The Definition of SAO: Sample Adaptive Offset(SAO) is a kind of in-loop filter in HEVC codec. (there are also Deblocking Filter and Adaptive Loop Filter). HEVC codec use 4×4-32×32 block size for motion-compensated prediction, while AVC only use 4×4-16×16. HEVC can also use rectangle unit(e.g. 16×4) to process prediction. The bigger unit used in encoding, the smaller file size it will be. But it can also cause more artifacts(such as Ringing). The key idea of SAO is to reduce sample distortion by first classifying…