Capturing audio data
Using the Android Visualizer class (http://developer.android.com/reference/android/media/audiofx/Visualizer.html), we can retrieve part of the audio data that is currently playing, at a specified sample rate. You can choose to capture data as waveform and/or frequency data:
- Waveform: This is an array of mono audio waveform bytes, or pulse code modulation (PCM) data, representing a sample series of audio amplitudes
- Frequency: This is an array of Fast Fourier Transform (FFT) bytes, representing a sampling of audio frequencies
The data is limited to 8 bits, so it's not useful for playback but is sufficient for visualizations. You can specify the sampling rate, although it must be a power of two.
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