X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=linux%2Fsndout_oss.c;h=ccadbba1255c53372abd782234407409a20aacfc;hb=dd59a74b2061298e73c13ddf1be7287cca3ebc74;hp=e2d0bdeaa6fdcc417d5a45cf79412545332cc55b;hpb=7bc9a680a24582b2cb3a82cbdaf383b2330c3b21;p=libpicofe.git

diff --git a/linux/sndout_oss.c b/linux/sndout_oss.c
index e2d0bde..ccadbba 100644
--- a/linux/sndout_oss.c
+++ b/linux/sndout_oss.c
@@ -10,6 +10,8 @@
 #include "sndout_oss.h"
 
 static int sounddev = -1, mixerdev = -1;
+static int can_write_safe;
+
 
 int sndout_oss_init(void)
 {
@@ -23,18 +25,21 @@ int sndout_oss_init(void)
 	return 0;
 }
 
-
-int sndout_oss_start(int rate, int bits, int stereo)
+int sndout_oss_start(int rate, int frame_samples, int stereo)
 {
-	static int s_oldrate = 0, s_oldbits = 0, s_oldstereo = 0;
-	int frag = 0, bsize, buffers, ret;
+	static int s_oldrate = 0, s_old_fsamples = 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)
+	if (rate == s_oldrate && s_old_fsamples == frame_samples && s_oldstereo == stereo)
 		return 0;
 
-	if (sounddev >= 0) close(sounddev);
+	if (sounddev >= 0) {
+		ioctl(sounddev, SOUND_PCM_SYNC, 0);
+		close(sounddev);
+	}
+
 	sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC);
 	if (sounddev == -1)
 	{
@@ -42,42 +47,67 @@ int sndout_oss_start(int rate, int bits, int stereo)
 		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");
+	// calculate buffer size. We one 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++)
+		;
 
-	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");
+	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");
+
+	// not sure if this is still needed (avoiding driver bugs?)
 	usleep(192*1024);
 
-	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_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;
@@ -87,7 +117,6 @@ void sndout_oss_setvol(int l, int r)
  	ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/
 }
 
-
 void sndout_oss_exit(void)
 {
 	if (sounddev >= 0) close(sounddev); sounddev = -1;