How to send video (from getUserMedia) to Node.js server?

navigator.webkitGetUserMedia({ video: true, audio: true }, function ( stream ) {
    video.src = window.webkitURL.createObjectURL( stream );
}, function ( err ) {
    console.log( 'error: ', err );
});​

var videoDiv = document.getElementById("video"),
    vendorUrl = window.URL || window.webkitURL;
    navigator.getMedia =    navigator.getUserMedia ||
                            navigator.webkitGetUserMedia ||
                            navigator.mozGetUserMedia ||
                            navigator.oGetUserMedia ||
                            navigator.msGetUserMedia;

var MediaStream;
function captureWebcam(video, audio){
    navigator.getMedia({
        video: video,
        audio: audio
    }, function(stream){
        videoDiv.src = vendorUrl.createObjectURL(stream);
        MediaStream = stream.getTracks()[0]; // create the stream tracker
    }, function(error){
        // An error occured
        // error.code
        console.log(error)
    }); 
}       
$("#stop").on("click", function(){
   // Stop the tracked stream
   MediaStream.stop()
}); 
$("#start").on("click", function(){
    captureWebcam(true, false)
});