use SNDCTL_DSP_SETFRAGMENT instead of SNDCTL_DSP_SUBDIVIDE

src/oss.c

@@ -40,7 +40,7 @@ static int configure_fd(int fd, int bits,int stereo, int rate, int *minsz)
 {
 	int p=0,cond=0;
 	int i=0;
-	int min_size=0,blocksize=512;
+	int min_size=0,blocksize=512,size_selector=9/*=512*/;
 	int err;
 	
 	//g_message("opening sound device");
@@ -79,22 +79,39 @@ static int configure_fd(int fd, int bits,int stereo, int rate, int *minsz)
 	
 	if (rate==16000) blocksize=4096;	/* oss emulation is not very good at 16khz */
 	else blocksize=blocksize*(rate/8000);
+
 	ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
 
-	/* try to subdivide BLKSIZE to reach blocksize if necessary */
-	if (min_size>blocksize)
-	{
-		cond=1;
-		p=min_size/blocksize;
-		while(cond)
-		{
-			i=ioctl(fd, SNDCTL_DSP_SUBDIVIDE, &p);
-			ms_message("subdivide bloc min_size [%i] block_size [%i]  said error=%i,errno=%i\n",min_size,blocksize,i,errno);
-			if ((i!=0) || (p==1)) cond=0;
-			else p=p/2;
+	/**
+	 * first try SNDCTL_DSP_SETFRAGMENT
+	 */
+	if (min_size>blocksize) {
+		int frag = (2 << 16) | (size_selector);
+		if (ioctl(fd, SNDCTL_DSP_SETFRAGMENT, &frag) == -1) {
+			ms_warning("This OSS driver does not support trying subdivise",SNDCTL_DSP_SETFRAGMENT);
+			ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
+
+			/* try to subdivide BLKSIZE to reach block size if necessary */
+			if (min_size>blocksize)
+			{
+				cond=1;
+				p=min_size/blocksize;
+				while(cond)
+				{
+					i=ioctl(fd, SNDCTL_DSP_SUBDIVIDE, &p);
+					ms_message("subdivide bloc min_size [%i] block_size [%i]  said error=%i,errno=%i\n",min_size,blocksize,i,errno);
+					if ((i!=0) || (p==1)) cond=0;
+					else p=p/2;
+				}
+			}
+			ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
+		} else {
+			/*it's working*/
+			min_size=1 << (frag&0x0FFFF);
+			ms_message("Max fragment=%x, size selector=%x block size=%i",frag>>16,frag&0x0FFFF,min_size);
 		}
 	}
-	ioctl(fd, SNDCTL_DSP_GETBLKSIZE, &min_size);
+
 	if (min_size>blocksize)
 	{
 		ms_warning("dsp block size set to %i.",min_size);