Dear, I have a basic question why vorbis window function is different from MP3's, for vorbis's is more complex than MP3's. If does anyone know the reason,please teach me. P.S. I made MDCT calculatin Excel sheet (although only 32point). I hope it will be good to comfirm MDCT. Check http://www9.ocn.ne.jp/%7Ehkato111/math7/node1.html hkato