The device lock (mutex) is grabbed before every access to the device. For python threading this is normally not neccessary, as C functions are called with the GIL held, but for grabFrame the GIL is released when each row is read in so as to increase interactivity when used in a threaded environment. Thus the lock prevents any other function from accessing the device until the entire frame has been read.
This allows more interactivity when acguiring images in a GUI driven application. The other FLI functions are fast enough that it probably isn't worth doing for them. Note that fli calls probably need to be protected by a lock, as libfli doesn't seem set up for concurrent operation.
Mention that the package is available and document installation on that platform.
That function is no longer supported and hasn't been since Windows 2000. This avoids a link error.
Add `out` argument to the functions grabRow grabFrame grabVideoFrame This allows image memory to be reused and provides automatic type conversion as well.