The computation in video codec mainly concentrates on transformation and motion search

which are the bottlenecks of realization of real time video codec.In order to reduce the computation in the transformation and motion search of H.263 encoder

float-point DCT is replaced by integer transform

which make video encoder free of float-point operations

and an all-zero decision technology based on integer transform is proposed in this paper. The all-zero decision is made in inter frame coding by comparing sum of the absolute differences(SAD) to a value related with quantization parameter during motion search.If the all-zero block is found

later computiaon of motion search and integer transform are eliminated

which can avoid a large amount of computiaon when mtion search is very accurate. This technology can basically maintain the quality of image

and highly improve the efficiency of real time H.263 encoder by skiping all-zero block before integer transformaion and shortening the code stream at the same time.