CODEWITHSUNDEEP
pythonaudioaws-lambdabase64
Shawn Zhang
Shawn Zhang

Reputation: 1769

Python - Read Audio Data Without Saving to File

I am sending audio data between the browser and my AWS Lambda function, but I find myself doing an intermediate step of saving to file for functionality purposes. Here is my code right now to work:

wavio.write(file="out.wav", data=out_file, rate=16000, sampwidth=2)  # where out_file is np.array
encode_output = base64.b64encode(open("out.wav", "rb").read())
return {
    'headers': {
        'Access-Control-Allow-Headers': 'Content-Type',
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'OPTIONS,POST,GET',
        'Content-Type': 'audio/wav'
    },
    'statusCode': 200,
    'body': encode_output,
    'isBase64Encoded': True
}

However, is there a smarter way to convert my numpy array and send encoded audio data back to the browser?

Upvotes: 0

Views: 1505

Answers (1)

furas
furas

Reputation: 142859

Base on source code function write can use file object instead of filename so you can try to use io.BytesIO() to create file-like object in memory

I couldn't test it but it should be something like this

import io

# ... code ...

file_in_memory = io.BytesIO()

wavio.write(file=file_in_memory, ...)

file_in_memory.seek(0) # move to the beginning of file 

encode_output = base64.b64encode(file_in_memory.read())

EDIT:

I took example from source code and used io.BytesIO() and it works

import numpy as np
import wavio
import base64
import io

rate = 22050  # samples per second
T = 3         # sample duration (seconds)
f = 440.0     # sound frequency (Hz)
t = np.linspace(0, T, T*rate, endpoint=False)
x = np.sin(2*np.pi * f * t)

file_in_memory = io.BytesIO()

wavio.write(file_in_memory, x, rate, sampwidth=3)

file_in_memory.seek(0)

encode_output = base64.b64encode(file_in_memory.read())

print(encode_output)

Upvotes: 1

Related Questions