Chroma subsampling is nice because it lets you "delay" some of the upsampling to later device in the pipeline, like your GPU outputs YUV4:2:0 and your monitor h

Chroma subsampling is nice because it lets you "delay" some of the upsampling to later device in the pipeline, like your GPU outputs YUV4:2:0 and your monitor hardware does the chroma upsampling. If you don't want that, use 4:4:4. This feature you're talking about where you assign different compression factor to different color planes is already implemented in x264: https://en.wikibooks.org/wiki/MeGUI/x264_Settings#chroma-qp-offset https://en.wikibooks.org/wiki/MeGUI/x264_Settings#chroma-qp-...