The script looks at the directories 720p/ and 1080p/ and tries to generate a
new directory "{resolution}p" where the numbers are adjusted. It does this by
going through all files in the initial directories and scaling changed numbers
linearly.
For example: If a number is 2 for 720p, 3 for 1080p, and you generate for 1400p
You will end up with 4 for 1440p.
Likewise 5 (2+3) (720p) and 6 (3+3) (1080p) would yield 7 (4+3).