diff toolboxes/MIRtoolbox1.3.2/MIRToolbox/@mircepstrum/mircepstrum.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/MIRtoolbox1.3.2/MIRToolbox/@mircepstrum/mircepstrum.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,149 @@
+function varargout = mircepstrum(orig,varargin)
+%   s = mircepstrum(x) computes the cepstrum, which indicates
+%       periodicities, and is used for instance for pitch detection.
+%   x can be either a spectrum, an audio signal, or the name of an audio file.
+%   Optional parameter:
+%       mircepstrum(...,'Min',min) specifies the lowest delay taken into
+%           consideration, in seconds.
+%           Default value: 0.0002 s (corresponding to a maximum frequency of 
+%               5 kHz).
+%       mircepstrum(...,'Max',max) specifies the highest delay taken into
+%           consideration, in seconds.
+%           Default value: 0.05 s (corresponding to a minimum frequency of 
+%               20 Hz).
+%       mircepstrum(...,'Freq') represents the cepstrum in the frequency 
+%           domain.
+
+        mi.key = 'Min';
+        mi.type = 'Integer';
+        mi.default = 0.0002;
+        mi.unit = {'s','Hz'};
+        mi.defaultunit = 's';
+        mi.opposite = 'ma';
+    option.mi = mi;
+
+        ma.key = 'Max';
+        ma.type = 'Integer';
+        ma.default = .05;
+        ma.unit = {'s','Hz'};
+        ma.defaultunit = 's';
+        ma.opposite = 'mi';
+    option.ma = ma;
+        
+        fr.key = 'Freq';
+        fr.type = 'Boolean';
+        fr.default = 0;
+    option.fr = fr;
+
+        complex.key = 'Complex';
+        complex.type = 'Boolean';
+        complex.default = 0;
+    option.complex = complex;
+
+specif.option = option;
+
+specif.defaultframelength = 0.05;
+specif.defaultframehop = 0.5;
+
+varargout = mirfunction(@mircepstrum,orig,varargin,nargout,specif,@init,@main);
+
+
+function [x type] = init(x,option)
+if not(isamir(x,'mircepstrum'))
+    x = mirspectrum(x);
+end
+type = 'mircepstrum';
+
+
+function c = main(orig,option,postoption)
+if iscell(orig)
+    orig = orig{1};
+end
+c.phase = [];
+if isa(orig,'mircepstrum')
+    c.freq = orig.freq;
+else
+    c.freq = 0;
+end
+c = class(c,'mircepstrum',mirdata(orig));
+c = purgedata(c);
+c = set(c,'Title','Cepstrum','Abs','quefrency (s)','Ord','magnitude');
+
+if isa(orig,'mircepstrum')
+    if option.ma < Inf || option.mi > 0 || get(orig,'FreqDomain')
+        mag = get(orig,'Magnitude');
+        pha = get(orig,'Phase');
+        que = get(orig,'Quefrency');
+        for h = 1:length(mag)
+            for k = 1:length(mag{h})
+                if get(orig,'FreqDomain')
+                    mag{h}{k} = flipud(mag{h}{k});
+                    que{h}{k} = flipud(1./que{h}{k});
+                    pha{h}{k} = flipud(pha{h}{k});
+                end
+                range = find(que{h}{k}(:,1,1) <= option.ma & ...
+                             que{h}{k}(:,1,1) >= option.mi);
+                mag{h}{k} = mag{h}{k}(range,:,:);
+                pha{h}{k} = pha{h}{k}(range,:,:);
+                que{h}{k} = que{h}{k}(range,:,:);
+            end
+        end
+        c = set(c,'Magnitude',mag,'Phase',pha,'Quefrency',que,'FreqDomain',0);
+    end
+    c = modif(c,option);
+elseif isa(orig,'mirspectrum')
+    mag = get(orig,'Magnitude');
+    pha = get(orig,'Phase');
+    f = get(orig,'Sampling');
+    q = cell(1,length(mag));
+    for h = 1:length(mag)
+        len = ceil(option.ma*f{h});
+        start = ceil(option.mi*f{h})+1;
+        q{h} = cell(1,length(mag{h}));
+        for k = 1:length(mag{h})
+            m = mag{h}{k}.*exp(1i*pha{h}{k});
+            m = [m(1:end-1,:) ; conj(flipud(m))];  % Reconstitution of the complete abs(FFT)
+            if not(option.complex)
+                m = abs(m);
+            end
+            m = log(m);
+            c0=fft(m);
+            q0=repmat((0:(size(c0,1)-1))'/f{k},[1,size(m,2),size(m,3)]);
+            len = min(len,floor(size(c0,1)/2));
+            mag{h}{k} = abs(c0(start:len,:,:));
+            if option.complex
+                pha{h}{k} = unwrap(angle(c0(start:len,:,:)));    
+            else
+                pha{h}{k} = nan(size(c0(start:len,:,:)));
+            end
+            q{h}{k} = q0(start:len,:,:);
+        end
+    end
+    c = set(c,'Magnitude',mag,'Phase',pha,'Quefrency',q);
+    c = modif(c,option);
+end
+
+
+function c = modif(c,option)
+mag = get(c,'Magnitude');
+que = get(c,'Quefrency');
+if option.fr && not(get(c,'FreqDomain'))
+    for k = 1:length(mag)
+        for l = 1:length(mag{k})
+            m = mag{k}{l};
+            q = que{k}{l};
+            if not(isempty(m))
+                if q(1,1) == 0
+                    m = m(2:end,:,:);
+                    q = q(2:end,:,:);
+                end
+                m = flipud(m);
+                q = flipud(1./q);
+            end
+            mag{k}{l} = m;
+            que{k}{l} = q;
+        end
+    end
+    c = set(c,'FreqDomain',1,'Abs','frequency (Hz)');
+end
+c = set(c,'Magnitude',mag,'Quefrency',que,'Freq');
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