Fft

Overview

Forward FFT of real data

Discussion

Computes the fast Fourier transform of a real input signal yielding a complex half spectrum. The blockSize, N, of the input must be a power of 2 in the range [4...16384]. The output pin is complex with a blockSize of N/2+1 complex samples. The output pin contains the complex transform data for FFT samples k=0, 1, ..., N/2. The DC (k=0) and Nyquist (k=N/2) samples always have an imaginary component of 0.

Type Definition

CODE

typedef struct _ModuleFft
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    void * hardware_specific_struct_pointer;      // This may point to a struct that varies based on the target platform
} ModuleFftClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
hardware_specific_struct_pointer	void *	state	1		Unrestricted	hardware_specific_struct_pointer

Pins

Input Pins

Name: in

Description: Real input

Data type: float

Channel range: Unrestricted

Block size range: 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Complex output

Data type: float

Scratch Pins

Channel count: 1

Block size: 5

Sample rate: 48000

MATLAB Usage

File Name: fft_module.m

CODE

 M=fft_module(NAME)
 Computes the forward FFT of real input data.  The input block 
 size must be a power of 2.  The module supports multichannel signals.
 Arguments:
    NAME - name of the module.