I've checked the licensing, and it's not clear
from the webpage;
I gathered that it's not GPL, right ?
Also, using PortAudio means it probably cannot be GPL.
I am uneasy about this statement of PortAudio which makes it not BSD:
Any person wishing to distribute modifications to the Software is requested to
send the modifications to the original developer so that they can be incorpor
ated into the canonical version.
this is a request, not a condition. therefore, it doesn't change the
license in any way.