A Computation Reduction Method for RDO Mode Decision Based on an Approximation of the Distortion

In this paper, we propose a computation reduction method for RDO mode decision in H.264/AVC. The distortion required for RDO mode decision has been shown to be equivalent to the total energy of quantization error. A statistical model of the quantization error for H.264/AVC was developed in order to approximate the distortion. In the proposed method, the reconstruction processes including quantization, inverse quantization, and inverse DCT are not needed. Simulation results demonstrate that the distortion is efficiently approximated with a quality and bit-rate comparable to conventional H.264/AVC.