Camera

// flag access to mediaservice
var mediaIsOk=false;
// dump status
function showMessage(msg){
    document.getElementById('msg').innerHTML=msg;
}
// called on startup, can this browser support media ?
function userMediaAvailable(){
    mediaIsOk = !!(navigator.getUserMedia ||
                          navigator.webkitGetUserMedia ||
                          navigator.mozGetUserMedia ||
                          navigator.msGetUserMedia);
    if(mediaIsOk){
        showMessage("ok");
        // show canvas, img, buttons
        var op=document.getElementById("operations");
        op.className="showMe";
    }
    else
        showMessage("cannot use media");
}

// streamobject, initiated when we start video
function startVideo(){
    navigator.getUserMedia  = navigator.getUserMedia ||
                          navigator.webkitGetUserMedia ||
                          navigator.mozGetUserMedia ||
                          navigator.msGetUserMedia;                          
    navigator.getUserMedia(        
        // selection of medium (and possible constraints ?)
        {video: true}, 
        
        // on success
        function(localMediaStream) {
            var video = document.getElementById('video1');
            video.src = window.URL.createObjectURL(localMediaStream);
            video.onloadedmetadata = function(e) {
               showMessage('ok, we are on' );              
            };
       }, 
       
       // on error
       function(e) {
            showMessage('error '+ e);
        }
   );
 }
 
// copy to canvas, and image
function freezeImage()
{
    var video = document.getElementById('video1');
    var can=document.getElementById('can1');
    var ctxt=can.getContext('2d');
    // check real videodimensions and adjust what we copy to canvas
    var W=video.videoWidth;
    var H=video.videoHeight;
    can.height=can.width*(H/W);
    // copy to canvas from video
    ctxt.drawImage(video, 0, 0, W,H,0,0, can.width,can.height );
    // copy to image from canvas
    var im=document.getElementById('im1');
    im.src=can.toDataURL('image/webp');
}