www.pudn.com > audioProcessingtoolbox.rar > frame2pitch.m

function [pitch, frame2, frame3, amdf]=frame2pitch(frame, plotOpt, PP, mainWindow, correctPitch); 
%frame2pitch: Frame to pitch conversion (模擬SPCE061A，所以盡量模擬整數運算) 
%	Usage: pitch=frame2pitch(frame, plotOpt, PP);  
%		frame: Each element is unsigned integer between 0 and 255 (inclusive). 
%		plotOpt: 1 for plotting, 0 for not plotting 
%		pitch: Output pitch in semitone 
 
%	Roger Jang, 20021201 
 
if nargin<1, selfdemo; return; end 
if nargin<2, plotOpt=0; end 
if nargin<3, [PP, CP]=setParam; end 
if nargin<4, mainWindow=0; end 
if nargin<5, correctPitch=0; end 
 
%saveAscii(frame, 'text/frame.txt') 
 
PP.maxFreq=pitch2freq(PP.maxPitch); 
PP.minFreq=pitch2freq(PP.minPitch); 
fs=PP.fs; 
maxShift=PP.maxShift; 
frameSize=length(frame); 
 
% 如果音量太小，則直接回傳 0 
%if sum(abs(frame-128)) < 9*256, 
%	pitch = 0; 
%	return; 
%end 
 
% 求 frame 的平均值為 
average=intDiv(sum(frame), frameSize); 
frame=frame-average; 
 
% frame2: 如果前半音框音量小於後半音框，進行鏡射 
frame2=frameFlip(frame, plotOpt); 
 
% frame3: 平滑化 
frame3=localAverage(frame2);	% Low-pass filter implemented as local average 
 
% ====== 計算 AMDF 曲線 
amdf=frame2smdf(frame3, maxShift, 3); 
 
% ====== 找出 ROI 
beginIndex=ceil(PP.fs/PP.maxFreq); 
endIndex=min(floor(PP.fs/PP.minFreq), PP.maxShift); 
% Move beginIndex forward until amdf is going down 
for i=beginIndex:endIndex-1, 
	if amdf(i)>amdf(i+1), 
		break; 
	end 
end 
beginIndex=i+1; 
if beginIndex==endIndex 
%	fprintf('beginIndex==endIndex ==> pitch = 0！\n'); 
	pitch=0; 
	plotFrame(plotOpt, frame, frame3, amdf, [], [], beginIndex, endIndex, mainWindow, correctPitch, PP.maxShift); 
	return; 
end 
 
% ====== 找出 ROI 的 local minima 
localMinIndex=[]; 
for i=beginIndex+1:endIndex-1 
	if amdf(i-1)>amdf(i) & amdf(i)<=amdf(i+1) 
		localMinIndex=[localMinIndex, i];	 
	end 
end 
 
n=20; 
if length(localMinIndex)>=n,	% 應該是氣音（但對女聲會誤判） 
	pitch=0; 
	if plotOpt, fprintf('Local minima 超過 %d 個 ==> pitch = 0！\n', n); end 
	plotFrame(plotOpt, frame, frame3, amdf, localMinIndex, [], beginIndex, endIndex, mainWindow, correctPitch, PP.maxShift); 
	return 
end 
 
% ====== 找最小值 in ROI 
roi=amdf(beginIndex:endIndex);	% region of interest 
[minValue, minIndex]=min(roi); 
minIndex=minIndex+beginIndex-1; 
 
