Merge pull request #3 from ltcptgeneral/DarellsAnnex

Darells annex

DarellsAnnex/Synthtest.m

@@ -0,0 +1,165 @@
+
+filename = '/Users/DarellCHUA/OneDrive - UC San Diego/FA2021/ECE 45/SynthesizerProject/Be Epic.mp3';
+[y,Fs] = audioread(filename);
+
+lengthy = length(y);
+new_y = zeros(1,lengthy);
+for n = 1:lengthy
+    new_y(n) = y(n,1) + y(n,2);
+end
+
+y = new_y;
+
+Time = (length(y)-1)/Fs;
+
+
+Freq = 200; %Hz
+Time = 20;
+
+LFO = 1; %Hz
+
+RangeFs = [20 22050];
+Fs = 2*RangeFs(2); %should be 44.1 khz
+
+
+x = 0:1/Fs:Time;
+Len = length(x);
+
+y = sin(Freq*2*pi*x); %sin wave
+
+beats = 1;
+y = y + sin((Freq+beats)*2*pi*x); %adding beats based on superposition
+y = y + sin((2*Freq)*2*pi*x);
+y = y + sin((2*Freq+beats)*2*pi*x);
+y = y + sin((2*Freq+5)*2*pi*x);
+y = y + sin((2*Freq+beats+5)*2*pi*x);
+y = y + sin((3*Freq)*2*pi*x);
+y = y + sin((3*Freq+beats)*2*pi*x);
+y = y + sin((3*Freq+5)*2*pi*x);
+y = y + sin((3*Freq+beats+5)*2*pi*x);
+y = y + 5*sin((10)*2*pi*x);
+y = y + sin((10*Freq+5)*2*pi*x);
+
+y = y + square(Freq*2*pi*x); %square wave
+y = y + square((Freq+beats)*2*pi*x);
+y = y + square(Freq*2*pi*x); %square wave
+y = y + square((Freq+beats)*2*pi*x);
+
+T = 4;
+overlay = Envelope(0.2,0.1,0.5,0.3,T,Fs);
+y = overlayAmp(x,y,overlay,T,Fs);
+
+f = Fs * (-Len/2 : (Len/2 - 1))/Len ;
+Mod_Freq = fft(y);
+figure(1)
+plot(f, abs(fftshift(Mod_Freq)));
+
+y = bandpassFilter(f,y,0,22000);
+Mod_Freq = fft(y);
+figure(2)
+plot(f, abs(fftshift(Mod_Freq)));
+
+T = 2;
+overlayPitch = Envelope(0.4,0.1,0.9,0.3,T,Fs);
+y = PitchEnvelope(f,y,1,overlayPitch,T,Fs,Time);
+sound(y,Fs);
+
+
+
+function output = bandpassFilter(F,y,LOW,HIGH)
+    Mod_Freq = fftshift(fft(y));
+    Mod_f = fftshift(fft(F));
+    lenf = length(F);
+    output =  0 .* Mod_f; % zero array of len f
+    
+    for n = 1:lenf
+        if ((LOW < abs(F(n))) && HIGH > abs(F(n)))
+            output(n) = 1;
+        else
+            output(n) = 0;
+        end
+    end
+        
+    filtered_Mod_Freq = fftshift(Mod_Freq .* output);
+    
+    output = real(ifft(filtered_Mod_Freq));
+    
+end
+
+function output = PitchEnvelope(f,y,percentile,shift,T,Fs,Time) %just need to change percentile to a graph
+    
+    x = 0:1/Fs:Time;
+    leny = length(y); %create zero array of y of len x
+    lengthxol = T * Fs;
+    shift = 1 - shift;
+    for n = 1:leny
+        y(n) = y(n)*cos(shift(mod(n,lengthxol)+1)*2*pi*x(n)); 
+    end
+    
+    Mod_Freq = fftshift(fft(y));
+    Mod_f = fftshift(fft(f));
+    lenf = length(f);
+    output =  0 .* Mod_f; % zero array of len f
+    midpoint = round(lenf/2);
+    
+    Filtered_Signal = fftshift(fft(bandpassFilter(f,y,0,22000)));
+    filtered_Signal = real(ifft(Filtered_Signal));
+    
+    demod_Signal = filtered_Signal .* 0; %create zero array of y of len filtersignal
+    
+    for n = 1:leny
+        demod_Signal(n) = 2* filtered_Signal(n) *cos(shift(mod(n,lengthxol)+1)*2*pi*x(n)); 
+    end
+    
+    
+    Message = fftshift(fft(bandpassFilter(f,demod_Signal,-5000,5000)));
+    message = real(ifft(Message));
+    output = y;
+    
+end
+function output = overlayAmp(x,y,overlay,T,Fs)
+    counter = 1;
+    lengthx = length(x);
+    lengthxol = T * Fs;
+    while counter < lengthx
+        y(counter) = y(counter) * overlay(mod(counter,lengthxol)+1);
+        counter = counter+1;
+    end
+    output = y;
+end
+
+
+function output = Envelope(attack,decay,sustain,release,T,Fs) %percentages for attack, decay, sustain, release
+    attacktime = attack * T * Fs;
+    decaytime = attacktime + decay * T * Fs;
+    sustaintime = (T - (release * T))* Fs;
+    
+    x = 0:1/Fs:T;
+    y = 0 .* x; %create zero array of y of len x
+    
+    tcounter = 1;
+    %attack phase
+    
+    while tcounter <= attacktime
+        y(tcounter) = (1/attacktime) * tcounter;
+        tcounter = tcounter+1;
+    end
+    istart = tcounter;
+    while tcounter<= decaytime
+        y(tcounter) = 1 - (((1-sustain)/(decay * T * Fs)) * (tcounter - istart));
+        tcounter = tcounter+1;
+    end
+
+    while tcounter<= sustaintime
+        y(tcounter) = sustain;
+        tcounter = tcounter+1;
+    end
+    istart = tcounter;
+    while tcounter < (T * Fs)
+        y(tcounter) = sustain - ((sustain/(release * T * Fs)) * (tcounter - istart));
+        tcounter = tcounter+1;
+    end
+    
+    plot(x,y)
+    output = y;
+end

README.md

@@ -4,6 +4,17 @@
  
  Will add member names shortly
  
+ ## Function Prototypes
+ 
+fuction x = envelope(input, fs, period, attack , decay, sustain, release)
+where attack, decay, sustain release are percentages between 0 to 1 of the period
+where period is the time in seconds
+
+function x = generate_wave(amplitude, frequency, phase, fs, duration, duty)
+
+function  output_timedomain = Filter(input_soundin_timedomain, Fs, LOW, MED, HIGH) 
+where LOW, MED, HIGH are user-selected variables of any value
+ 
  ## Useful websites
  
  - https://learningsynths.ableton.com