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> Carla 2.4.2 has been released
On 2022-02-19 by falkTX

This is a bugfix release for Carla version v2.4 series, with some extra user-experience related changes.


Carla is an audio plugin host, with support for many audio drivers and plugin formats.
It has some nice features like automation of parameters via MIDI CC (and send output back as MIDI too) and full OSC control.


  • Fix a few crashes with JACK applications inside Carla
  • Fix build on non-supported systems by JUCE
  • Fix crash when LV2 X11 UI has non-mapped child window
  • Fix compatibility with Python 3.10
  • Fix default SF2/3 path
  • Fix LV2 UI resizing on macOS
  • Fix missing VST3 plugins not being searched recursively
  • Disable GraphicsScene indexing method to prevent crashes
  • Ensure custom data state save and restore always match


  • Add "[carla]" prefix to printed messages
  • Add appdata metadata information
  • Add notice when Carla needs to be restarted after an LV2 rescan
  • Add VST3 Windows common files to the default path (required by the latest VST3 spec)
  • Default to JACK backend if pipewire-jack replacement is installed
  • Implement dry/wet, volume and balance on JUCE hosted plugins
  • Reload audio file if sample rate changes
  • Use temporary files for big custom data values in bridges

Changes for using Carla as library

  • Add 8 CV, 32 IO and 64 IO CarlaPatchbay variants
  • Add audio port hints to backend, starting with lv2 sidechain
  • Add static plugin build target
  • Add WITH_LTO build option, disabled by default
  • Allow setting a custom C++ namespace
  • More work on experimental embed plugin UIs, now also possible on plugin bridges


To download Carla binaries or source code, jump on over to the KXStudio downloads section.
If you're using the KXStudio repositories, you can simply install "carla".
Bug reports and feature requests are welcome! Jump on over to the Carla's Github project page for those.

Notes for users

This was already the case for v2.2 and v2.3 but it is worth reiterating:
When using JACK2, the canvas - plugin integrations requires at least JACK2 v1.9.13.
This is because Carla relies on JACK meta-data in order to store information about each plugin/client, and meta-data was only added to JACK2 in version 1.9.13.
Alternatively, you can use JACK1 instead of JACK2, which has meta-data support since a long time.

Also there are still no official Linux binary builds for v2.4.2.
Carla v2.4.2 is provided in the KXStudio repositories and in many official Linux distribution repositories anyway.