It's a DSP firmware turned into silicon. If you look at for example the VP8 decoder registers for a Rockchip VPU here: https://patchwork.kernel.org/patch/81189

It's a DSP firmware turned into silicon. If you look at for example the VP8 decoder registers for a Rockchip VPU here: https://patchwork.kernel.org/patch/8118991/ https://patchwork.kernel.org/patch/8118991/ You can see it's quite specific to the primitives the codec needs. If you want general purpose, we now have Vulkan for that. (And this one is reasonably low-level. On some like the Raspberry Pi, you throw bitstream over the wall to a coprocessor which gives you YUV back)