A time and pitch shifting library
Designed for digital audio developers
For Windows and Mac OS X
* Changes time and pitch independently.
* It has a stable bass and accurate channel locking.
* No choices for music or percussion.
   Works for both, with sharp attacks and
   smooth sustains.
* Runs to 192Khz.
* Envelope shaping or locking to preserve formants.
* Phase locked for up to 8 channel processing.
* Easy to use SDK, with looping and streaming callbacks
click picture for full size
Copula is a unique audio engine that separates time from pitch. It produces professional quality sound, and it's simple to use. Perfect for any audio or video software, from computer games to digital audio workstations.

Time stretching.
Copula allows you to stretch or compress a sound without changing pitch. Creating glitch free tempo changes in audio tracks allows the user to manipulate freely any audio in real-time.
It processes audio as single spectral units. This allows for very stable transients, without multiple hits at different frequencies. Where some engines exhibit 'barking' or judder effects on slowed down transients like drums, Copula attacks them perfectly and above all accurately.

Pitch shifting.
This pitches the sound up or down independently from time, allowing tuning of instruments irrespective of the desired tempo.
It can process sound to well over 4 octaves if you wish. Copula's unique pitch shifting engine eliminates the warble effects heard on all other pitch-shifters available at extreme shifts.

The above demo only loads 'wav' files, but the Copula engine can be fully tested.
Audio demos wave files:-
Time varying audio demo. Speeds up slowly, then up to 400%, then back down to time frozen. Then reverse, and then back to normal.
Percussion, Pitch and speed audio demo.
Demonstrates the high accuracy of the sharp hits no matter what speed or pitch.
Extreme slow speeds, and vocal freeze.
Speech pitch and then formant preserving.
About the library
Copula is a software library to be used by developers of DAWs and other audio software. It comes as a DYLIB file (Mac) and a DLL (Win). Along with an include file for the C++ class with simple to use functions.
The Copula library allows pitch and time settings every 5ms, to a large range of values.
Very fine adjustments possible, so for example a speed of 100.001% is allowed.
Speeds can be any value including negative for backwards and zero for frozen audio.
Start and stop or looping points can be set during play back.
A call-back function allows the developer to direct any type of data, including streamed audio if they wish.
Processing though single sample frames or any block asked for by the calling application, similar to plug-in architecture.
Very efficiently coded, single threaded operation.

It is available as a dynamic library for PC and Mac, and the license covers both.

Please use the contact page to for queries about downloading the library and pricing.

All QuikQuak plug-ins and software are copyright © 2005-2011 David J Hoskins. All rights reserved. All technical specifications and prices of the products specified on this web site may be subject to change without notice. Copyright notices may not be removed or changed. QuikQuak and all QuikQuak product names are trademarks of David J Hoskins. Microsoft® and Windows® are trademarks of Microsoft Corporation. Cubase and VST are registered trademarks of Steinberg Media Technologies GmbH. Mac and Intel Mac logos are trademarks of Apple Computer, Inc. All other trademarks are the property of their respective owners.