NOTE: THIS DOCUMENT IS OBSOLETE, PLEASE CHECK THE NEW VERSION: "The Digital Audio Resampling Home Page", by Julius O. Smith III, Copyright © 2016-05-17 by Julius O. Smith III - Center for Computer Research in Music and Acoustics (CCRMA), Stanford University
<< Previous page TOC Next page >>
This tutorial describes a technique for bandlimited interpolation of discrete-time signals which supports signal evaluation at an ``arbitrary'' time, and which performs well for smoothly changing sampling rates, such as needed for digital audio ``scrubbing.'' The method is based on interpolated look-up in a table of filter coefficients, so as to make the filter impulse response available effectively in continuous-time form. A single pre-computed filter table handles all interpolation times and sampling-rate conversion ratios. Formulas are given for determining the look-up table size needed for a given precision requirement. This tutorial is an expansion of the conference paper [Smith and Gossett 1984].