source: roaraudio/libroarpulse/volume.c @ 3466:6d461930b82b

Last change on this file since 3466:6d461930b82b was 3459:d5eff217fea2, checked in by phi, 10 years ago

implemented a lot volume functions

File size: 4.3 KB
Line 
1//volume.c:
2
3/*
4 *      Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2010
5 *  The code (may) include prototypes and comments (and maybe
6 *  other code fragements) from libpulse*. They are mostly copyrighted by:
7 *  Lennart Poettering <poettering@users.sourceforge.net> and
8 *  Pierre Ossman <drzeus@drzeus.cx>
9 *
10 *  This file is part of libroarpulse a part of RoarAudio,
11 *  a cross-platform sound system for both, home and professional use.
12 *  See README for details.
13 *
14 *  This file is free software; you can redistribute it and/or modify
15 *  it under the terms of the GNU General Public License version 3
16 *  as published by the Free Software Foundation.
17 *
18 *  RoarAudio is distributed in the hope that it will be useful,
19 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
20 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21 *  GNU General Public License for more details.
22 *
23 *  You should have received a copy of the GNU General Public License
24 *  along with this software; see the file COPYING.  If not, write to
25 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
26 *
27 *  NOTE for everyone want's to change something and send patches:
28 *  read README and HACKING! There a addition information on
29 *  the license of this document you need to read before you send
30 *  any patches.
31 *
32 *  NOTE for uses of non-GPL (LGPL,...) software using libesd, libartsc
33 *  or libpulse*:
34 *  The libs libroaresd, libroararts and libroarpulse link this libroar
35 *  and are therefore GPL. Because of this it may be illigal to use
36 *  them with any software that uses libesd, libartsc or libpulse*.
37 */
38
39#include <libroarpulse/libroarpulse.h>
40
41/** Return non-zero when *a == *b */
42int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) {
43 int i;
44
45 if ( a == b )
46  return 1;
47
48 if ( a == NULL || b == NULL )
49  return 0;
50
51 if ( a->channels != b->channels )
52  return 0;
53
54 for (i = 0; i < a->channels; i++)
55  if ( a->values[i] != b->values[i] )
56   return 0;
57
58 return 1;
59}
60
61/** Set the volume of all channels to the specified parameter */
62pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v) {
63 int i;
64
65 if ( a == NULL )
66  return NULL;
67
68 if ( channels > PA_CHANNELS_MAX )
69  return NULL;
70
71 a->channels = channels;
72
73 for (i = 0; i < channels; i++) {
74  a->values[i] = v;
75 }
76
77 return a;
78}
79
80/** Pretty print a volume structure */
81char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c);
82
83/** Return the average volume of all channels */
84pa_volume_t pa_cvolume_avg(const pa_cvolume *a) {
85 int64_t sum = 0;
86 int i;
87
88#ifndef PA_VOLUME_INVALID
89#define PA_VOLUME_INVALID ((pa_volume_t) UINT32_MAX)
90#endif
91
92 if ( a == NULL )
93  return PA_VOLUME_INVALID;
94
95 for (i = 0; i < a->channels; i++)
96  sum += a->values[i];
97
98 return sum/a->channels;
99}
100
101/** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */
102int pa_cvolume_valid(const pa_cvolume *v) {
103 if ( v == NULL )
104  return 0;
105
106 if ( v->channels <= 0 )
107  return 0;
108
109 if ( v->channels > PA_CHANNELS_MAX )
110  return 0;
111
112 return 1;
113}
114
115/** Return non-zero if the volume of all channels is equal to the specified value */
116int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) {
117 int i;
118
119 if ( a == NULL )
120  return 0;
121
122 for (i = 0; i < a->channels; i++)
123  if ( a->values[i] != v )
124   return 0;
125
126 return 1;
127}
128
129/** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. This is only valid for software volumes! */
130pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b);
131
132/** Multiply to per-channel volumes and return the result in *dest. This is only valid for software volumes! */
133pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);
134
135/** Convert a decibel value to a volume. This is only valid for software volumes! \since 0.4 */
136pa_volume_t pa_sw_volume_from_dB(double f);
137
138/** Convert a volume to a decibel value. This is only valid for software volumes! \since 0.4 */
139double pa_sw_volume_to_dB(pa_volume_t v);
140
141/** Convert a linear factor to a volume. This is only valid for software volumes! \since 0.8 */
142pa_volume_t pa_sw_volume_from_linear(double v);
143
144/** Convert a volume to a linear factor. This is only valid for software volumes! \since 0.8 */
145double pa_sw_volume_to_linear(pa_volume_t v);
146
147//ll
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