#include "sndout_oss.h"
static int sounddev = -1, mixerdev = -1;
+static int can_write_safe;
+
+#define FRAG_COUNT 4
int sndout_oss_init(void)
{
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 bits, int stereo)
+int sndout_oss_start(int rate, int stereo, int frames_in_frag)
{
- static int s_oldrate = 0, s_oldbits = 0, s_oldstereo = 0;
- int frag = 0, bsize, buffers, ret;
+ static int s_oldrate = 0, s_oldstereo = 0;
+ int frag, bsize, bits, ret;
- // if no settings change, we don't need to do anything,
- // since audio is never stopped
- if (rate == s_oldrate && s_oldbits == bits && s_oldstereo == stereo)
+ // 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_oldstereo == stereo)
return 0;
- if (sounddev >= 0) close(sounddev);
- sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC);
+ sndout_oss_stop();
+ sounddev = open("/dev/dsp", O_WRONLY);
if (sounddev == -1)
{
perror("open(\"/dev/dsp\")");
- return -1;
+ sounddev = open("/dev/dsp1", O_WRONLY);
+ if (sounddev == -1) {
+ perror("open(\"/dev/dsp1\")");
+ return -1;
+ }
}
- // calculate buffer size
- // this is tuned for GP2X
- buffers = 16;
- bsize = rate / 32;
- if (rate > 22050) { bsize*=4; buffers*=2; }
- while ((bsize>>=1)) frag++;
- frag |= buffers<<16; // 16 buffers
- ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag);
- if (ret) perror("SNDCTL_DSP_SETFRAGMENT failed");
+ // try to fit frames_in_frag frames worth of data in fragment
+ // ignore mono because it's unlikely to be used and
+ // both GP2X and Wiz mixes mono to stereo anyway.
+ bsize = (frames_in_frag * rate / 50) * 4;
- ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo);
- ret |= ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits);
- ret |= ioctl(sounddev, SNDCTL_DSP_SPEED, &rate);
- if (ret) printf("failed to set audio format\n");
+ for (frag = 0; bsize; bsize >>= 1, frag++)
+ ;
+
+ frag |= FRAG_COUNT << 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("gp2x_set_sound: %i/%ibit/%s, %i buffers of %i bytes\n",
- rate, bits, stereo?"stereo":"mono", frag>>16, 1<<(frag&0xffff));
+ 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_oldbits = bits; s_oldstereo = stereo;
+ s_oldrate = rate; s_oldstereo = stereo;
+ can_write_safe = 0;
return 0;
}
-
int sndout_oss_write(const void *buff, int len)
{
return write(sounddev, buff, len);
}
+#include "../common/plat.h"
+
+/* not really non-blocking, just detects if blocking occurs
+ * and starts skipping writes in case it does. */
+int sndout_oss_write_nb(const void *buff, int len)
+{
+ static int lag_counter, skip_counter;
+ unsigned int t;
+ int ret;
+
+ if (lag_counter > 2) {
+ // skip writes if audio starts blocking
+ lag_counter = 0;
+ skip_counter = FRAG_COUNT;
+ }
+
+ if (skip_counter > 0) {
+ skip_counter--;
+ return len;
+ }
+
+ t = plat_get_ticks_ms();
+ ret = sndout_oss_write(buff, len);
+ t = plat_get_ticks_ms() - t;
+ if (t > 1) {
+ // this shouldn't really happen, most likely audio is out of sync
+ lag_counter++;
+ if (lag_counter > 2)
+ printf("audio lag %u\n", t);
+ }
+ else
+ lag_counter = 0;
+
+ return ret;
+}
+
+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 + 1 frag
+ return bi.bytes - bi.fragsize >= 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;
ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/
}
-
void sndout_oss_exit(void)
{
if (sounddev >= 0) close(sounddev); sounddev = -1;