Dear friends,

I am forwarding this mail to you all to ask for advice. Antoine Lefebvre
has done a nice job at separating input and output devices for double-
device linux setups in order to be able to use two cards on the same
machine (full-duplex, hence).

I'd like to include the patch at least in the unofficial distribution
(so jpff may have a chance to see if it works at all before including
it in the official one) but I'm undecided on how to handle it, because
all the solutions I can think of have drawbacks.

solution 1:	insert names for I/O devices in the configure process,
		all defaulting to the same device (when no two-cards
		setups are present), as in:
		--output-device=DEV      (default: dsp)
		--input-device=DEV       (default: dsp)
		so that whatever is set gets compiled in.
		Drawbacks: compile-time option
		Plusses:   should remain command-line compatible, simple
		           and clean job

solution 2:	allow run-time options to carry the name of the device
		(without the '/dev' of course - or perhaps with that too?),
		as in: csound -o dsp -i dsp1 etc.
		(this could be done like this: when csound reads the -[io]
		option, it checks whether the given name matches a possible
		device: if it does, 'tis the device, otherwise it's a
		file)
		Drawbacks: pretty ugly if you ask me, and not command-
		           line compatible (if that has some meaning),
			   not so simple
		Plusses:   run-time option, quite convenient when you are
		           juggling around with cards...

Advice is more than welcome (it is needed!).

ciao ciao

Nicola

P.S. jpff, I don't get any mail from the csound list since Feb.17; are
     we all *that* busy? (I certainly did not write...)
------------------------------------------------------------------------
Nicola Bernardini
E-mail: nicb@axnet.it
 
Re graphics: A picture is worth 10K words -- but only those to describe
the picture.  Hardly any sets of 10K words can be adequately described
with pictures.

---------- Forwarded message ----------
Date: Wed, 3 Mar 1999 17:39:33 -0500
From: Antoine Lefebvre 
To: Nicola Bernardini 
Subject: rtaudio.c modif for linux

Hello,
it is the first time I use CVS, it is a very great tool! So have have what you said me. I include the diff file of my patch. I don't put any notice about my modification because I don't know how you made that habitually. 

The modification is very little as you see. The disavantage is that you have to recompile to change de devices choice...I should be a great idea to add a command line option.

The file rtlinux.diff is include

Thanks
-- 
Antoine Lefebvre
antoinelefebvre@softhome.net
http://pages.infinit.net/linux/music/music.html
--- rtlinux.c.orig	Wed Mar  3 17:33:37 1999
+++ rtlinux.c	Wed Mar  3 17:34:10 1999
@@ -10,8 +10,10 @@
 
 #include 
 #include 
-#define DSP_NAME    "/dev/dsp"
-static int dspfd;
+#define DSPIN_NAME    "/dev/dsp1"
+#define DSPOUT_NAME   "/dev/dsp"
+static int dspinfd;
+static int dspoutfd
 void setsndparms(int, int, int, float, unsigned);
 void setvolume(unsigned);
 
@@ -45,11 +47,11 @@
       oMaxLag = IODACSAMPS;   /*    use the default value               */
     /* Jonathan Mohr  1995 Oct 17 */
     /* open DSP device for reading */
-    if ( (dspfd = open(DSP_NAME, O_RDONLY)) == -1 )
+    if ( (dspinfd = open(DSPIN_NAME, O_RDONLY)) == -1 )
       die("unable to open soundcard for audio input");
     
     /* initialize data format, channels, sample rate, and buffer size */
-    setsndparms( dspfd, O.informat, nchnls, esr, oMaxLag * O.insampsiz );
+    setsndparms( dspinfd, O.informat, nchnls, esr, oMaxLag * O.insampsiz );
     ishift = getshift(dsize);
 }
 
@@ -67,11 +69,11 @@
    channels, but allows the user to set the output volume.                  */
     {
         /* open DSP device for writing */
-        if ( (dspfd = open(DSP_NAME, O_WRONLY)) == -1 )
+        if ( (dspoutfd = open(DSPOUT_NAME, O_WRONLY)) == -1 )
           die("unable to open soundcard for audio output");
 
         /* set sample size/format, rate, channels, and DMA buffer size */
-        setsndparms( dspfd, O.outformat, nchnls, esr,
+        setsndparms( dspoutfd, O.outformat, nchnls, esr,
                      O.outbufsamps * O.outsampsiz);
 
         /* check if volume was specified as command line parameter */
@@ -90,7 +92,7 @@
 int rtrecord(char *inbuf, int nbytes) /* get samples from ADC */
 {
     /*  J. Mohr  1995 Oct 17 */
-    if ( (nbytes = read(dspfd, inbuf, nbytes)) == -1 )
+    if ( (nbytes = read(dspinfd, inbuf, nbytes)) == -1 )
       die("error while reading DSP device for audio input");
     return(nbytes);
 }
@@ -110,7 +112,7 @@
 {
         long sampframes = nbytes >> oshift;
         /*  J. Mohr  1995 Oct 17 */
-        if (write(dspfd, outbuf, nbytes) < nbytes)
+        if (write(dspoutfd, outbuf, nbytes) < nbytes)
             printf("/dev/dsp: couldn't write all bytes requested\n");
         nrecs++;
 }
@@ -118,7 +120,9 @@
 void rtclose(void)              /* close the I/O device entirely  */
 {                               /* called only when both complete */
     /*  J. Mohr  1995 Oct 17 */
-    if (close(dspfd) == -1)
+    if (close(dspinfd) == -1)
+      die("unable to close DSP device");
+    if (close(dspoutfd) == -1)
       die("unable to close DSP device");
     if (O.Linein) {
 #ifdef PIPES