Comment by astrange

The code would be architecture specific anyway. ffmpeg is meant to be fast, so it's split into architecture independent and dependent (DSP) parts. The first relies on compiler optimizations, second is what uses SIMD, asm etc.

There is no such thing as a generic "SIMD API" it could use because it uses all specific hardware tools it can to be performant. Anyone who thinks this is posssible is simply mistaken. You can tell because none of them have written ffmpeg.

(There are some things called "array languages" or "stream processing" or "autoscalarization" that work better than SIMD - an example is ispc. But they're not a great fit here, because ffmpeg isn't massively parallel. It's just parallel enough to work.)