function [fea, pitch, segment]=trFeaExtract(au, trOpt, showPlot)
% trFeaExtract: Feature extraction for tone recognition
%
%	Usage:
%		[fea, segment]=trFeaExtract(au, trOpt, showPlot)
%
%	Description:
%		fea=trFeaExtract(au, trOpt, showPlot) returns the feature used for tone recognition.
%		[fea, pitch, segment]=trFeaExtract(au, trOpt, showPlot) also returns the segment after EPD.
%
%	Example:
%		auFile='wo3.wav';
%		trOpt=trOptSet;
%		[fea, pitch, segment]=trFeaExtract(auFile, trOpt, 1);
%
%	See also trOptSet.

%	Category: tone recognition
%	Roger Jang, 20171005

if nargin<1, selfdemo; return; end
% ====== Set the default options
if nargin<2 && ischar(au) && strcmpi(au, 'defaultOpt')
	fea=trOptSet;
	return
end
if nargin<2||isempty(au), trOpt=feval(mfilename, 'defaultOpt'); end
if nargin<3, showPlot=0; end

if isstr(au), au=myAudioRead(au); end
%% EPD
[epInSampleIndex, epInFrameIndex, segment]=epdByVol(au, trOpt.epdOpt, showPlot);
au.signal=au.signal(epInSampleIndex(1):epInSampleIndex(2));
%% PT
if showPlot, figure; end
pitch=pitchTrackForcedSmooth(au, trOpt.ptOpt, showPlot);
%% Polynomial fitting
pitchNorm=pitch-mean(pitch);
%coef=polyfit(x, pitchNorm, trOpt.feaOpt.polyOrder);			% Common polynomial fitting
coef=polyFitChebyshev(pitchNorm, trOpt.feaOpt.polyOrder);	% Chebysheve polynomial fitting. Why pitchNorm does not give better performance?

fea=coef;

if showPlot
%	figure; plot(1:length(pitch), pitchNorm, 'marker', '.'); grid on
%	xlabel('Pitch index');
%	ylabel('Semitone');
end

% ====== Self demo
function selfdemo
mObj=mFileParse(which(mfilename));
strEval(mObj.example);