Vamp is an audio processing plugin system for plugins that extract descriptive information from audio data - typically referred to as audio analysis plugins or audio feature extraction plugins.

This package contains the following example plugins:

* Zero Crossings calculates the positions and density of zero-crossing points in an audio waveform.

* Spectral Centroid calculates the centre of gravity of the frequency domain representation of each block of audio.

* Simple Power Spectrum calculates a power spectrum from the input audio. Actually, it doesn't do any work except calculating power from a cartesian complex FFT output. The work of calculating this frequency domain output is done for it by the host or host SDK; the plugin just needs to declare that it wants frequency domain input. This is the simplest of the example plugins.

* Amplitude Follower is an implementation of SuperCollider's amplitude-follower algorithm as a simple Vamp plugin.

* Simple Percussion Onset Detector: estimates the locations of percussive onsets using a simple method described in "Drum Source Separation using Percussive Feature Detection and Spectral Modulation" by Dan Barry, Derry Fitzgerald, Eugene Coyle and Bob Lawlor, ISSC 2005.

* Simple Fixed Tempo Estimator: calculates a single beats-per-minute value which is an estimate of the tempo of a piece of music that is assumed to be of fixed tempo, using autocorrelation of a frequency domain energy rise metric. It has several outputs that return intermediate results used in the calculation, and may be a useful example of a plugin having several outputs with varying feature structures.

Also included is a simple host that can enumerate plugins, list their features, and process an audio file as well as a utility to generate Vamp plugin RDF templates.