While I have remuxed most of my files to correctly mark the audio track language, I want to locate the remainders. I was hoping to be able to show this in plex as other metadata tools have simply crashed when trying to scrape it from my 1500+ video files. I would be happy with a list in any format.
accepted answer, export tool allowed me to create a csv spreadsheet that was easily opened in MS excel. I since have used MKVtoolNIX to mark the language appropriately, and now subtitles work automatically in plex.
Just a note that this feature has been added as a built in filter. This can be closed.