Mercurial > hg > smallbox
view util/matlab_midi/synth.m @ 201:5140b0e06c22 luisf_dev
Added separate dictionary decorrelation
author | bmailhe |
---|---|
date | Tue, 20 Mar 2012 14:50:35 +0000 |
parents | a30e8bd6d948 |
children |
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function y=synth(freq,dur,amp,Fs,type) % y=synth(freq,dur,amp,Fs,type) % % Synthesize a single note % % Inputs: % freq - frequency in Hz % dur - duration in seconds % amp - Amplitude in range [0,1] % Fs - sampling frequency in Hz % type - string to select synthesis type % current options: 'fm', 'sine', or 'saw' % Copyright (c) 2009 Ken Schutte % more info at: http://www.kenschutte.com/midi if nargin<5 error('Five arguments required for synth()'); end N = floor(dur*Fs); if N == 0 warning('Note with zero duration.'); y = []; return; elseif N < 0 warning('Note with negative duration. Skipping.'); y = []; return; end n=0:N-1; if (strcmp(type,'sine')) y = amp.*sin(2*pi*n*freq/Fs); elseif (strcmp(type,'saw')) T = (1/freq)*Fs; % period in fractional samples ramp = (0:(N-1))/T; y = ramp-fix(ramp); y = amp.*y; y = y - mean(y); elseif (strcmp(type,'fm')) t = 0:(1/Fs):dur; envel = interp1([0 dur/6 dur/3 dur/5 dur], [0 1 .75 .6 0], 0:(1/Fs):dur); I_env = 5.*envel; y = envel.*sin(2.*pi.*freq.*t + I_env.*sin(2.*pi.*freq.*t)); else error('Unknown synthesis type'); end % smooth edges w/ 10ms ramp if (dur > .02) L = 2*fix(.01*Fs)+1; % L odd ramp = bartlett(L)'; % odd length L = ceil(L/2); y(1:L) = y(1:L) .* ramp(1:L); y(end-L+1:end) = y(end-L+1:end) .* ramp(end-L+1:end); end