ivan@81: function [y,Fs]=midi2audio(input,Fs,synthtype)
ivan@81: % y = midi2audio(input, Fs, synthtype)
ivan@81: % y = midi2audio(input, Fs)
ivan@81: % y = midi2audio(input)
ivan@81: %
ivan@81: % Convert midi structure to a digital waveform
ivan@81: %
ivan@81: % Inputs:
ivan@81: %  input - can be one of:
ivan@81: %    a structure: matlab midi structure (created by readmidi.m)
ivan@81: %    a string: a midi filename
ivan@81: %    other: a 'Notes' matrix (as ouput by midiInfo.m)
ivan@81: %
ivan@81: %  synthtype - string to choose synthesis method
ivan@81: %      passed to synth function in synth.m
ivan@81: %      current choices are: 'fm', 'sine' or 'saw'
ivan@81: %      default='fm'
ivan@81: %
ivan@81: %  Fs - sampling frequency in Hz (beware of aliasing!)
ivan@81: %       default =  44.1e3
ivan@81: 
ivan@81: % Copyright (c) 2009 Ken Schutte
ivan@81: % more info at: http://www.kenschutte.com/midi
ivan@81: 
ivan@81: if (nargin<2)
ivan@81:   Fs=44.1e3;
ivan@81: end
ivan@81: if (nargin<3)
ivan@81:   synthtype='fm';
ivan@81: end
ivan@81: 
ivan@81: endtime = -1;
ivan@81: if (isstruct(input))
ivan@81:   [Notes,endtime] = midiInfo(input,0);
ivan@81: elseif (ischar(input))
ivan@81:   [Notes,endtime] = midiInfo(readmidi(input), 0);
ivan@81: else
ivan@81:   Notes = input;
ivan@81: end
ivan@81: 
ivan@81: % t2 = 6th col
ivan@81: if (endtime == -1)
ivan@81:   endtime = max(Notes(:,6));
ivan@81: end
ivan@81: if (length(endtime)>1)
ivan@81:   endtime = max(endtime);
ivan@81: end
ivan@81: 
ivan@81: 
ivan@81: y = zeros(1,ceil(endtime*Fs));
ivan@81: 
ivan@81: for i=1:size(Notes,1)
ivan@81: 
ivan@81:   f = midi2freq(Notes(i,3));
ivan@81:   dur = Notes(i,6) - Notes(i,5);
ivan@81:   amp = Notes(i,4)/127;
ivan@81: 
ivan@81:   yt = synth(f, dur, amp, Fs, synthtype);
ivan@81: 
ivan@81:   n1 = floor(Notes(i,5)*Fs)+1;
ivan@81:   N = length(yt);  
ivan@81: 
ivan@81:   % ensure yt is [1,N]:
ivan@81:   y(n1:n1+N-1) = y(n1:n1+N-1) + reshape(yt,1,[]);
ivan@81: 
ivan@81: end