Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!apple!desnoyer From: desnoyer@Apple.COM (Peter Desnoyers) Newsgroups: comp.sys.next Subject: Re: Voice Mail Format Keywords: voice mail Message-ID: <21949@apple.Apple.COM> Date: 9 Dec 88 02:13:30 GMT References: <19355@ames.arc.nasa.gov> Distribution: na Organization: Apple Computer Inc, Cupertino, CA Lines: 24 In article <19355@ames.arc.nasa.gov> bhine@nike.UUCP (Butler Hine sst) writes: >[gobble] > >I kept the sample of NeXT voice mail sent out a while ago, but I never >saw any explanation of the format. Does anyone know what the format is? >I saw a note from someone saying they had decoded it, but I can't find >their address. Help! Thanks in advance. > > Butler Hine > NASA Ames Research Center > hine@galileo.arc.nasa.gov I posted that message. The format is simple, like uuencoded data but just a hair different. The binary data is standard mu-law PCM voice at 8k samples/second, with 8 bit samples. the ascii format is lines of:abcdabcd...(64chars) where each group of 4 characters ('abcd') decodes to 3 bytes as follows: subtract 33 (decimal) from each character to get a 6-bit value. Concatenate 4 6-bit values to get 3 8-bit values. Peter Desnoyers