Emulator

Since https://github.com/dolphin-emu/dolphin/pull/10530 utvideo can be used for dumping, and its compatibility is much higher than ffv1's: to import an ffv1 dump into avisynth you have to install ffdshow, but it breaks all VFW codecs until you fix the registry, which then makes ffv1 not work. So all tasvideos encoders either dump straight to utvideo if possible, or reencode ffv1 to it.

The problem however is that this option is buried in configs and isn't documented or intuitive. To enable utvideo codec you need this in GFX.ini

UseFFV1 = False
DumpCodec = utvideo

So it'd be ideal if the codec option in Graphics -> Advanced was a dropdown with 3 options - mpeg4/utvideo/ffv1 - indicating which is lossless and which is lossy. Since option descriptions are a thing, the basic legend is that FFV1 is slow and less compatible, but compresses heavier, while UtVideo is fast and very compatible, but compresses less.