JS Canvas Webcam Custom Stretching Effect SRC V1

<canvas id="canvas" width='1000' height='1000'></canvas>
<body bgcolor="black" onmousemove="drawe();" onmousedown="drawe" onchange="drawe" ondoubleclick="drawe;">
<button onclick="zoomin();">Stretch Out</button>
<button onclick="zoomout();">Stretch In</button>
<br>
<video id="video" autoplay hidden>
</video>
<canvas id="canvas" width="1000" height="1000"style="opacity:0.0;fillColor:none;">
<script>
var ii=444;
var video = document.getElementById("video");
var c = document.getElementById("canvas");
var ctx = c.getContext("2d");
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
var video = document.getElementById('video');
var mediaConfig = { video: true,audio:true};
function zoomin(){
    ii+=5;
}
  function zoomout(){
    ii-=5;
}
navigator.mediaDevices.getUserMedia(mediaConfig).then(function(stream) {
video.src = this.window.URL.createObjectURL(stream);
video.play();
video.addEventListener("play", function() {i = window.setInterval(function() {
canvas.style.opacity+=1.9;
ctx.drawImage(video,0,500,ii,500)},1);
ctx.draw();
drawe();
}, false);
});
</script>
</center>