<package name="libxtract" project="Multimedia">

  <title>A simple, portable, lightweight library of audio feature extraction functions</title>

  <description>LibXtract is a simple, portable, lightweight library of audio feature

extraction functions. The purpose of the library is to provide a

relatively exhaustive set of feature extraction primatives that are

designed to be 'cascaded' to create a extraction hierarchies.

​

For example, 'variance', 'average deviation', 'skewness' and

'kurtosis', all require the 'mean' of the input vector to be

precomputed. However, rather than compute the 'mean' 'inside' each

function, it is expected that the 'mean' will be passed in as an

argument. This means that if the user wishes to use all of these

features, the mean is calculated only once, and then passed to any

functions that require it.

​

This philosophy of 'cascading' features is followed throughout the

library, for example with features that operate on the magnitude

spectrum of a signal vector (e.g. 'irregularity'), the magnitude

spectrum is not calculated 'inside' the respective function, instead,

a pointer to the first element in an array containing the magnitude

spectrum is passed in as an argument.

​

Hopefully this not only makes the library more efficient when

computing large numbers of features, but also makes it more flexible

because extraction functions can be combined arbitrarily (one can

take the irregularility of the Mel Frequency Cepstral Coefficients

for example).

​

Author: Jamie Bullock <jamie@postlude.co.uk>

​

</description>

  <person userid="detrei" role="bugowner"/>

  <person userid="detrei" role="maintainer"/>

  <url>http://libxtract.sourceforge.net/</url>

</package>

​