[LAU] Fluidsynth, soundfonts, jack, and latency
Guru Prasad B. R.
prasadbrg at gmail.com
Mon Nov 2 03:03:32 EST 2009
So I've been trying out AVLinux. By the looks of it, quite impressive
- but I soon ran into a rather serious issue, but I doubt whether it has
anything to do with AVLinux or not. I need your help in this knowing for
My usual setup involves a piano sample on Linuxsampler and a strings
soundfont on qsynth. I had an unusual gig last week that required no
piano sounds, but instead use of multiple layered samples. I therefore
used only qsynth, with 3 engines running concurrently. So in my brand
new AVLinux setup, I loaded up my samples, and had sooperlooper running
2-3 loops concurrently, all on a core2-duo macbook.
Initially, all was ok. No noticeable latency, no xruns whatsoever.But
during the rehearsals, this happened: after sometime, specially at some
point when sooperlooper was running full steam, suddenly there was this
HUGE latency, coupled with lots of dropped notes. As in, I could hold
down a dozen keys simultaneously on the midi controller, and not all
notes could be heard; those that did, would be heard at various
instants upto about half a second later. Completely unuseable.
This would persist even after restarting the jack server, but dissappear
on rebooting the OS.
To me, what is scary and irksome, is not (only) that this glitch
happened consistently, but that there were no error messages in the
qjackctl window. No xruns. Nothing that suggested that something had
gone terribly wrong somewhere (which it had).
I actually compromised on my gig sound, by offloading a lot of samples
what I wanted layered. I don't know if it was because of this, but I
didn't notice this particular issue on the gig itself (but it gave me
sleepless nights prior). But then, 5 mins before the start of the
program, I was left with no audio out of my system! (again, no error
messages). Restarted jack server, and everything back to normal.
Again, no error messages/warnings. Not so much as a by-your-leave. ;)
I'm now intent on finding the source of the problem. I'm looking for
pointers... where do I begin? Where's the 'smoking gun'?
Thanks in advance!
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