So I just wrote an atrac3+ frame decode library (2013-06-03)

[xsacha]

I got it working at last. Turns out PPSSPP couldn't find the library. I had to change Core/HW/atrac3plus.cpp, function GetInstalledFilename:
return "libat3plusdecoder.so";
to
return "./libat3plusdecoder.so";

I wonder how did it work for the other linux users.

For other users, they just make sure it's in the LD_LIBRARY_PATH