Daniel@0: function varargout = mirlowenergy(x,varargin)
Daniel@0: %   p = mirlowenergy(f) computes the percentage of frames showing a RMS 
Daniel@0: %       energy that is lower than a given threshold. 
Daniel@0: %   For instance, for a musical excerpt with some very loud frames and 
Daniel@0: %       lots of silent frames, we would get a high low-energy rate.
Daniel@0: %   Optional argument:
Daniel@0: %       mirlowenergy(...,'Threshold',t) expressed as a ratio to the average
Daniel@0: %           energy over the frames.
Daniel@0: %           Default value: t = 1
Daniel@0: %       mirlowenergy(...,'Frame',l,h) specifies the use of frames of
Daniel@0: %           length l seconds and a hop rate h.
Daniel@0: %           Default values: l = .05 s, h = .5
Daniel@0: %       mirlowenergy(...,'Root',0) uses mean square instead of root mean
Daniel@0: %           square
Daniel@0: %       mirlowenergy(...,'ASR') computes the Average Silence Ratio, which
Daniel@0: %           corresponds in fact to mirlowenergy(...,'Root',0,'Threshold',t)
Daniel@0: %           where t is fixed here by default to t = .5
Daniel@0: %   [p,e] = mirlowenergy(...) also returns the RMS energy curve.
Daniel@0:     
Daniel@0:         asr.key = 'ASR';
Daniel@0:         asr.type = 'Boolean';
Daniel@0:         asr.default = 0;
Daniel@0:     option.asr = asr;
Daniel@0:     
Daniel@0:         root.key = 'Root';
Daniel@0:         root.type = 'Boolean';
Daniel@0:         root.default = 1;
Daniel@0:     option.root = root;
Daniel@0:     
Daniel@0:         thr.key = 'Threshold';
Daniel@0:         thr.type = 'Integer';
Daniel@0:         thr.default = NaN;
Daniel@0:     option.thr = thr;
Daniel@0: 
Daniel@0:         frame.key = 'Frame';
Daniel@0:         frame.type = 'Integer';
Daniel@0:         frame.number = 2;
Daniel@0:         frame.default = [.05 .5];
Daniel@0:     option.frame = frame;
Daniel@0: 
Daniel@0: specif.option = option;
Daniel@0: 
Daniel@0: specif.combinechunk = {'Average',@nothing};
Daniel@0: specif.extensive = 1;
Daniel@0: 
Daniel@0: varargout = mirfunction(@mirlowenergy,x,varargin,nargout,specif,@init,@main);
Daniel@0: 
Daniel@0: 
Daniel@0: function [x type] = init(x,option)
Daniel@0: if option.asr
Daniel@0:     option.root = 0;
Daniel@0: end
Daniel@0: if isamir(x,'miraudio')
Daniel@0:     if isframed(x)
Daniel@0:         x = mirrms(x,'Root',option.root);
Daniel@0:     else
Daniel@0:         x = mirrms(x,'Frame',option.frame.length.val,option.frame.length.unit,...
Daniel@0:                              option.frame.hop.val,option.frame.hop.unit,...
Daniel@0:                              'Root',option.root);
Daniel@0:     end
Daniel@0: end
Daniel@0: type = 'mirscalar';
Daniel@0: 
Daniel@0: 
Daniel@0: function e = main(r,option,postoption)
Daniel@0: if iscell(r)
Daniel@0:     r = r{1};
Daniel@0: end
Daniel@0: if isnan(option.thr)
Daniel@0:     if option.asr
Daniel@0:         option.thr = .5;
Daniel@0:     else
Daniel@0:         option.thr = 1;
Daniel@0:     end
Daniel@0: end
Daniel@0: v = mircompute(@algo,get(r,'Data'),option.thr);
Daniel@0: fp = mircompute(@noframe,get(r,'FramePos'));
Daniel@0: e = mirscalar(r,'Data',v,'Title','Low energy','Unit','/1','FramePos',fp);
Daniel@0: e = {e,r};
Daniel@0: 
Daniel@0: 
Daniel@0: function v = algo(d,thr)
Daniel@0: v = sum(d < repmat(thr*mean(d,2),[1 size(d,2) 1]));
Daniel@0: v = v / size(d,2);
Daniel@0: 
Daniel@0: 
Daniel@0: function fp = noframe(fp)
Daniel@0: fp = [fp(1);fp(end)];
Daniel@0: 
Daniel@0: 
Daniel@0: function y = nothing(old,new)
Daniel@0: y = old;