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added rdfpy and rdfonto directories
author nothing@tehis.net
date Tue, 23 Apr 2013 11:49:20 +0100
parents 62d2c72e4223
children
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<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:local="http://sovarr.c4dm.eecs.qmul.ac.uk/features/"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>
  <rdf:Description rdf:about="BeatTrack">
    <dc:description>Autocorrelation based beat tracker</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="BeatTrack2">
    <dc:description>based on exhaustively testing particular template patterns against feature streams</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="Chromagram">
    <dc:description>measures the energy at particular chroma within an nTET tuning system</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralFlatness">
    <dc:description>a power spectrum's geometric mean divided by its arithmetic mean</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralPercentile">
    <dc:description>calculates the cumulative distribution of the frequency spectrum, and outputs the frequency value which corresponds to the desired percentile</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralCentroid">
    <dc:description>the weighted mean frequency, or the "centre of mass" of the spectrum</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="ZeroCrossingRate">
    <dc:description>Outputs a frequency based upon the distance between interceptions of the X axis. The X intercepts are determined via linear interpolation so this gives better than just integer wavelength resolution. This is a very crude pitch follower, but can be useful in some situations.</dc:description>	  
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="MFCC">
    <dc:description>Generates a set of MFCCs; these are obtained from a band-based frequency representation (using the Mel scale by default), and then a discrete cosine transform (DCT). The DCT is an efficient approximation for principal components analysis, so that it allows a compression, or reduction of dimensionality, of the data, in this case reducing 42 band readings to a smaller set of MFCCs. A small number of features (the coefficients) end up describing the spectrum. The MFCCs are commonly used as timbral descriptors.</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="Onsets">
    <dc:description>An onset detector for musical audio signals</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="Pitch">
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="Loudness">
    <dc:description>A perceptual loudness function which outputs loudness in sones; this is a variant of an MP3 perceptual model, summing excitation in ERB bands. It models simple spectral and temporal masking, with equal loudness contour correction in ERB bands to obtain phons (relative dB), then a phon to sone transform. The final output is typically in the range of 0 to 64 sones, though higher values can occur with specific synthesised stimuli.</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="KeyTrack">
    <dc:description>A (12TET major/minor) key tracker based on a pitch class profile of energy across FFT bins and matching this to templates for major and minor scales in all transpositions. It assumes a 440 Hz concert A reference. Output is 0-11 C major to B major, 12-23 C minor to B minor.</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralCrest">
    <dc:description>produces the spectral crest measure, which is an indicator of the "peakiness" of the spectral energy distribution</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralSpread">
    <dc:description>measures the spectral spread, which is the magnitude-weighted variance</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="SpectralSlope">
    <dc:description>measures the spectral slope, which is the slope of the linear correlation line derived from the spectral magnitudes</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
  <rdf:Description rdf:about="Crest">
    <dc:description>measures the "crest factor" of a time-domain signal, i.e. the ratio of the absolute peak to the absolute mean over a certain time period</dc:description>
    <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
  </rdf:Description>
</rdf:RDF>