BizHawk/libmupen64plus/mupen64plus-audio-sdl/src/volume.c

89 lines
2.9 KiB
C

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Mupen64plus-sdl-audio - volume.c *
* Mupen64Plus homepage: http://code.google.com/p/mupen64plus/ *
* Copyright (C) 2007-2008 Richard42 Ebenblues *
* Copyright (C) 2002 Hacktarux *
* *
* 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., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#if defined(HAS_OSS_SUPPORT)
/* Sound volume functions. */
#include <sys/soundcard.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <unistd.h> /* close() */
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include "volume.h"
/* volSet
* Sets volume of left and right PCM channels to given percentage (0-100) value.
*/
void volSet(int percent)
{
int ret, vol;
int mixerfd = open("/dev/mixer", O_RDONLY);
if(mixerfd < 0)
{
perror("/dev/mixer");
return;
}
if(percent > 100)
percent = 100;
else if(percent < 0)
percent = 0;
vol = (percent << 8) + percent; // set both left/right channels to same vol
ret = ioctl(mixerfd, MIXER_WRITE(SOUND_MIXER_PCM), &vol);
if(ret < 0)
perror("Setting PCM volume");
close(mixerfd);
}
/* volGet
* Returns volume of PCM channel as a percentage (0-100).
* Returns 0 on error.
*/
int volGet(void)
{
int vol, ret;
int mixerfd = open("/dev/mixer", O_RDONLY);
if(mixerfd < 0)
{
perror("/dev/mixer");
return 0;
}
ret = ioctl(mixerfd, MIXER_READ(SOUND_MIXER_PCM), &vol);
if(ret < 0)
perror("Reading PCM volume");
close(mixerfd);
return vol & 0xff; // just return the left channel
}
#endif /* defined(HAS_OSS_SUPPORT) */