www.pudn.com > wodegaozhiliangvoicebox.rar > frq2midi.m

function [n,t]=frq2midi(f) 
%FRQ2MIDI Convert frequencies to musical note numbers [N,T]=(F) 
% notes are numbered in semitones with middle C being 60 
% Note 69 (the A above middle C) has a frequency of 440 Hz. 
% These note numbers are used by MIDI. Note numbers are not necessarily 
% integers. 
% 
% t is a text representation of the note in which 
% C4# denotes C sharp in octave 4. Octave 4 goes 
% from middle C up to the B above middle C. For the white 
% notes on the piano, the third character is a space. 
% 
% Negative frequencies are equivalent to positive frequencies 
% except that flats will be used instead of sharps. Thus 
% C4# would become D4- 
% 
% see MIDI2FRQ for the inverse transform 
 
 
 
 
%      Copyright (C) Mike Brookes 1998 
%      Version: $Id: frq2midi.m,v 1.3 2005/02/21 15:22:12 dmb Exp $ 
% 
%   VOICEBOX is a MATLAB toolbox for speech processing. 
%   Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html 
% 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%   This program is free software; you can redistribute it and/or modify 
%   it under the terms of the GNU General Public License as published by 
%   the Free Software Foundation; either version 2 of the License, or 
%   (at your option) any later version. 
% 
%   This program is distributed in the hope that it will be useful, 
%   but WITHOUT ANY WARRANTY; without even the implied warranty of 
%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
%   GNU General Public License for more details. 
% 
%   You can obtain a copy of the GNU General Public License from 
%   ftp://prep.ai.mit.edu/pub/gnu/COPYING-2.0 or by writing to 
%   Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
n=(69+12*log(abs(f)/440)/log(2)); 
if nargout > 1 
  m=round(n(:)); 
  o=floor(m/12)-1; 
  m=m-12*o+6*sign(f(:))-5; 
  a=('CDDEEFGGAABBCCDDEFFGGAAB')'; 
  b=(' - -  - - -  # #  # # # ')'; 
  t=setstr([a(m) mod(o,10)+'0' b(m)]); 
end