Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!agate!shelby!csli!poser
From: poser@csli.Stanford.EDU (Bill Poser)
Newsgroups: comp.dsp
Subject: Re: A simple, practical sound board
Message-ID: <16150@csli.Stanford.EDU>
Date: 1 Nov 90 20:25:34 GMT
References: <15912@netcom.UUCP> <16113@csli.Stanford.EDU> <16002@netcom.UUCP>
Reply-To: poser@csli.stanford.edu (Bill Poser)
Organization: Center for the Study of Language and Information, Stanford U.
Lines: 18

In article <16002@netcom.UUCP> ergo@netcom.UUCP (Isaac Rabinovitch) writes:
>All right, my goal of an hour of sound in a megabyte betrayed my
>ignorance of signal theory.  So let's bump up the space requirement by
>an order of magnitude.  Are we into the real world yet?

Well, if you just want to use simple sample and not any kind of coding,
you'll need a bit more. Here's how to do the calculation. Suppose you're
going to use one byte per sample. That gives you passable resolution,
though not what you'd want for research or real hi-fi. It's also the
resolution of all of the cheap digitizers. To get good quality speech
you should sample at a minimum of 12K samples/second. This gives you
room for anti-aliasing filtering at about 5KHz (you need to allow
for the fact that the filter cutoff is not perfectly sharp). So,
you need 12K bytes per second. That is 1.2e4 * 3.6e3 = 4.32e7
bytes per hour, or 43.2MB per hour. So you need another half an order
of magnitude to get into the ballpark.

Bill