[op25-dev] difference between op25.decoder_bf and op25.decoder_ff

Hi Whats the difference between these 2? I'm new to Gnuradio & python to be honest; I'm writing my own ap25 listener for the funcube... So far, I've got my software tuning, FM decoding, and then sending data into the FSK4 decoder; I can see it fine tuning.. but I don't get anything out of the decoder_bf function. Is there any easy way, to debug what its doing?? Digging around in code there doesn't seem to be much debugging. I did create some network sinks, and forward the output of the FM demod to a a scope inside gnuradio companion.. the signal looks like FSK4 with the funky phase changes. Sean