view rdfn3/af-SuperCollider.n3 @ 18:d5012016bf64 tip

added rdfpy and rdfonto directories

@prefix SuperCollider: <file:///Users/alo/MusicOntology/features/rdf/> .
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

SuperCollider:BeatTrack a rdfs:Resource ;
    dc:description "Autocorrelation based beat tracker" .

SuperCollider:BeatTrack2 a rdfs:Resource ;
    dc:description "based on exhaustively testing particular template patterns against feature streams" .

SuperCollider:Chromagram a rdfs:Resource ;
    dc:description "measures the energy at particular chroma within an nTET tuning system" .

SuperCollider:Crest a rdfs:Resource ;
    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" .

SuperCollider:KeyTrack a rdfs:Resource ;
    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." .

SuperCollider:Loudness a rdfs:Resource ;
    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." .

SuperCollider:MFCC a rdfs:Resource ;
    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." .

SuperCollider:Onsets a rdfs:Resource ;
    dc:description "An onset detector for musical audio signals" .

SuperCollider:Pitch a rdfs:Resource .

SuperCollider:SpectralCentroid a rdfs:Resource ;
    dc:description "the weighted mean frequency, or the \"centre of mass\" of the spectrum" .

SuperCollider:SpectralCrest a rdfs:Resource ;
    dc:description "produces the spectral crest measure, which is an indicator of the \"peakiness\" of the spectral energy distribution" .

SuperCollider:SpectralFlatness a rdfs:Resource ;
    dc:description "a power spectrum's geometric mean divided by its arithmetic mean" .

SuperCollider:SpectralPercentile a rdfs:Resource ;
    dc:description "calculates the cumulative distribution of the frequency spectrum, and outputs the frequency value which corresponds to the desired percentile" .

SuperCollider:SpectralSlope a rdfs:Resource ;
    dc:description "measures the spectral slope, which is the slope of the linear correlation line derived from the spectral magnitudes" .

SuperCollider:SpectralSpread a rdfs:Resource ;
    dc:description "measures the spectral spread, which is the magnitude-weighted variance" .

SuperCollider:ZeroCrossingRate a rdfs:Resource ;
    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." .