What is a 500MiG? A war plane?

This is a problem in my opinion with how Windows (xxx) works. I would try splitting the movie into three and then as the first loads quickly load the other two in  the background...

This only reduces the delay and then you have the issue of seemless transition from one movie to the other..

You can also try the other video handling libraries and see how they handle large files.

It sounds like you're asking for a way to 'stream' the video...  No idea if any of the video libraries support this; you'll have to look for yourself.  Hint: from the Processing Reference follow the 'Libraries' link ;)

Mb is megabits, not megabytes, and I suppose you wanted to write 500MiB, then.

There are two alternatives which I employ.

1. Have a processing server do the heavy lifting. However this is kind of an expensive work around. Where in the processing server is an
additional physical computer responsible for handling procesing rendering commands. The server simply returns an image of which to display. The server could  have the video pre-loaded.

2. Have an external application like VLC player be responsible for streaming the video wherein it already has the video to play and the player plays it and/or streams it to the processing sketch.

I have not the programming skills to suggest another processing sketch to be pre-loaded and run the movie, this still would be limited to physical RAM.

The only suggestion is to utilize a technology like HTML 5 Canvas wherein the application is not attempting to read a physical file, but the application is sent instructions, even 3D signals and in realtime create the movie. This last one is hypothetical.