Add a Transpose / Pitch shift effect

[RJ Skerry-Ryan]

We should package up RubberBand as a transpose effect for pitch shifting.

http://en.wikipedia.org/wiki/Transposition_(music)

[RJ Skerry-Ryan (rryan)]

Kicking to 1.13.0 unless there is a candidate for 1.12.0 that emerges soon!

This would be an easy weekend bug for someone to get ramped up (hint hint).

[Daniel Schürmann (daschuer)]

This can be also used to fix Bug #1398299 "pitch knob is too coarse" by adding an additional pitch knob with finer or coarser scale.
This way we need no extra space in The GUI and controlling by Controllers with effect region is possible as well.

We have also not found a place for the helpful sync_key control. This can be also made accessible from an effect Rack.

In a later version, we may also add additional harmonic mixing controls, described here:
http://www.mixshare.com/wiki/doku.php?id=mixing_harmonically

I am thinking about an COs only implementation that just, passes values to the normal deck scaler. This way it will not consume much extra CPU.

For channels without a scaler, we may add a own scaler instance inside the effect.

Anny thoughts?

[jus (jus)]

On Dec 9, 2014, at 7:55 PM, Daniel Schürmann <email address hidden> wrote:

> We have also not found a place for the helpful sync_key control.

What does this exactly?
See my questions in https://bugs.launchpad.net/mixxx/+bug/1300616

We`ll find a place in the skins.

[Sean M. Pappalardo (pegasus-renegadetech)]

Doesn't this duplicate having a pitch/key knob? What's the use case for having it as a separate effect?

[Daniel Schürmann (daschuer)]

For the harmonic mixing use case, we need a control, that is able to tweak < 10 cts. The nearest harmonic key is always <= 2.5
way. So from this point of view, a 0,05 ct click and +- 3,2 halftones knob should be sufficient.
For a chipmunk effect, the current +- 12 halftones scale is just fine.

So we may decide to use the fine scale on a permanent knob and move the coarse knob to an effect Rack. We may also duplicate the fine knob for users who wish to have a shared FX/Pitch knob on the controller.
This will also reduce the need for a pitch knob in all skins.

We may also implement a two buttons to shift a track by 5 halftones Up and down (or other fixed jumps). This allows to produce cool chord effects during mixing.

[Be (be.ing)]

> Doesn't this duplicate having a pitch/key knob? What's the use case for having it as a separate effect?

I am not aware of any controller that has a dedicated key knob, but plenty of controllers have effects controls.

[Be (be.ing)]

There has been no progress on this lately, so I am removing the 2.1.0 milestone.

[Be (be.ing)]

Any volunteers to take this up for 2.2? I had thought about implementing this as a hack that controls the input channel's key knob to save CPU use, but that would only work if the pitch shifting effect was loaded in the first spot in the chain.

[Daniel Schürmann (daschuer)]

An other use case could be a tempo locked key wobbling, like auto tune effect.

[Be (be.ing)]

That is a cool idea!

[David Chocholatý (davidchocholaty)]

The independent pitch shift effect feature will be implemented as a part of the Google Summer of Code 2022 project.

[Daniel Schürmann (daschuer)]

https://github.com/mixxxdj/mixxx/pull/4775

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/7389