I am facing this problem of mico stuttering of videos in all web browsers (firefox, chrome & chromium). The videos play absolutely smoothly in VLC (or any offline video player) but in web browser the playback suffers. The audio has no problems. In windows 10 there is no problem at all. So, I guess the hardware is not the issue.

My build
Ubuntu 18.04.2 LTS
Hp dv6 2165tu
Core i5 430M 2.27ghz
8gb DDR3 RAM
Nvidia gt230m