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/* $Id$ */
/***
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;
}
}
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