Firefox and youtube playback

[jordanjay29]

For starters you may want to make sure to prevent pinch-to-zoom behaviour by setting:
zoom.maxPercent to 100
zoom.minPercent to 100

If you want to retain the ability to zoom with the ctrl and +/- buttons, you can alter the mousewheel.with_control.action setting instead. From Mozilla's wiki:

Customizing default action of "wheel" event. The value 0 means "Do nothing", 1 means "Scroll contents", 2 means "Go back or forward in the history", 3 means "Zoom in or out the contents".