I have been encoding my blurays using MakeMKV and Handbrake.
Some of them seem to have “Unknown” audio languages. See screenshot: http://i.imgur.com/AixZWq2.jpg
Is there a way I can go into the MP4 files and edit the audio tracks data so that Plex knows it is English? If so what tools would I need to use? I’m using Windows 10.
Thanks
The only way I know of to do that without resorting to the command line is to remux the mp4 file with AVIdemux.
Wow thanks for quick reply 
I will try this now it looks like it what I was looking for.
Just tried it works perfectly!
Addendum:
after doing the above, you might wanna ‘Optimize for streaming’ your newly muxed file.
Plex loves ‘optimzed’ files, it might make the difference between ‘Direct Play’ or ‘Direct Stream’ a file.
Among others, mp3tag allows to optimize your mp4 files.
