Single-Channel Biquadratic IIR Filters

Overview

Biquad filtering is implemented as a cascade of individual IIR filters called sections; each section has its own set of feedback and feedforward coefficients.

Each section implements a direct-form 1 filter. When the biquad filter function executes, the sections execute in sequence, each section processing the entire input signal and leaving its output to be processed by the next section.

Topics

Creating a Single-Channel Biquadratic IIR Setup

func vDSP_biquad_CreateSetup(UnsafePointer<Double>, vDSP_Length) -> vDSP_biquad_Setup?

Builds a data structure that contains precalculated data for use by the single-precision cascaded biquad IIR filter function vDSP_biquad(_:_:_:_:_:_:_:).

func vDSP_biquad_CreateSetupD(UnsafePointer<Double>, vDSP_Length) -> vDSP_biquad_SetupD?

Builds a data structure that contains precalculated data for use by double-precision cascaded biquad IIR filter functions.

Destroying a Single-Channel Biquadratic IIR Setup