Today I learned how to tell VLC to use an audio track which is in a separate file, to play with the 4k video file I was watching.

It’s not hard, as the linked docs explain:

• Go to Media -> Open Multiple Files…
• In the Open Media window, click Add…
• In the Select one or multiple files window, select the desired first media (the video file) and add it.
• In the Open Media window, tick Show more options, then tick Play another media synchronously. Click Browse and add the second media (audio to play).
• Then click Play
• (You may need to manually select the correct audio track if there is more than one now)

Of course if you need to synchronize the audio and video better you can go to the menu and select Tools > Track Synchronization to adjust as needed!

I’d gotten the video and audio separately via Invidious from youtube, because there seems to be no way to get a file for 4k video which includes audio straight through the UI. (Is there a good way to get a single file off youtube with 4k video and audio via some site so I don’t need to merge or sync them manually?)