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FFTs Using AltiVec on Linux and Mac OS X

Posted by pudge on from the mmmm-fourier dept.

GregAllen writes "After searching for a good open-source AltiVec implementation of the Fast Fourier Transform (FFT), I have put together the AltiVec FFT page. It has all of the source, some benchmarks, and runs on Mac OS X or LinuxPPC. I even compared it to the venerable (but scalar) FFTW."

1 of 33 comments (clear)

  1. Re:What's a FFT by ndevice · · Score: 5, Informative

    an fft is a fast fourier transform. It is commonly used to transform data from the time domain to the frequency domain.

    What this means is that is if you have a time-varying signal like audio for example, you can run an fft on it and get a frequency analysis on the sound. i.e. from the sound in a waveform format, after an fft, you can pick out which are the dominant frequencies, and what the relationship between frequencies are.

    Although the fft is strictly not necessary because it is, after all, just a transform, it turns out that many media compression techniques use them because humans aren't as discriminating in the frequency domain so if you do lossy compression in the frequency domain, we won't notice/mind as much.

    fyi, you do an fft any time you view a .jpg, or listen to an .mp3, or watch a dvd, etc. Lots of uses for them, and that doesn't even get into the engineering/scientific uses...