reverse engineer / create Atrac3PLUS encoder

if you dont know; offical POP's format has CDDA audio in ATRAC3 format instead of PCM; the only tool i know of to encode ATRAC3Plus audio, is sony's own 'at3tool' it has a Linux and Windows version, - its the only external dependency that isn't open source / can be built ourselves - it's the only thing blocking a MacOS port - creating temporary wav files from CDDA audio, converting them, then stripping the header from them is messy.