Parameter Caching

Overview

Parameter Caching is a technique that uses some sort of memory caching to keep track of changes to a parameter. In the context of DSP, this is often used for filters so that filter coefficients do not need to be constantly updated.

Coding Conventions in Sndkit

In sndkit, the convention for parameter caching is to use two variables var and pvar, with pvar being the cached variable, and var being the one externally set. In the compute loop, these variables would be checked for changes:

if (var != pvar) {
    pvar = var;
    /* expensive computation goes here */
}

Examples

Some algorithms that use parameter caching include bigverb, peakeq, and env.