When jack_connect is called without any argument, it causes a segfault
in
snprintf( portA, sizeof(portA), "%s", argv[argc-1] );
snprintf( portB, sizeof(portB), "%s", argv[argc-2] );
Reported in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=662199
alsa_in/alsa_out need to close the ALSA device they use when freewheeling starts and then reopen it, along with reset resampling parameters, when it ends. this avoids bizarre behaviour during freewheeling as they try to do audio i/o with a still open PCM device