Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

I'm trying to reduce the size of my video collection because I'm running out of storage.

My strategy is to look for smaller sized files to replace very large ones. When that fails, I am using handbrake to rencode. Its working, but very slowly due to my ancient computer. Redownloading is the much faster method.

Some titles, which were originally released as non-english, have existing small files, but the English audio is only available less commonly as a huge file.

Is it possible to redownload the non-english video and map the English audio onto it? It might be too much fooling around to get syncing correct.

Extra question, does anybody know how to set up sonarr/radarr to try to reduce filesize automatically? Ive been doing all the downloading by hand.