jp_makemono.m

function jp_makemono(inputDirs);
% Make sure all .wav files are mono.
%
% If 2 (or more) channels, just use the first channel, and re-write.
%
%  From https://github.com/jpeelle/jp_matlab

fprintf('\n');

if ischar(inputDirs)
    inputDirs = {inputDirs};
end

for i=1:length(inputDirs)
    d = dir(inputDirs{i});
    for j = 1:length(d)
        fileName = d(j).name;
        if length(fileName)>4 && strcmpi(fileName(end-3:end),'.wav')

            wavFile = fullfile(inputDirs{i},fileName);

            try
                [y,fs] = audioread(wavFile);
            catch
                error('Error reading %s.', wavFile);
            end

            if size(y,2) > 1
                fprintf('Made %s mono.\n', wavFile);
                audiowrite(wavFile, y(:,1), fs);
            end
        end
    end
end % going through inputDirs to get files

fprintf('All done.\n\n');