Statistical rate-distortion estimation for H.264/AVC coders

Based on statistical analyses of transform coefficients, we suggest estimations of bit-rate and distortion functions directly from spatial-domain statistics. Simulations show that the proposed rate and distortion estimators achieve similar results as the true rate-quantization (R-Q) and distortion-quantization (D-Q) curves. By exploiting the proposed statistical estimations, two major applications are suggested. One is the fast rate-distortion optimized (RDO) mode decision and the other is the improved rate control (RC) in video encoding. Simulation results show that the rate-distortion estimators have sufficient accuracy such that we could achieve considerably better performance in both applications. We achieved 51.69% R-D cost computation time reduction in average for the rate-distortion optimized mode decision, and a 0.20 dB average peak signal-to-noise ratio (PSNR) improvement for rate-control in H.264/AVC, respectively