5774 shaares
recommanded as intermediate lossless codec (alternative to huffyuv)
https://trac.ffmpeg.org/wiki/Encode/PremierePro
http://umezawa.dyndns.info/archive/utvideo/?C=M;O=D
In general YUV420 ... 601/709 deal with the colors, how RGB is converted to YUV. For HD, 709 is supposed to be used by convention; and 601 for SD. In a perfect world, that would work.
