From bff17fb1d0e39583e44ba93ea214d7434ecef2ce Mon Sep 17 00:00:00 2001 From: Klaus Schmidinger Date: Fri, 3 Aug 2001 14:18:08 +0200 Subject: Added support for replaying DVDs --- ac3dec/downmix.c | 428 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 428 insertions(+) create mode 100644 ac3dec/downmix.c (limited to 'ac3dec/downmix.c') diff --git a/ac3dec/downmix.c b/ac3dec/downmix.c new file mode 100644 index 00000000..94bc51a8 --- /dev/null +++ b/ac3dec/downmix.c @@ -0,0 +1,428 @@ +/* + * + * downmix.c + * + * Copyright (C) Aaron Holtzman - Sept 1999 + * + * Originally based on code by Yuqing Deng. + * + * This file is part of ac3dec, a free Dolby AC-3 stream decoder. + * + * ac3dec is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * ac3dec 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Make; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + * + * + */ + +#include +#include +#include +#include "ac3.h" +#include "ac3_internal.h" + + +#include "decode.h" +#include "downmix.h" +#include "debug.h" + + +//Pre-scaled downmix coefficients +static float cmixlev_lut[4] = { 0.2928, 0.2468, 0.2071, 0.2468 }; +static float smixlev_lut[4] = { 0.2928, 0.2071, 0.0 , 0.2071 }; + +static void +downmix_3f_2r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float right_tmp; + float left_tmp; + float clev,slev; + float *centre = 0, *left = 0, *right = 0, *left_sur = 0, *right_sur = 0; + + left = samples[0]; + centre = samples[1]; + right = samples[2]; + left_sur = samples[3]; + right_sur = samples[4]; + + clev = cmixlev_lut[bsi->cmixlev]; + slev = smixlev_lut[bsi->surmixlev]; + +#if defined DOLBY_SURROUND + for (j = 0; j < 256; j++) + { + right_tmp = *left_sur++ + *right_sur++; + left_tmp = 1.4142f * *left++ + *centre - right_tmp; + right_tmp += 1.4142f * *right++ + *centre++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 16000.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 16000.0f); + } +#else + for (j = 0; j < 256; j++) + { + left_tmp = 0.4142f * *left++ + clev * *centre + slev * *left_sur++; + right_tmp= 0.4142f * *right++ + clev * *centre++ + slev * *right_sur++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f); + } +#endif +} + +static void +downmix_2f_2r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float right_tmp; + float left_tmp; + float slev; + float *left = 0, *right = 0, *left_sur = 0, *right_sur = 0; + + left = samples[0]; + right = samples[1]; + left_sur = samples[2]; + right_sur = samples[3]; + + slev = smixlev_lut[bsi->surmixlev]; + + for (j = 0; j < 256; j++) + { + left_tmp = 0.4142f * *left++ + slev * *left_sur++; + right_tmp= 0.4142f * *right++ + slev * *right_sur++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f); + } +} + +static void +downmix_3f_1r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float right_tmp; + float left_tmp; + float clev,slev; + float *centre = 0, *left = 0, *right = 0, *sur = 0; + + left = samples[0]; + centre = samples[1]; + right = samples[2]; + //Mono surround + sur = samples[3]; + + clev = cmixlev_lut[bsi->cmixlev]; + slev = smixlev_lut[bsi->surmixlev]; + + for (j = 0; j < 256; j++) + { + left_tmp = 0.4142f * *left++ + clev * *centre++ + slev * *sur; + right_tmp= 0.4142f * *right++ + clev * *centre + slev * *sur++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f); + } +} + + +static void +downmix_2f_1r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float right_tmp; + float left_tmp; + float slev; + float *left = 0, *right = 0, *sur = 0; + + left = samples[0]; + right = samples[1]; + //Mono surround + sur = samples[2]; + + slev = smixlev_lut[bsi->surmixlev]; + + for (j = 0; j < 256; j++) + { + left_tmp = 0.4142f * *left++ + slev * *sur; + right_tmp= 0.4142f * *right++ + slev * *sur++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f); + } +} + +static void +downmix_3f_0r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float right_tmp; + float left_tmp; + float clev; + float *centre = 0, *left = 0, *right = 0; + + left = samples[0]; + centre = samples[1]; + right = samples[2]; + + clev = cmixlev_lut[bsi->cmixlev]; + + for (j = 0; j < 256; j++) + { + left_tmp = 0.4142f * *left++ + clev * *centre; + right_tmp= 0.4142f * *right++ + clev * *centre++; + + s16_samples[j * 2 ] = (sint_16) (left_tmp * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (right_tmp * 32767.0f); + } +} + +static void +downmix_2f_0r_to_2ch(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + