Help me finish my FFMPEG script written as a bash script -- 2

Job ID: 33357567

Budget: $15 – $25 USD

I have a script that upscales, crops and merges Two movies (animated cartoons), At the moment it is i the form of a bash script. It might be better as a Makefile (or Python Script), or at least 'if' statements in the bash script to not regenerate parts that have already been created. Also to get a HD version I use lossless for all the intermediate steps, this takes perhaps 12 hours. So some idea of how to speed it up might be useful. I am quite capable of finishing this myself but I have other things to work on. I can assist of course.
The final movie needs to be checked against the original so it is frame accurate as well, so the job may be laborious.
Please do not quote a low bid, then ask me what my budget is, I will simply reject people that do this. If you need to ask questions first then go ahead.
Related categories: Linux Shell Script Scripting Bash Scripting Bash