www.pudn.com > voiceprocessingtoolbox.rar > endPointDetect02.m

function out = endPointDetect02(y, fs, plotOpt, epdParam) 
% ENDPOINT End point detection 
%	Usage: out = endPointDetection(y, fs, plotOpt, epdParam) 
 
if nargin==0, selfdemo; return; end 
if nargin<4, 
	epdParam.frameSize = 256; 
	epdParam.overlap = 86; 
	epdParam.deltaEnergyLevel1 = -20; 
	epdParam.deltaEnergyLevel2 = -10; 
	epdParam.zcrRatio = 0.2; 
end 
if nargin<3, plotOpt=0; end 
if nargin<2, fs=8000; end 
 
frameSize=epdParam.frameSize; 
overlap=epdParam.overlap; 
deltaEnergyLevel1=epdParam.deltaEnergyLevel1; 
deltaEnergyLevel2=epdParam.deltaEnergyLevel2; 
zcrRatio=epdParam.zcrRatio; 
 
% ====== Zero adjusted 
y = y-mean(y); 
%wavplay(y, fs, 'sync'); 
 
% ====== Take frames 
framedY  = buffer2(y, frameSize, overlap); 
frameNum = size(framedY, 2);	% Number of frames 
 
% ====== Compute log energy 
energy = frame2logEnergy(framedY); 
time = ((0:frameNum-1)*(frameSize-overlap)+0.5*frameSize)/fs; 
energyLevel1 = max(energy)+deltaEnergyLevel1; 
energyLevel2 = max(energy)+deltaEnergyLevel2; 
 
% ====== Compute zero crossing rate 
zcr = zcrate(framedY-0.03); 
 
% ====== Find initial end points according energy level2 (upper level) 
voicedIndex = find(energy>=energyLevel2); 
zcrThreshold = max(zcr)*zcrRatio; 
sound = []; 
k = 1; 
sound(k).begin = voicedIndex(1); 
for i=2:length(voicedIndex)-1, 
	if voicedIndex(i+1)-voicedIndex(i)>1, 
		sound(k).end = voicedIndex(i); 
		sound(k+1).begin = voicedIndex(i+1); 
		k = k+1; 
	end 
end 
sound(k).end = voicedIndex(end); 
 
% ====== Delete short sound clips 
index = []; 
for i=1:length(sound), 
	if (sound(i).end-sound(i).begin)<3 
		index = [index, i]; 
	end 
end 
%index 
%sound(i).end 
%sound(i).begin 
sound(index) = []; 
 
%minIndex = localmax(-energy);	% Find index of local minima 
% ====== Expand end points to energy level1 (lower level) 
for i=1:length(sound), 
	head = sound(i).begin; 
%	while (head-1)>=1 & energy(head-1)>energyLevel1 & ~minIndex(head-1), 
	while (head-1)>=1 & energy(head-1)>=energyLevel1, 
		head=head-1; 
	end 
	sound(i).begin = head; 
	tail = sound(i).end; 
%	while (tail+1)<=length(energy) & energy(tail+1)>energyLevel1 & ~minIndex(tail+1), 
	while (tail+1)<=length(energy) & energy(tail+1)>energyLevel1, 
		tail=tail+1; 
	end 
	sound(i).end = tail; 
end 
 
% ====== Expand end points to include high zcr region 
for i=1:length(sound), 
	head = sound(i).begin; 
	while (head-1)>=1 & zcr(head-1)>=zcrThreshold, 
		head=head-1; 
	end 
	sound(i).begin = head; 
end 
 
% ====== Delete repeated sound segments 
if length(sound) ~=0, 
	index = []; 
	for i=1:length(sound)-1, 
		if sound(i).begin==sound(i+1).begin & sound(i).end==sound(i+1).end, 
			index=[index, i]; 
		end 
	end 
	sound(index) = []; 
end; 
 
% ====== Transform sample-point-based index 
if length(sound) ~=0, 
	for i=1:length(sound), 
		out(i).begin = (sound(i).begin-1)*(frameSize-overlap)+1; 
		out(i).end   = (sound(i).end)*(frameSize-overlap)+overlap; 
	end 
else 
	out = []; 
end; 
 
if plotOpt 
	subplot(3,1,1); 
	plot((1:length(y))/fs, y); 
	axis([-inf inf -1 1]); 
	ylabel('Amplitude'); 
	title('Wave form'); 
 
	subplot(3,1,2); 
	plot(time, energy, '.-'); 
	line([min(time), max(time)], energyLevel1*[1 1], 'color', 'c'); 
	line([min(time), max(time)], energyLevel2*[1 1], 'color', 'c'); 
	axis tight 
	ylabel('Log energy (dB)'); 
	title('Log energy'); 
 
	subplot(3,1,3); 
	plot(time, zcr, '.-'); 
	line([min(time), max(time)], zcrThreshold*[1 1], 'color', 'c'); 
	axis([-inf inf 0 inf]); 
	ylabel('ZCR'); 
	title('Zero crossing rate'); 
 
	% Plot end points 
	subplot(3,1,1); 
	yBound = [-1 1]; 
	for i=1:length(sound), 
		line(sound(i).begin*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'r'); 
		line(  sound(i).end*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'g'); 
	end 
	% Plot end points 
	subplot(3,1,2); 
	yBound = [min(energy) max(energy)]; 
	for i=1:length(sound), 
		line(sound(i).begin*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'r'); 
		line(  sound(i).end*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'g'); 
	end 
	 
	% Plot end points 
	subplot(3,1,3); 
	yBound = [0 max(zcr)]; 
	for i=1:length(sound), 
		line(sound(i).begin*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'r'); 
		line(  sound(i).end*(frameSize-overlap)/fs*[1,1], yBound, 'color', 'g'); 
	end 
 
	% Play the segmented sound 
%	fprintf('%g sound clips are collected.\n', length(sound)); 
%	for i=1:length(sound), 
%		head = sound(i).begin*(frameSize-overlap); 
%		tail = min(length(y), sound(i).end*(frameSize-overlap)); 
%		thisY = y(head:tail); 
%		fprintf('His return to hear the cutted sound %g:', i); 
%		pause; 
%		fprintf('\n'); 
%		wavplay(thisY, fs, 'sync'); 
%	end 
%	fprintf('\n'); 
end 
 
% ====== Self demo 
function selfdemo 
epdParam.frameSize = 256; 
epdParam.overlap = 128; 
epdParam.deltaEnergyLevel1 = -20; 
epdParam.deltaEnergyLevel2 = -10; 
epdParam.zcrRatio = 0.1; 
fs = 8000; 
duration = 3; 
plotOpt = 1; 
%y = recsound('test.wav', duration, fs); 
wavefile='清華大學資訊系.wav'; 
[y, fs, nbits] = wavread(wavefile); 
%y=y*(2^nbits/2); 
out = feval(mfilename, y, fs, plotOpt, epdParam);