I had an interesting silent failure with libmad (under xcode 4.5 with ios6 and using gcc rather than apples llvm). After applying a bunch of changes suggested by http://stackoverflow.com/questions/12015396/ios-sdk-5-1-linker-error-for-non-lazy-ptr-in-xcode-4-4-1 and http://forum.videolan.org/viewtop...