to_the_sun

What's the best/ideal/recommended way of interpolating across loop points, so as to achieve clickless, seamless loops? My project is almost done and it's currently built around groove~, but groove~'s interpolation option seems to do very little if anything. Even in the help file demos you can hear massive clicks. I'm also aware of grooveduck~, but that just ducks the loop point and so still isn't seamless.

I threw a little something together in gen~ to place after groove~ and interpolate its output, which seemed to be helping at first, but now seems to be broken. Before I spend any more time on this I thought I'd see if there's an easier way than writing something from the ground up. Any suggestions?

What's the best/ideal/recommended way of interpolating across loop points, so as to achieve clickless, seamless loops? My project is almost 

ideal-interpolation-method-for-seamless-clickless-loops

Maybe "wave~' object can solve your problem.

Messing around with the wave~ help file, the clicks did seem significantly more subdued, but after implementing it in my project I think it actually made it worse. I think I've "perfected" my gen~ interpolation method though and can demonstrate significant click reduction in the groove~ help file,

although in practice I keep running into situations where, even if I can subdue them somewhat, clicks seem inevitable. Is truly seamless looping 100% of the time really just a pipe dream?

I've struggled with this myself, and my solution for getting click-less loops was just windowing the loop linearly for a small amount of samples (64, 128, what have you) before the start/end points. My playback engine was built in gen~ so I had good access to timing information so this worked well for my purposes. Not sure if this would be a good option for you, I am not totally up to speed on what timing/playback position information groove gives you, and if it's accurate enough for this. 

Another idea would be to have 2 copies of ~groove and crossfade them. As the instance being heard approaches the end of the loop, start playing the other instance the same distance from the start of loop, and crossfade them. Maybe that would work? Kinda just spitballing here.

I've struggled with this myself, and my solution for getting click-less loops was just windowing the loop linearly for a small amount of samples (64, 128, what have you) before the start/end points.  My playback engine was built in gen~ so I had good access to timing information so this worked well for my purposes. Not sure if this would be a good option for you, I am not totally up to speed on what timing/playback position information groove gives you, and if it's accurate enough for this. 
Another idea would be to have 2 copies of ~groove and crossfade them. As the instance being heard approaches the end of the loop, start playing the other instance the same distance from the start of loop, and crossfade them.  Maybe that would work? Kinda just spitballing here. 

A belated thanks for your insights! Since I last posted I've tried everything you suggested and then some. Your idea of just drawing a straight line between two known points on either end of a window was a lot easier to understand. In the end I went with my interp() method after all, which was actually more straightforward to implement, once I understood what I was doing better and realized I needed the control ramp peaking at the loop point (rather than at .5 there).

I feel like I got equal results with either method and they do eliminate clicks, but quieter "knocks" and "croaks" seem inevitable. Perhaps especially when two more-periodic waveforms are on either side of the loop point and their phases don't match up.

I did have to write my playback into gen~ as well, not because groove~'s sync signal isn't accurate enough, but because it can jump around unexpectedly if the object's start or end points are changed.

Ideal interpolation method for seamless, clickless loops?