CASampledSP is a JNI-based service provider for the javax.sound.sampled.spi interfaces. As such it is capable of decoding many popular audio formats (like mp3 and aac) at native speed taking advantage of Apple's CoreAudio library. The focus is currently on decoding and converting to LPCM, not on writing or exporting.
A plethora of issues with stream-(not file-)based conversion was fixed along with issues with formats that require a magic cookie for decompression (e.g. Apple Lossless).
URL: CASampledSP - Introduction