Overview

Modulated time delay using cubic interpolation

Discussion

This module implements a time-varying delay. The first input pin (mod) specifies the modulation factor; the second input pin is the multichannel audio signal. The module computes the instantaneous delay to apply on a sample-by-sample basis. The instantaneous delay is a floating-point value computed as:

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The instantaneous delay time is a floating-point value and the module implements fractional sample interpolation using cubic (third order) interpolation. A related module is delayi which implements the same function but uses linear interpolation.

Type Definition

typedef struct _ModuleDelayci
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 maxDelay;                               // Maximum delay that can be realized, in samples. The size of the delay buffer (maxDelay+1)*numChannels
    FLOAT32 currentDelay;                         // Current delay
    FLOAT32 modDepth;                             // Maximum depth, in samples, of the modulation signal
    INT32 stateIndex;                             // Index of the oldest state variable in the array of state variables
    INT32 stateHeap;                              // Heap in which to allocate memory
    FLOAT32* state;                               // State variable array
} ModuleDelayciClass;

Variables

Properties

Pins

Input Pins

Name: mod

Description: modulation input

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Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: float

MATLAB Usage

File Name: delayci_module.m

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