diff Problems/generateAMT_Learning_Problem.m @ 10:207a6ae9a76f version1.0

(none)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Problems/generateAMT_Learning_Problem.m	Mon Mar 22 15:06:25 2010 +0000
@@ -0,0 +1,84 @@
+function data = generateAMT_Learning_Problem(nfft, windowSize, overlap)
+%%% Generate Automatic Music Transcription Problem
+%   Ivan Damnjanovic 2010
+%   
+%
+%   generateAMT_Learning_Problem is a part of the SMALLbox and generates
+%   a problem that can be used for comparison of Dictionary Learning/Sparse
+%   Representation techniques in automatic music transcription scenario.
+%   The function prompts a user for an audio file (mid, wav, mat) reads it
+%   and generates a spectrogram given fft size (default nfft=4096), analysis
+%   window size (windowSize=2822), and analysis window overlap (overlap =
+%   0.5).
+%   
+%   The output of the function is stucture with following fields:
+%       b - matrix with magnitudes of the spectrogram
+%       f - vector of frequencies at wihch spectrogram is computed
+%       windowSize - analysis window size
+%       overlap - analysis window overlap
+%       fs - sampling frequency
+%       m - number of frequenciy points in spectrogram
+%       n - number of time points in the spectrogram
+%       p - number of dictionary elements to be learned (eg 88 for piano)
+%       notesOriginal - notes of the original audio to be used for
+%                       comparison (if midi of the original exists)
+%       name - name of the audio file to transcribe
+    
+%%
+FS=filesep;
+if ~ exist( 'nfft', 'var' ) || isempty(nfft), nfft = 4096; end
+if ~ exist( 'windowSize', 'var' ) || isempty(windowSize), windowSize = 2822; end
+if ~ exist( 'overlap', 'var' ) || isempty(overlap), overlap = 0.5; end
+
+%%
+%ask for file name
+TMPpath=pwd;
+[pathstr1, name, ext, versn] = fileparts(which('SMALLboxSetup.m'));
+cd([pathstr1,FS,'data',FS,'audio']);
+[filename,pathname] = uigetfile({'*.mat; *.mid; *.wav'},'Select a file to transcribe');
+[pathstr, name, ext, versn] = fileparts(filename);
+data.name=name;
+
+data.notesOriginal=[];
+
+if strcmp(ext,'.mid')
+    midi=readmidi(filename);
+    data.notesOriginal=midiInfo(midi);
+    y=midi2audio(midi);
+    wavwrite(y, 44100, 16, 'temp.wav');
+    [x.signal, x.fs, x.nbits]=wavread('temp.wav');
+    delete('temp.wav');
+elseif strcmp(ext,'.wav')
+    cd([pathstr1,FS, 'data', FS, 'audio', FS, 'midi']);
+    filename1=[name, '.mid'];
+    if exist(filename1, 'file')
+        midi=readmidi(filename1);
+        data.notesOriginal=midiInfo(midi);
+    end
+    cd([pathstr1,FS, 'data', FS, 'audio', FS, 'wav']);
+    [x.signal, x.fs, x.nbits]=wavread(filename);
+else
+    cd([pathstr1,FS, 'data', FS, 'audio', FS, 'midi']);
+    filename1=[name, '.mid'];
+    if exist(filename1, 'file')
+        midi=readmidi(filename1);
+        data.notesOriginal=midiInfo(midi);
+    end
+    cd([pathstr1,FS, 'data', FS, 'audio', FS, 'mat']);
+    x=load([pathname,filename]);
+end
+%%
+[X, frX]=spectrogram(x.signal, hanning(windowSize), overlap*windowSize, nfft, x.fs);
+%%
+data.b=abs(X);
+data.f=frX;
+data.windowSize=windowSize;
+data.overlap=overlap;
+data.fs=x.fs;
+data.m=size(X,1);
+data.n=size(X,2);
+
+data.p=88; %number of dictionary elements (ie notes to recover)
+cd(TMPpath);
+
+end