Create a wav file from blob audio django

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On the client side, I am sending a blob audio (wav) file. On the server side, I am trying to convert the blob file to an audio wav file. I did the following:

blob = request.FILES['file']
name = "TEST.wav"
audio =, 'wb')

I thought that converting the blob would be similar to converting a blob image to a jpeg file, but was very incorrect in that assumption. That didn’t work; I get an error – “Error: sample width not specified.” I then used setsampwidth() and tossed in an arbitrary number between 1 and 4 (after looking at the source file…I don’t know why the bytes have to be between 1 and 4). After that another error is thrown – “Error: sampling rate not specified.” How do I specify the sampling rate?

What does the setnchannels(), setsampwidth() methods do? Is there an “easy” way I generate the wav file from the blob?


Previously, I never do it before.. but, in my test this script below is worked well for me.. (But the audio output isn’t same like original file).

>>> nchannels = 2
>>> sampwidth = 2
>>> framerate = 8000
>>> nframes = 100
>>> import wave
>>> name = 'output.wav'
>>> audio =, 'wb')
>>> audio.setnchannels(nchannels)
>>> audio.setsampwidth(sampwidth)
>>> audio.setframerate(framerate)
>>> audio.setnframes(nframes)
>>> blob = open("original.wav").read() # such as ``
>>> audio.writeframes(blob)

I found this method at

Finally, by changing the value of nchannels and sampwidth with 1. and I got an audio that same with original file.

nchannels = 1
sampwidth = 1
framerate = 8000
nframes = 1

Tested under Python2, and got an error UnicodeDecodeError: 'utf-8' codec can't decode byte 0x95 in position 4: invalid start byte on Python3.

Source: stackoverflow