F32

Object Hierarchy:

Gst.FFT.F32 Gst.FFT.F32 Gst.FFT.F32

Description:

[ CCode ( has_type_id = false ) ]
[ Compact ]
[ GIR ( name = "FFTF32" ) ]
public class F32

F32 provides a FFT implementation and related functions for 32 bit float samples.

To use this call F32 for allocating a F32 instance with the appropriate parameters and then call fft or inverse_fft to perform the FFT or inverse FFT on a buffer of samples.

After use free the F32 instance with free.

For the best performance use fft_next_fast_length to get a number that is entirely a product of 2, 3 and 5 and use this as the len parameter for F32.

The len parameter specifies the number of samples in the time domain that will be processed or generated. The number of samples in the frequency domain is len/2 + 1. To get n samples in the frequency domain use 2*n - 2 as len.

Before performing the FFT on time domain data it usually makes sense to apply a window function to it. For this window can comfortably be used.

Be aware, that you can't simply run inverse_fft on the resulting frequency data of fft to get the original data back. The relation between them is iFFT (FFT (x)) = x * nfft where nfft is the length of the FFT. This also has to be taken into account when calculation the magnitude of the frequency data.


Namespace: Gst.FFT
Package: gstreamer-fft-1.0

Content:

Creation methods:

  • public F32 (int len, bool inverse)
    This returns a new F32 instance with the given parameters.

Methods:

  • public void fft (float timedata, F32Complex freqdata)
    This performs the FFT on timedata and puts the result in freqdata.
  • public void free ()
    This frees the memory allocated for this.
  • public void inverse_fft (F32Complex freqdata, float timedata)
    This performs the inverse FFT on freqdata and puts the result in timedata.
  • public void window (float timedata, Window window)
    This calls the window function window on the timedata sample buffer.