In VLC for Windows it’s possible to add a separate audio track to a video that either has no audio stream or that has one but you want to play a different audio.
With that said the process is a bit long-winded compared to doing it on PotPlayer and MPC-HC. The steps are as follows:
1. Open VLC and on the toolbar go to Media -> Open Multiple Files… or press Ctrl+Shift+O.
2. Browse and select your video file by clicking the Add button. You can also load a video by dragging it inside the window.
3. At the bottom of the window check the Show more option setting.
4. Next check the Play another media synchronously option then click the Browse button beside the Extra media box.
5. Browse and add the external audio (e.g. aac/m4a, ac3, mp3, ogg/opus etc) file by clicking the Add button. You can also select another video to use its audio stream as the external audio.
Click the Select button when you’re done.
|Select external audio|
5. Click the Play button to start playback or Enqueue if you need to add other files to play.
Having a Problem Loading External AAC Audio?
I’ve noticed VLC ignores the external audio track if it’s in AAC (filename.aac). To solve this issue, change the extension of the audio file to M4A (filename.m4a) and try again.
M4A and AAC are technically the same audio file format so this shouldn’t affect playback of the file with other media players.