1 /*****************************************************************************
2 * ac3_downmix_c.c: ac3 downmix functions
3 *****************************************************************************
4 * Copyright (C) 1999, 2000, 2001 VideoLAN
6 * Authors: Renaud Dartus <reno@videolan.org>
7 * Aaron Holtzman <aholtzma@engr.uvic.ca>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
26 #include "int_types.h"
28 #include "ac3_decoder.h"
29 #include "ac3_internal.h"
30 #include "ac3_bit_stream.h"
32 #include "ac3_downmix.h"
34 void __inline__ downmix_3f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
37 float *left, *right, *center, *left_sur, *right_sur;
38 float left_tmp, right_tmp;
41 center = samples + 256;
42 right = samples + 256*2;
43 left_sur = samples + 256*3;
44 right_sur = samples + 256*4;
46 for (i=0; i < 256; i++) {
47 left_tmp = dm_par->unit * *left + dm_par->clev * *center + dm_par->slev * *left_sur++;
48 right_tmp = dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
50 *center++ = right_tmp;
54 void __inline__ downmix_2f_2r_to_2ch_c (float *samples, dm_par_t *dm_par)
57 float *left, *right, *left_sur, *right_sur;
58 float left_tmp, right_tmp;
61 right = &samples[256];
62 left_sur = &samples[512];
63 right_sur = &samples[768];
65 for (i = 0; i < 256; i++) {
66 left_tmp = dm_par->unit * *left + dm_par->slev * *left_sur++;
67 right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
73 void __inline__ downmix_3f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
76 float *left, *right, *center, *right_sur;
77 float left_tmp, right_tmp;
80 right = &samples[512];
81 center = &samples[256];
82 right_sur = &samples[768];
84 for (i = 0; i < 256; i++) {
85 left_tmp = dm_par->unit * *left + dm_par->clev * *center - dm_par->slev * *right_sur;
86 right_tmp= dm_par->unit * *right++ + dm_par->clev * *center + dm_par->slev * *right_sur++;
88 *center++ = right_tmp;
93 void __inline__ downmix_2f_1r_to_2ch_c (float *samples, dm_par_t *dm_par)
96 float *left, *right, *right_sur;
97 float left_tmp, right_tmp;
100 right = &samples[256];
101 right_sur = &samples[512];
103 for (i = 0; i < 256; i++) {
104 left_tmp = dm_par->unit * *left - dm_par->slev * *right_sur;
105 right_tmp= dm_par->unit * *right + dm_par->slev * *right_sur++;
107 *right++ = right_tmp;
112 void __inline__ downmix_3f_0r_to_2ch_c (float *samples, dm_par_t *dm_par)
115 float *left, *right, *center;
116 float left_tmp, right_tmp;
119 center = &samples[256];
120 right = &samples[512];
122 for (i = 0; i < 256; i++) {
123 left_tmp = dm_par->unit * *left + dm_par->clev * *center;
124 right_tmp= dm_par->unit * *right++ + dm_par->clev * *center;
126 *center++ = right_tmp;
131 void __inline__ stream_sample_2ch_to_s16_c (s16 *out_buf, float *left, float *right)
134 for (i=0; i < 256; i++) {
135 *out_buf++ = (s16) (*left++ * NORM);
136 *out_buf++ = (s16) (*right++ * NORM);
141 void __inline__ stream_sample_1ch_to_s16_c (s16 *out_buf, float *center)
146 for (i=0; i < 256; i++) {
147 *out_buf++ = tmp = (s16) (0.7071f * *center++ * NORM);
148 *out_buf++ = tmp * NORM;