<html>
    <head>
        <script>
            function pageLoaded() {
                document.getElementById("video").play().then(function() {
                    window.parent.postMessage('autoplayed', '*');
                }).catch(function() {
                    window.parent.postMessage('did-not-play', '*');
                });
            }

            function videoDidPause() {
                window.parent.postMessage('on-pause', '*');
            }
        </script>
    </head>
    <body onload="pageLoaded()">
        <video id="video" onpause=videoDidPause() playsinline src="test.mp4" />
    </body>
</html>