New answers tagged jack
Apparently (ubuntu forums thread), it's a buffer under-or-overrun, X stands for under or over. It's a sign that your system did not process some buffers in time, so some data is missed. It is particularly true when you run at very low buffer size where the sound card should process incoming buffers very fast (overrun). Some chips cannot cope with small ...
/usr/include/jack/jack.h is provided by libjack-dev (jackd1) or libjack-jackd2-dev (jackd2) package. You need to install either of them. Debian has the service where you can search for packages which contain specific files. Here's the result for jack/jack.h.
Top 50 recent answers are included