Standard RDO makes decisions based on a cost formula: $$Cost = Distortion + \lambda \times Rate$$
(Psychological Rate-Distortion Optimization for Quantization) is an advanced encoder technique designed to bridge this gap. It modifies the quantization process to prioritize detail retention and texture preservation over strict mathematical accuracy, resulting in encoded video that looks better to the human eye, even if traditional metrics suggest it should look worse. psy-rdoq
Psy-RDOQ is typically measured on a scale (default is often 1.0 in x265) and interacts heavily with other settings: Standard RDO makes decisions based on a cost
: By keeping these coefficients, the resulting video retains more natural-looking grain and sharpness rather than appearing plastically smooth. Key Settings and Interactions psy-rdoq