A universal, digital sampling frequency converter for digital audio

Digital Audio requires high-quality signal conversion between a variety of sampling frequencies, often in non-trivial integer ratios. In such applications, conventional methods based on analog processing or classical FIR filter rate-changing are not adequate. A novel approach to digital sampling frequency conversion based on a single, multistage filter and adapted to conversion between arbitrary, a priori unknown sampling frequency ratios is presented. Its design, implementation and control are discussed in some detail.