| It's interesting that you brought this up right now. I've just gotten most of the 'basics' on my DSP56366 reverb working. No presets, no saving of effects, and only a single algorithm. But I can vary the parameters manually, and reload firmware to adjust the algorithm.
Just to test the performance, I set up 72 output taps, three loops, eight allpasses, and two low-pass filters. That all takes 8.3 microseconds. That ends up being about double that (double the speed - half the time) of an AL3201, or I would guess about three times the performance of a Lexichip, which isn't hugely fast, but not bad, either. But I can see how I could cut that almost in half - I just need to rewrite the multitap summer to not waste half of the clock cycles in pipeline stalls.
Anyways, glides and chorus are the next set of algorithms I want to look at. One option I was thinking of was making a high-boost EQ after the interpolate that varied its coefficient with the interpolation fraction, but that would be a bit tricky to get working, I think. Plus, unless the chorus was done entirely on the host, it would be more of a DSP hog to calculate the warping, though not horrible if there were only a couple of interpolates actually moving at any one time. |