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0 pointsjorvi7y ago0 comments

I'm curious (genuine curiosity, not meant sarcastic), why is Firefox only now switching to CoreAnimation? AFAIK CoreAnimation has been around since Leopard which makes it nearly 12 year old, which is positively ancient in the tech world.

Also, coincidentally, do you know what exactly causes the H264 problem on macOS? I've tried to track it down in bugzilla to no success, but I am 100% sure it is a bug. The energy impact for playing a H264 YouTube video in Safari has an energy impact of ~25. Firefox used to be ~60, but these days its ~180 (!)

> In the meantime, setting gfx.compositor.glcontext.opaque to true in about:config helps battery life significantly, at the cost of rounded corners and vibrancy.

Thanks for this! :)

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pcwalton7y ago

> I'm curious (genuine curiosity, not meant sarcastic), why is Firefox only now switching to CoreAnimation? AFAIK CoreAnimation has been around since Leopard which makes it nearly 12 year old, which is positively ancient in the tech world.

I think CA was only moved to the window server relatively recently. Before then, my understanding is that it simply used OpenGL in-process, so it had no energy advantages over Firefox's built-in compositor. There was also a long time when the APIs to host CA content in the window server were private APIs and only Safari could use them.

> Also, coincidentally, do you know what exactly causes the H264 problem on macOS?

I believe, but am not sure, that H.264 is decoded in software in Firefox but is decoded in hardware in Safari.

jorviOP7y ago

Thanks for clearing up the CA stuff

> I believe, but am not sure, that H.264 is decoded in software in Firefox but is decoded in hardware in Safari.

I am 100% certain it is (was?) on Firefox as well, because it would have been impossible to hit the aforementioned 60 energy impact without hardware acceleration. This is done through VideoToolBox, but that might have changed.

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