HTML5 video player for playing partial video from browsers File system

Question

I wrote HTML5 code (javascript) to download a video file from a set of servers, I can do this using the FILE API, which is currently only implemented on chrome.

After I load / merge all the parts, I instantiate the HTML5 player

var video = document.createElement('video'); video.src = fileEntry.toURL(); video.autoplay = true; console.log(fileEntry.toURL()); document.body.appendChild(video); 

This works great.

But now I want my player to start playing the file after they say (20 out of 300) pieces, when I do this, the player starts playing the file, but stops after part of the 20th part, and if I drag the progress bar player in fwd or back a little, he plays everything else.

Is there any way to fix this? play smoothly without manual user intervention?