comparison util/SMALL_swipe.m @ 8:33850553b702

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+function [p,s] = SMALL_swipe(X,fs, f, plim,dlog2p,dERBs,woverlap,sTHR)
+% 
+% Ivan Damnjanovic 2010
+%
+% This is modified swipep MATLAB code that is working directly in spectral
+% domain and uses only one window size. The results are suboptimal
+% comparing to original code. It is also converted to SWIPE which uses all
+% the harmonics of the signal. 
+%
+%SWIPEP Pitch estimation using SWIPE'.
+%    P = SWIPEP(X,Fs,[PMIN PMAX],DT,DLOG2P,DERBS,STHR) estimates the pitch 
+%    of the vector signal X every DT seconds. The sampling frequency of
+%    the signal is Fs (in Hertz). The spectrum is computed using a Hann
+%    window with an overlap WOVERLAP between 0 and 1. The spectrum is
+%    sampled uniformly in the ERB scale with a step size of DERBS ERBs. The
+%    pitch is searched within the range [PMIN PMAX] (in Hertz) with samples
+%    distributed every DLOG2P units on a base-2 logarithmic scale of Hertz. 
+%    The pitch is fine-tuned using parabolic interpolation with a resolution
+%    of 1 cent. Pitch estimates with a strength lower than STHR are treated
+%    as undefined.
+%    
+%    [P,T,S] = SWIPEP(X,Fs,[PMIN PMAX],DT,DLOG2P,DERBS,WOVERLAP,STHR) 
+%    returns the times T at which the pitch was estimated and the pitch 
+%    strength S of every pitch estimate.
+%
+%    P = SWIPEP(X,Fs) estimates the pitch using the default settings PMIN =
+%    30 Hz, PMAX = 5000 Hz, DT = 0.001 s, DLOG2P = 1/48 (48 steps per 
+%    octave), DERBS = 0.1 ERBs, WOVERLAP = 0.5, and STHR = -Inf.
+%
+%    P = SWIPEP(X,Fs,...,[],...) uses the default setting for the parameter
+%    replaced with the placeholder [].
+%
+%    REMARKS: (1) For better results, make DLOG2P and DERBS as small as 
+%    possible and WOVERLAP as large as possible. However, take into account
+%    that the computational complexity of the algorithm is inversely 
+%    proportional to DLOG2P, DERBS and 1-WOVERLAP, and that the  default 
+%    values have been found empirically to produce good results. Consider 
+%    also that the computational complexity is directly proportional to the
+%    number of octaves in the pitch search range, and therefore , it is 
+%    recommendable to restrict the search range to the expected range of
+%    pitch, if any. (2) This code implements SWIPE', which uses only the
+%    first and prime harmonics of the signal. To convert it into SWIPE,
+%    which uses all the harmonics of the signal, replace the word
+%    PRIMES with a colon (it is located almost at the end of the code).
+%    However, this may not be recommendable since SWIPE' is reported to 
+%    produce on average better results than SWIPE (Camacho and Harris,
+%    2008).
+%
+%    EXAMPLE: Estimate the pitch of the signal X every 10 ms within the
+%    range 75-500 Hz using the default resolution (i.e., 48 steps per
+%    octave), sampling the spectrum every 1/20th of ERB, using a window 
+%    overlap factor of 50%, and discarding samples with pitch strength 
+%    lower than 0.2. Plot the pitch trace.
+%       [x,Fs] = wavread(filename);
+%       [p,t,s] = swipep(x,Fs,[75 500],0.01,[],1/20,0.5,0.2);
+%       plot(1000*t,p)
+%       xlabel('Time (ms)')
+%       ylabel('Pitch (Hz)')
+%
+%    REFERENCES: Camacho, A., Harris, J.G, (2008) "A sawtooth waveform 
+%    inspired pitch estimator for speech and music," J. Acoust. Soc. Am.
+%    124, 1638-1652.
+if ~ exist( 'plim', 'var' ) || isempty(plim), plim = [30 5000]; end
+%if ~ exist( 'dt', 'var' ) || isempty(dt), dt = 0.001; end
+if ~ exist( 'dlog2p', 'var' ) || isempty(dlog2p), dlog2p = 1/48; end
+if ~ exist( 'dERBs', 'var' ) || isempty(dERBs), dERBs = 0.05; end
+% if ~ exist( 'woverlap', 'var' ) || isempty(woverlap)
+%     woverlap = 0.5;
+% elseif woverlap>1 || woverlap<0
+%     error('Window overlap must be between 0 and 1.')
