Every once in awhile, you might encounter a video with out of sync audio caused by encoding at the wrong frame rate. This often happens when a PAL video is incorrectly encoded to NTSC. These out of sync issues cannot be fixed by delaying or adding time while watching the video since the problem gets progressively worse as the video progresses.
Fix it in 20 seconds
There is a easy fix for this.
- Download MKVMerge GUI (MKVToolnix) PC/MAC and install.
- Run MKVMerge and add the video.
- Highlight the video track and click the Format specific options tab.
- In the FPS box, select 24p.
- Change the output file name.
- Click Start muxing.