A New Recursive Decomposition Algorithm for Realizing Fast IMDCT Computation

摘要

In this paper, a new decomposition algorithm for realizing fast inverse modified discrete cosine transform (IMDCT) computation is presented. The decomposition algorithm can convert a pair of long transforms into 2 pairs of short transforms with half size of the long transforms. In addition, the decomposition algorithm can be utilized recursively to attain shorter transforms and reduce computational cycles. Based on the previous experimental results, the number of computational cycles of 512-point IMDCT is estimated to be 9641, which is less than those in previous reports.