Merge pull request #5 from ltcptgeneral/DarellsAnnex

DarellsAnnex updates to include DarellPitchEnvelope and DarellBandPassFilter Examples
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darrll27 2021-12-01 23:01:32 -08:00 committed by GitHub
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6 changed files with 76 additions and 6 deletions

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@ -6,14 +6,16 @@
## Function Prototypes ## Function Prototypes
function x = generate_wave(amplitude, frequency, phase, fs, duration, duty) function x = generate_wave(amplitude, frequency, phase, fs, duration, duty)
fuction x = envelope(input, fs, period, attack , decay, sustain, release) 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 attack, decay, release are percentages between 0 to 1 of the period
where period is the time in seconds sustain is the percentage of the amplitude it should sustain for
**envelope can be pitch or amplitude envelope**
function output_timedomain = Filter(input_soundin_timedomain, Fs, LOW, MED, HIGH) function output_timedomain = Filter(input_soundin_timedomain, Fs, LOW, MED, HIGH)
where LOW, MED, HIGH are user-selected variables of any value. **try to make an envelope for the filter as well** where LOW, MED, HIGH are user-selected variables of any value.
**output should be in time domain for all functions (new sound)**
## Useful websites ## Useful websites

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src/DarellPitchEnvelope.m Normal file
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function output = DarellPitchEnvelope(input, Fs, attack,decay,sustain,release) %percentages for attack, decay, sustain, release
len = length(input);
T = (len-1)/Fs;
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
output = y;%create zero array of output 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
for counter = 1:1:len
output(counter) = y(counter) * input(counter);
end
end

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@ -0,0 +1,20 @@
function output_y = DarellbandpassFilter(y,Fs,LOW,MED,HIGH)
Len = length(y);
F = Fs * (-Len/2 : (Len/2 - 1))/Len ;
Mod_Freq = fftshift(fft(y));
lenf = length(F);
output = 0 .* Mod_Freq; % 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_y = real(ifft(filtered_Mod_Freq));
end

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@ -11,7 +11,7 @@ duty = 0;
x = generate_sine(amplitude, frequency, phase, fs, duration, duty); x = generate_sine(amplitude, frequency, phase, fs, duration, duty);
x = x + generate_sine(amplitude, (frequency+5), phase, fs, duration, duty); x = x + generate_sine(amplitude, (frequency+5), phase, fs, duration, duty);
%play over 5 counts, should hear both frequencies, 5 beats between the 2 frequencies %play over 5 counts, should hear both frequencies, 5 beats per second between the 2 frequencies
playtime = 5; playtime = 5;
play_continuous(x, fs, playtime) play_continuous(x, fs, playtime)
@ -23,3 +23,14 @@ x = DarellbandpassFilter(x,fs,LOW,MED,HIGH);
%play over 5 counts, should only hear 200hz %play over 5 counts, should only hear 200hz
playtime = 5; playtime = 5;
play_continuous(x, fs, playtime) play_continuous(x, fs, playtime)
attack = 0.2;
decay = 0.2;
sustain = 0.2;
release = 0.1;
x = DarellPitchEnvelope(x, fs, attack,decay,sustain,release); %output new sound in time domain
%play over 5 counts, should only hear 200hz
playtime = 5;
play_continuous(x, fs, playtime)