Yes, it is literally based on the fan film. There was some shenanigans going on shortly after it was announced that Andy Serkis would make a professional adaptation of the film and the studio struck down the original film and channel on youtube for copyright infringement, but they were luckily able to plead their case and the movie is back up.

I forget when this was going on exactly, just that I was a spectator in real time while the drama was happening.