Yes, same here,
it don't trouble myself too much.
My Settings:
x64 Machine
Win 8.1
Firefox Version 34.0
Chrome: Version 41.0.2251.0 dev-m
Blender 27.2
Blend4Web version 14.11

Hello

I try to Animate Video Textures, for now it works only with the m4v Videoformat and only in my chrome browser.

My Question: Is this the only supported format from the engine, or if i miss something?