If I ran a perl environment under wine, I couldn't be able to call back to Linux's x265. Video encoding is slow enough as it is. I don't feel like making it slower through OS emulation (running Windows encoders). The frame serving is fast. Granted wine will slow it down, but it still can serve frames many times faster than the encoder can process them. There are Linux avisynth-like ports, but the actual Avisynth has a huge ecosystem of plugins that won't work in those ports (they're compiled DLLs).