It may happen that the video playback when using VLC player in Ubuntu may be choppy.
The audio would be fine but the video would stutter or lag with pauses.
Here is how to fix it :
Open VLC player and go to Tools > Preferences. Over there select Input/Codecs.
Disable the option of Hardware-accelerated decoding.
Save the changes and close all the running instances of VLC player.
Restart the playback, it won’t stutter anymore.