[CLAM] ClamExtractorExample LowFreqEnergyRelation

vincenzo.dimattia vincenzo.dimattia at libero.it
Tue Feb 26 03:05:56 PST 2008


Yes, I opted for xml navigation instead of xpath, but I'm interested also in your matlab/java code in order to improve the communication between clam and matlab.
Thanks
Vincenzo







---------- Initial Header -----------

>From      : "David García Garzón" dgarcia at iua.upf.edu
To          : "vincenzo.dimattia" vincenzo.dimattia at libero.it
Cc          : "clam" clam at iua.upf.edu
Date      : Tue, 26 Feb 2008 02:37:50 +0100
Subject : Re: [CLAM] ClamExtractorExample LowFreqEnergyRelation







> A student at UPF also needed to use MFCC from the ClamExampleExtractor 
> descriptors in matlab and we tried the xml toolbox you mention with no luck 
> (we were blocked by a missimplementation of XPath standard). Maybe we missed 
> something or maybe you opted by xml navigation instead of xpath. We finally 
> used a small  Java snippet to get them with XPath and convert it into a 
> proper matlab matrix.
> 
> I planned to eventually post such matlab/java code on the wiki. Almost sure 
> you have that part covered but as you could be still interested I'll hurry 
> and ask her the code.
> 
> David.
> 
> 
> On Monday 25 Febrer 2008, vincenzo.dimattia wrote:
> > Dear David thanks a lot for your help. My final project consists on an
> > automatic audio segmentation system which I have implemented in matlab
> > modifying the Alexander Haubold’s Matlab resources
> > [http://www.aquaphoenix.com/research/matlab/]. The modified program
> > requires as input the audio file (wav) and the CLAM XML file. In order to
> > interface Matlab with CLAM I used an XML parser which is able to extract
> > the values of the MFCC descriptor from the CLAM XML file. In particular I
> > used XMLTree an XML toolbox for Matlab
> > [http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=1
> >757&objectType=file]. Thanks again
> > Best regards
> > Vincenzo
> >
> > ---------- Initial Header -----------
> >
> > From      : "David García Garzón" dgarcia at iua.upf.edu
> >
> > To          : clam at iua.upf.edu
> > Cc          : "vincenzo.dimattia" vincenzo.dimattia at libero.it,"clam"
> > clam at iua.upf.edu Date      : Mon, 25 Feb 2008 15:16:41 +0100
> > Subject : Re: [CLAM] ClamExtractorExample LowFreqEnergyRelation
> >
> > > On Monday 25 February 2008 12:25:24 vincenzo.dimattia wrote:
> > > > Dear all,I am Vincenzo Dimattia, I am developing my final project, an
> > > > automatic segmentation system,and I am using the programm
> > > > ClamExtractorExample for the extraction of the audio descriptors . I
> > > > would like to know how is calculated the LowFreqEnergyRelation.This
> > > > should be higher for low frequency signal and lower for high frequncy
> > > > signal. Is it right? Thanks
> > > > Vincenzo Dimattia
> > >
> > > Hi, Vincenzo.
> > >
> > > There was an error on doxygen description. LowFreqEnergyRelation had the
> > > description of MaxMagFreq. I just fixed it on the svn. The description
> > > for LowFreqEnergyRelation is now this one:
> > >
> > > "Ratio between the energy over 0-100 Hz band and the whole spectrum
> > > energy. To avoid singularities while keeping descriptor continuity, when
> > > the whole spectrum energy drops bellow $10^{-4}$, such value is
> > > considered as whole spectrum energy."
> > >
> > > So you are right with your interpretation. But keep in mind that 0-100 Hz
> > > is a very narrow band and it is used to spot bass sounds. If you are
> > > interested in locating high frequencies, HighEnergyContent is more
> > > appropiated. It is defined as:
> > >
> > > "Sum of the squared spectrum magnitude multiplied by the wave number of
> > > the bin. It is pretty similar to the derivative of the energy, or a high
> > > pass filter, which gives higher values for high frequency content."
> > >
> > > We would be glad if you report back to the mailinglist your progress with
> > > your final project :-) And, please, consider also integration of your
> > > work into CLAM code base. Integration into a big existing project is
> > > often appreciated by evaluators. Just drop us a line if you want to.
> > >
> > > David.
> 
> 
> 
> -- 
> David García Garzón
> (Work) dgarcia at iua dot upf anotherdot es
> http://www.iua.upf.edu/~dgarcia
> 





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