pythonnumpyboto3wavwave

How to convert a numpy array waveform into a wav file-like object?


I want to convert a numpy array waveform into a wav-like object so that I can upload it to S3 without having to save the waveform to file locally. Imagine I have a numpy array waveform, y,

y, sr = librosa.load('something.wav', sr = 44100)

How can I convert this numpy array, y into a wav file-like object to upload to S3 using boto3's upload_fileobj method?

According to the boto3 docs, the file-like object must have the properties:

A file-like object to upload. At a minimum, it must implement the read method, and must return bytes.

This is how I would like to upload the file-like object:

import boto3
s3 = boto3.resource('s3')
bucket = s3.Bucket('mybucket')

# with open('filename', 'rb') as data:
#    bucket.upload_fileobj(data, 'mykey')
bucket.upload_fileobj(wav_object, 'something.wav')

TLDR:

I want a function that converts a numpy array into a wav-like object that implements the read method and returns bytes.


Solution

  • You can try like this:

    import io 
    from scipy.io.wavfile import write
    import boto3
    
    bytes_wav = bytes()
    wav_object = io.BytesIO(bytes_wav)
    write(wav_object, sr, y) # y is your numpy array
    
    
    s3 = boto3.resource('s3')
    bucket = s3.Bucket('mybucket')
    
    bucket.upload_fileobj(wav_object, 'something.wav')