QUOTE(MikaBomb @ Apr 2 2008, 02:22)

Now, intMDCT is widely used in the Lossless Audio Coding,
widely used? I don't think so.
QUOTE(MikaBomb @ Apr 2 2008, 02:22)

however, I could not find any source code of it.
That's probably because it's not widely used.

You might find something if you dig for a current version of the MPEG4 audio reference software. I'm not sure about that, though.
Cheers!
SG