Improvements from Matjaz Thaler

ac3dec/downmix_c.c

@@ -0,0 +1,161 @@
+/*
+ *  downmix_c.c
+ *    
+ *	Copyright (C) Aaron Holtzman - May 1999
+ *
+ *  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 <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include "ac3.h"
+#include "ac3_internal.h"
+
+#include "debug.h"
+#include "downmix.h"
+#include "downmix_c.h"
+
+
+void downmix_3f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
+{
+	int i;
+	float *left, *right, *center, *left_sur, *right_sur;
+	float left_tmp, right_tmp;
+
+	left = samples;
+	right = samples + 256 * 2;
+	center = samples + 256;
+	left_sur = samples + 256 * 3;
+	right_sur = samples + 256 * 4;
+
+	for (i=0; i < 256; i++) {
+#if defined DOLBY_SURROUND
+	  	left_tmp = dm_par->unit * *left  + dm_par->clev * *center - dm_par->slev * (*left_sur + *right_sur);
+	  	right_tmp= dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * (*left_sur++ + *right_sur++);
+#else
+		left_tmp = dm_par->unit * *left  + dm_par->clev * *center + dm_par->slev * *left_sur++;
+		right_tmp= dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
+#endif
+		*left++ = left_tmp;
+		*center++ = right_tmp;
+
+	}
+}
+
+
+void downmix_2f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
+{
+	int i;
+	float *left, *right, *left_sur, *right_sur;
+	float left_tmp, right_tmp;
+               
+	left = &samples[0];
+	right = &samples[256];
+	left_sur = &samples[512];
+	right_sur = &samples[768];
+
+	for (i = 0; i < 256; i++) {
+		left_tmp = dm_par->unit * *left  + dm_par->slev * *left_sur++;
+		right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
+		*left++ = left_tmp;
+		*right++ = right_tmp;
+	}
+}
+
+
+void downmix_3f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
+{
+	int i;
+	float *left, *right, *center, *right_sur;
+	float left_tmp, right_tmp;
+
+	left = &samples[0];
+	right = &samples[512];
+	center = &samples[256];
+	right_sur = &samples[768];
+
+	for (i = 0; i < 256; i++) {
+		left_tmp = dm_par->unit * *left  + dm_par->clev * *center  - dm_par->slev * *right_sur;
+		right_tmp= dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
+		*left++ = left_tmp;
+		*center++ = right_tmp;
+	}
+}
+
+
+void downmix_2f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
+{
+	int i;
+	float *left, *right, *right_sur;
+	float left_tmp, right_tmp;
+
+	left = &samples[0];
+	right = &samples[256];
+	right_sur = &samples[512];
+
+	for (i = 0; i < 256; i++) {
+		left_tmp = dm_par->unit * *left  - dm_par->slev * *right_sur;
+		right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
+		*left++ = left_tmp;
+		*right++ = right_tmp;
+	}
+}
+
+
+void downmix_3f_0r_to_2ch_c (float *samples, dm_par_t *dm_par)
+{
+	int i;
+	float *left, *right, *center;
+	float left_tmp, right_tmp;
+
+	left = &samples[0];
+	center = &samples[256];
+	right = &samples[512];
+
+	for (i = 0; i < 256; i++) {
+		left_tmp = dm_par->unit * *left  + dm_par->clev * *center;
+		right_tmp= dm_par->unit * *right++ + dm_par->clev * *center;
+		*left++ = left_tmp;
+		*center++ = right_tmp;
+	}
+}
+
+
+void stream_sample_2ch_to_s16_c (int16_t *s16_samples, float *left, float *right)
+{
+	int i;
+
+	for (i=0; i < 256; i++) {
+		*s16_samples++ = (int16_t) *left++;
+		*s16_samples++ = (int16_t) *right++;
+	}
+}
+
+
+void stream_sample_1ch_to_s16_c (int16_t *s16_samples, float *center)
+{
+	int i;
+	float tmp;
+
+	for (i=0; i < 256; i++) {
+		*s16_samples++ = tmp = (int16_t) (0.7071f * *center++);
+		*s16_samples++ = tmp;
+	}
+}