Hey folks

Here's that audio filter I was telling you about. It records whatever you have
your mixer set up for as the recording source.

Try setting it to CD, and turning the CD volume down to 20. Line or Mic is
good if you have something hooked up to the soundcard.

PCM volume should be way up, near 100.

I know, I haven't played with ioctl on dev/mixer, but I will someday.

A problem recently popped up for me, I installed alsa-0.9 and now there is a
clicking sound. I think if I was using a real time kernel or had a sched
priority it might go away. Anyway it's mildly annoying. Maybe it's just my
card.

To make this truly real time, it would probably need to start a rendering
thread while waiting for a SIGALRM timed to the latency. Using sem_wait and
sem_post to protect a global flag for checking if the filter thread were done,
you could kill a render pass that was taking too long, push unfiltered input
audio back out, and lower the complexity of filter for the next pass.

You would have (hopefully) unbroken audio even if slocate were to kick in!

Have fun,

Jason Downer
comtaco@cableone.net