% ===== 從 minIndex 往回找可能出現的 2, 3, 4, 5, 6 倍頻 
[maxValue, maxIndex]=max(roi); 
difthreshold=minValue+floor((maxValue-minValue)/8); 
for i=1:length(localMinIndex) 
	if amdf(localMinIndex(i)) <= difthreshold 
		if abs(floor((minIndex-1+3)/6)-(localMinIndex(i)-1)) <= floor(6/6) 
			if plotOpt, fprintf('代換成 6 倍頻！\n'); end 
			minIndex=localMinIndex(i); 
			break; 
		elseif abs(floor((2*minIndex-1+5)/10)-(localMinIndex(i)-1)) <= floor(6/5) 
			if plotOpt, fprintf('代換成 5 倍頻！\n'); end 
			minIndex=localMinIndex(i); 
			break; 
		elseif abs(floor((minIndex-1+2)/4)-(localMinIndex(i)-1)) <= floor(6/4) 
			if plotOpt, fprintf('代換成 4 倍頻！\n'); end 
			minIndex=localMinIndex(i); 
			break; 
		elseif abs(floor((2*minIndex-1+3)/6)-(localMinIndex(i)-1)) <= floor(6/3) 
			if plotOpt, fprintf('代換成 3 倍頻！\n'); end 
			minIndex=localMinIndex(i); 
			break; 
		elseif abs(floor((minIndex-1+1)/2)-(localMinIndex(i)-1)) <= floor(6/2) 
			if plotOpt, fprintf('代換成 2 倍頻！\n'); end 
			minIndex=localMinIndex(i); 
			break; 
		end 
	end 
end 
 
 
%freq=floor((10*PP.fs+floor((minIndex-1)/2))/(minIndex-1));	% 取第一個 minimum 來計算基頻（會爆掉！） 
freq=10*floor((PP.fs+floor((minIndex-1)/2))/(minIndex-1));	% 取第一個 minimum 來計算基頻 
%fprintf('minIndex=%d\n', minIndex); 
%fprintf('freq=%d\n', freq); 
pitch=freq2pitch(freq); 
% ====== Plot all related information 
plotFrame(plotOpt, frame, frame3, amdf, localMinIndex, minIndex, beginIndex, endIndex, mainWindow, correctPitch, PP.maxShift); 
 
% ====== Plot related information 
function plotFrame(plotOpt, frame, frame3, amdf, localMinIndex, minIndex, beginIndex, endIndex, mainWindow, correctPitch, maxShift) 
if plotOpt, 
	frameSize=length(frame); 
	subplot(2,1,1); 
%	plot(1:length(frame), frame, '.-', 1:length(frame3), frame3, '.-'); grid on 
	frameH=plot(1:length(frame), frame, '.-'); grid on 
	set(frameH, 'tag', 'frame'); 
	title(['Frame (frameSize=', int2str(frameSize), ')']); 
	set(gca, 'xlim', [1 frameSize]); 
	subplot(2,1,2); 
	amdfH=plot(amdf, '.-'); grid on 
	set(amdfH, 'tag', 'amdf'); 
	amdfAxisH=gca; 
	set(gca, 'tag', 'amdfAxis'); 
	title(['amdf (maxShift=', int2str(maxShift), ')']); 
	set(gca, 'xlim', [1 maxShift]); 
	if ~isempty(localMinIndex) 
		localMinIndexH=line(localMinIndex, amdf(localMinIndex), 'linestyle', 'none', 'color', 'k', 'marker', 'o', 'tag', 'localMinIndexH'); 
	end 
	if ~isempty(minIndex) 
		minIndexH=line(minIndex, amdf(minIndex), 'linestyle', 'none', 'color', 'r', 'marker', 'o', 'tag', 'minIndexH'); 
		if correctPitch==0 
			minIndex=nan; 
		else 
			minIndex=round(1+8000/(440*2^((correctPitch/10-69)/12))); 
		end 
		manualBarH=line(minIndex*[1 1], get(amdfAxisH, 'ylim'), 'color', 'm', 'erase', 'xor', 'tag', 'manualBar'); 
	end 
	line(beginIndex*[1 1], get(gca, 'ylim'), 'color', 'r'); 
	line(  endIndex*[1 1], get(gca, 'ylim'), 'color', 'r'); 
	set(gcf, 'name', mfilename); 
	 
	% 設定滑鼠按鈕的反應動作，以便讓使用者修正 pitch 
	if mainWindow>0; 
		set(gcf, 'userdata', mainWindow); 
		frameWinMouseAction; 
	end 
end 
 
 
% ====== selfdemo 
function selfdemo 
waveFile='兩隻老虎.wav'; 
[y, PP.fs, nbits]=wavread(waveFile); 
y=y*(2^nbits/2); 
 
frameSize=256; 
overlap=-256; 
framedY=buffer2(y, frameSize, overlap); 
frame=framedY(:, 100); 
plotOpt=1; 
feval(mfilename, frame,  plotOpt);