Package: vamphost
This module allows Python code to load and use native-code Vamp
plugins (http://vamp-plugins.org) for audio feature analysis.The module consists of a native-code extension (“vampyhost”) that
provides a low-level wrapper for the Vamp plugin SDK, along with a
Python wrapper (“vamp”) that provides a higher-level abstraction.No code for loading audio files is included; you’ll need to use some
other module for that. This code expects to receive decoded audio data
of one or more channels, either as a series of frames or as a single
whole buffer.Written by Chris Cannam and George Fazekas at the Centre for Digital
Music, Queen Mary University of London. Copyright 2008-2015 Queen
Mary, University of London. Refer to COPYING.rst for licence details.See home page athttps://code.soundsoftware.ac.uk/projects/vampy-hostfor more details.A simple exampleUsing librosa (http://bmcfee.github.io/librosa/) to read an audio
file, and the NNLS Chroma Vamp plugin
(https://code.soundsoftware.ac.uk/projects/nnls-chroma/) for
analysis:>>>importvamp>>>importlibrosa>>>data,rate=librosa.load("example.wav")>>>chroma=vamp.collect(data,rate,"nnls-chroma:nnls-chroma")>>>chroma{'matrix':(0.092879819,array([[61.0532608,60.27478409,59.3938446,...,182.13394165,42.40084457,116.55457306],[68.8901825,63.98115921,60.77633667,...,245.88218689,68.51251984,164.70120239],[58.59794617,50.3429184,45.44804764,...,258.02362061,83.95749664,179.91200256],...,[0.,0.,0.,...,0.,0.,0.],[0.,0.,0.,...,0.,0.,0.],[0.,0.,0.,...,0.,0.,0.]],dtype=float32))}>>>stepsize,chromadata=chroma["matrix"]>>>importmatplotlib.pyplotasplt>>>plt.imshow(chromadata)<matplotlib.image.AxesImageobjectat0x7fe9e0043fd0>>>>plt.show()And a pitch-chroma plot appears.High-level interface (vamp)This module contains three sorts of function:1. Basic info and lookup functionsvamp.list_pluginsvamp.get_outputs_ofvamp.get_category_ofThese retrieve the installed plugin keys and get basic information
about each plugin. (For more detailed information, load a plugin
and inspect it using the low-level interface described below.)2. Process functionsvamp.process_audiovamp.process_framesvamp.process_audio_multiple_outputsvamp.process_frames_multiple_outputsThese accept audio input, and produce output in the form of a list
of feature sets structured similarly to those in the C++ Vamp
plugin SDK. The plugin to be used is specified by its key (the
identifier as returned byvamp.list_plugins). A dictionary of
plugin parameter settings may optionally be supplied.The_audioversions take a single (presumably long) array of
audio samples as input, and chop it into frames according to the
plugin’s preferred step and block sizes. The_framesversions
instead accept an enumerable sequence of audio frame arrays.3. The process-and-collect functionvamp.collectThis accepts a single array of audio samples as input, and returns
an output structure that reflects the underlying structure of the
feature output (depending on whether it is a curve, grid, etc). The
plugin to be used is specified by its key. A dictionary of plugin
parameter settings may optionally be supplied.Thecollectfunction processes the whole input before returning
anything; if you need to supply a streamed input, or retrieve
results as they are calculated, then you must use one of theprocessfunctions (above) or else the low-level interface
(below).Low-level interface (vampyhost)This extension contains facilities that operate on Vamp plugins in a
way analogous to the existing C++ Vamp Host SDK:list_plugins,get_plugin_path,get_category_of,get_library_for,get_outputs_of,load_plugin, and a utility functionframe_to_realtime.Callingload_plugingets you avampyhost.Pluginobject, which
then exposes all of the methods found in the Vamp SDK Plugin class.(Note that methods wrapped directly from the Vamp SDK are named using
camelCase, so as to match the names found in the C++ SDK. Elsewhere
this module follows Python PEP8 naming.)See the individual module and function documentation for further
details.Python Vamp Host
Copyright (c) 2008-2015 Queen Mary, University of LondonPermission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the “Software”), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.Except as contained in this notice, the names of the Centre for
Digital Music and Queen Mary, University of London shall not be
used in advertising or otherwise to promote the sale, use or other
dealings in this Software without prior written authorization.