Re: playthrough

On Fri, 12 Feb 1999, |L_| wrote:

hi is it possible to mute the playthrough/(monitoring) when you re using "live" input on linux & oss drivers? tks,oss

-- 1337777.16662735

Yes, basically it should be possible. Yet, I have not seen a mixer implementation which has this feature. The second problem is that not all soundcards seem to support this feature, and the third that not all soundcard drivers implement this feature.

I am attaching a small program which should mute the recording monitor ...

compile it with gcc -o mute_mon mute_mon.c

and pray .....

Guenter

mute_mon.c

#include <stdio.h> #include <linux/soundcard.h>

char* mix_dev = "/dev/mixer";

main() { int fd; int res; int param=0;

fd = open (mix_dev);
    if (fd <0) {
        fprintf(stderr,"Could not open mixer device %s\n",mix_dev);
        exit(0);
    }


res = ioctl(fd,SOUND_MIXER_READ_DEVMASK,&param);
if (res < 0) fprintf(stderr,"Mixer ioctl failed - No mixer present ?\n");
fprintf(stderr,"Devices supported = %x\n",param);

if (param&SOUND_MIXER_IMIX) 
        fprintf(stderr,"Can change recording monitor\n");
    else
        fprintf(stderr,"Unable to change recording monitor\n");


param = 0;
    res = ioctl(fd,SOUND_MIXER_WRITE_IMIX,&param);
if (res < 0) fprintf(stderr,"Muting recording monitor failed\n");
else fprintf(stderr,"Recording monitor muted\n");

}