Large video files require too much RAM to be processed

[pmdevita]

The server that currently runs GRB doesn't have enough RAM to process some larger requests. By my own estimates, FFMPEG wants at least 10GB of RAM for large requests. Most requests handle fine but some larger jobs are simply impossible.

There are a couple solutions to this

• Pass these requests (current solution)
• ~~Download~~ Buy more RAM
• From what I understand, FFMPEG renders out frames in memory and then concats. Doing it ourselves would allow us to better control storage usage and split up the process into smaller, manageable chunks
• Determine if FFMPEG has RAM constraints that we can lower so that it doesn't run out of memory attempting the job.