Overview

Applies a time domain window

Discussion

This module applies a time domain window to a signal. This operation is useful prior to taking the FFT of a signal and commonly occurs in STFT-based filterbanks. The module operates on multiple channels with all channels having the same window. The length of the window (WLEN) is specified at instantiation time. The module outputs a block of size [WLEN numChannels], where numChannels equals the number of channels in the input signal. This block is output everytime that the module's processing function is called.

The window coefficients are set to a Hamming window (raised cosine) at instantiation time. The window coefficients may subsequently be changed.

Type Definition

typedef struct _ModuleWindowFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 winLen;                                 // Length of the window
    INT32 postShift;                              // Number of bits to shift
    FLOAT32* window;                              // Window coefficients
    fract32* windowFract32;                       // Window coefficients in fractional representation
} ModuleWindowFract32Class;

Variables

Properties

Pins

Input Pins

Name: in

Description: audio input

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Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: fract32

MATLAB Usage

File Name: window_fract32_module.m

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