yes it makes sense to use C/ASM here, but if you're curious, there is a rust port of dav1d named rav1d: https://github.com/memorysafety/rav1d

it's not much slower than the original C/ASM implementation (last i checked ~5%?) but that matters here

It's a Rust/ASM port, look there: https://github.com/memorysafety/rav1d/blob/main/src/ext/x86/...

I am not sure if it is that much safer than the C version when raw assembly is still required.

It is much slower than 5%, there were other independent tests that put it around 20%.

there's a rav2d now too fwiw — https://github.com/stukenov/rav2d same playbook: safe Rust + asm kernels via FFI. just shipped 0.1.0.