Anyone knows a library (or an algorithm or something) for CPU efficient pitch-shifting? Essentially, i want to take arbitrary audio input and pitch shift it just a little bit, indeed very little - the shift should be so small as it would not even qualify as out-of-tune for most practical purposes (provided that the original sound is perfectly in-tune). A shift not bigger than the usual tuning error of ordinary unplugged instruments. I also need to vary the shift, not too fast (the pitch shifting modulator will change the shift up and down a couple times per second or less), but still change it dynamically. The algorythm should be efficient enough to allow real-time processing of at least 16 sound channels simultaneously, and still leave some CPU power untouched. All this should be incorporated into a LADSPA plugin that i plan to build (and it's only a part of the functionality). -- Florin Andrei http://florin.myip.org/