| Sonic Visualiser | |
| Developer: | Centre for Digital Music at Queen Mary, University of London |
| Operating System: | Linux, MacOS, Windows |
| Programming Language: | C++ |
| Genre: | Audio analysis |
| License: | GPL-2.0-or-later[1] |
Sonic Visualiser is an application for viewing and analysing the contents of music audio files. It is a free software distributed under the GPL-2.0-or-later licence.[2]
Sonic Visualiser was developed at the Queen Mary University of London's Centre for Digital Music in 2007. It was written in C++ with Qt and released under the terms of the GNU GPL.[2]
Sonic Visualiser represents acoustic features of the audio file either as a waveform or as a spectrogram.[3] Spectrogram is a heatmap, where horizontal axis represents time, vertical axis represents frequency, and the colors show presence of frequencies. Sharpness and smoothness of the spectrogram can be configured.[4] There are three types of spectrogram:
Generic spectrogram covers the full frequency range and uses linear frequency scale. Melodic-range spectrogram covers the range which usually contains musical detail. Peak-frequency spectrogram performs phase difference calculations and estimates exact frequencies at each peak cell.[2]
The interface consists of panes and layers. Panes allow to display multiple visualisations simultaneously, and they get aligned in the time axis. A pane can have multiple layers which are used for annotation.[2] The user can configure color schemes for layers, and they can be navigated by clicking the labeled tabs.[4]
There are multiple types of annotation layers which can be edited, including time instants, time-value plots, labels and images. Time instants do not have any associated value, and they can be used to annotate points (e.g. beat locations).[2] Annotations allow the user to clarify relationships between musical parameters.[3]
Sonic Visualiser supports third-party plugins in the Vamp plugin format. The plugins take audio input and parameters and return values for display.[2] There are plugins which compute spectral flux and spectral centroid. Other plugins include automatic melody extraction, beat finding, chord analysis, etc.[4]
Sonic Visualiser is available for Linux, OS X, and Windows operating systems.[2]