快速dct和idct的C程序源码，而且提供了一些优化了的idct的汇编代码。-C source code of fast DCT and IDCT, and some optimized compilation code of IDCT

8*8DCT,基于流水线设计，比较经典，可以用于JPEG，也可以用于H.264（需改为4*4）-8* 8DCT, based on the pipeline design, compare a classic, can be used in JPEG, can also be used for H.264 (to be replaced 4* 4)