Overview

Time delay with multiple output taps

Discussion

Time delay with multiple output taps. The module has a mono input and multiple output "taps". The module can be configured to have multiple output pins (ONEOUTPUTPIN = 0, the default), or a single multichannel output pin(ONEOUTPUTPIN = 1). Each tap has its own delay time and its own output pin (or channel). The delay of each output channel can be independently set by the currentDelay array. The number of output channels (NUMTAPS) is specified at construction time and this also equals the length of the currentDelay array. Delays are specified in samples and are in the range of [0 MAXDELAY].

At construction time, you specify the maximum delay (maxDelay) of the module. The variable, maxDelay determines the size of the internal state buffer. This module saves memory by using a 16-bit array of samples. The input and output pins are fract32 and only the high 16-bits of the input audio data is stored in the state array. The output pins have fract32 data but only the high 16-bits have audio data; the bottom 16-bits are all zeros. The size of the internal state buffer equals (maxDelay+blockSize+1)/2 32-bit samples. The 16-bit audio samples are packed two per 32-bit word. The delay time per channel is specified by the currentDelay array. Delays can be adjusted at run-time. However, the module is not smoothly updating and you may get audible clicks when adjusting the currentDelay at run-time.

Type Definition

typedef struct _ModuleDelayNTap16Fract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numTaps;                                // Number of output taps
    INT32 maxDelay;                               // Maximum delay, in samples.
    INT32 oneOutputPin;                           // Specifies a single multichannel output pin.
    INT32 stateIndex;                             // Index of the oldest state variable in the array of state variables.
    INT32 stateHeap;                              // Heap in which to allocate memory.
    INT32* currentDelay;                          // Current delay.
    INT32* state;                                 // State variable array.
} ModuleDelayNTap16Fract32Class;

Variables

Properties

Pins

Input Pins

Name: in

Description: audio input

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Sample rate range: Unrestricted

Complex support: Real

Output Pins

 Name: out1

Description: Audio output

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Description: Audio output

Data type: fract32

MATLAB Usage

File Name: delayntap16_fract32_module.m

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