RetroArch/oss.c
2010-05-28 18:21:33 +02:00

128 lines
2.6 KiB
C

/* SSNES - A Super Ninteno Entertainment System (SNES) Emulator frontend for libsnes.
* Copyright (C) 2010 - Hans-Kristian Arntzen
*
* Some code herein may be based on code found in BSNES.
*
* SSNES 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 Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* SSNES 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 SSNES.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "driver.h"
#include <stdlib.h>
#include <sys/soundcard.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
static void* __oss_init(const char* device, int rate, int latency)
{
int *fd = calloc(1, sizeof(int));
if ( fd == NULL )
return NULL;
const char *oss_device = "/dev/dsp";
if ( device != NULL )
oss_device = device;
if ( (*fd = open(oss_device, O_WRONLY)) < 0 )
{
free(fd);
return NULL;
}
int frags = (latency * rate * 4)/(1000 * (1 << 9));
int frag = (frags << 16) | 9;
if ( ioctl(*fd, SNDCTL_DSP_SETFRAGMENT, &frag) < 0 )
{
close(*fd);
free(fd);
return NULL;
}
int channels = 2;
int format = AFMT_S16_LE;
if ( ioctl(*fd, SNDCTL_DSP_CHANNELS, &channels) < 0 )
{
close(*fd);
free(fd);
return NULL;
}
if ( ioctl(*fd, SNDCTL_DSP_SETFMT, &format) < 0 )
{
close(*fd);
free(fd);
return NULL;
}
if ( ioctl(*fd, SNDCTL_DSP_SPEED, &rate) < 0 )
{
close(*fd);
free(fd);
return NULL;
}
return fd;
}
static ssize_t __oss_write(void* data, const void* buf, size_t size)
{
int *fd = data;
if ( size == 0 )
return 0;
ssize_t ret;
if ( (ret = write(*fd, buf, size)) <= 0 )
return -1;
return ret;
}
static bool __oss_stop(void *data)
{
int *fd = data;
ioctl(*fd, SNDCTL_DSP_RESET, 0);
return true;
}
static bool __oss_start(void *data)
{
return true;
}
static void __oss_free(void *data)
{
int *fd = data;
ioctl(*fd, SNDCTL_DSP_RESET, 0);
close(*fd);
free(fd);
}
const audio_driver_t audio_oss = {
.init = __oss_init,
.write = __oss_write,
.stop = __oss_stop,
.start = __oss_start,
.free = __oss_free
};