Don’t you need a media server for this? I haven’t coded a player yet, but I was using flowplayer, and when I just upped my properly rendered mp4 videos and tried to play them there was no way to scrub ahead to not yet loaded part. I think flowplayer is pretty advanced so if there was a way they would have done it. Maybe they did since then, this was like 2 years ago. Then I installed wowza media server, added the videos to it then voila it worked via rtmp protocol. Wowza is just awesome! I was able to do many things with it let it be real time video streaming, my own public cam project, streaming my tv set top box’s picture to the garden to the notebook and via a private link to anywhere basically. I was able to share my iPhone’s screen in realtime as a video and stuff like that I also needed flash media live encoder. I was working with videos back then and I had so much fun with them. So to get the youtube like feature you need a media server imho.