summaryrefslogtreecommitdiffstats
path: root/polyp/sample-util.c
blob: 6a09478f6108376e445a25021997e94b4047b261 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/* $Id$ */

/***
  This file is part of polypaudio.
 
  polypaudio 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 of the License,
  or (at your option) any later version.
 
  polypaudio 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 polypaudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <assert.h>

#include "sample-util.h"

struct pa_memblock *pa_silence_memblock(struct pa_memblock* b, const struct pa_sample_spec *spec) {
    assert(b && b->data && spec);
    pa_silence_memory(b->data, b->length, spec);
    return b;
}

void pa_silence_memchunk(struct pa_memchunk *c, const struct pa_sample_spec *spec) {
    assert(c && c->memblock && c->memblock->data && spec && c->length);
    pa_silence_memory(c->memblock->data+c->index, c->length, spec);
}

void pa_silence_memory(void *p, size_t length, const struct pa_sample_spec *spec) {
    char c = 0;
    assert(p && length && spec);

    switch (spec->format) {
        case PA_SAMPLE_U8:
            c = 127;
            break;
        case PA_SAMPLE_S16LE:
        case PA_SAMPLE_S16BE:
        case PA_SAMPLE_FLOAT32:
            c = 0;
            break;
        case PA_SAMPLE_ALAW:
        case PA_SAMPLE_ULAW:
            c = 80;
            break;
        default:
            assert(0);
    }
                
    memset(p, c, length);
}

size_t pa_mix(struct pa_mix_info channels[], unsigned nchannels, void *data, size_t length, const struct pa_sample_spec *spec, pa_volume_t volume) {
    unsigned c, d;
    assert(channels && data && length && spec);
    assert(spec->format == PA_SAMPLE_S16NE);

    for (d = 0;; d += sizeof(int16_t)) {
        int32_t sum = 0;

        if (d >= length)
            return d;
        
        for (c = 0; c < nchannels; c++) {
            int32_t v;
            uint32_t volume = channels[c].volume;
            
            if (d >= channels[c].chunk.length)
                return d;

            if (volume == PA_VOLUME_MUTED)
                v = 0;
            else {
                v = *((int16_t*) (channels[c].chunk.memblock->data + channels[c].chunk.index + d));

                if (volume != PA_VOLUME_NORM)
                    v = (int32_t) ((float)v*volume/PA_VOLUME_NORM);
            }

            sum += v;
        }

        if (volume == PA_VOLUME_MUTED)
            sum = 0;
        else if (volume != PA_VOLUME_NORM)
            sum = (int32_t) ((float) sum*volume/PA_VOLUME_NORM);
        
        if (sum < -0x8000) sum = -0x8000;
        if (sum > 0x7FFF) sum = 0x7FFF;
        
        *((int16_t*) data) = sum;
        data += sizeof(int16_t);
    }
}


void pa_volume_memchunk(struct pa_memchunk*c, const struct pa_sample_spec *spec, pa_volume_t volume) {
    int16_t *d;
    size_t n;
    assert(c && spec && (c->length % pa_frame_size(spec) == 0));
    assert(spec->format == PA_SAMPLE_S16NE);

    if (volume == PA_VOLUME_NORM)
        return;

    if (volume == PA_VOLUME_MUTED) {
        pa_silence_memchunk(c, spec);
        return;
    }

    for (d = (c->memblock->data+c->index), n = c->length/sizeof(int16_t); n > 0; d++, n--) {
        int32_t t = (int32_t)(*d);

        t *= volume;
        t /= PA_VOLUME_NORM;

        if (t < -0x8000) t = -0x8000;
        if (t > 0x7FFF) t = 0x7FFF;
        
        *d = (int16_t) t;
    }
}