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- From: bame@hpfcbig.SDE.HP.COM (Paul Bame)
- Date: Tue, 22 Dec 1992 00:21:43 GMT
- Subject: Re: MU-law and A-law tables in the DSP56000
- Message-ID: <6380001@hpfcbig.SDE.HP.COM>
- Organization: HP SESD, Fort Collins, CO
- Path: sparky!uunet!cs.utexas.edu!sdd.hp.com!hpscit.sc.hp.com!hplextra!hpfcso!hpfcbig!bame
- Newsgroups: comp.dsp
- References: <6682@tuegate.tue.nl>
- Lines: 19
-
- In comp.dsp, bartjan@blade.stack.urc.tue.nl (Bartjan Wattel) writes:
-
- > I'm starting on studying the DSP56000 for an exam at the Eindhoven University
- > of Technology (the Netherlands). I ran into the terms 'MU-law' and 'A-law'.
-
- > Could anybody tell me in what way these tables can be used ? I have the idea
- > that the tables have something to do with (data)compression, but I might be
- > wrong...
-
- These are defined in section G.711 in the CCITT "Blue Book" (I think I've
- got that right). Mu-law effectively allows 14 bits of dynamic range
- to be stuffed into 8 bits and is rather like a signed logarithm - but it's
- not really a logarithm which is why conversion tables are used. A-law
- is a variant of mu-law with which I'm unfamiliar which is also defined in
- G.711. If you have an HP workstation with audio I/O hardware, chances are
- good it understands mu-law, a-law, and linear encoding (which hasn't
- made it into the FAQ yet).
-
- -Paul Bame
-