VST audio plugin and .txt output file

Hello,

I have written a VST plugin that processes input signals and would like to save the results of these calculations in a .txt file, but I don't understand how to do this.

Can anyone help me?

Thank you

Answer 1

[jibrahim]

It is not clear from the question if you want this writing capability to be part of the plugin, or if it is something you want to run outside the plugin as part of a script for example. either way, refer to dsp.BinaryFIleWriter for real-time use case for writing data to binary files:

https://www.mathworks.com/help/dsp/ref/dsp.binaryfilewriter-system-object.html

[earmello]

What I want is for the writing capability to be part of the plugin. I also want to be able to choose from the plugin interface the destination and the name of the .txt file where the processing data is to be stored.

In the meantime, thank you for the information.

[jibrahim]

Here is the pattern to write results from within the plugin:

classdef myPlugin < audioPlugin
    properties (Access = private)
        fid 
    end
    methods
        function plugin = myPlugin
            plugin.fid = fopen('results.bin','w'); 
        end
        function y = process(plugin,x)
            y = x;
            fwrite(plugin.fid,y,class(x));
        end
    end
end

Here is an example with the generated plugin:

generateAudioPlugin myPlugin
p = loadAudioPlugin("myPlugin.dll");

process(p,1.5*ones(1024,2));

% Read results
reader = dsp.BinaryFileReader('results.bin');
reader()

It is currently not possible to specify the desired output binary file name on the plugin interface.

Here is a workaround where you specify the desired output file name in a txt file. The plugin will use that name. to write data.

classdef myPlugin < audioPlugin
    properties (Access = private)
        fid 
    end
    methods
        function plugin = myPlugin

            % Get the desired file name
            fid0 = fopen('name.txt');
            name = char(fread(fid0)).';
            
            plugin.fid = fopen(name,'w'); 
        end

        function y = process(plugin,x)
            y = x;
            fwrite(plugin.fid,y,class(x));
        end
    end
end

For example:

First, set the string in name.txt to myresults.bin:

generateAudioPlugin myPlugin
p = loadAudioPlugin("myPlugin.dll");
 p = loadAudioPlugin("myPlugin.dll");
process(p,1.5*ones(1e3,2));
reader = dsp.BinaryFileReader('myresults.bin','SamplesPerFrame',1000);

Now change the name in name.txt to myresults2.bin

p = loadAudioPlugin("myPlugin.dll"); 
process(p,pi*ones(1e3,2)); 
reader = dsp.BinaryFileReader('myresults2.bin','SamplesPerFrame',1000); 
reader()

Notice that you only have to generate the plugin once, and can write to your desired location.