语音合成与识别

开发平台：
Matlab

endpoint_bb.m：源码内容
							function out = endpoint(y, fs, plotOpt, epdParam)
% ENDPOINT End point detection
if nargin==0, selfdemo; return; end
if nargin<4,
	epdParam.frameSize = 256;
	epdParam.overlap = 86;
	epdParam.deltaEnergyLevel1 = -28;
	epdParam.deltaEnergyLevel2 = -14;
	epdParam.zcrRatio = 0.5;
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 = buffer(y, frameSize, overlap);
frameNum = size(framedY, 2);	% Number of frames
% ====== Compute log energy
energy = 10*log10(mean(framedY.^2));
time = (1:frameNum)*(frameSize-overlap)/fs;
energyLevel1 = max(energy)+deltaEnergyLevel1;
energyLevel2 = max(energy)+deltaEnergyLevel2;
% ====== Compute zero crossing rate
zcr = zcrate(framedY);
% ====== Find initial end points according energy level2 (upper level)
voicedIndex = find(energy>=energyLevel2);
zcrRatio = 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)<5
		index = [index, i];
	end
end
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)>zcrRatio,
		head=head-1;
	end
	sound(i).begin = head;
end
% ====== Delete repeated sound segments
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) = [];
% ====== Transform sample-point-based index
for i=1:length(sound),
	out(i).begin = sound(i).begin*(frameSize-overlap);
	out(i).end   = min(length(y), sound(i).end*(frameSize-overlap));
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)], zcrRatio*[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 = 86;
epdParam.deltaEnergyLevel1 = -28;
epdParam.deltaEnergyLevel2 = -14;
epdParam.zcrRatio = 0.5;
fs = 8000;
duration = 3;
plotOpt = 1;
y = recsound('test.wav', duration, fs);
out = feval(mfilename, y, fs, plotOpt, epdParam);

						