How to Debug the audio plugin project


I try to write a vst in win,but I don’t know how to Debug the Project after setting some Breakpoints,just for help.thank for any reply!


In your project settings you have to add a vst host as executable (in “Debugging” ) in which you load the plugin. You can pass arguments which might be the plugin executable if you use a simple vst host. In case of a sequencer you have to load the plugin in your project (the debug executable has to be in the sequencer’s vst search paths of course).



thanks chris.
So I need “a simple vst host”. You means that using some DAW or I must to write a simple vs host Project to test MyPlugin.and debugging in the host’s Project?
if not ,which vst host can be used ?


Yes. I can debug it with the Juce Plug-In Host Thanks a lot !


I normally use VST Pluginanalyzer which takes a plugin path as parameter and is quite handy for a basic check what the plugin does (frequency response, pink noise input…).
In the end it should be something you can work with.



the same problem in Mac’s xcode ,how I can start the Audio Unit to Debug? I need help.thanks!


It’s the same as with Windows - get XCode to a launch a host and use that to load your plugin.


i have the JuceDempPlugin set up in visual studio 2008 to open with the Plugin Host.exe, but when I go to debug it just opens the Plugin Host. I’ve tried sending the filepath of the JuceDempPlugin.dll in command arguments but it shoes up in Plugin Host as “Failed to open file … not a valid filtergraph file”. how can i debug the dll project?


You need to scan the debug output folder for plugins and select the plugin manually. IIRC the Plugin Host stores the last plugin layout so you don’t need to do anything when you start it after that.



cheers mate, its working. just read the documentation thats kept in julianstorer-JUCE-d24ee13\extras\audio plugin demo that says there are helper classes to create a standalone app that can load the plugin for testing so im going to have a look at that too.


For my VST dev under Windows, I’m using SAVIHost for years, by Herman Seib.

You just have to rename the executable with your plugin’s name, put it on the debug folder next to your plugin dll, and refer to this exe as the program to be launched for debug session.


Any SAVIHost alternative  for osx lion? 


How can I debug a plugin in a daw with breakpoints?

I'm using VS2012.

In project setting I have:

Debuggind -> Command: C:\Program Files\REAPER (x64)\reaper.exe

Build Events -> Post-Build Event: xcopy "$(TargetPath)" "C:\VSTPlugIns\Debug" /Y

When I hit F5, Reaper runs and when I load my plugin in a track, the breakpoints in VS have no effects... frown


Ok, I found what was the problem with breakpoints, I guess.

Tried to build a project as x64 platform and it seems to work fine!

Probably 32bit bridge in Reaper is blocking proper debugging on a 64bit system.

Hope it will save time for someone. yes


Hey guys, I have the same Problem and I spent a lot of time but without success.
I am working wir Microsoft Visual Studio 2010 Express and I add in the project settings the Command to the Juce Plugin Host
But I cant debug with Breakpoints. Its only start the GUI from the PluginHost I have wrote in the Command.

I hope someone can help me 

Thanks for taking time for my Problem




I'm not much of a Windows user but I think the express versions don't support dll (plugin) debugging:




VS Express can be used to debug dlls. I’d rather think the dll used isn’t the dll built, for example due to not copying the newly built plugin to the host search path.