Archived entries for audio

Short Time Fourier Transform using the Accelerate framework

Using the libraries pkmFFT and pkm::Mat, you can very easily perform a highly optimized short time fourier transform (STFT) with direct access to a floating-point based object.

Get the code on my github:
http://github.com/pkmital/pkmFFT
Depends also on: http://github.com/pkmital/pkmMatrixContinue reading...

Real FFT/IFFT with the Accelerate Framework

Apple’s Accelerate Framework can really speed up your code without thinking too much. And it will also run on an iPhone. Even still, I did bang my head a few times trying to get a straightforward Real FFT and IFFT working, even after consulting the Accelerate documentation (reference and source code), stackoverflow (here and here), and an existing implementation (thanks to Chris Kiefer and Mick Grierson). Still, the previously mentioned examples weren’t very clear as they did not handle the case of overlapping FFTs which I was doing in the case of a STFT or they did not recover the power spectrum, or they just didn’t work for me (lots of blaring noise).

Get the code on my github:
http://github.com/pkmital/pkmFFTContinue reading...


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