求助（哪位高手能帮我把提取部分续完啊）

generalwu

clc
[a,fs,bits]=wavread('D:\MATLAB6p5\work\music.wav');
wavplay(a,8000);
figure(1)
subplot(2,1,1)
plot(a);
title('原始音频波形图')
w=imread('D:\MATLAB6p5\work\liu.BMP');
subplot(2,1,2)
imshow(w)
title('原始水印')
w1=w;
[c,l]=wavedec(a,3,'haar');
ca3=appcoef(c,l,3,'haar');
[cd1,cd2,cd3]=detcoef(c,l,[1 2 3]);
q=abs(min(ca3));
for i=256:1024
ave(i)=sum(ca3(i*20i+1)*20))/20;
z(i)=fix(ave(i)/q+1/2);
end
for i=256:1024
if mod(z(i),2)==w1(i)
cxzc=0;
else
if mod(z(i),2)~=w1(i)&&z(i)==fix(ave(i)/q)&&z(i)>=0||mod(z(i),2)~=w1(i)&&z(i)~=fix(ave(i)/q)&&z(i)<0
ca3(i*20i+1)*20)=ca3(i*20i+1)*20)+q;
else
ca3(i*20:(i+1)*20)=ca3(i*20:(i+1)*20)-q;
end
end
end
c1=[ca3',cd3',cd2',cd1'];
b=waverec(c1,l,'haar');
figure(2)
subplot(2,1,1)
plot(b);
title('嵌入水印后的音频')
wavwrite(b,fs,bits,'D:\MATLAB6p5\work\music1.wav')
这是嵌入部分