Undefined function 'preprocessAudio' for input arguments of type 'single'

Dear all Coding Experts in Matlab.

I am trying to Train Generative Adversarial Network (GAN) for Sound Synthesis.

https://in.mathworks.com/help/audio/ug/train-gan-for-sound-synthesis.html

But while operating perfor i am getting following error.

for the parfor-loop that is trying to execute on the worker could not be found.

Caused by:

Undefined function 'preprocessAudio' for input arguments of type 'single'.

Error using remoteParallelFunction

Worker unable to find file.

Undefined function 'preprocessAudio' for input arguments of type 'single'.

What Am i Doing Wrong ? I am implementing the code as it is.

Here is my code

downloadFolder = 'audio_folder';% Some folder that contains 100 audio files type .wav
percussivesoundsFolder = fullfile(downloadFolder);
ads = audioDatastore(percussivesoundsFolder,IncludeSubfolders=true);
fftLength = 256;
win = hann(fftLength,"periodic");
overlapLength = 128;
if canUseParallelPool
    pool = gcp;
    numPar = numpartitions(ads,pool);
else
    numPar = 1;
end
parfor ii = 1:numPar
    subds = partition(ads,numPar,ii);
    STrain = zeros(fftLength/2+1,128,1,numel(subds.Files));
    
    for idx = 1:numel(subds.Files)
        
        % Read audio
        [x,xinfo] = read(subds);
        % Preprocess
        x = preprocessAudio(single(x),xinfo.SampleRate);
        % STFT
        S0 = stft(x,Window=win,OverlapLength=overlapLength,FrequencyRange="onesided");
        
        % Magnitude
        S = abs(S0);
        STrain(:,:,:,idx) = S;
    end

Please help. Thank you in Advance.

Answer 1

[Steven Lord]

Look at the Utility Functions section at the end of that example's documentation page. The preprocessAudio function is part of that example and so is not on the MATLAB search path by default. You will need to create a file named preprocessAudio.m in a directory that is on the search path (in the directory whose path is returned by userpath is a good place if you don't already have a folder for the code you're trying to run) and copy that code into it.

Since that uses the trimOrPad utility function also included in that example you'll need to either make a similar trimOrPad.m file or copy the trimOrPad function as a subfunction inside preprocessAudio.m.

[Saurabh Deshmukh]

Steven Lord

I have tried doing everything you have suggested. Still the error remains same as it expects a Single Data type of variable numPar and Double Data Type is generated from the statements given below

if canUseParallelPool

pool = gcp;

numPar = numpartitions(ads,pool);

else

numPar = 1;

end

The Error is

Error using signal.internal.resample.orientToNdim

Expected input number 1, X, to be one of these types:

double

Instead its type was single.

[Steven Lord]

Still the error remains same as it expects a Single Data type of variable numPar and Double Data Type is generated from the statements given below

No, it's the other way around. As stated in the documentation for the resample function in Signal Processing Toolbox, the first input argument (x) must be of data type double. The code checks whether that first input is a double and in your application it's not. It's single precision. So you need to convert your data to double or find an alternate way to resample your data (perhaps using interp1?)

[Saurabh Deshmukh]

Ohh. Yes. My mistake. Understood. Thank you so much

It helps.

Thanks again