FFT power spectrum visualizer

A high-quality demonstration of the application can be found at

This program utilized discrete Fourier transformation to obtain the time-frequency-domain of a audio file. The result can be explained as following:

The top part of the program, we can see the raw time-amplitude data as it can be found in any WAV file. While this is the intuitive way for how we think of data, it is not very informative.
The bottom part of the program is the output of the algorithm, combined with some waterfall effect. This parts display the heart of DFT or Fourier Transformation in general, which allows us to decompose the data into their frequencies and how much each frequency contributes to the final sound. This kind of data has many nice attributes to which allow us to deploy many other tools from signal processing, machine learning and pattern recognition to wrangle data in a more effective way.

This program is on the other hand just a nice artistic demonstration of the algorithm, notice how much better we can see which piano key is being pressed, which is almost impossible to achieve with time-amplitude.

Build and run it yourself (C++11 / SFML 2.5)

Install the dependencies

sudo apt-get install libsfml-dev

Clone the repository

git clone https://github.com/longmakesstuff/FFT-Power-Spectrum.git --depth 1

Compile

cd FFT-Power-Spectrum
mkdir build
cd build
cmake ..
make -j8

And play any WAV song you want with

./bin/main [song-path.wav]

References

Louisa Renz's bachelor thesis - University Tübingen
RosettaCode's Cooley-Tukey FFT
Hann's function
Fourier transform for dummies

Kyle's notes

brew install fmt cppunit sfml

rm -rfd build
mkdir build; cd build
cmake ..
make VERBOSE=1
./bin/main ../kyle-interview.wav

I tried using CC=gcc-10 CXX=g++-10 cmake .. and leaving-fopenmp in the root directory CMakeLists.txt, but a single function from SFML was not found at link time. This is likely because https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/sfml.rb was compiled with Apple's Clang, not GCC?

My Issue

https://github.com/longmakesstuff/FFT-Power-Spectrum/issues/1

Anything with a GUI is outside of my C++ wheelhouse, so I was hoping to play around with your very cool project to get some experience in the area. I also have limited CMake experience, so apologies for wasting your time if I am doing something silly.

I am on macOS, so I installed brew install fmt cppunit sfml to get all the necessary dependencies for the project. Then,

mkdir build
cd build
CC=gcc-10 CXX=g++-10 cmake ..

But unfortunately that failed due to

CMake Error at tests/CMakeLists.txt:1 (find_library):
  Could not find CPPUNIT using the following names:


-- Configuring incomplete, errors occurred!

I tried adding a Findcppunit.cmake to cmake_modules/ , but that did not avoid the error. So I commented out add_subdirectory(tests) and CMake was able to finish. However, when I attempted make:

[ 14%] Linking CXX shared library libFFT-Spectrum.dylib
Undefined symbols for architecture x86_64:
  "__ZN2sf11SoundBuffer12loadFromFileERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE", referenced from:
      __ZN3fft3app10ControllerC2EPNS0_3GUIEyRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE in Controller.cpp.o
      __ZN3fft3app10ControllerC1EPNS0_3GUIEyRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE in Controller.cpp.o
...

Any tips?

Your recent changes on master indeed fixed the CPPUNIT error; thanks! But the make link error still happens for me.

I am on macOS, not Linux. But the development libraries for SFML are installed via Homebrew. E.g.

/usr/local/lib/cmake/SFML
/usr/local/lib/libsfml-audio.2.5.1.dylib
/usr/local/lib/libsfml-audio.2.5.dylib
/usr/local/lib/libsfml-audio.dylib
/usr/local/lib/libsfml-graphics.2.5.1.dylib
/usr/local/lib/libsfml-graphics.2.5.dylib
/usr/local/lib/libsfml-graphics.dylib
/usr/local/lib/libsfml-network.2.5.1.dylib
/usr/local/lib/libsfml-network.2.5.dylib
/usr/local/lib/libsfml-network.dylib
/usr/local/lib/libsfml-system.2.5.1.dylib
/usr/local/lib/libsfml-system.2.5.dylib
/usr/local/lib/libsfml-system.dylib
/usr/local/lib/libsfml-window.2.5.1.dylib
/usr/local/lib/libsfml-window.2.5.dylib
/usr/local/lib/libsfml-window.dylib
/usr/local/lib/pkgconfig/sfml-all.pc
/usr/local/lib/pkgconfig/sfml-audio.pc
/usr/local/lib/pkgconfig/sfml-graphics.pc
/usr/local/lib/pkgconfig/sfml-network.pc
/usr/local/lib/pkgconfig/sfml-system.pc
/usr/local/lib/pkgconfig/sfml-window.pc
/usr/local/share/SFML
...

all exist. Here is the complete error: