b@11: function gain(filename, gainIndB, fs, bitdepth)
b@11: % GAIN amplifies the audio in 'filename' by 'gainIndB'. 
b@11: %
b@11: % by Brecht De Man at Centre for Digital Music on 21 May 2015
b@11: 
b@11: if nargin < 4
b@11:     bitdepth = 24;
b@11: end
b@11: if nargin < 3
b@11:     fs = 96000;
b@11: end
b@11: 
b@11: [audio,fsfile] = audioread(filename); % read part of file
b@11: assert(fsfile == fs); % check file has expected sampling rate
b@11: audiowrite(filename, (10^(gainIndB/20))*audio, fs, 'BitsPerSample', bitdepth);
b@11: 
b@11: end