%% Speed4PiV_03.m

% Simple variable speed playback using running pointers

% matching window length to signal period



%% init

speedcoef=0.7;

%N=1152;             % window length

N=2560;             % window length

% N=1200;             % window length



% N=round(N-mod(N,2*44100/900));



window=0:1/(N/2-1):1; window=[window fliplr(window)]; window=[0 window 0];

% window=KaiserBesselWin(N/2).^2; window=[window fliplr(window)]; window=[0 window 0];



%% read audio file



% s = wavread('test.wav');

% Fs=44100;

% s=sin(2*pi/Fs*[0:Fs*2-1]*1000)';

% s=s1';



% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\corean_course_06.wav'); s=s(1:Fs*20,:);

%[s,Fs]=audioread('G:\TestSignals\MatLabSamples\Samples\svejk.wav'); s=s(1:Fs*5,:);

[s,Fs]=audioread('D:\MATLAB_Workspace\VSP\original_decoding\breath_192k_change_dec.wav'); s=s(1:Fs*5,:);

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\ET.wav');  %s=s(1:Fs*10,:);

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\Put_it.wav'); %s=s(1:Fs*6,:);

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\KJ.wav'); %s=s(1:Fs*10,:); %s=s(0.75*Fs+(1:Fs*5),:);

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\China In Her Eyes.wav'); %s=s(Fs*7:end,:);

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\odejoy.wav'); s=s(1:Fs*10,:);

% [s,Fs]=wavread('D:\TestSignals\BabyTalk_44kHz.wav');



% s=wavread('D:\TestSignals\MatLabSamples\Samples\mus.wav');



% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\WildwoodFlower.wav');

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\BW_KissingMyLove.wav');

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\BW_UseMe.wav');

% [s,Fs]=wavread('D:\TestSignals\MatLabSamples\Samples\NJ_dont_know.wav');



% DM AudioLab samples

% [s,Fs]=wavread('d:\shared\AudioLab Demo\Variable Speed Playback Demo\KP01s_000.wav');        % s=s(1:Fs*2,:);        % 0.5, 2.0

% [s,Fs]=mp3read('D:\TestSignals\TestSamples\VSP_samples\music1_original.mp3');  s=s(1:Fs*5,:);       % 1/1.5, 1/0.74, 

% [s,Fs]=wavread('d:\shared\AudioLab Demo\Variable Speed PlaybackDemo\music2_original.wav');   % s=s(1:Fs*5,:);        % 0.5, 2.0



% [s,Fs]=wavread('D:\Work\2011_03_07\VC_130726_073649.WAV');      % constant pitch

% [s,Fs]=wavread('D:\Work\2011_03_07\VC_130726_120011.WAV');      % sweep pitch



% make mono

if min(size(s))>1,

    s=mean(s');

else

    s=s';

end



%% perform speed change



winleftbdr=1:speedcoef:length(s)-N;

idx1=1:length(winleftbdr);

tmp=mod(idx1-winleftbdr,N);

wnd1=(window(floor(tmp)+2)-window(floor(tmp)+1)).*(tmp-floor(tmp))+window(floor(tmp)+1);

idx1=ceil(winleftbdr)+floor(tmp);

idx2=(1:length(winleftbdr))+N/2;

tmp=mod(idx2-winleftbdr,N);

wnd2=(window(floor(tmp)+2)-window(floor(tmp)+1)).*(tmp-floor(tmp))+window(floor(tmp)+1);

idx2=ceil(winleftbdr+floor(tmp));



y=s(idx1).*wnd1+s(idx2).*wnd2;



%% plot output

figure(1)

plot(y)



%% write

%OutFileName='Out__WinSize_'+num2str(N)+'__Speed_'+num2str(speedcoef)+'_.wav';

s1 = strcat('Out__WinSize_',num2str(N));

s2 = strcat('__Speed_',num2str(speedcoef));

OutFileName = strcat(s1,s2);

OutFileName = strcat(OutFileName,'_.wav');

audiowrite(OutFileName,y,Fs)

%audiowrite('y.wav',y,Fs)