Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!aunro!adec23!mark
From: mark@adec23.uucp (Mark Salyzyn)
Newsgroups: comp.dsp
Subject: Re: 48k to 44.1k Sample rate conversion
Message-ID: <1991May13.162821.4935@adec23.uucp>
Date: 13 May 91 16:28:21 GMT
References: <5826@media-lab.media.mit.edu.MEDIA.MIT.EDU>
Distribution: na
Organization: ADEC Systems Inc.
Lines: 15

>As we all know, the classic technique of sample rate conversion would have us
>upsample to the lowest common multiple, low-pass filter, and downsample to the
>desired rate. The only problem is that the LCM of 44.1k and 48k is 21.168 Meg!

Why not, on the fly in a DSP chip for example, perform a first order hold
function (linear interpolation) and use the interpolated values to feed a
48K sampling rate output function. You could perform the first order hold
every 21.168M to proove your point, but all you need do is figure out the
interpolated value at a 48K rate. The DSP chip would still have to be pretty
fast since a TMS320C25 would be hard pressed to do this and perform it's
A/D and D/A interface functions ...

Sorry, no code, since that would be telling secrets :-) :-)

Ciao, Mark Salyzyn  mark@adec23.UUCP