So far the svxlink on raspi is working stable. It runs several days without problems, no system lockup or svxlink crash.
There is however a problem with the behaviour of svxlink. Besides the “normal” audio delay, svxlink sometimes sits there and does nothing…
The squelch events stop to be processed and there is no audio output. After a few seconds svxlink seems to catch up an at least a short audio tail is send. After this, everything is back to normal for a few more minutes.
Looking at the cpu usage of svxlink with top, it appears that during those hangs the cpu usage drops down to idle level from the normally higher cpu level associated with processing audio.
I took some strace of the svxlink process during such events, but I’m not familiar with the code enough…
In meanwhile I’m working on the pre-/de-emphasis of the repeater to make echolink/announcements AND repeated audio to sound good.
A recent article on audio processing shows that even low delay audio processing can be done on the raspi (<= 10ms) ! Have a look at: