Single Cycle waves polyphase fir (in: DSP and Plugin Devel…)

By: Marvinh
26 May 02:20

I have the following code snippet for single cycle wave interpolation and resampling.

if i hard reset the counter I get absolutely no aliasing.

It resamples perfectly 5 octaves up with no mip mapping required

if( counter >= len) {
counter = 0;
}

If i wrap the counter I get tons of artifacts like amplitude modulation and phasiness and need for mip mapping possibly

if( counter >= len) {
counter %= len;
}

Any idea which is correct?

I would prefer:

if( counter >= len) {
…