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pcm_utils: moved channel conversion functions to pcm_channels.c 

Separate code from pcm_utils.c to keep it small and simple.
This commit is contained in:
Max Kellermann 2008-10-23 20:03:14 +02:00
parent af7cb932fb
commit a0bcbb37f4
4 changed files with 138 additions and 82 deletions
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2
src/Makefile.am
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@ -66,6 +66,7 @@ mpd_headers = \
path.h \
mapper.h \
pcm_utils.h \
pcm_channels.h \
pcm_resample.h \
pcm_dither.h \
permission.h \
@ -147,6 +148,7 @@ mpd_SOURCES = \
path.c \
mapper.c \
pcm_utils.c \
pcm_channels.c \
pcm_resample.c \
pcm_dither.c \
permission.c \

102
src/pcm_channels.c Normal file
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@ -0,0 +1,102 @@
/* the Music Player Daemon (MPD)
* Copyright (C) 2008 Max Kellermann <max@duempel.org>
* This project's homepage is: http://www.musicpd.org
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pcm_channels.h"
#include "utils.h"
#include "log.h"
#include <assert.h>
static void
pcm_convert_channels_16_1_to_2(int16_t *dest, const int16_t *src,
unsigned num_frames)
{
while (num_frames-- > 0) {
int16_t value = *src++;
*dest++ = value;
*dest++ = value;
}
}
static void
pcm_convert_channels_16_2_to_1(int16_t *dest, const int16_t *src,
unsigned num_frames)
{
while (num_frames-- > 0) {
int32_t a = *src++, b = *src++;
*dest++ = (a + b) / 2;
}
}
static void
pcm_convert_channels_16_n_to_2(int16_t *dest,
unsigned src_channels, const int16_t *src,
unsigned num_frames)
{
unsigned c;
assert(src_channels > 0);
while (num_frames-- > 0) {
int32_t sum = 0;
int16_t value;
for (c = 0; c < src_channels; ++c)
sum += *src++;
value = sum / (int)src_channels;
/* XXX this is actually only mono ... */
*dest++ = value;
*dest++ = value;
}
}
const int16_t *
pcm_convert_channels_16(int8_t dest_channels,
int8_t src_channels, const int16_t *src,
size_t src_size, size_t *dest_size_r)
{
static int16_t *buf;
static size_t len;
unsigned num_frames = src_size / src_channels / sizeof(*src);
unsigned dest_size = num_frames * dest_channels * sizeof(*src);
if (dest_size > len) {
len = dest_size;
buf = xrealloc(buf, len);
}
*dest_size_r = dest_size;
if (src_channels == 1 && dest_channels == 2)
pcm_convert_channels_16_1_to_2(buf, src, num_frames);
else if (src_channels == 2 && dest_channels == 1)
pcm_convert_channels_16_2_to_1(buf, src, num_frames);
else if (dest_channels == 2)
pcm_convert_channels_16_n_to_2(buf, src_channels, src,
num_frames);
else {
ERROR("conversion %u->%u channels is not supported\n",
src_channels, dest_channels);
return NULL;
}
return buf;
}

30
src/pcm_channels.h Normal file
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@ -0,0 +1,30 @@
/* the Music Player Daemon (MPD)
* Copyright (C) 2008 Max Kellermann <max@duempel.org>
* This project's homepage is: http://www.musicpd.org
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef MPD_PCM_CHANNELS_H
#define MPD_PCM_CHANNELS_H
#include <stdint.h>
#include <stddef.h>
const int16_t *
pcm_convert_channels_16(int8_t dest_channels,
int8_t src_channels, const int16_t *src,
size_t src_size, size_t *dest_size_r);
#endif

86
src/pcm_utils.c
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@ -17,6 +17,7 @@
*/
#include "pcm_utils.h"
#include "pcm_channels.h"
#include "log.h"
#include "utils.h"
#include "conf.h"
@ -213,85 +214,6 @@ void pcm_convert_init(struct pcm_convert_state *state)
pcm_dither_24_init(&state->dither);
}
static void
pcm_convert_channels_1_to_2(int16_t *dest, const int16_t *src,
unsigned num_frames)
{
while (num_frames-- > 0) {
int16_t value = *src++;
*dest++ = value;
*dest++ = value;
}
}
static void
pcm_convert_channels_2_to_1(int16_t *dest, const int16_t *src,
unsigned num_frames)
{
while (num_frames-- > 0) {
int32_t a = *src++, b = *src++;
*dest++ = (a + b) / 2;
}
}
static void
pcm_convert_channels_n_to_2(int16_t *dest,
unsigned src_channels, const int16_t *src,
unsigned num_frames)
{
unsigned c;
assert(src_channels > 0);
while (num_frames-- > 0) {
int32_t sum = 0;
int16_t value;
for (c = 0; c < src_channels; ++c)
sum += *src++;
value = sum / (int)src_channels;
/* XXX this is actually only mono ... */
*dest++ = value;
*dest++ = value;
}
}
static const int16_t *
pcm_convert_channels(int8_t dest_channels,
int8_t src_channels, const int16_t *src,
size_t src_size, size_t *dest_size_r)
{
static int16_t *buf;
static size_t len;
unsigned num_frames = src_size / src_channels / sizeof(*src);
unsigned dest_size = num_frames * dest_channels * sizeof(*src);
if (dest_size > len) {
len = dest_size;
buf = xrealloc(buf, len);
}
*dest_size_r = dest_size;
if (src_channels == 1 && dest_channels == 2)
pcm_convert_channels_1_to_2(buf, src, num_frames);
else if (src_channels == 2 && dest_channels == 1)
pcm_convert_channels_2_to_1(buf, src, num_frames);
else if (dest_channels == 2)
pcm_convert_channels_n_to_2(buf, src_channels, src,
num_frames);
else {
ERROR("conversion %u->%u channels is not supported\n",
src_channels, dest_channels);
return NULL;
}
return buf;
}
static void
pcm_convert_8_to_16(int16_t *out, const int8_t *in,
unsigned num_samples)
@ -375,9 +297,9 @@ size_t pcm_convert(const struct audio_format *inFormat,
exit(EXIT_FAILURE);
if (inFormat->channels != outFormat->channels) {
buf = pcm_convert_channels(outFormat->channels,
inFormat->channels,
buf, len, &len);
buf = pcm_convert_channels_16(outFormat->channels,
inFormat->channels,
buf, len, &len);
if (!buf)
exit(EXIT_FAILURE);
}