[FR] Add Option for Post-Processing

[SenorFusion]

Is your feature request related to a problem? Please describe. I have to have my files archived in a certain format - specifically mp4 / h264 / aac

I understand it's hard or impossible to get yt-dlp to pull the exact format you want every single time.

Describe the solution you'd like Add a Config setting: If you dont get the video/audio codec you requested > then --use-postprocessor of ffmpeg to convert it to the format you wanted.

Describe alternatives you've considered The only alternative I can see if going back to another service like TA that will let me manage this.

Additional context I do understand that Pinchflat is somewhat opinionated about how videos should be downloaded.

I understand if this is out of scope for the project, but without a way to force into the formats I need, I end up having to do a bunch of manual post processing or scripts, which kind've defeats the purpose of a nice easy tool.

Thanks for considering!