What we are missing here is, how to extend this solution for the videos played in mobile phones.
Since the video is played on different types of video players which are embedded on different types of mobile phones, is it possible to track these videos in milestones (Started, 25% played, 50% played, 75% played and completed)?
In our mobile site, videos are embedded in to anchors as below;
<a href="../video.mp4" />
Therefore when the user clicks the video link, video will be played in specific player in the mobile phone.