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Diffstat (limited to 'libavfilter/af_aconvert_rematrix.c')
| -rw-r--r-- | libavfilter/af_aconvert_rematrix.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/libavfilter/af_aconvert_rematrix.c b/libavfilter/af_aconvert_rematrix.c new file mode 100644 index 0000000000..d75ca5aa40 --- /dev/null +++ b/libavfilter/af_aconvert_rematrix.c @@ -0,0 +1,172 @@ +/* + * 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 |