What does it do, exactly? I see the option for linear/cubic interpolation not only in Pcsx2, but in other programs that I commonly use (such as Guitar Pro). I know that None<Linear<Cubic (at least I think so), but that's it. Also, I know Cubic is posted as broken in the latest stable release. Is this still true for the latest beta/svn?
Interpolation is a way to determine new information/data from the limited data you're given.
Like for example if you have 2 points, A and C, you can use interpolation to 'guess' where an extra point B should be added.
Linear interpolation basically would make a line between point A and C, and then place B somewhere on that line.
A more advanced interpolation algorithm, might check more data, and base where point B should be placed from that data.
Take a look at these 2 pics from wikipedia:
http://upload.wikimedia.org/wikipedia/co...linear.svg
http://upload.wikimedia.org/wikipedia/co...nomial.svg
that shows you the difference different-interpolation methods make.
now in the case of SPU2-X, the 'data' that's being interpolated is sound data, instead of dots on a graph.
I haven't looked at the SPU2-X code yet, so I can't explain in-detail what its doing exactly.
Interesting stuff. Good explanation, I understand what you mean by the sound-graph comparison. I don't see much of a speed difference between no and linear interpolation, so I guess I'll leave it on. Thanks, cottonvibes.