Spectrogram C++ library

c++ fft scientific-computing spectrum spectrogram
gregseth picture gregseth · Jan 25, 2010 · Viewed 15.6k times · Source

For my current project in C++ / Qt I need a library (LGPL is preferred) which can calculate a spectrogram from a signal ( basically an array of doubles ). I already use Qwt for the GUI part.

Any suggestions? Thanks.

Answer

Paul R picture Paul R · Jan 25, 2010

It would be fairly easy to put together your own spectrogram. The steps are:

  1. window function (fairly trivial, e.g. Hanning)
  2. FFT (FFTW would be a good choice but if licensing is an issue then go for Kiss FFT or similar)
  3. calculate log magnitude of frequency domain components (trivial: log(sqrt(re * re + im * im))

Related questions

How to generate the audio spectrum using fft in C++?

I want to generate an audio spectrum (as seen in this video) of a mp3 audio file. Basically this problem requires calculating the fft of the audio signal. How do I program this in C/C++? I've looked at a …

Read More
Fast Fourier Transform

I need to multiply two polynomials each having small integral coefficients. I need a fast FFT routine in C/C++ which can convolve them. I have seen several libraries but they seem to be too large spread over multiple files. …

Read More
Real-time pitch detection using FFT

I'm trying to do real-time pitch detection using C++. I'm testing some code from performous (http://performous.org/), because everything else hasn't worked for me. I know for sure that this works, but i just cant get it to work. …

Read More