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.


Pretty sure ffmpeg lets you extract audio channels from a video and even add them. You can probably look up the commands online, I don’t remember off the top of my head
To show all stream:
ffprobe -i FILESelect stream number with your audio.
To get stream X into AUDIO:
ffmpeg -i FILE -map X -c copy AUDIOTo put AUDIO onto FILE:
ffmpeg -i FILE -i AUDIO -c copy OUTPUTIf FILE only has 1 video and 1 audio, to replace FILE audio with AUDIO:
ffmpeg -i FILE -i AUDIO -map 0:v -map 1:a -c copy OUTPUTIt’s a mix of
--codec copyto not reencode the streams,--map 0:1to select the audio stream of the input file and for merging back you need multiple-iinput files and then--map 0:0to map the first input file’s video stream and--map 1to map the second input file (English audio stream). Mappings may vary - useffprobeto check your files.