Ladspa Plug-ins

From Audacity Wiki
Revision as of 11:20, 9 April 2012 by PeterSampson (talk | contribs) (Linux: excising beta)
Jump to: navigation, search
LADSPA (Linux Audio Developers Simple Plugin API) is an audio plug-in standard originally developed on Linux, but which can be ported to Windows and Mac too. Audacity has built-in support for LADSPA plug-ins.
Related article(s):

Writing LADPSA plug-ins

Audacity behaves as an excellent LADSPA host. Just read up about LADSPA, and make your plug-ins correctly. As a starting point, look at the LADSPA developers' documentation and the LADSPA site's example plug-ins. Keep in mind that Audacity "runs" the plug-in multiple times with some specific number of samples. So, don't assume that your plug-in will get the entire selection the first time. Here is an example LADSPA plug-in made by a user for plotting frequency variation.

Using LADSPA plug-ins


It's usually most convenient to place your LADSPA plug-ins in one of the following:

  • /usr/local/lib/ladspa
  • $LIBDIR/ladspa
  • $INSTALL_PREFIX/ladspa
  • any colon-delimited path specified by the LADSPA_PATH environment variable.

In addition, LADSPA plug-ins installed using the package manager will frequently be installed in:

  • /usr/lib/ladspa
  • /usr/lib64/ladspa.

Note that if building Audacity from the source code, these paths will not be seen by Audacity unless there is some other mechanism to direct Audacity to look there, for example:

  1. Audacity is configured to install in /usr/
  2. /usr/lib/ladspa or /usr/lib64/ladspa are added to the LADSPA_PATH environment variable. (See this Frequently Asked Question for information regarding the LADSPA_PATH environment variable).

Restart Audacity and the plug-ins should be in the Effect menu, underneath the divider.

If you have the ladspa-sdk installed, you can run listplugins from a terminal to list all plug-ins in your LADSPA_PATH.

Advanced users on Linux can compile the latest Audacity development code and enable experimental support for LV2. This is an extensible, "second-generation" version of LADSPA that has a wider range of effects, can use LV2 synthesizer plug-ins as powerful tone generators, and supports effect categorisation.

Windows and Mac OS

Audacity also supports LADSPA plug-ins on Windows and Mac OS. Any LADSPA plug-in compiled as a Windows .dll or Mac .dylib shared library will work on these platforms. An extensive set of LADSPA plug-ins is available for Windows and Mac OS X.

To add LADSPA plug-ins to Audacity, place them in the Plug-Ins folder inside the Audacity installation folder. Restart Audacity and the plug-ins should be in the Effect menu, underneath the divider. The Audacity installation folder is usually under C:\Program Files on Windows, or under Mac Hard Disk > Applications on OS X.

As on Linux, Audacity will also detect LADSPA plug-ins if you put them in a folder specified in the LADSPA_PATH environment variable.