source: roaraudio/libroardsp/filter_downmix.c @ 5823:f9f70dbaa376

Last change on this file since 5823:f9f70dbaa376 was 5823:f9f70dbaa376, checked in by phi, 11 years ago

updated copyright

File size: 3.1 KB
Line 
1//filter_downmix.c:
2
3/*
4 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2008-2013
5 *
6 *  This file is part of libroardsp a part of RoarAudio,
7 *  a cross-platform sound system for both, home and professional use.
8 *  See README for details.
9 *
10 *  This file is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License version 3
12 *  as published by the Free Software Foundation.
13 *
14 *  libroardsp 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.
18 *
19 *  You should have received a copy of the GNU General Public License
20 *  along with this software; see the file COPYING.  If not, write to
21 *  the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 *  Boston, MA 02110-1301, USA.
23 *
24 */
25
26#include "libroardsp.h"
27
28int roardsp_downmix_calc162  (struct roardsp_filter * filter, void * data, size_t samples) {
29 int16_t * samp = (int16_t *) data;
30 register int32_t mode = (ROAR_INSTINT)filter->inst;
31 register union {
32//  int16_t i16;
33  int32_t i32;
34  int64_t i64;
35 } s;
36 size_t i;
37
38 ROAR_DBG("roardsp_downmix_calc162(*): mode=%i", mode);
39
40 switch (mode) {
41  case ROARDSP_DOWNMIX_LEFT:
42    for (i = 0; i < samples; i += 2)
43     samp[i+1] = samp[i];
44   break;
45  case ROARDSP_DOWNMIX_RIGHT:
46    for (i = 0; i < samples; i += 2)
47     samp[i] = samp[i+1];
48   break;
49  case ROARDSP_DOWNMIX_ARITHMETIC:
50    for (i = 0; i < samples; i += 2) {
51     s.i32     = (samp[i] + samp[i+1])/2;
52     samp[i  ] = s.i32;
53     samp[i+1] = s.i32;
54    }
55   break;
56  case ROARDSP_DOWNMIX_ARITHMETIC_INVERSE:
57    for (i = 0; i < samples; i += 2) {
58     s.i32     = (float)(samp[i] + samp[i+1])/2.1;
59     samp[i  ] = s.i32;
60     samp[i+1] = -s.i32;
61    }
62   break;
63#ifdef ROAR_HAVE_LIBM
64  case ROARDSP_DOWNMIX_RMS:
65    for (i = 0; i < samples; i += 2) {
66     s.i64      = (int64_t)samp[i]*samp[i] + (int64_t)samp[i+1]*samp[i+1];
67#ifdef ROAR_HAVE_SQRTL
68     s.i64      = sqrtl((long double)s.i64/2.0);
69#else
70     s.i64      = sqrt((double)s.i64/2.0);
71#endif
72//     s.i64     /=  2;
73
74     if ( (samp[i] + samp[i+1]) < 0 )
75      s.i64    *= -1;
76
77     samp[i  ]  = s.i64;
78     samp[i+1]  = s.i64;
79    }
80   break;
81#endif
82  default:
83   ROAR_DBG("roardsp_downmix_calc162(*) = -1 // unknown mode");
84   return -1;
85  break;
86 }
87
88 ROAR_DBG("roardsp_downmix_calc162(*) = 0");
89 return 0;
90}
91
92int roardsp_downmix_ctl   (struct roardsp_filter * filter, int cmd, void * data) {
93 int32_t old;
94
95 if ( cmd == ROARDSP_FCTL_MODE ) {
96  old = (ROAR_INSTINT)filter->inst;
97  filter->inst = (void*)(ROAR_INSTINT)*(int32_t*)data;
98  *(int32_t*)data = old;
99 } else {
100  return -1;
101 }
102
103
104 return 0;
105}
106
107int roardsp_downmix_reset  (struct roardsp_filter * filter, int what) {
108 int32_t mode = ROARDSP_DOWNMIX_ARITHMETIC;
109
110 if ( filter == NULL )
111  return -1;
112
113 switch (what) {
114  case ROARDSP_RESET_NONE:
115  case ROARDSP_RESET_STATE:
116    return  0;
117   break;
118  case ROARDSP_RESET_FULL:
119    roardsp_downmix_ctl(filter, ROARDSP_FCTL_MODE, &mode);
120    return  0;
121   break;
122  default:
123    return -1;
124 }
125
126 return -1;
127}
128
129//ll
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