Comment by fleabitdev
Comment by fleabitdev a day ago
Happy to hear that they've introduced video encoders and decoders based on compute shaders. The only video codecs widely supported in hardware are H.264, H.265 and AV1, so cross-platform acceleration for other codecs will be very nice to have, even if it's less efficient than fixed-function hardware. The new ProRes encoder already looks useful for a project I'm working on.
> Only codecs specifically designed for parallelised decoding can be implemented in such a way, with more mainstream codecs not being planned for support.
It makes sense that most video codecs aren't amenable to compute shader decoding. You need tens of thousands of threads to keep a GPU busy, and you'll struggle to get that much parallelism when you have data dependencies between frames and between tiles in the same frame.
I wonder whether encoders might have more flexibility than decoders. Using compute shaders to encode something like VP9 (https://blogs.gnome.org/rbultje/2016/12/13/overview-of-the-v...) would be an interesting challenge.
> Happy to hear that they've introduced video encoders and decoders based on compute shaders.
This is great news. I remember being laughed at when I initially asked whether the Vulkan enc/dec were generic because at the time it was all just standardising interfaces for the in-silicon acceleration.
Having these sorts of improvements available for legacy hardware is brilliant, and hopefully a first route that we can use to introduce new codecs and improve everyone's QOL.