else if (matrix_encoding == AV_MATRIX_ENCODING_DPLII) {
matrix[FRONT_LEFT ][SIDE_LEFT ] -= surround_mix_level * SQRT3_2;
matrix[FRONT_LEFT ][SIDE_RIGHT] -= surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level * SQRT3_2;
} else {
matrix[FRONT_LEFT ][SIDE_LEFT ] += surround_mix_level;
matrix[FRONT_RIGHT][SIDE_RIGHT] += surround_mix_level;
}
} else if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][SIDE_LEFT ] += surround_mix_level * M_SQRT1_2;
matrix[FRONT_CENTER][SIDE_RIGHT] += surround_mix_level * M_SQRT1_2;
} else
return AVERROR_PATCHWELCOME;
}
/* mix left-of-center/right-of-center into front left/right or center */
if (unaccounted & AV_CH_FRONT_LEFT_OF_CENTER) {
if (out_layout & AV_CH_FRONT_LEFT) {
matrix[FRONT_LEFT ][FRONT_LEFT_OF_CENTER ] += 1.0;
matrix[FRONT_RIGHT][FRONT_RIGHT_OF_CENTER] += 1.0;
} else if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][FRONT_LEFT_OF_CENTER ] += M_SQRT1_2;
matrix[FRONT_CENTER][FRONT_RIGHT_OF_CENTER] += M_SQRT1_2;
} else
return AVERROR_PATCHWELCOME;
}
/* mix LFE into front left/right or center */
if (unaccounted & AV_CH_LOW_FREQUENCY) {
if (out_layout & AV_CH_FRONT_CENTER) {
matrix[FRONT_CENTER][LOW_FREQUENCY] += lfe_mix_level;
} else if (out_layout & AV_CH_FRONT_LEFT) {
matrix[FRONT_LEFT ][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
matrix[FRONT_RIGHT][LOW_FREQUENCY] += lfe_mix_level * M_SQRT1_2;
} else
return AVERROR_PATCHWELCOME;
}
/* transfer internal matrix to output matrix and calculate maximum
per-channel coefficient sum */
for (out_i = i = 0; out_i < out_channels && i < 64; i++) {
double sum = 0;
for (out_j = j = 0; out_j < in_channels && j < 64; j++) {
matrix_out[out_i * stride + out_j] = matrix[i][j];
sum += fabs(matrix[i][j]);
if (in_layout & (1ULL << j))
out_j++;
}
maxcoef = FFMAX(maxcoef, sum);
if (out_layout & (1ULL << i))
out_i++;
}
/* normalize */
if (normalize && maxcoef > 1.0) {
for (i = 0; i < out_channels; i++)
for (j = 0; j < in_channels; j++)
matrix_out[i * stride + j] /= maxcoef;
}
return 0;
}