MATLAB: HRTF plugin Filter error

audio pluginsAudio Toolboxhrtfmatlab coder

Hi
I´m trying to create a dll based on interporlatedHRTF function. Inside audioTestBench enviroment runs perfect, but when I try to compile it , the following error appears:
"Cannot compute constant value for argument #2 for this System object constructor. All arguments to the constructor of this System object must be constants for code generation….."
Seem is related to dsp.FIRFilter constructor, but I don´t know how to solve the situation. Coeficient must change during the process because location of the source must be able to change according to inputs parameter.
classdef HRTF_test < audioPlugin
    properties
        Sx=5;
        Sy=8;
        Rx=5;
        Ry=5;
    end
    
    properties (Access = private)
        
azimuth
elevation
Tdata=load('S005_marl_NYU_DATA.mat');
Tposition=load ('S005_marl_NYU_POS.mat');
leftIR=zeros(1,512)
rightIR=zeros(1,512)
leftfilter 
rightfilter
    end
    
    properties (Constant)
        PluginInterface = audioPluginInterface(...
            audioPluginParameter('Sx',...
            'DisplayName','Position Source X',...
            'Mapping',{'lin',0,10},...
            'Label','meters'),...
            audioPluginParameter('Sy',...
            'DisplayName','Position Source Y',...
            'Mapping',{'lin',0,10},...
            'Label','meters'));
    end
    methods
        function plugin=HRTF_test
             needtocalculateAzimuth(plugin);          
        end
        
        function out = process(plugin, in)
            
            out=[step(plugin.leftfilter,in(:,1)),step(plugin.rightfilter,in(:,2))];
        end
        
        function set.Sx(plugin, val)
           plugin.Sx = val;
           needtocalculateAzimuth(plugin);
           
        end
        
        function set.Sy(plugin,val)
           plugin.Sy=val;
           needtocalculateAzimuth(plugin);
        end
        
        function needtocalculateAzimuth(plugin) % Filter Calculation
           
            if plugin.Sy==5
            plugin.azimuth=0;
            else
            plugin.azimuth=rad2deg(atan((plugin.Sx-plugin.Rx)/(plugin.Sy-plugin.Ry)));
            end
            
            plugin.elevation=0;
            sourcePosition1 = [plugin.Tposition.dposition(:,1),plugin.Tposition.dposition(:,2)];
            desiredPosition = [plugin.azimuth plugin.elevation];
            interpolatedIR  = interpolateHRTF(plugin.Tdata.Tdata,sourcePosition1,desiredPosition);
            plugin.leftIR = squeeze(interpolatedIR(:,1,:))';
            plugin.rightIR = squeeze(interpolatedIR(:,2,:))'; 
            plugin.leftfilter=dsp.FIRFilter('Numerator',plugin.leftIR);
            plugin.rightfilter=dsp.FIRFilter('Numerator',plugin.rightIR);          
        end
        function reset(plugin)
           
        end
    end       
end

Best Answer

Hi Pablo,
The following code compiles for me (and should for you). Initialize the Numerator's with the correct size at construction, then call needtocalculateAzimuth to set the values.
classdef HRTF_test < audioPlugin
    properties
        Sx=5;
        Sy=8;
        Rx=5;
        Ry=5;
    end
    
    properties (Access = private)
        azimuth
        elevation
        Tdata = coder.load('S005_marl_NYU_DATA.mat');
        Tposition = coder.load ('S005_marl_NYU_POS.mat');
        leftfilter
        rightfilter
    end
    
    properties (Constant)
        PluginInterface = audioPluginInterface( ...
            audioPluginParameter('Sx', ...
            'DisplayName','Position Source X', ...
            'Mapping',{'lin',0,10}, ...
            'Label','meters'), ...
            audioPluginParameter('Sy', ...
            'DisplayName','Position Source Y', ...
            'Mapping',{'lin',0,10}, ...
            'Label','meters'));
    end
    methods
        function plugin = HRTF_test
            plugin.leftfilter = dsp.FIRFilter('Numerator',zeros(1,512));
            plugin.rightfilter = dsp.FIRFilter('Numerator',zeros(1,512));
            needtocalculateAzimuth(plugin)
        end
        
        function out = process(plugin, in)
            out = [step(plugin.leftfilter,in(:,1)),step(plugin.rightfilter,in(:,2))];
        end
        
        function set.Sx(plugin, val)
            plugin.Sx = val;
            needtocalculateAzimuth(plugin);
        end
        
        function set.Sy(plugin,val)
            plugin.Sy=val;
            needtocalculateAzimuth(plugin);
        end
        
        function needtocalculateAzimuth(plugin) % Filter Calculation
            
            if plugin.Sx == 5
                plugin.azimuth = 0;
            else
                plugin.azimuth = rad2deg(atan((plugin.Sx-plugin.Rx)/(plugin.Sy-plugin.Ry)));
            end
            
            plugin.elevation = 0;
            sourcePosition1 = [plugin.Tposition.dposition(:,1),plugin.Tposition.dposition(:,2)];
            desiredPosition = [plugin.azimuth plugin.elevation];
            interpolatedIR = interpolateHRTF(plugin.Tdata.Tdata,sourcePosition1,desiredPosition);
            leftIR = squeeze(interpolatedIR(:,1,:))';
            rightIR = squeeze(interpolatedIR(:,2,:))';
            plugin.leftfilter.Numerator = leftIR;
            plugin.rightfilter.Numerator = rightIR;
        end
        function reset(plugin)
            reset(plugin.leftfilter)
            reset(plugin.rightfilter)
        end
    end
end
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