A novel early prediction method of all-zero coefficients in h.263

For most sequences at very low bit rates, the value of motion compensation data usually is very small, and will all be reduced into zero after DCT and quantization. Alice Yu method(1997) and Zhou method(1998) both are effective to predicting these All-Zero Coefficients (AZC) blocks, but these two methods will, to a large extent, mis-justice and leak out the AZC blocks respectively, especially for complex sequences. In order to overcome these disadvantages, a new method of early predicting AZC blocks is proposed in this paper. In this method, no additional computation is needed and the threshold can be changed with the quantization level. Applying this method to H.2G3 encoder, about 40%-80% blocks of Miss America and News picture sequences can be determined to be AZC blocks before DCT and quantization. It can greatly reduce the encoding computation time and is very useful to the software implementation of H.263 in real-time. In addition, PSNR of decoding sequences is controlled within O.OOOSdB.