Ut Video Codec Suite 7.0.2
Ut Video Codec Suite is a free-software lossless video codec for Windows developed by Takeshi Umezawa. It’s implemented as a VCM codec (also called “VfW codec”). It can currently encode YUV422 and RGB sources.
You should use Ut Video YUV420 to encode with x264. For example:
-make AviSynth scripts to imput and edit a video file (with ConvertToYV12),
-save the file at VirtualDubMod with Ut Video Codec YUV420(ULY0) on the setting of your numbers of CPU cores and “predict left” for decode preference (“predict median” is for compression-ratio preference),
-make x264 imput the video by “AviSource” of a new AviSynth scripts.
Runs on Windows x86 and x64.
Download: Ut Video Codec Suite 7.0.2
Original download (Japanese) here.