%水印提取

%讀取原始宿主音頻
audio_name='D:\sound\鋼琴曲 - 少女的祈禱.wav';%
% audio_name='D:\sound\大地.wav';
% audio_name='D:\sound\001.wav';
[y,fs,br]=wavread(audio_name);
audio=y(:,1);

%讀取嵌入水印后的音頻
audio_name_new='D:\sound\鋼琴曲 - 少女的祈禱_new22.wav';
% audio_name='D:\sound\重采樣\大地_new.wav';
% audio_name_new='D:\sound\001_new.wav';
[audio_1,fs]=wavread(audio_name_new);
audio_h_length=size(audio_1,1);
water_length=4096;
watermark=ones(1,water_length);
% audio_h=audio_1;
%白噪聲攻擊
% audio_h=audio_1+randn(1,audio_h_length)'/100;%加入高斯白噪聲


%低通濾波攻擊，截止頻率6khz，濾波后采樣點(diǎn)平移279位
load('C:\MATLAB7\work\filter_44100_6k.mat')%截止頻率6khz
L1=length(filter_44100_6k);
audio_h=conv(filter_44100_6k,audio_1);

sect=1024;
% k1=100000;
k1=100000+279;%低通濾波
k=100000;

w=1;%w為水印標(biāo)號

%漢明窗
for i=0:1023
    h(i+1)=sqrt(8/3)*0.5*(1-cos(2*pi*i/1024));
end

while k<=audio_h_length&w<=water_length
    for i=1:sect
        audio1(i)=audio(k,1);
        audio2(i)=audio_h(k1,1);
        k=k+1;
        k1=k1+1;
    end
    
    power=sum(audio1.^2);
    if power>0.02%在能量大于0.02的幀嵌入水印
    audio11=audio1.*h;
    f=abs(fft(audio11)).^2;
    t=10*log10(geomean(f(1:128))/mean(f(1:128)));
     %對每幀進(jìn)行分析，判斷水印嵌入位數(shù)
    if t>=-14.5
        N=4;
    else
        N=0;
        k=k-512;
        k1=k1-512;
    end
    if N>0
    [C1,L1]=wavedec(audio1,3,'db1');
    [C2,L2]=wavedec(audio2,3,'db1');
    a1=appcoef(C1,L1,'db1',3);
    a2=appcoef(C2,L2,'db1',3);
    watermark1=tiqu_3(a1,a2,N);
    watermark(w:w+N-1)=watermark1;
    w=w+N;
    end
    end
end
miyao=ones(1,12);
watermark=huifu(watermark,miyao);%置亂逆處理

%升維操作
k=1;
for i=1:64
    for j=1:64
        image(i,j)=watermark(k);
        k=k+1;
    end
end
imwrite(image,'D:\wav\水印_new.bmp','bmp');
image=imread('D:\wav\水印_new.bmp');
figure(1)
imshow(image,[])

%計(jì)算誤碼率
image_name='D:\wav\水印.bmp';
watermark_image=imread(image_name);
ww=1;
for i=1:64
    for j=1:64
        watermark0(ww)=watermark_image(i,j);
        ww=ww+1;
    end
end
err=sum(xor(watermark,watermark0))/4096
% image_write;
% err=sum(xor(watermark,water_mark))/water_length
% figure(3)
% subplot(2,1,1)
% plot(audio_1)
% subplot(2,1,2)
% plot(audio_h)
% wavwrite(audio_h,fs,'D:\wav\鋼琴曲 - 少女的祈禱_new4.wav')