1 /*****************************************************************************
2 * ac3_downmix_c.c: ac3 downmix functions
3 *****************************************************************************
4 * Copyright (C) 1999, 2000, 2001 VideoLAN
5 * $Id: ac3_downmix_c.c,v 1.7 2001/05/06 04:32:02 sam Exp $
7 * Authors: Renaud Dartus <reno@videolan.org>
8 * Aaron Holtzman <aholtzma@engr.uvic.ca>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
27 #include <string.h> /* memcpy() */
34 #include "stream_control.h"
35 #include "input_ext-dec.h"
37 #include "ac3_decoder.h"
38 #include "ac3_internal.h"
40 #include "ac3_downmix.h"
42 void __inline__ downmix_3f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
45 float *left, *right, *center, *left_sur, *right_sur;
46 float left_tmp, right_tmp;
49 center = samples + 256;
50 right = samples + 256*2;
51 left_sur = samples + 256*3;
52 right_sur = samples + 256*4;
54 for (i=0; i < 256; i++) {
55 left_tmp = dm_par->unit * *left + dm_par->clev * *center + dm_par->slev * *left_sur++;
56 right_tmp = dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
58 *center++ = right_tmp;
62 void __inline__ downmix_2f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
65 float *left, *right, *left_sur, *right_sur;
66 float left_tmp, right_tmp;
69 right = &samples[256];
70 left_sur = &samples[512];
71 right_sur = &samples[768];
73 for (i = 0; i < 256; i++) {
74 left_tmp = dm_par->unit * *left + dm_par->slev * *left_sur++;
75 right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
81 void __inline__ downmix_3f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
84 float *left, *right, *center, *right_sur;
85 float left_tmp, right_tmp;
88 right = &samples[512];
89 center = &samples[256];
90 right_sur = &samples[768];
92 for (i = 0; i < 256; i++) {
93 left_tmp = dm_par->unit * *left + dm_par->clev * *center - dm_par->slev * *right_sur;
94 right_tmp= dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
96 *center++ = right_tmp;
101 void __inline__ downmix_2f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
104 float *left, *right, *right_sur;
105 float left_tmp, right_tmp;
108 right = &samples[256];
109 right_sur = &samples[512];
111 for (i = 0; i < 256; i++) {
112 left_tmp = dm_par->unit * *left - dm_par->slev * *right_sur;
113 right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
115 *right++ = right_tmp;
120 void __inline__ downmix_3f_0r_to_2ch_c (float *samples, dm_par_t *dm_par)
123 float *left, *right, *center;
124 float left_tmp, right_tmp;
127 center = &samples[256];
128 right = &samples[512];
130 for (i = 0; i < 256; i++) {
131 left_tmp = dm_par->unit * *left + dm_par->clev * *center;
132 right_tmp= dm_par->unit * *right++ + dm_par->clev * *center;
134 *center++ = right_tmp;
139 void __inline__ stream_sample_2ch_to_s16_c (s16 *out_buf, float *left, float *right)
142 for (i=0; i < 256; i++) {
143 *out_buf++ = (s16) (*left++);
144 *out_buf++ = (s16) (*right++);
149 void __inline__ stream_sample_1ch_to_s16_c (s16 *out_buf, float *center)
154 for (i=0; i < 256; i++) {
155 *out_buf++ = tmp = (s16) (0.7071f * *center++);