Adding video using sencha

Question

I want to add a youtube video in mysite using sencha.i use the follwing code

 var pnl = new Ext.Panel({
            layout: {
                type: 'vbox',
                pack: 'center'
            },
            items: [{
                xtype:'video',
                url: "space.mp4",
                loop: true,
                width: 500,
                height: 400,
                poster: 'Screenshot.png'
            }],
            fullscreen: true
        })

Here i replace the space.mp4 with you tube url but it doesn't works.instead i give html:'you tube link'.it works on browser in my system.but not working on iphone... Thanks in advance.