sources.txt

https://ccrma.stanford.edu/~jos/filters/What_Filter.html
K. K. Parhi, VLSI Digital Signal Processing Systems: Design and Implementation, John Wiley, 1999
https://www.allaboutcircuits.com/technical-articles/an-introduction-to-digital-signal-processing/
Introductory Signal Processing - Roland Priemer
https://www.nti-audio.com/en/support/know-how/fast-fourier-transform-fft
https://cs.wmich.edu/gupta/teaching/cs5260/5260Sp15web/studentProjects/tiba&hussein/03278999.pdf
The Scientist and Engineer's Guide to Digital Signal Processing By Steven W. Smith, Ph.D.
http://www.ti.com/lit/an/spra104/spra104.pdf
http://www.analog.com/en/design-center/landing-pages/001/beginners-guide-to-dsp.html
https://www.ritchievink.com/blog/2017/04/23/understanding-the-fourier-transform-by-example/
http://samcarcagno.altervista.org/blog/basic-sound-processing-python/
http://people.csail.mit.edu/hubert/pyaudio/docs/
https://mkonrad.net/uploads/projects/mastersthesis-mkonrad-mobile-gpgpu.pdf
https://eklitzke.org/blocking-io-nonblocking-io-and-epoll
https://github.com/mojofunk/portaudio/blob/master/src/hostapi/alsa/pa_linux_alsa.c
https://stackoverflow.com/questions/824234/what-is-a-callback-function