H.264 is magic (2016)
Chroma subsampling is a terrible idea in the digital era. You should just assign a different compression factor to the chroma channels instead. I don't understand why we keep using this system of discarding 75% of the color data BEFORE applying the lossy compression algorithm. (Well I do know of one argument - apparently it reduces the amount of CPU time required to compress and decompress the data, but I think that's a pretty lame reason)