I am creating a MediaStream object and adding a video track to it from a canvas using the captureStream() function. This works fine.
However I am trying to add audio as a separate track from a video element. I cant seem to find a way to get an AudioTrack object from a html video element.
Currently HTMLMediaElement.audioTracks is not supported in Chrome. According to the mozilla developer site I should be able to use HTMLMediaElement.captureStream() to return a MediaStream object from which I should be able to retrieve the separate tracks but I just get 'captureStream is not a function' error.
Perhaps i'm missing something very obvious but I would greatly appreciate any help on this.
Below is my current code:
var stream = new MediaStream();
//Works fine for adding video source
var videotracks = myCanvas.captureStream().getTracks();
var videostream = videotracks[0];
stream.addTrack(videostream);
//Currently not supported in Chrome
var audiotracks = myVid.audioTracks;
var audiostream = audiotracks[0];
stream.addTrack(audiostream);
To get an audio stream from a video element in a cross-browser way :
AudioContext API createMediaStreamDestination + createMediaElementSource.
// if all you need is the audio, then you should even probably load your video in an Audio element
var vid = document.createElement('video');
vid.onloadedmetadata = generateAudioStream;
vid.crossOrigin = 'anonymous';
vid.src = 'https://dl.dropboxusercontent.com/s/bch2j17v6ny4ako/movie720p.mp4';
function generateAudioStream() {
var audioCtx = new AudioContext();
// create a stream from our AudioContext
var dest = audioCtx.createMediaStreamDestination();
// connect our video element's output to the stream
var sourceNode = audioCtx.createMediaElementSource(this);
sourceNode.connect(dest)
// start the video
this.play();
// your audio stream
doSomethingWith(dest.stream)
}
function doSomethingWith(audioStream) {
// the audio element that will be shown in the doc
var output = new Audio();
output.srcObject = audioStream;
output.controls = true;
output.play();
document.body.appendChild(output);
}
To add audio to a canvas stream :