Estimate size of encoding job

[Plutocratic]

This might be rather useful, and simple to implement:

When performing a preview, get the size of the resultant "preview.mkv" and use a simple calculation to guesstimate the overall size of the corresponding finished job and show this somewhere on the preview window.

(Total duration to be encoded/Chosen preview duration) × size of "preview.mkv" = estimated size of completed job

Obviously there are caveats based on the content etc. (and a longer preview is more likely to give a better estimate), but better than nothing.

[Plutocratic]

Posted here in error