mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-09-12 02:14:56 +02:00
![Stefano Sabatini](/assets/img/avatar_default.png)
Add aconvert filter to perform sample format, channel layout, and packing format conversion. The aconvert code depends on audio conversion code in libavcodec, so this requires a dependency on libavcodec. Based on previous work by S.N. Hemanth Meenakshisundaram and Mina Nagy Zaki, performed for the GSoC 2010 and 2011.
173 lines
4.9 KiB
C
173 lines
4.9 KiB
C
/*
|
|
* Copyright (c) 2011 Mina Nagy Zaki
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* audio rematrixing functions, based on functions from libavcodec/resample.c
|
|
*/
|
|
|
|
#if defined(FLOATING)
|
|
# define DIV2 /2
|
|
#else
|
|
# define DIV2 >>1
|
|
#endif
|
|
|
|
REMATRIX_FUNC_SIG(stereo_to_mono_packed)
|
|
{
|
|
while (nb_samples >= 4) {
|
|
outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
|
|
outp[0][1] = (inp[0][2] + inp[0][3]) DIV2;
|
|
outp[0][2] = (inp[0][4] + inp[0][5]) DIV2;
|
|
outp[0][3] = (inp[0][6] + inp[0][7]) DIV2;
|
|
outp[0] += 4;
|
|
inp[0] += 8;
|
|
nb_samples -= 4;
|
|
}
|
|
while (nb_samples--) {
|
|
outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
|
|
outp[0]++;
|
|
inp[0] += 2;
|
|
}
|
|
}
|
|
|
|
REMATRIX_FUNC_SIG(stereo_downmix_packed)
|
|
{
|
|
while (nb_samples--) {
|
|
*outp[0]++ = inp[0][0];
|
|
*outp[0]++ = inp[0][1];
|
|
inp[0] += aconvert->in_nb_channels;
|
|
}
|
|
}
|
|
|
|
REMATRIX_FUNC_SIG(mono_to_stereo_packed)
|
|
{
|
|
while (nb_samples >= 4) {
|
|
outp[0][0] = outp[0][1] = inp[0][0];
|
|
outp[0][2] = outp[0][3] = inp[0][1];
|
|
outp[0][4] = outp[0][5] = inp[0][2];
|
|
outp[0][6] = outp[0][7] = inp[0][3];
|
|
outp[0] += 8;
|
|
inp[0] += 4;
|
|
nb_samples -= 4;
|
|
}
|
|
while (nb_samples--) {
|
|
outp[0][0] = outp[0][1] = inp[0][0];
|
|
outp[0] += 2;
|
|
inp[0] += 1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This is for when we have more than 2 input channels, need to downmix to mono
|
|
* and do not have a conversion formula available. We just use first two input
|
|
* channels - left and right. This is a placeholder until more conversion
|
|
* functions are written.
|
|
*/
|
|
REMATRIX_FUNC_SIG(mono_downmix_packed)
|
|
{
|
|
while (nb_samples--) {
|
|
outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
|
|
inp[0] += aconvert->in_nb_channels;
|
|
outp[0]++;
|
|
}
|
|
}
|
|
|
|
REMATRIX_FUNC_SIG(mono_downmix_planar)
|
|
{
|
|
FMT_TYPE *out = outp[0];
|
|
|
|
while (nb_samples >= 4) {
|
|
out[0] = (inp[0][0] + inp[1][0]) DIV2;
|
|
out[1] = (inp[0][1] + inp[1][1]) DIV2;
|
|
out[2] = (inp[0][2] + inp[1][2]) DIV2;
|
|
out[3] = (inp[0][3] + inp[1][3]) DIV2;
|
|
out += 4;
|
|
inp[0] += 4;
|
|
inp[1] += 4;
|
|
nb_samples -= 4;
|
|
}
|
|
while (nb_samples--) {
|
|
out[0] = (inp[0][0] + inp[1][0]) DIV2;
|
|
out++;
|
|
inp[0]++;
|
|
inp[1]++;
|
|
}
|
|
}
|
|
|
|
/* Stereo to 5.1 output */
|
|
REMATRIX_FUNC_SIG(stereo_to_surround_5p1_packed)
|
|
{
|
|
while (nb_samples--) {
|
|
outp[0][0] = inp[0][0]; /* left */
|
|
outp[0][1] = inp[0][1]; /* right */
|
|
outp[0][2] = (inp[0][0] + inp[0][1]) DIV2; /* center */
|
|
outp[0][3] = 0; /* low freq */
|
|
outp[0][4] = 0; /* FIXME: left surround: -3dB or -6dB or -9dB of stereo left */
|
|
outp[0][5] = 0; /* FIXME: right surroud: -3dB or -6dB or -9dB of stereo right */
|
|
inp[0] += 2;
|
|
outp[0] += 6;
|
|
}
|
|
}
|
|
|
|
REMATRIX_FUNC_SIG(stereo_to_surround_5p1_planar)
|
|
{
|
|
while (nb_samples--) {
|
|
*outp[0]++ = *inp[0]; /* left */
|
|
*outp[1]++ = *inp[1]; /* right */
|
|
*outp[2]++ = (*inp[0] + *inp[1]) DIV2; /* center */
|
|
*outp[3]++ = 0; /* low freq */
|
|
*outp[4]++ = 0; /* FIXME: left surround: -3dB or -6dB or -9dB of stereo left */
|
|
*outp[5]++ = 0; /* FIXME: right surroud: -3dB or -6dB or -9dB of stereo right */
|
|
inp[0]++; inp[1]++;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
5.1 to stereo input: [fl, fr, c, lfe, rl, rr]
|
|
- Left = front_left + rear_gain * rear_left + center_gain * center
|
|
- Right = front_right + rear_gain * rear_right + center_gain * center
|
|
Where rear_gain is usually around 0.5-1.0 and
|
|
center_gain is almost always 0.7 (-3 dB)
|
|
*/
|
|
REMATRIX_FUNC_SIG(surround_5p1_to_stereo_packed)
|
|
{
|
|
while (nb_samples--) {
|
|
*outp[0]++ = inp[0][0] + (0.5 * inp[0][4]) + (0.7 * inp[0][2]); //FIXME CLIPPING!
|
|
*outp[0]++ = inp[0][1] + (0.5 * inp[0][5]) + (0.7 * inp[0][2]); //FIXME CLIPPING!
|
|
|
|
inp[0] += 6;
|
|
}
|
|
}
|
|
|
|
REMATRIX_FUNC_SIG(surround_5p1_to_stereo_planar)
|
|
{
|
|
while (nb_samples--) {
|
|
*outp[0]++ = *inp[0] + (0.5 * *inp[4]) + (0.7 * *inp[2]); //FIXME CLIPPING!
|
|
*outp[1]++ = *inp[1] + (0.5 * *inp[5]) + (0.7 * *inp[2]); //FIXME CLIPPING!
|
|
|
|
inp[0]++; inp[1]++; inp[2]++; inp[3]++; inp[4]++; inp[5]++;
|
|
}
|
|
}
|
|
|
|
#undef DIV2
|
|
#undef REMATRIX_FUNC_NAME
|
|
#undef FMT_TYPE
|