Mercurial > hg > python-tutorial-skeleton
view audiofile.py @ 0:a8cde97eae7b
Initialise with test files and simple audio-file reading code
author | Chris Cannam |
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date | Wed, 03 Oct 2012 11:54:18 +0100 |
parents | |
children | ea2387fd1b90 |
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import wave import numpy as np def decode_to_mono_samples(rawdata, n_channels): """Given raw PCM16 interleaved WAV-format audio data as a binary string, decode and return as floating-point samples in range [-1,1)""" samples = np.fromstring(rawdata, 'Int16').astype(float) samples = samples / 32768 totals = sum(samples[c::n_channels] for c in range(0, n_channels)) return totals / n_channels def read_all_mono_samples_from_file(filename): """Read the whole of the given PCM16 WAV-format given audio file, mix down to mono by taking means across channels, and return as an array of floating-point sampless in range [-1,1)""" wavfile = wave.open(filename, 'r') n_channels = wavfile.getnchannels() rawdata = wavfile.readframes(-1) # read all data decoded = decode_to_mono_samples(rawdata, n_channels) return (decoded, wavfile.getframerate())