picodrive/platform/linux/sndout_oss.c
notaz d08e732614 pandora: tripplebuffer fbdev out, refactoring
git-svn-id: file:///home/notaz/opt/svn/PicoDrive@845 be3aeb3a-fb24-0410-a615-afba39da0efa
2009-12-20 19:47:55 +00:00

137 lines
3.1 KiB
C

/* sound output via OSS */
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include <unistd.h>
#include "sndout_oss.h"
static int sounddev = -1, mixerdev = -1;
static int can_write_safe;
int sndout_oss_init(void)
{
if (mixerdev >= 0) close(mixerdev);
mixerdev = open("/dev/mixer", O_RDWR);
if (mixerdev == -1)
{
perror("open(\"/dev/mixer\")");
}
return 0;
}
void sndout_oss_stop(void)
{
if (sounddev < 0)
return;
ioctl(sounddev, SOUND_PCM_SYNC, 0);
close(sounddev);
sounddev = -1;
}
int sndout_oss_start(int rate, int frame_samples, int stereo)
{
static int s_oldrate = 0, s_old_fsamples = 0, s_oldstereo = 0;
int frag, bsize, bits, ret;
// GP2X: if no settings change, we don't need to do anything,
// since audio is never stopped there
if (sounddev >= 0 && rate == s_oldrate && s_old_fsamples == frame_samples && s_oldstereo == stereo)
return 0;
sndout_oss_stop();
sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC);
if (sounddev == -1)
{
perror("open(\"/dev/dsp\")");
sounddev = open("/dev/dsp1", O_WRONLY|O_ASYNC);
if (sounddev == -1) {
perror("open(\"/dev/dsp1\")");
return -1;
}
}
// calculate buffer size. We want to fit 1 frame worth of sound data.
// Also ignore mono because both GP2X and Wiz mixes mono to stereo anyway.
bsize = frame_samples << 2;
for (frag = 0; bsize; bsize >>= 1, frag++)
;
frag |= 16 << 16; // fragment count
ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag);
if (ret < 0)
perror("SNDCTL_DSP_SETFRAGMENT failed");
bits = 16;
ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo);
if (ret == 0)
ret = ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits);
if (ret == 0)
ret = ioctl(sounddev, SNDCTL_DSP_SPEED, &rate);
if (ret < 0)
perror("failed to set audio format");
#ifdef __GP2X__
// not sure if this is still needed (avoiding driver bugs?)
usleep(192*1024);
#endif
printf("sndout_oss_start: %d/%dbit/%s, %d buffers of %i bytes\n",
rate, bits, stereo ? "stereo" : "mono", frag >> 16, 1 << (frag & 0xffff));
s_oldrate = rate; s_old_fsamples = frame_samples; s_oldstereo = stereo;
can_write_safe = 0;
return 0;
}
int sndout_oss_write(const void *buff, int len)
{
return write(sounddev, buff, len);
}
int sndout_oss_can_write(int bytes)
{
audio_buf_info bi;
int ret;
#ifdef __GP2X__
// note: SNDCTL_DSP_GETOSPACE crashes F100 kernel for some reason
// if called too early, so we work around here
if (can_write_safe++ < 8)
return 1;
#endif
ret = ioctl(sounddev, SNDCTL_DSP_GETOSPACE, &bi);
if (ret < 0)
return 1;
// have enough bytes to write + 4 extra frags
return bi.bytes - bi.fragsize * 4 >= bytes ? 1 : 0;
}
void sndout_oss_sync(void)
{
ioctl(sounddev, SOUND_PCM_SYNC, 0);
}
void sndout_oss_setvol(int l, int r)
{
if (mixerdev < 0) return;
l=l<0?0:l; l=l>255?255:l; r=r<0?0:r; r=r>255?255:r;
l<<=8; l|=r;
ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/
}
void sndout_oss_exit(void)
{
if (sounddev >= 0) close(sounddev); sounddev = -1;
if (mixerdev >= 0) close(mixerdev); mixerdev = -1;
}