My question is why HD movies play slower in Firefox after proprietary ATI drivers were installed.
Allow me some explaining first.
ATI proprietary driver does not build on VL 7.1. Copmiler reports an error while building fglrx module. I have found a patch here.http://henryhermawan.blogspot.hr/2014/12/amd-catalyst-omega-145011003-1412-for.html
One could find patches for other kernel and other driver version. Since it is a kernel module which does not compile, it is important to match kernel version rather than driver version. For those who don't know. kernel version can be found by executing command 'uname -r'.
Patched fglrx module compiled fine. fgl_glxgears runs fine, display was sharper and colors more intensive. However, frame rates for HD movies in firefox dropped sharply. They used to play fine on default driver. Webkit based browsers have no problem, it is difficult to say, but I think they are playing HD movies even better with new driver. I have Chrome and Opera 35.
Note that HD movies are played directly in browser and not via plugin. I used this guide to force HW acceleration: http://en.librehat.com/blog/force-enable-hardware-acceleration-in-firefox-on-linux/
Firefox about:support page indicated that HW acceleration was enabled, indeed, but browser started to freeze and crash. Then I tried version downloaded from Mozilla site, rather than one from repository. It worked slightly better, but still unusable.
I am pretty sure it is something with firefox. When I start it from terminal, I am getting:
Can't find symbol 'EGLImageTargetRenderbufferStorageOES'.
As if I am using wrong version of some library or something....