An early detection of all-zero DCT blocks in H.264

In this paper, a new early detection algorithm for all-zero DCT blocks in H.264 video encoding is proposed. We have analyzed the properties of the DCT and quantization in H.264. These analyses show that a great reduction in the number of calculations can be achieved by investigating the individual conditions for the frequency components of (1,1), (1,3), (3,1), and (3,3). Based on these facts, a more precise sufficient condition is proposed by modifying the calculation order of the minimum SAD. Simulation results show that the redundant DCT and Q are efficiently removed without video-quality degradation.