River Past Wave@MP3 is a simple and FREE software which converts between MP3 audio and WAV file. Select the file to convert from, and click on "Convert". It is that simple. River Past Wave@MP3 is a free download. There is no limitations, and it does not contain adware or spyware. River Past Wave@MP3 requires DirectX 8.0 or above. River Past Wave@MP3 does not include the MP3 codec. Instead, we use the decoder and encoder codec included in standard DirectX installation.