How can we enable this mode for youtube and other embed flash , because when not in full screen it's just using Software Acceleration , Hardware Acceleration instead Hardware , Hardware.
For YouTube you might want to give YouTubeCenter a try. I am currently using it on Firefox and quite happy with the results. It also gives several other customization options specific to YouTube as well.
i just tried youtube centre on latest firefox beta and it does not work videos throw up errors about having to try later .. turn it off and boom works again
Pepper Flash Window mode acceleration only works with the Pepper Flash player that is bundled with Chrome. You can check chrome://plugins to see if you might have to disable any other version. You want to disable NPAPI version and enable PPAPI version.
For chrome and IE, it is force enabled by default, you just need to change this for Firefox. You can check for it by using YouTube Center, and then force Flash Player, then you can right click the Flash Player, and see the debug info.
Make sure you are using the latest development build from github. The current "stable" build on addon center has problems.