It sounds like your ask is for a recommendation to back up personal files from disparate locations to a server.

I use a self hosted Nextcloud instance for this purpose.

You may want to pass through the audio so it’s not reencoded. The top answer on this stack overflow article has an example. https://stackoverflow.com/questions/9913032/how-can-i-extract-audio-from-video-with-ffmpeg

And a copy/paste:

ffmpeg -i input-video.avi -vn -acodec copy output-audio.aac

Relevant example, with afraid.org you can do it with a wget or curl command.