Sifft

Sifft VST (Sample + Inverse Fast Fourier Transform) is an open source FFT based WAV player that allows separate control over time and pitch. This simple method of timestretching uses the phase difference between blocks to reproduce accurate pitch at the expense of creating diffusion due to phase being misaligned on stretched/compressed blocks. The result sounds noisy with minor adjustments but reproduces accurate pitch even with extreme modification (e.g. 1024 times timestretching or much more is possible). The sample may be scanned as if it were "frozen". With the inclusion of frequency shifting, Sifft is well suited for experimental sounds and percussion resynthesis.

Features include:

• loads 8, 16, or 24-bit wavs.
• 3 waveform interpolation modes: none (floor), linear, and cubic.
• emulated downsampling to 1 bit.
• a bunch of filter modes (low, band, high, cut, peak in Moog, Simper svf or RBJ biquad).
• curveable envelopes and modulating LFO contours.

Sifft includes the core process as a SEM module for SynthEdit users and c++ source for the process with notes. A selection of other SEMs are included, e.g. envelopes and filters.