mirror of https://git.ffmpeg.org/ffmpeg.git
173 lines
4.9 KiB
C
173 lines
4.9 KiB
C
/*
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* Copyright (c) 2011 Mina Nagy Zaki
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* audio rematrixing functions, based on functions from libavcodec/resample.c
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*/
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#if defined(FLOATING)
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# define DIV2 /2
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#else
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# define DIV2 >>1
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#endif
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REMATRIX_FUNC_SIG(stereo_to_mono_packed)
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{
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while (nb_samples >= 4) {
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outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
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outp[0][1] = (inp[0][2] + inp[0][3]) DIV2;
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outp[0][2] = (inp[0][4] + inp[0][5]) DIV2;
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outp[0][3] = (inp[0][6] + inp[0][7]) DIV2;
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outp[0] += 4;
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inp[0] += 8;
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nb_samples -= 4;
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}
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while (nb_samples--) {
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outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
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outp[0]++;
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inp[0] += 2;
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}
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}
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REMATRIX_FUNC_SIG(stereo_downmix_packed)
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{
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while (nb_samples--) {
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*outp[0]++ = inp[0][0];
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*outp[0]++ = inp[0][1];
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inp[0] += aconvert->in_nb_channels;
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}
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}
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REMATRIX_FUNC_SIG(mono_to_stereo_packed)
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{
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while (nb_samples >= 4) {
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outp[0][0] = outp[0][1] = inp[0][0];
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outp[0][2] = outp[0][3] = inp[0][1];
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outp[0][4] = outp[0][5] = inp[0][2];
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outp[0][6] = outp[0][7] = inp[0][3];
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outp[0] += 8;
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inp[0] += 4;
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nb_samples -= 4;
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}
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while (nb_samples--) {
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outp[0][0] = outp[0][1] = inp[0][0];
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outp[0] += 2;
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inp[0] += 1;
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}
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}
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/**
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* This is for when we have more than 2 input channels, need to downmix to mono
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* and do not have a conversion formula available. We just use first two input
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* channels - left and right. This is a placeholder until more conversion
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* functions are written.
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*/
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REMATRIX_FUNC_SIG(mono_downmix_packed)
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{
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while (nb_samples--) {
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outp[0][0] = (inp[0][0] + inp[0][1]) DIV2;
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inp[0] += aconvert->in_nb_channels;
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outp[0]++;
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}
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}
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REMATRIX_FUNC_SIG(mono_downmix_planar)
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{
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FMT_TYPE *out = outp[0];
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while (nb_samples >= 4) {
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out[0] = (inp[0][0] + inp[1][0]) DIV2;
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out[1] = (inp[0][1] + inp[1][1]) DIV2;
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out[2] = (inp[0][2] + inp[1][2]) DIV2;
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out[3] = (inp[0][3] + inp[1][3]) DIV2;
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out += 4;
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inp[0] += 4;
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inp[1] += 4;
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nb_samples -= 4;
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}
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while (nb_samples--) {
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out[0] = (inp[0][0] + inp[1][0]) DIV2;
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out++;
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inp[0]++;
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inp[1]++;
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}
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}
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/* Stereo to 5.1 output */
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REMATRIX_FUNC_SIG(stereo_to_surround_5p1_packed)
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{
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while (nb_samples--) {
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outp[0][0] = inp[0][0]; /* left */
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outp[0][1] = inp[0][1]; /* right */
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outp[0][2] = (inp[0][0] + inp[0][1]) DIV2; /* center */
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outp[0][3] = 0; /* low freq */
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outp[0][4] = 0; /* FIXME: left surround: -3dB or -6dB or -9dB of stereo left */
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outp[0][5] = 0; /* FIXME: right surroud: -3dB or -6dB or -9dB of stereo right */
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inp[0] += 2;
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outp[0] += 6;
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}
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}
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REMATRIX_FUNC_SIG(stereo_to_surround_5p1_planar)
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{
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while (nb_samples--) {
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*outp[0]++ = *inp[0]; /* left */
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*outp[1]++ = *inp[1]; /* right */
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*outp[2]++ = (*inp[0] + *inp[1]) DIV2; /* center */
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*outp[3]++ = 0; /* low freq */
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*outp[4]++ = 0; /* FIXME: left surround: -3dB or -6dB or -9dB of stereo left */
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*outp[5]++ = 0; /* FIXME: right surroud: -3dB or -6dB or -9dB of stereo right */
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inp[0]++; inp[1]++;
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}
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}
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/*
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5.1 to stereo input: [fl, fr, c, lfe, rl, rr]
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- Left = front_left + rear_gain * rear_left + center_gain * center
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- Right = front_right + rear_gain * rear_right + center_gain * center
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Where rear_gain is usually around 0.5-1.0 and
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center_gain is almost always 0.7 (-3 dB)
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*/
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REMATRIX_FUNC_SIG(surround_5p1_to_stereo_packed)
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{
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while (nb_samples--) {
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*outp[0]++ = inp[0][0] + (0.5 * inp[0][4]) + (0.7 * inp[0][2]); //FIXME CLIPPING!
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*outp[0]++ = inp[0][1] + (0.5 * inp[0][5]) + (0.7 * inp[0][2]); //FIXME CLIPPING!
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inp[0] += 6;
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}
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}
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REMATRIX_FUNC_SIG(surround_5p1_to_stereo_planar)
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{
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while (nb_samples--) {
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*outp[0]++ = *inp[0] + (0.5 * *inp[4]) + (0.7 * *inp[2]); //FIXME CLIPPING!
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*outp[1]++ = *inp[1] + (0.5 * *inp[5]) + (0.7 * *inp[2]); //FIXME CLIPPING!
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inp[0]++; inp[1]++; inp[2]++; inp[3]++; inp[4]++; inp[5]++;
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}
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}
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#undef DIV2
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#undef REMATRIX_FUNC_NAME
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#undef FMT_TYPE
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