关于双门限端点检测的问题
为什么检测不到后面几个信号啊，就是用的就是网上下的双门限端点检测程序，什么原因啊，难道是方法本身的缺陷，请论坛的各位高手给予指教，谢谢大家=wavread('04a');
x1=x1(:,1);
leng=length(x1);
=wavread('white',leng);
xn=0*xn;
x=x1+xn;
SNR=snr(x1,xn)
%function = vad(x)
%幅度归一化到[-1,1]
x = double(x);
x = x / max(abs(x));
%常数设置
FrameLen = 256;
FrameInc =128;
%amp1 = 10;
%amp2 = 2;
zcr1 = 10;
zcr2 = 5;
maxsilence = 8;% 6*10ms= 30ms
minlen= 15; % 15*10ms = 150ms
status= 0;
count = 0;
silence = 0;
%计算过零率
tmp1= enframe(x(1:end-1), FrameLen, FrameInc);
tmp2= enframe(x(2:end), FrameLen, FrameInc);
signs = (tmp1.*tmp2)<0;
diffs = (tmp1 -tmp2)>0.02;
zcr = sum(signs.*diffs, 2);
%计算短时能量
amp = sum(abs(enframe(filter(, 1, x), FrameLen, FrameInc)), 2);
%调整能量门限
%amp1 = min(amp1, max(amp)/4);
%amp2 = min(amp2, max(amp)/8);
%amp1=max(amp)/4;
%amp2=max(amp)/8;
amp1=10+min(amp);
amp2=5+min(amp);
%开始端点检测
x1 = 0;
x2 = 0;
for n=1:length(zcr)
goto = 0;
switch status
case {0,1} % 0 = 静音, 1 = 可能开始
if amp(n) > amp1 % 确信进入语音段
x1 = max(n-count-1,1);
status= 2;
silence = 0;
count = count + 1;
elseif amp(n) > amp2 | ... % 可能处于语音段
zcr(n) > zcr2
status = 1;
count= count + 1;
else % 静音状态
status= 0;
count = 0;
end
case 2, % 2 = 语音段
if amp(n) > amp2 | ... % 保持在语音段
zcr(n) > zcr2
count = count + 1;
else % 语音将结束
silence = silence+1;
if silence < maxsilence % 静音还不够长，尚未结束
count= count + 1;
elseif count < minlen % 语音长度太短，认为是噪声
status= 0;
silence = 0;
count = 0;
else % 语音结束
status= 3;
end
end
case 3,
break;
end
end
count = count-silence/2;
x2 = x1 + count -1;
subplot(311)
plot(x)
axis()
xlabel('采样点数')
ylabel('Speech');
line(, [-1 1], 'Color', 'red');
line(, [-1 1], 'Color', 'green');
subplot(312)
plot(amp);
axis()
xlabel('帧数')
ylabel('Energy');
line(, , 'Color', 'red');
line(, , 'Color', 'green');
subplot(313)
plot(zcr);
axis()
xlabel('帧数')
ylabel('ZCR');
line(, , 'Color', 'red');
line(, , 'Color', 'green');
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