The Lagarith codec offers some of the best and most excellent compression, the MSU Lossless Codec and FFV1 are the only two codecs that can outperform the Lagarith in terms of its compression.
It is able to operate in several colorspaces – RGB24, RGB32, RGBA, YUY2, and YV12. No the Lagarith codec will never down-sample video, preventing inadvertent quality loss. For DVD video, the compression is typically only 10-30% better than Huffyuv. However, for high static scenes or highly compressible scenes, Lagarith significantly outperforms Huffyuv. A comparison for various types of video can be found here.
Right-click on lagarith.inf and select install to install the codec. If you do not see an install option, make sure you extracted the files, and are using the extracted lagarith.inf file.
Lagarith Lossless Video Codec