Timestretching?

[yaxu]

Ref tidalcycles/Tidal#554 , is there a quick way to add timestretching to superdirt, so e.g. samples can be played higher without getting shorter?

[bgold-cosmos]

Timestretching tends to sound terrible unless you use a quite sophisticated method; I've experimented a little in SuperCollider but have never gotten very good results. Doing a little Googling suggests there might be a way to implement a WSOLA algorithm in there (someone has probably already done it). I'll keep looking.

[bgold-cosmos]

AREUREEEADY.zip

Two problems so far

• It may not be fast enough for realtime. My test code is in Python, though, so it might be OK when translated to SuperCollider
• The actual amount of stretch is different from the requested because it tries to do some wavelet similarity matching, so it's really hard to control the duration of the output with this method

There may be some variations I can try, though, this is fun stuff...

[yaxu]

That sounds good to me, nice one!

[telephon]

yes, I'm sure it would make a good plugin! You may have to design it in a way that it conforms to the scsynth way (very very little memory allocation at startup of the ugen).

[bgold-cosmos]

Example implementation in #149

I couldn't get any of the wavelet similarity stuff to work well for all samples, so fell back to a fairly simple overlap-add method. The nice part about this is no extra memory allocation is needed, and the whole thing can be done by just making some custom phase inputs to BufRd and summing over them.

[yaxu]

I saw there is a new(?) time stretch quark: https://github.com/spluta/TimeStretch
It would still be great to get #229 merged, as a flavourful stretch!

[yaxu]

Ah now I look, I see that that timestretch quark isn't realtime.

[telephon]

It would still be great to get #229 merged, as a flavourful stretch!

Yes, I've just made a comment, it is not fully resolved yet, but not far away.

[aptrn]

Any update on this?
Seems like #229 has been merged but the wordy counterpart is not yet implemented in Tidal?

Totally my most wanted feature 🥇

[telephon]

I has already been merged :)

[ndr-brt]

@aptrn you just need to define the timescale parameter:
let timescale = pF "timescale"

then you can use with your samples, like:
d1 $ s "cp" # timestretch 5

[yaxu]

We still need to add the parameters to tidal. @bgold-cosmos is it timescale and timescalewin that we want? Does it make sense to use these parameters with control buses?

[yaxu]

I tried it, and they don't work with control buses - just went silent when I tried with timescalebus.. So added them to the 'nobus' list.