chanvocoder.m

@@ -1,57 +0,0 @@
-function y = chanvocoder(carrier, modul, chan, numband, overlap)
-% y = chanvocoder(carrier, modul, chan, numband, overlap)
-% The Channel Vocoder modulates the carrier signal with the modulation signal
-% chan = number of channels         (e.g., 512)
-% numband = number of bands (<chan) (e.g., 32)
-% overlap = window overlap          (e.g., 1/4)
-
-if numband>chan
-	error('# bands must be < # channels')
-end
-
-[rc, cc]   = size(carrier);
-if cc>rc
-	carrier = carrier';
-end
-
-[rm, cm]   = size(modul);
-if cm>rm
-	modul = modul';
-end
-
-st         = min(rc,cc);                         % stereo or mono?
-if st~= min(rm,cm)
-	error('carrier and modulator must have same number of tracks');
-end
-
-len        = min(length(carrier),length(modul)); % find shortest length
-carrier    = carrier(1:len,1:st);                % shorten carrier if needed
-modul      = modul(1:len,1:st);                  % shorten modulator if needed
-L          = 2*chan;                             % window length/FFT length
-w          = hanning(L); 
-if st==2
-	w=[w w];
-end  % window/ stereo window
-
-bands      = 1:round(chan/numband):chan;         % indices for frequency bands     
-bands(end) = chan;
-y          = zeros(len,st);                      % output vector
-
-ii         = 0;
-while ii*L*overlap+L <= len
-    ind    = round([1+ii*L*overlap:ii*L*overlap+L]);
-    FFTmod = fft( modul(ind,:) .* w );    % window & take FFT of modulator
-    FFTcar = fft( carrier(ind,:) .* w );  % window & take FFT of carrier  
-    syn    = zeros(chan,st);              % place for synthesized output
-    for jj = 1:numband-1                  % for each frequency band
-        b        = [bands(jj):bands(jj+1)-1]; % current band
-        syn(b,:) = FFTcar(b,:)*diag(mean(abs(FFTmod(b,:))));
-    end                                   % take product of spectra
-    midval   = FFTmod(1+L/2,:).*FFTcar(1+L/2,:); % midpoint is special
-    synfull  = [syn; midval; flipud( conj( syn(2:end,:) ) );]; % + and - frequencies
-    timsig   = real( ifft(synfull) );     % invert back to time
-    y(ind,:) = y(ind,:) + timsig;         % add back into time waveform   
-    ii       = ii+1;
-end
-y = 0.8*y/max(max(abs(y)));               % normalize output
-

vocoded.m

@@ -1,49 +0,0 @@
-%Speech Processing
-pkg load signal
-
-modfile = "modulator22.wav";
-carfile = "carrier22.wav";
-white = "white.wav";
-white_p = "white_periodic.wav";
-outfile = "vocodedsound.wav";
-[modul, sr1] = audioread(modfile);
-[carrier, sr2] = audioread(carfile);
-[carrier_w, sr2_w] = audioread(carfile);
-[carrier_wp, sr2_wp] = audioread(carfile);
-
-
-if sr1 ~= sr2
-  disp('Your sampling rates dont match');
-endif
-
-y = chanvocoder(carrier,modul, 512, 32, .2);
-audiowrite("vocodedsound.wav", y, sr1);
-y_w = chanvocoder(carrier_w,modul, 512, 32, .2);
-audiowrite("vocodedsound_w.wav", y, sr1);
-y_wp = chanvocoder(carrier_wp,modul, 512, 32, .2);
-audiowrite("vocodedsound_wp.wav", y, sr1);
-
-%Plot
-figure;
-subplot(3,1,1);
-plot(modul);
-xlabel("TIme in [s]");
-ylabel("frequency in [dB]");
-legend(modfile);
-
-subplot(3,1,2);
-plot(carrier,'-r');
-xlabel("TIme in [s]");
-ylabel("frequency in [dB]");
-legend(carfile);
-
-subplot(3,1,3);
-plot(y,'-g');
-xlabel("TIme in [s]");
-ylabel("frequency in [dB]");
-legend(outfile);
-
-%spectogram
-%frequencySpectrum(modul,sr1,1);
-%frequencySpectrum(carrier,sr2,1);
-%frequencySpectrum(y,sr1,1);