用ADI汇编指令编的DCT变换，ADI自带的DCT变换在实际运用中存在很大误差，这个是改进的DCT变换，误差很小，可达到实际应用-ADI compilation directives made by the DCT transform, ADI' s own DCT transform in the practical application of the existence of a large error, this is to improve the DCT transform, t