Get .wav file length or duration

Question

I'm looking for a way to find out the duration of a audio file (.wav) in python. So far i had a look at python wave library, mutagen, pymedia, pymad i was not able to get the duration of the wav file. Pymad gave me the duration but its not consistent.

Thanks in advance.

Answer 1

The duration is equal to the number of frames divided by the framerate (frames per second):

import wave import contextlib fname = '/tmp/test.wav' with contextlib.closing(wave.open(fname,'r')) as f:     frames = f.getnframes()     rate = f.getframerate()     duration = frames / float(rate)     print(duration) 

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Regarding @edwards' comment, here is some code to produce a 2-channel wave file:

import math import wave import struct FILENAME = "/tmp/test.wav" freq = 440.0 data_size = 40000 frate = 1000.0 amp = 64000.0 nchannels = 2 sampwidth = 2 framerate = int(frate) nframes = data_size comptype = "NONE" compname = "not compressed" data = [(math.sin(2 * math.pi * freq * (x / frate)),         math.cos(2 * math.pi * freq * (x / frate))) for x in range(data_size)] try:     wav_file = wave.open(FILENAME, 'w')     wav_file.setparams(         (nchannels, sampwidth, framerate, nframes, comptype, compname))     for values in data:         for v in values:             wav_file.writeframes(struct.pack('h', int(v * amp / 2))) finally:     wav_file.close() 

If you play the resultant file in an audio player, you'll find that is 40 seconds in duration. If you run the code above it also computes the duration to be 40 seconds. So I believe the number of frames is not influenced by the number of channels and the formula above is correct.

Answer 2

the librosa library can do this: librosa

import librosa librosa.get_duration(filename='my.wav')