I have several video files, that are in 2-5gb range that I am streaming using Infuse.
Whenever I start to play, Infuse downloads the entire video. Many times, I am able to watch only for a few minutes and then close the app. I reopen the video and infuse downloads the entire video again.
This is unoptimised as it increases data usage, disk I/O, memory and battery usage. So, like youtube, there is need for optimised streaming where only a few minutes get streamed and progressive streaming occurs based on position in video.