// audio tag
const $tar = document.getElementById('audio_remote');

const mimeType = 'audio/webm';
const recorder = new MediaRecorder($tar.captureStream(), {
    mimeType
});
recorder.onstart = function(e){
    console.log('start', e);
};
recorder.ondataavailable = function(e){
    console.log('ondata', e);
    saveBlobData(e.data);
};
recorder.onstop = function(e){
    console.log('stop', e);
};
recorder.start(1000);

function saveBlobData(data){
    const blob = new Blob(data, {
        type: mimeType
    });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    document.body.appendChild(a);
    a.style = 'display: none';
    a.href = url;
    a.download = document.title;
    a.click();
    window.URL.revokeObjectURL(url);
};