+% end
+if ~ exist( 'sTHR', 'var' ) || isempty(sTHR), sTHR = -Inf; end
+%t = [ 0: dt: length(x)/fs ]'; % Times
+% Define pitch candidates
+log2pc = [ log2(plim(1)): dlog2p: log2(plim(2)) ]';
+pc = 2 .^ log2pc;
+S = zeros( length(pc), 1 ); % Pitch strength matrix
+% Determine P2-WSs
+%logWs = round( log2( 8*fs ./ plim ) ); 
+ws = [2822];%2.^[ logWs(1): -1: logWs(2) ]; % P2-WSs
+pO = 8 * fs ./ ws; % Optimal pitches for P2-WSs
+% Determine window sizes used by each pitch candidate
+d = 1 + log2pc - log2( 8*fs./ws(1) );
+% Create ERB-scale uniformly-spaced frequencies (in Hertz)
+fERBs = erbs2hz([ hz2erbs(min(pc)/4): dERBs: hz2erbs(fs/2) ]');
+for i = 1 : length(ws)
+    %dn = max( 1, round( 8*(1-woverlap) * fs / pO(i) ) ); % Hop size
+    % Zero pad signal
+    %xzp = [ zeros( ws(i)/2, 1 ); x(:); zeros( dn + ws(i)/2, 1 ) ];
+    % Compute spectrum
+    %w = hanning( ws(i) ); % Hann window 
+    %o = max( 0, round( ws(i) - dn ) ); % Window overlap
+    %[ X, f, ti ] = specgram( xzp, ws(i), fs, w, o );
+    % Select candidates that use this window size
+    if length(ws) == 1
+        j=[1:size(pc)]'; k = [];
+    elseif i == length(ws)
+        j=find(d-i>-1); k=find(d(j)-i<0);
+    elseif i==1
+        j=find(d-i<1); k=find(d(j)-i>0);
+    else
+        j=find(abs(d-i)<1); k=1:length(j);
+    end
+    % Compute loudness at ERBs uniformly-spaced frequencies
+    fERBs = fERBs( find( fERBs > pc(1)/4, 1, 'first' ) : end );
+    L = sqrt( max( 0, interp1( f, X, fERBs, 'spline', 0) ) );
+    % Compute pitch strength
+    Si = pitchStrengthAllCandidates( fERBs, L, pc );
+    % Interpolate pitch strength at desired times
+%     if size(Si,2) > 1
+%         warning off MATLAB:interp1:NaNinY
+%         Si = interp1( ti, Si', t, 'linear', NaN )';
+%         warning on MATLAB:interp1:NaNinY
+%     else
+%         Si = repmat( NaN, length(Si),1 );
+%     end
+    % Add pitch strength to combination
+%     lambda = d( j(k) ) - i;
+    mu = ones( size(j) );
+%     mu(k) = 1 - abs( lambda );
+    S(j,:) = S(j,:) + repmat(mu,1,size(Si,2)) .* Si;
+end
+% Fine tune pitch using parabolic interpolation
+p = repmat( NaN, size(S,2), 1 );
+s = repmat( NaN, size(S,2), 1 );
+for j = 1 : size(S,2)
+    [ s(j), i ] = max( S(:,j), [], 1 );
+    if s(j) < sTHR, continue, end
+    if i == 1 || i == length(pc)
+        p(j) = pc(i);
+    else
+        I = i-1 : i+1;
+        tc = 1 ./ pc(I);
+        ntc = ( tc/tc(2) - 1 ) * 2*pi;
+        c = polyfit( ntc, S(I,j), 2 );
+        ftc = 1 ./ 2.^[ log2(pc(I(1))): 1/12/100: log2(pc(I(3))) ];
+        nftc = ( ftc/tc(2) - 1 ) * 2*pi;
+        [s(j) k] = max( polyval( c, nftc ) );
+        p(j) = 2 ^ ( log2(pc(I(1))) + (k-1)/12/100 );
+%         if (p(j)-pc(I(1)))<0.75*abs(p(j)-pc(I(2)))
+%             p(j)=pc(I(1));
+%         elseif (pc(I(3))-p(j))<0.75*abs(p(j)-pc(I(2)))
+%             p(j)=pc(I(3));
+%         else
+            p(j)=pc(I(2));
+%         end
+    end
+end
+
+function S = pitchStrengthAllCandidates( f, L, pc )
+% Create pitch strength matrix
+S = zeros( length(pc), size(L,2) );
+% Define integration regions
+k = ones( 1, length(pc)+1 );
+for j = 1 : length(k)-1
+    k(j+1) = k(j) - 1 + find( f(k(j):end) > pc(j)/4, 1, 'first' );
+end
+k = k(2:end);
+% Create loudness normalization matrix
+N = sqrt( flipud( cumsum( flipud(L.*L) ) ) );
+for j = 1 : length(pc)
+    % Normalize loudness
+    warning off MATLAB:divideByZero
+    NL = L(k(j):end,:) ./ repmat( N(k(j),:), size(L,1)-k(j)+1, 1);
+    warning on MATLAB:divideByZero
+    % Compute pitch strength
+
+    S(j,:) = pitchStrengthOneCandidate( f(k(j):end), NL, pc(j) );
+end
+
+function S = pitchStrengthOneCandidate( f, NL, pc )
+n = fix( f(end)/pc - 0.75 ); % Number of harmonics
+if n==0, S=NaN; return, end
+k = zeros( size(f) ); % Kernel
+% Normalize frequency w.r.t. candidate
+q = f / pc;
+% Create kernel
+for i = [ 1:n] % primes(n) ]
+    a = abs( q - i );
+    % Peak's weigth
+    p = a < .25; 
+    k(p) = cos( 2*pi * q(p) );
+    % Valleys' weights
+    v = .25 < a & a < .75;
+    k(v) = k(v) + cos( 2*pi * q(v) ) / 2;
+end
+% Apply envelope
+k = k .* sqrt( 1./f  ); 
+% K+-normalize kernel
+k = k / norm( k(k>0) ); 
+% Compute pitch strength
+S = k' * NL; 
+
+function erbs = hz2erbs(hz)
+erbs = 21.4 * log10( 1 + hz/229 );
+
+function hz = erbs2hz(erbs)
+hz = ( 10 .^ (erbs./21.4) - 1 ) * 229;