How to detect when a youtube video finishes playing?

I am working on a site that has a ton of embedded youtube videos, the client wants to show a popup whenever a video stops splaying.

I looked at the youtube api and there seems to be a way to detect when a video ends:

http://code.google.com/apis/youtube/js_api_reference.html

but I can't embed the videos like they mentioned on that page since the videos are all already on the site (thousands that have been added manually by pasting embed code).

Is there a way to detect the ending of these videos without changing any of the existing videos (using javascript)?

Solution 1:

This can be done through the youtube player API:

http://jsfiddle.net/7Gznb/

Working example:

    <div id="player"></div>

    <script src="http://www.youtube.com/player_api"></script>

    <script>

        // create youtube player
        var player;
        function onYouTubePlayerAPIReady() {
            player = new YT.Player('player', {
              width: '640',
              height: '390',
              videoId: '0Bmhjf0rKe8',
              events: {
                onReady: onPlayerReady,
                onStateChange: onPlayerStateChange
              }
            });
        }

        // autoplay video
        function onPlayerReady(event) {
            event.target.playVideo();
        }

        // when video ends
        function onPlayerStateChange(event) {        
            if(event.data === 0) {          
                alert('done');
            }
        }

    </script>