How to handle in_data in Pyaudio callback mode?

Question

I\'m doing a project on Signal Processing in python. So far I\'ve had a little succes with the nonblocking mode, but it gave a considerable amount of delay and clipping to t

Answer 1

Found the answer to my question in the meantime, the callback looks like this:

def callback(in_data, frame_count, time_info, flag):
    global b,a,fulldata #global variables for filter coefficients and array
    audio_data = np.fromstring(in_data, dtype=np.float32)
    #do whatever with data, in my case I want to hear my data filtered in realtime
    audio_data = signal.filtfilt(b,a,audio_data,padlen=200).astype(np.float32).tostring()
    fulldata = np.append(fulldata,audio_data) #saves filtered data in an array
    return (audio_data, pyaudio.paContinue)