Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST) From: Hannu Savolainen Subject: Re: SDL uses obsolete OSS features I did some work on getting OSS to work better with SDL. There have been some problems with select which should be fixed now. I'm having some problems in understanding what is the purpose of the DSP_WaitAudio() routine. I added a return to the very beginning of this routine and commendted out the define for USE_BLOCKING_WRITES. At least lbreakout2 seems to work as well as earlier. The latencies are the same. An ordinary blocking write does exactly the same thing than DSP_WaitAudio does. So I would recommend using the USE_BLOCKING_WRITES approach and removing everything from the DSP_WaitAudio routine. Also enabling USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because you don't need to handle the partial writes (the do-while loop). Attached is a patch against SDL-1.2.7. After these changes SDL will use OSS as it's designed to be used (make it as simple as possible). This code should work with all OSS implementations because it uses only the very fundamental features that have been there since the jurassic times.

--- a/src/audio/dsp/SDL_dspaudio.h	Fri Nov 12 21:29:52 2004 +0000
+++ b/src/audio/dsp/SDL_dspaudio.h	Fri Nov 12 21:39:04 2004 +0000
@@ -43,10 +43,6 @@
 	/* Raw mixing buffer */
 	Uint8 *mixbuf;
 	int    mixlen;
-
-	/* Support for audio timing using a timer, in addition to select() */
-	float frame_ticks;
-	float next_frame;
 };
 #define FUDGE_TICKS	10	/* The scheduler overhead ticks per frame */