diracLE~ is a high quality realtime timestretching and pitchshifting external.
    It is based on the DIRAC LE algorithm by DSP Dimension. It can playback from a buffer~ with no latency, in streaming mode there is quite some latency though.
    There are some limitations: the samplerate should be 44.1kHz or 48kHz and smooth parameter transitions are not possible. It can function in stereo, but the channels are not linked internally, so they can have slight offset.
    The zip file contains besides the external and a helpfile also 3 Max for Live devices which illustrate what you can do with it.
    (note: it is currently Mac only)
    update: the object is now max 6 ready, it uses 64 bit precision in max 6 (and still works fine in 32 bit mode in max 5)

    • Sep 27 2011 | 7:25 pm
      Thank you this is awesome! Actually having quite a bit of fun with a drum loop and the maxhelp file :)
    • Apr 23 2014 | 12:34 pm
      This is a great external! Nice Work! Is there a windows version coming soon? :) thanks
    • Aug 08 2014 | 11:22 pm
      Hey Timo,
      Been hearing great things about this external/M4L devices, but I can't get it to open in Max 6.1.8 64 bit. I can load the external when running Max in 32 bit mode. Although your update says it runs in 64 bit, I get the "...wrong architecture" message in my max window.
      Any help, greatly appreciated.
    • Aug 12 2014 | 2:27 pm
      Evan - I have exactly the same problem. Anyone able to help?
    • Aug 12 2014 | 5:59 pm
      DiracLE doesn't support 64bit binaries. Timo was referring to updating for Max 6's 64bit audio sample based signal chain (which is separate from a 64bit architecture binary...I know a little confusing). Stay tuned for Max 7, where these kinds of features are available on both 32/64 bit architectures as well as other features above and beyond DiracLE.
    • Aug 12 2014 | 6:11 pm
      Thanks for the clarification! I guess I'll have to wait until version 7 to incorporate this into my devices.
    • Oct 01 2015 | 2:22 pm
      @Timo and @Joshua
      Any news on x64 support for diracLE~? Thanks!
    • Oct 15 2015 | 3:18 am
      As far as I can tell (because I tried to build this on Windows a few months back), DiracLE~ was built on a free open source library from DSP Dimension (DiracLE), which was acquired by Zynaptiq in 2014. The library is now known as ZTX, and some of this technology is built into Max 7 objects (pitchshift~, retune~, stretch~). The Help libraries alternate between describing these objects as being built on Dirac or ZTX. However, you can do realtime pitch shifting with pitchshift~ and retune~, but only non-realtime pitch shifting with formant preservation (stretch~).
      The free (and limited) Open Source DiracLE release was used to build DiracLE~, and is required to rebuild the external from source. This library is no longer available, and I was not able to find an original copy.
      When the ownership changed, so did some of the functionality - the free open source ZTX library does not support Formant preservation. This means that DiracLE~ cannot be compiled using the ZTX LE library with the same functionality - you can do realtime pitch shift, but not Formant Preservation (which I wanted). To get the full functionality of the ZTX library, you would need to buy the full commercial license and comply to the license requirements.
      If you want to use an external for (near) realtime pitchshifting with optional formant preservation, I have written a rubberband~ external (based on the open source RubberBand time/pitch shifting library). There are 32 and 64 bit externals available for Windows - and it can be compiled for Mac, but I don't have the Mac binaries.