On Sat, Aug 25, 2012 at 12:44:12AM +0100, Harry van Haaren wrote: > On Fri, Aug 24, 2012 at 11:48 PM, Fons Adriaensen <[email protected]>wrote: > > > The easiest way in the case of wavetable synthesis is to upsample > > your waves by a factor of say 8, then use linear interpolation. > > > > So the preparation process is: > -record the sounds > -upsample x8 > > Live playing: > -downsample the wavetable to the size needed for the frequency that is > played > > Do I understand the steps correctly?
Basically just multiply all samples indices by 8. For example if when using the original you would need the value at 3.4, and interpolate between samples 3 and 4, in the upsampled table that becomes 3.4 * 8 = 27.2 and you interpolate between samples 27 and 28. The run-time CPU load is just the same, you only need more memory. But since now you can interpolate witout artefacts, you don't need a perfect fit of K cycles in N samples, and that allows the waves to be shorter. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
