Objective Quality vs Performance
There is a trade-off between Objective Quality and Encoder Performance. Using the rdoLevel and enableRdoQuant parameters this trade-off can be adjusted.
The rdoLevel specifies the number of candidates to use for Rate Distortion Optimization. RDO is a method for improving video quality during compression. Lower RDO values will generate lower quality, but performance is improved. Higher RDO values will generate higher quality, but again, this will cause lower performance. Similarly, enableRdoQuant specifies whether to enable or disable the RDO Quantization.