uint_32 j; + float *left = 0, *right = 0; + + left = samples[0]; + right = samples[1]; + + for (j = 0; j < 256; j++) + { + s16_samples[j * 2 ] = (sint_16) (*left++ * 32767.0f); + s16_samples[j * 2 + 1] = (sint_16) (*right++ * 32767.0f); + } +} + +static void +downmix_1f_0r_to_2ch(float *centre,sint_16 *s16_samples) +{ + uint_32 j; + float tmp; + + //Mono program! + + for (j = 0; j < 256; j++) + { + tmp = 32767.0f * 0.7071f * *centre++; + + s16_samples[j * 2 ] = s16_samples[j * 2 + 1] = (sint_16) tmp; + } +} + +// +// Downmix into 2 or 4 channels (4 ch isn't in quite yet) +// +// The downmix function names have the following format +// +// downmix_Xf_Yr_to_[2|4]ch[_dolby] +// +// where X = number of front channels +// Y = number of rear channels +// [2|4] = number of output channels +// [_dolby] = with or without dolby surround mix +// + +void downmix(bsi_t* bsi, stream_samples_t samples,sint_16 *s16_samples) +{ + if(bsi->acmod > 7) + dprintf("(downmix) invalid acmod number\n"); + + // + //There are two main cases, with or without Dolby Surround + // + if(ac3_config.flags & AC3_DOLBY_SURR_ENABLE) + { + fprintf(stderr,"Dolby Surround Mixes not currently enabled\n"); + exit(1); + } + + //Non-Dolby surround downmixes + switch(bsi->acmod) + { + // 3/2 + case 7: + downmix_3f_2r_to_2ch(bsi,samples,s16_samples); + break; + + // 2/2 + case 6: + downmix_2f_2r_to_2ch(bsi,samples,s16_samples); + break; + + // 3/1 + case 5: + downmix_3f_1r_to_2ch(bsi,samples,s16_samples); + break; + + // 2/1 + case 4: + downmix_2f_1r_to_2ch(bsi,samples,s16_samples); + break; + + // 3/0 + case 3: + downmix_3f_0r_to_2ch(bsi,samples,s16_samples); + break; + + case 2: + downmix_2f_0r_to_2ch(bsi,samples,s16_samples); + break; + + // 1/0 + case 1: + downmix_1f_0r_to_2ch(samples[0],s16_samples); + break; + + // 1+1 + case 0: + downmix_1f_0r_to_2ch(samples[ac3_config.dual_mono_ch_sel],s16_samples); + break; + } +} + + + +#if 0 + + //the dolby mixes lay here for the time being + switch(bsi->acmod) + { + // 3/2 + case 7: + left = samples[0]; + centre = samples[1]; + right = samples[2]; + left_sur = samples[3]; + right_sur = samples[4]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.2265f * *left_sur++ + 0.2265f * *right_sur++; + left_tmp = -1 * right_tmp; + right_tmp += 0.3204f * *right++ + 0.2265f * *centre; + left_tmp += 0.3204f * *left++ + 0.2265f * *centre++; + + samples[1][j] = right_tmp; + samples[0][j] = left_tmp; + } + + break; + + // 2/2 + case 6: + left = samples[0]; + right = samples[1]; + left_sur = samples[2]; + right_sur = samples[3]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.2265f * *left_sur++ + 0.2265f * *right_sur++; + left_tmp = -1 * right_tmp; + right_tmp += 0.3204f * *right++; + left_tmp += 0.3204f * *left++ ; + + samples[1][j] = right_tmp; + samples[0][j] = left_tmp; + } + break; + + // 3/1 + case 5: + left = samples[0]; + centre = samples[1]; + right = samples[2]; + //Mono surround + right_sur = samples[3]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.2265f * *right_sur++; + left_tmp = -1 * right_tmp; + right_tmp += 0.3204f * *right++ + 0.2265f * *centre; + left_tmp += 0.3204f * *left++ + 0.2265f * *centre++; + + samples[1][j] = right_tmp; + samples[0][j] = left_tmp; + } + break; + + // 2/1 + case 4: + left = samples[0]; + right = samples[1]; + //Mono surround + right_sur = samples[2]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.2265f * *right_sur++; + left_tmp = -1 * right_tmp; + right_tmp += 0.3204f * *right++; + left_tmp += 0.3204f * *left++; + + samples[1][j] = right_tmp; + samples[0][j] = left_tmp; + } + break; + + // 3/0 + case 3: + left = samples[0]; + centre = samples[1]; + right = samples[2]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.3204f * *right++ + 0.2265f * *centre; + left_tmp = 0.3204f * *left++ + 0.2265f * *centre++; + + samples[1][j] = right_tmp; + samples[0][j] = left_tmp; + } + break; + + // 2/0 + case 2: + //Do nothing! + break; + + // 1/0 + case 1: + //Mono program! + right = samples[0]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.7071f * *right++; + + samples[1][j] = right_tmp; + samples[0][j] = right_tmp; + } + + break; + + // 1+1 + case 0: + //Dual mono, output selected by user + right = samples[ac3_config.dual_mono_ch_sel]; + + for (j = 0; j < 256; j++) + { + right_tmp = 0.7071f * *right++; + + samples[1][j] = right_tmp; + samples[0][j] = right_tmp; + } + break; +#endif -- cgit v1.2.3