%dtmfrun.m

function keys = dtmfrun(xx,L,fs)
%DTMFRUN keys = dtmfrun(xx,L,fs)
% returns the list of key names found in xx.
% keys = array of characters, i.e., the decoded key names
% xx = DTMF waveform
% L = filter length
% fs = sampling freq
%
dtmf.keys = ...
['1','2','3','A';
'4','5','6','B';
'7','8','9','C';
'*','0','#','D'];
dtmf.colTones = ones(4,1)*[1209,1336,1477,1633]; % defines col matrix
dtmf.rowTones = [697;770;852;941]*ones(1,4); % defines row matrix
center_freqs = [dtmf.rowTones(:,1)' , dtmf.colTones(1,:)]; 
% defines 1X8 vector of freqs
hh = dtmfdesign( center_freqs,L,fs ); % calls dtmfdesign to form matrix of filters
% hh = L by 8 MATRIX of all the filters. Each column contains the
% impulse response of one BPF (bandpass filter)
%
[nstart,nstop] = dtmfcut(xx,fs); %<--Find the tone bursts
keys = []; %initializes keys
ansset=[]; %initializes ansset
for kk=1:length(nstart) %cycle through each tone
    ansset = []; %clears ansset from previous itterations
    x_seg = xx(nstart(kk):nstop(kk)); %<--Extract one DTMF tone

    for jj=1:length(center_freqs) %cycle through each filter
        ansset = [ansset, dtmfscore(x_seg,hh(:,jj))];
        %creates a vector of ones and zeros repersenting where 
        %the frequency components lie.
    end
    aa = find(ansset==1); %creates a vector of indicies where ones occur
    if length(aa) ~= 2 | aa(1) > 4 | aa(2) < 5
        %cheks for impossible scores and skips if they are found
        keys = [keys,'e'];
        continue
    end
    row = aa(1); % decodes row position from aa
    col = aa(2)-4; %decodes col position from aa
    keys = [keys, dtmf.keys(row,col)]; %sets keys equal to the current keys
                                       %and the key found in this itteration.
                                   end