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""" |
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Measure the frequencies coming in through the microphone |
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Mashup of wire_full.py from pyaudio tests and spectrum.py from Chaco examples |
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""" |
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import pyaudio |
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import numpy as np |
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import scipy.signal |
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CHUNK = 1024*2 |
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WIDTH = 2 |
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DTYPE = np.int16 |
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MAX_INT = 32768.0 |
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CHANNELS = 1 |
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RATE = 11025*1 |
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RECORD_SECONDS = 20 |
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j = np.complex(0,1) |
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p = pyaudio.PyAudio() |
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stream = p.open(format=p.get_format_from_width(WIDTH), |
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channels=CHANNELS, |
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rate=RATE, |
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input=True, |
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output=True, |
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frames_per_buffer=CHUNK) |
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print("* recording") |
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# initialize filter variables |
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fir = np.zeros(CHUNK * 2) |
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fir[:(2*CHUNK)] = 1. |
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fir /= fir.sum() |
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fir_last = fir |
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avg_freq_buffer = np.zeros(CHUNK) |
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obj = –np.inf |
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t = 10 |
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# initialize sample buffer |
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buffer = np.zeros(CHUNK * 2) |
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#for i in np.arange(RATE / CHUNK * RECORD_SECONDS): |
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while True: |
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# read audio |
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string_audio_data = stream.read(CHUNK) |
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audio_data = np.fromstring(string_audio_data, dtype=DTYPE) |
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normalized_data = audio_data / MAX_INT |
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freq_data = np.fft.fft(normalized_data) |
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# synthesize audio |
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buffer[CHUNK:] = np.random.randn(CHUNK) |
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freq_buffer = np.fft.fft(buffer) |
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freq_fir = np.fft.fft(fir) |
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freq_synth = freq_fir * freq_buffer |
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synth = np.real(np.fft.ifft(freq_synth)) |
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# adjust fir |
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# objective is to make abs(freq_synth) as much like long-term average of freq_buffer |
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MEMORY=100 |
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avg_freq_buffer = (avg_freq_buffer*MEMORY + \ |
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np.abs(freq_data)) / (MEMORY+1) |
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obj_last = obj |
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obj = np.real(np.dot(avg_freq_buffer[1:51], np.abs(freq_synth[1:100:2])) / np.dot(freq_synth[1:100:2], np.conj(freq_synth[1:100:2]))) |
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if obj > obj_last: |
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fir_last = fir |
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fir = fir_last.copy() |
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# adjust filter in frequency space |
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freq_fir = np.fft.fft(fir) |
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#t += np.clip(np.random.randint(3)-1, 0, 64) |
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t = np.random.randint(100) |
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freq_fir[t] += np.random.randn()*.05 |
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# transform frequency space filter to time space, click-free |
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fir = np.real(np.fft.ifft(freq_fir)) |
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fir[:CHUNK] *= np.linspace(1., 0., CHUNK)**.1 |
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fir[CHUNK:] = 0 |
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# move chunk to start of buffer |
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buffer[:CHUNK] = buffer[CHUNK:] |
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# write audio |
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audio_data = np.array(np.round_(synth[CHUNK:] * MAX_INT), dtype=DTYPE) |
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string_audio_data = audio_data.tostring() |
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stream.write(string_audio_data, CHUNK) |
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print("* done") |
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stream.stop_stream() |
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stream.close() |
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p.terminate() |
