Real-time spectrum analyzer with API

c++ spectrum analyzer fft signal-processing
bobobobo picture bobobobo · May 22, 2010 · Viewed 8.8k times · Source

I'm looking for a C or C++ API that will give me real-time spectrum analysis of a waveform on Windows.

I'm not entirely sure how large a sample window it should need to determine frequency content, but the smaller the better. For example, if it can work with a 0.5 second long sample and determine frequency content to the Hz, that would be wicked-awesome.

Answer

please delete me picture please delete me · May 22, 2010

I used FFTW a few years ago. It is supposedly fast (though I didn't use it for anything real-time myself) and was certainly pretty easy to use, even on Windows.

Regarding the window size, see the Nyquist-Shannon sampling theorem.

(I imagine there are other issues involved when using a window on the data, particularly for low frequencies, but I'm no expert and I couldn't find any useful-looking info about this, so maybe I'm wrong.)

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
Spectrogram C++ library

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.

Read More
Easiest way to convert int to string in C++

What is the easiest way to convert from int to equivalent string in C++. I am aware of two methods. Is there any easier way? (1) int a = 10; char *intStr = itoa(a); string str = string(intStr); (2) int a = 10; stringstream ss; ss &…

Read More