(8.D.2.5) Cfft
Overview
Forward and inverse FFT of complex data
Discussion
Computes the forward or inverse FFT of complex data. At instantiation time (on the module name and arguments dialog) you specify whether a forward or an inverset transform should be computed. The internal hidden variable .dir controls whether a forward (= +1) or inverse (= -1) FFT is computed. The module supports multichannel signals.
Type Definition
typedef struct _ModuleCfft
{
ModuleInstanceDescriptor instance; // Common Audio Weaver module instance structure
INT32 dir; // Transform direction. Forward = 1. Inverse = -1
void * hardware_specific_struct_pointer; // This may point to a struct that varies based on the target platform
void * fft_size_aligned_io_buffer_pointer; // This points to a buffer which is aligned by fft size on SHARC
void * fft_twiddle_buffer_pointer; // This points to twiddle buffer on SHARC
} ModuleCfftClass;
Variables
Properties
Name | Type | Usage | isHidden | Default value | Range | Units |
dir | int | const | 0 | 1 | -1, 1 | Â |
hardware_specific_struct_pointer | void * | state | 1 | Â | Unrestricted | Â |
fft_size_aligned_io_buffer_pointer | void * | state | 1 | Â | Unrestricted | Â |
fft_twiddle_buffer_pointer | void * | state | 1 | Â | Unrestricted | Â |
Pins
Input Pins
Name: in
Description: Complex 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: Complex
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: cfft_module.m
M=cfft_module(NAME, ISFFT)
Computes the forward or inverse FFT of complex input data. The input
block size must be a power of 2. The module supports multichannel
signals. Arguments:
NAME - name of the module.
ISFFT : 1 for calculating FFT
-1 for calculating IFFT
ISFFT is an optional argument and is used to set the internal const
variable 'dir'. You can change .dir in design mode but not in tuning
mode.
Â