如何将 Javascript 音频 blob 写入 Python 波？

Question

I'm trying to create a Flask endpoint that accepts an audio blob every n seconds and write it to a wave file:

Flask:

@app.route('/api/v01/post/audio-blob/', methods=['POST'])
def api_post_audio_blob():
    blob = request.data
    with open('file.wav', 'ab') as f:
        f.write(blob)
    return Response(status=200)

Javascript:

const startButton = document.getElementById("start");
startButton.addEventListener("click", function() {

    /* Get client-side audio stream */
    var constraints = { audio: true }
    var chunks = []
    navigator.mediaDevices.getUserMedia(constraints)
    .then(function(stream) {
        const recorder = new MediaRecorder(stream);
        recorder.ondataavailable = event => {
            chunks.push(event.data);
            var blob = new Blob(chunks, {
                type: "audio/wav"
            });
            var xmlhttp = new XMLHttpRequest();
            var url = "http://127.0.0.1:5000/api/v01/post/audio-blob/";
            xmlhttp.open("POST", url, true);
            xmlhttp.setRequestHeader("Content-type", "audio/wav");
            xmlhttp.send(blob);
        };
        recorder.start(10000);
    })
    .catch(function(err) {
        /* handle the error */
    });

It seems like binary is written to file.wav, but it doesn't play any sound. Anyone knows how to resolve this? Help would be much appreciated!

Answer 1

the code above works. Tried another audio player which resolved the 'issue'