Interesting, I was under the impression that the source code wasn't available. But since you said you had it, I googled it and I found it too right here:
https://code.google.com/archive/p/n64oid/source/default/commitsIs that the same thing you found?
I'll take a look at their source code and see what they are doing differently.
Also, is there a specific game that runs a lot faster when using N64oid?
Edit: Hmmm, I was wrong, it's actually based off Rice video plugin.
Edit 2: The source code in the google code webpage is very out of date. hehk1234, do you have a newer version of the source code? I believe he made many improvements after this source code was posted.