Stream binary audio data from http request for librosa analysis

Question

I have a large audio file streaming from a web service.

I would like to load the audio data into librosa for batched stream analysis.

I took a look at librosa.core.stream where the description mentiones:

Any codec supported by soundfile is permitted here.

But I can't seem to figure out how I can feed the binary batch data from requests:

import requests
import numpy as np

audio_url = "http://localhost/media/audioplayback.m4a"

response = requests.get(
    audio_url,
    stream=True,
)

for chunk in response.iter_content(chunk_size=4096):
    npChunk = np.frombuffer(chunk, dtype=np.float64)
    # Load chunk data into librosa

I know I need to convert the audio format but I'm not sure what is the recommended way to do this. I know it is possible to load the data directly into numpy array instead of calling librosa.stream. But I can't figure out the combination of soundfile, audioread, or GStreamer to do the format conversion.

I am using python==3.6.5 inside conda environtment inside Windows Subsystem for Linux

Any help would be greatly appreciated! Thank you!

Answer 1

My current solution is this:

You need to install pydub

from pydub import AudioSegment

audio_bytes = []
for b in request.files['audio_data'].stream.read():
    audio_bytes += [b]
audio_bytes = bytes(audio_bytes)    
s = io.BytesIO(audio_bytes)
audioObj = AudioSegment.from_file(s)
audioObj = audioObj.set_sample_width(2).set_frame_rate(16000).set_channels(1)
audioObj.export("input_audio.wav")
wav, sr = librosa.load("input_audio.wav")
wav = librosa.core.resample(wav, sr, 16000)
return wav

my frontend code is this:

recorder.onComplete = function(recorder, blob) { 
            console.log("Encoding complete");
            createDownloadLink(blob,recorder.encoding);

            //START AJAX HERE
            var fd = new FormData();
            fd.append('audio_data', blob);
            console.log('Transcribing...')
            document.getElementById('res_stat').innerHTML = "Waiting For Server's Response"

            $.ajax({
            type: 'POST',
            url: "/audio",
            data: fd,
            processData: false,
            contentType: false,
            dataType: "json",
            success: function(text){
                                    console.log("Output Received")

                                    document.getElementById("predOut").value = text.text;
                            }
            });

            console.log("Waiting For Server's Response")
        }