FreeverbReverberator example Plugin error

Hi

I´m trying to use the FreeverbReverberator as part of a more complex plugin. When I test it through audioTestBench as MatlabCode everything ok, but when I try to validate it for plugin creation, the following error appears:

"Unable to perform assignment because the left and right sides have a different number of elements.

Error in audioexample.FreeverbReverberator/parallelComb (line 261)

in(1:end) = sum(drySignal,2); "

Debugging the FreeverbReverberator code, I could verify that this missmatch in number of elements happens after the 1st cycle. So I have two questions:

1) Why this doesn´t happen when running as .m?

2) Is there any way to fix it for plugin creation porpouse?

If someone can shed light on this, I´d appretiatted.

Thanks

Pablo

PS: Follows the simple code, just in case you want to reproduce the issue described above. Bear in mind the error is refered to FreeverbReverberator code.

classdef Freeverb < audioPlugin
    properties
RoomSize=0.6
WetDryMix = 1;
    end
    
    properties (Access = private)
preverb
    end
    
    properties (Constant)
        
          PluginInterface = audioPluginInterface('PluginName','Ambience Creator','VendorName','Orion',......
            audioPluginParameter('RoomSize',...
            'DisplayName','',...
            'Mapping',{'lin',0,1},...
            'Label','m',...
            'Style', 'hslider'),...
             audioPluginParameter('WetDryMix',...
            'DisplayName','',...
            'Mapping',{'lin',0,1},...
            'Label','m',...
            'Style', 'hslider'));

    end

    methods
        
         function plugin=Freeverb

            plugin.preverb=audioexample.FreeverbReverberator;  

         end
         
         function out = process(plugin, in)
        
         outrev=plugin.preverb(in);
         
         out=outrev;
                                    
        end
             
%%        
        function set.RoomSize(plugin, val)
           plugin.RoomSize = val;
            calculatesize(plugin)
        end
        
        function set.WetDryMix(plugin, val)
           plugin.WetDryMix = val;
            calculatesize(plugin)
        end
        
        function calculatesize(plugin)
           plugin.preverb.RoomSize=plugin.RoomSize;
           plugin.preverb.WetDryMix=plugin.WetDryMix;
        end
        
 %%       
        function reset(plugin)
            reset(plugin.preverb);

        end
        
    end       

end

Answer 1

[Brian Hemmat]

Hi Pablo,

Audio plugin API requires plugins to support variable-sized input. The audioexample.FreeverbReverberator does not support variable-sized input. The validateAudioPlugin function exercises the plugin by inputting different size inputs, which is how you hit that error.

Consider using the reverberator object instead. You can use it within another audio plugin, or use createAudioPluginClass to convert it to an audio plugin.

[Pablo Panitta]

Thanks Brian for you clear answer. Actually I did it with reverberator, but that object consume lot of DSP (as expected) and I was looking others options to deal with it.

[Charlie DeVane]

Hi Pablo,

You might be interested in Warren Koontz's MVPlugin. I don't anything about its relative CPU consumption, though.

hth,

Charlie

[Pablo Panitta]

Thanks Charlie! Actually is what I´m using. Its CPU consumption is much much lower than reverberator. However, I find reverberator algorithm better in sound than MV´s one.