Hi all: First post on the list. Quite some time ago I set out to create a lv2 plugin re-creation of the electroharmonix freeze guitar effect. The idea is that when you click the button it takes a short sample and loops it for a drone like effect, sort of a granular synthesis sustainer thing. (e.g. https://youtu.be/bPeeJrv9wb0?t=58)
I use an autocorrelation-like function to identify the wave period but on looping I always have artifacts rather than a smooth sound like the original I'm trying to emulate. I've tried some compression to get a constant rms through the sample, tried various forms of crossfading, tried layering several periods, and many combinations of these. I ended up releasing it using 2 layers, compression, and a 64 sample linear crossfade, but I've never been satisfied with the results and have been trying more combinations. It works well on simple signals but on something not perfectly periodic like a guitar chord it always has the rhythmic noise of a poor loop. I'm hoping either someone can help me find a bug in the code that's spoiling the effect or a better approach. I've considered applying subsample loop lengths, but I don't think that will help. The next thing I could think of is taking the loop into the frequency domain and removing all phase data so that it becomes a pure even function which should loop nicely and still contain the same frequencies. I thought I'd ask here for suggestions though, before spending too much more time on it. The GPL C code is here for review if anyone is curious: https://github.com/ssj71/infamousPlugins/blob/master/src/stuck/stuck.c I'm happy to offer more explanations of the code. Thanks for your time. _Spencer _______________________________________________ dupswapdrop: music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
