So, I talked to you all a while ago about layers, and how we are going to be using it to accelerate composition of web pages across all platforms. There's more news on that front! Recently we landed a first version of the OpenGL layers backend onto trunk (See bug 546517). That backend included all the necessary code to use OpenGL for both image upscaling and YUV to RGB color space conversion.
Currently in general the code using layers is not at a point yet where it can benefit from the hardware layers backend for all rendering. For this reason the OpenGL backend is not used yet for your normal browsing. However as many of you may know the performance of fullscreen HTML5 video is not fantastic at the moment for lesser CPUs. Since fullscreen video in particular needs that extra push over the cliff, we decided to enable the OpenGL layers backend by default specifically for the fullscreen video case. What that means is that we upload the Y, Cb and Cr planes to your GPU, draw them to a fullscreen quad and then combine them to create the RGB image on your monitor. Ultimately what matters is that for those of you using compatible hardware and software it should lead to a big improvement in fullscreen video performance when using our latest Nightlies (get them here) and the upcoming Alpha!
Compatible Hardware And Software?
So, currently there's a little bit of work that still needs to be done to make OpenGL layers work on Mac OS X and Linux, so first of all you'll need Windows. Second of all you will need OpenGL 2 compatible drivers for your graphics hardware. Performance may vary across both hardware and drivers.
Eep! I'm running into issues
If you do run into issues with fullscreen video, do go to http://bugzilla.mozilla.org/ and check if your issue has already been reported. If it hasn't, we're very interested in hearing from you so we can address it as quickly as possible. Don't forget to note your graphics hardware and driver version, as this is invaluable information when trying to diagnose issues.
If you're interested in hearing more about layers, Robert O'Callahan has a very informative blogpost here.