Hi Duilio Foschi. This link is from my bookmarks. Hope it will gives you primary information. Anyway you can search whatever you want by altavista engine. WBR Dmitry. http://alpha.science.unitn.it/~oss/audioform/AudioFormats.html ----- > I'd like to know how both PCM and ADPCM formats represent a digitized sound. > > Also I'd like to find source code in C that will convert from PCM to ADPCM > and viceversa. > > Thank you > > Duilio Foschi