@audio/mir-chordino

Chordino (Mauch 2010): chord sequence from NNLS chroma, as the reference Vamp plugin.

npm install @audio/mir-chordino @audio/mir-nnls-chroma

import chromagram from '@audio/mir-nnls-chroma'
import chordino from '@audio/mir-chordino'

let chords = chordino(chromagram(samples, { fs }), { end: samples.length / fs })
// [{ time, duration, root, quality, bass, label, confidence }, …]: 'N', 'C', 'Am', 'G7', 'C/E', …

As the reference plugin (c4dm/nnls-chroma) with its built-in dictionary: each frame's 24-D bass and treble chroma scores 217 chords: 18 types on 12 roots (maj, min, 7, maj7, min7, maj6, min6, dim, aug, hdim7; maj over its 3rd, 5th, 2nd or ♭7th, 7 over its 3rd, hdim7 over its ♭7th) and no-chord; a Viterbi path, 0.99 to stay, starting on no-chord, gives the sequence. quality is Harte's shorthand, bass the pitch class in the bass. On the plugin's own regression recording (Zweieck, "Duell", 237 s) its labels and change times equal the plugin's.

Options: - boostN: lifts the no-chord profile (default 0.1) · end: where the last chord ends (s)

Ref: M. Mauch, "Automatic chord transcription from audio using computational models of musical context", PhD thesis, Queen Mary University of London, 2010.

License: GPL-2.0-or-later, as the plugin it translates (LICENSE).

Part of @audio/mir.