annotate util/matlab_midi/midi2audio.m @ 247:ecce33192fcc tip

Added tag ver_2.1 for changeset cef4500b936f
author luisf <luis.figueira@eecs.qmul.ac.uk>
date Wed, 31 Oct 2012 12:24:44 +0000
parents a30e8bd6d948
children
rev   line source
ivan@81 1 function [y,Fs]=midi2audio(input,Fs,synthtype)
ivan@81 2 % y = midi2audio(input, Fs, synthtype)
ivan@81 3 % y = midi2audio(input, Fs)
ivan@81 4 % y = midi2audio(input)
ivan@81 5 %
ivan@81 6 % Convert midi structure to a digital waveform
ivan@81 7 %
ivan@81 8 % Inputs:
ivan@81 9 % input - can be one of:
ivan@81 10 % a structure: matlab midi structure (created by readmidi.m)
ivan@81 11 % a string: a midi filename
ivan@81 12 % other: a 'Notes' matrix (as ouput by midiInfo.m)
ivan@81 13 %
ivan@81 14 % synthtype - string to choose synthesis method
ivan@81 15 % passed to synth function in synth.m
ivan@81 16 % current choices are: 'fm', 'sine' or 'saw'
ivan@81 17 % default='fm'
ivan@81 18 %
ivan@81 19 % Fs - sampling frequency in Hz (beware of aliasing!)
ivan@81 20 % default = 44.1e3
ivan@81 21
ivan@81 22 % Copyright (c) 2009 Ken Schutte
ivan@81 23 % more info at: http://www.kenschutte.com/midi
ivan@81 24
ivan@81 25 if (nargin<2)
ivan@81 26 Fs=44.1e3;
ivan@81 27 end
ivan@81 28 if (nargin<3)
ivan@81 29 synthtype='fm';
ivan@81 30 end
ivan@81 31
ivan@81 32 endtime = -1;
ivan@81 33 if (isstruct(input))
ivan@81 34 [Notes,endtime] = midiInfo(input,0);
ivan@81 35 elseif (ischar(input))
ivan@81 36 [Notes,endtime] = midiInfo(readmidi(input), 0);
ivan@81 37 else
ivan@81 38 Notes = input;
ivan@81 39 end
ivan@81 40
ivan@81 41 % t2 = 6th col
ivan@81 42 if (endtime == -1)
ivan@81 43 endtime = max(Notes(:,6));
ivan@81 44 end
ivan@81 45 if (length(endtime)>1)
ivan@81 46 endtime = max(endtime);
ivan@81 47 end
ivan@81 48
ivan@81 49
ivan@81 50 y = zeros(1,ceil(endtime*Fs));
ivan@81 51
ivan@81 52 for i=1:size(Notes,1)
ivan@81 53
ivan@81 54 f = midi2freq(Notes(i,3));
ivan@81 55 dur = Notes(i,6) - Notes(i,5);
ivan@81 56 amp = Notes(i,4)/127;
ivan@81 57
ivan@81 58 yt = synth(f, dur, amp, Fs, synthtype);
ivan@81 59
ivan@81 60 n1 = floor(Notes(i,5)*Fs)+1;
ivan@81 61 N = length(yt);
ivan@81 62
ivan@81 63 % ensure yt is [1,N]:
ivan@81 64 y(n1:n1+N-1) = y(n1:n1+N-1) + reshape(yt,1,[]);
ivan@81 65
ivan@81 66 end