Random File Sizes in Flask

[Trancemaster]

Does anyone know how Flask decides how big a file is going to be?

I encoded both Tomb Raider (PAL, 96 mins, 912MB) and What Lies Beneath (PAL, 126 mins, 712MB) in Flask, on 1 pass quality based (no need to set bitrate), and despite WL'sB being the longer film, it has the lowest file size. I have not noticed any difference in quality, so is the file size difference due to the number of high and low motion scenes, or something else?

[khp]

Flask does not control the output file size.
Output filesize depend on the bitrate selected or in you case, with divx 4 1 pass quality based, by the quality setting and the complexity of the input, this means that a movie with a lot of movemet will come out larger than one with very little movement.

With 1 pass quality based encoding it's extremely hard to predict output file size.