Comment 52 for bug 1424201

(In reply to Jean-Yves Avenard [:jya] from comment #38)
> We currently don't have OpenGL layers enabled on Linux.
>
> So the only way we can use VAAPI or VDPAU at this stage, is to decode using
> the GPU and then copy the GPU surface back into RAM. This has a high cost
> taking away most of the benefits of HW decoding.
>
> VAAPI will be the simplest to support at this stage, and likely the first
> one we will work on.

Ok, I see it's bad to copy the surface back to RAM from GPU and the performance benefits will be small.

But what about the OpenGL compositor, are there any ongoing works on that or what are the reasons that it's not enabled by deafult?
Maybe on older machines it could cause problems, but I believe it should work on newer systems.
I'm using OpenGL compositor in Firefox for half a year (MOZ_USE_OMTC=1, GPU Accelerated Windows: 1/1 OpenGL in about:support).
I didn't noticed any problems with that settings for half a year.

(In reply to Jean-Yves Avenard [:jya] from comment #39)
> when you use HTML5 on Linux with YouTube, you will get webm with VP9.
Yes, in default you will get VP9. But you can force YouTube to use H264 (I managed this for the tests above by setting media.mediasource.webm.enabled to false).
There are also other ways - eg. there is extension (only for Chromium currently, but I'm sure it can be done for Firefox too) h264ify, which does precisely this.

It will be interesting to see how the new hybrid VP9 decoding works.

(In reply to Jean-Yves Avenard [:jya] from comment #39)
> The difference you're seeing in CPU usage on Linux is mostly a matter of h264 vs VP9.
Sorry, but I think that I cannot agree with that, you can see my test with CPU usages 3 posts above.

I made sure I use H264 version for all tests (you can see stats for HTML5 player and there you can find used codec).
Both tests with HTML5 and adobe-flash used H264 video and the difference in CPU usage was quite big.