主题音乐 - 试图获得持续时间和密钥一起工作

Question

我在写一个MATLAB函数播放一首歌（权力游戏主题）。

我有正确的击键和持续时间。我试图让两个（高音和低音）一次演奏，并且每个击键都是正确的持续时间。出于某种原因，我无法获得按键的持续时间（他们都在持续时间= 1时）或两组一起玩。有任何想法吗？

function xx = key2note(X, keynum, dur) 
% KEY2NOTE Produce a sinusoidal waveform corresponding to a given piano key number 
% usage: xx = key2note (X, keynum, dur) 
% xx = the output sinusoidal waveform 
% X = complex amplitude for the sinusoid, X = A*exp(j*phi). 
% keynum = the piano keyboard number of the desired note 
% dur = the duration (in seconds) of the output note 

fs = 8000; 
tt = (1/fs):(1/fs):dur; 
freq = 440*(2^((keynum-49)/12)); %<=============== fill in this line 
xx = real(X*exp(j*2*pi*freq*tt)); %<=============== fill in this line 
end 

t = 0.17; 
%treble - 40 is middle C 
throne.keys = [47 40 43 45, 47 40 43 45, 47 40 43 45, 47 40 43 45, 47 40 44 45, 47 40 44 45, 47 40 44 45, 47 40 44 45, 47, 40, 40 45 47, 40 43 45, 42 47 36 40]; 
throne.dur = [ 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 4, 4, 1 1 2 1, 2 1 1, 1 1 1 1]; 

%bass 
throne.keys2 = [ 21, 21 25 28 31 28 25, 21 25 28 31 28 25]; 
throne.dur2 = [ 32, 1/3 1/3 1/3 1/3 1/3 1/3, 1/3 1/3 1/3 1/3 1/3 1/3]; 

throne.durations = 0.2 * ones(1,length(throne.dur)); 
fs = 8000; % 11025 Hz also works 
f = 329.62; 
xx = zeros(1, sum(throne.dur)*fs + length(throne.keys)); 
n1 = 1; 
for kk = 1:length(throne.keys) 
    keynum = throne.keys(kk); 
    tone = key2note(1,keynum,0.25); %amplitude 1, keynum, 0.38s % <------- Fill in this line 
    n2 = n1 + length(tone) - 1; 
    xx(n1:n2) = tone; %<------- Insert the note 
    n1 = n2 + 1; 
end 

fs = 8000; 
%xt = zeros(1, sum(tdur)*fs + length(keyst)); 
%xb = zeros(1, sum(bdur)*fs + 1); 
%xa = zeros(1, sum(adur)*fs+1); 
%xd = zeros(1, sum(ddur)*fs+1); 
%xx = xt + xb + xa + xd 
xx = xt + xb; 
soundsc(xx,fs) 

Answer 1

我评论一些从未使用过线了 - 你可能要取消注释他们，如果他们使用了别的东西以后。此外，我感到如此自由，使t全球速度控制。

t = 0.17; % this variable was never used. 
%I assumed you wanted to control the overall speed with it and felt so free to adjust the durations with it. 

%treble - 40 is middle C 
throne.keys = [47 40 43 45, 47 40 43 45, 47 40 43 45, 47 40 43 45, 47 40 44 45, 47 40 44 45, 47 40 44 45, 47 40 44 45, 47, 40, 40 45 47, 40 43 45, 42 47 36 40]; 
throne.dur = t*[ 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 1 1 0.5 0.5, 4, 4, 1 1 2 1, 2 1 1, 1 1 1 1]; 

%bass 
throne.keys2 = [ 21, 21 25 28 31 28 25, 21 25 28 31 28 25]; 
throne.dur2 = t*[ 32, 1/3 1/3 1/3 1/3 1/3 1/3, 1/3 1/3 1/3 1/3 1/3 1/3]; 

%throne.durations = 0.2 * ones(1,length(throne.dur)); % this was never used - no clue what you intended to do with it 
fs = 8000; % 11025 Hz also works 
%f = 329.62; % is also never used 

%treble loop 
xt = zeros(1, ceil(sum(throne.dur)*fs + length(throne.keys))); 
n1 = 1; 
for kk = 1:length(throne.keys) 
    tone = key2note(1,throne.keys(kk),throne.dur(kk)); % You used here the constant length of 0.25 instead of taking the duration value from throne.dur 
    n2 = n1 + length(tone) - 1; 
    xt(n1:n2) = tone; %<------- Insert the note 
    n1 = n2 + 1; 
end 

%Bass loop 
xb = zeros(1, ceil(sum(throne.dur2)*fs + length(throne.keys2))); 
n1 = 1; 
for kk = 1:length(throne.keys2) 
    tone2 = key2note(1,throne.keys2(kk),throne.dur2(kk)); 
    n2 = n1 + length(tone2) - 1; 
    xb(n1:n2) = tone2; %<------- Insert the note 
    n1 = n2 + 1; 
end 
xb(length(xb)+1:length(xt)) = 0; %bass voice has a much shorter duration currently - padding to same size as xt with 0's at the end. 
%If you add more voices, you have to pad them all to the length of the longest one. 


%xt = zeros(1, sum(tdur)*fs + length(keyst)); 
%xb = zeros(1, sum(bdur)*fs + 1); 
%xa = zeros(1, sum(adur)*fs+1); 
%xd = zeros(1, sum(ddur)*fs+1); 
%xx = xt + xb + xa + xd 
xx = xt + xb; 
soundsc(xx,fs) 

当然，你可以只下载主题曲的地方，并使用[y,Fs] = audioread(filename)将其转换。但是，这甚至不会像你在做什么那么酷。