Chris@9: 
Chris@9: pYIN
Chris@9: ====
Chris@9: 
Chris@9: pYIN is a modification of the well-loved YIN algorithm for fundamental
Chris@9: frequency (F0) estimation in monophonic audio.
Chris@9: 
Chris@159: This is a Vamp plugin (https://vamp-plugins.org) implementation of
Chris@9: pYIN, as well as the original YIN method. The plugin can be used by
Chris@9: any Vamp host such as Sonic Visualiser and Sonic Annotator.
Chris@9: 
Chris@9: 
Chris@9: Method
Chris@9: ======
Chris@9: 
Chris@9: The pYIN method is a modification of the method known as YIN (De
Chris@9: Cheveigné, Alain, and Hideki Kawahara. "YIN, a fundamental frequency
Chris@9: estimator for speech and music." The Journal of the Acoustical Society
Chris@9: of America 111 (2002)).
Chris@9: 
Chris@9: The original YIN has one threshold parameter. In pYIN this parameter
Chris@9: is replaced by a parameter distribution, and for every frame several
Chris@9: fundamental frequency candidates obtained, conditional on this prior
Chris@9: parameter distribution. In the second phase, a hidden Markov model
Chris@9: (HMM) is Viterbi-decoded to find a "smooth" path through the
Chris@9: fundamental frequency candidates. Note that this smoothed path is not
Chris@9: smudging or averaging pitch estimates: any pitch estimate contains
Chris@9: only fundamental frequency estimates that are genuine estimates of the
Chris@9: original YIN method for some threshold parameter.
Chris@9: 
Chris@9: The note estimator is a post-processing step on the pYIN pitch track,
Chris@9: also performed as Viterbi decoding of an HMM.
Chris@9: 
Chris@9: 
Chris@9: Limitations
Chris@9: ===========
Chris@9: 
Chris@9: The pYIN method is designed to reliably extract the fundamental
Chris@9: frequency of audio recordings of a monophonic, harmonic instrument
Chris@9: such as the human voice. Being based on YIN means that pYIN exploits
Chris@9: the periodicity of the signal. In some circumstances it will not be
Chris@9: reliable. Such circumstances occur, e.g.
Chris@9: 
Chris@9:     ... if the source audio is not monophonic, e.g. a singer with
Chris@9:     accompanying instruments,
Chris@9: 
Chris@9:     ... if the recording has reverb/echo (this essentially makes it
Chris@9:     polyphonic),
Chris@9: 
Chris@9:     ... if, in a stringed instrument such as the cello, one string
Chris@9:     keeps ringing while the melody turns to a different pitch.
Chris@9: 
Chris@9: 
Chris@9: Authors, Citation, License and Use
Chris@9: ==================================
Chris@9: 
Chris@159: pYIN was written by Matthias Mauch. Copyright 2012-2020 Matthias Mauch
Chris@9: and Queen Mary, University of London.
Chris@9: 
Chris@9: The YIN code was drawn from the Java implementation in the TarsosDSP
Chris@9: library by Joren Six.
Chris@9: 
Chris@9: If you make use of this software for any public or commercial purpose,
Chris@9: we ask you to kindly mention the authors and Queen Mary, University of
Chris@9: London in your user-visible documentation. We're very happy to see
Chris@9: this sort of use but would much appreciate being credited, separately
Chris@9: from the requirements of the software license itself (see below).
Chris@9: 
Chris@9: If you make use of this software for academic purposes, please cite
Chris@9: one of the publications indicated on the Publications page:
Chris@9: 
Chris@9: https://code.soundsoftware.ac.uk/publications?project_id=pyin
Chris@9: 
Chris@9: This program is free software: you can redistribute it and/or modify
Chris@9: it under the terms of the GNU General Public License as published by
Chris@9: the Free Software Foundation, either version 2 of the License, or (at
Chris@9: your option) any later version.
Chris@9: 
Chris@9: This program is distributed in the hope that it will be useful, but
Chris@9: WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@9: MERCHANTABILITY or FITNESS FOR A ARTICULAR PURPOSE. See the GNU
Chris@9: General Public License for more details. You should have received a
Chris@9: copy of the GNU General Public License along with this program. If
Chris@9: not, see http://www.gnu.org/licenses/.
Chris@9: