Sonic Visualiser aims at analysis and inspection of data within an audio file, not at what you might call collection-level analysis such as classification or searching. Although there is a Vamp plugin in the QM set that is capable of calculating similarity metrics for audio files, it is not really useful within Sonic Visualiser because SV has no way to provide it with data across collections of files, or to cluster and make use of the results.
The QM similarity plugin expects its input to be in the form of "one audio track per channel" for 2..n channels, and it calculates and returns distance metrics for the channels with respect to each other. You can (laboriously) get meaningful results from this within SV, if you generate an audio file "by hand" that contains a different track on each channel and then load this file and run the plugin on it. But it's far from ideal.
It would be nice to have an option in SV's plugin configuration dialog to tell it to use all of a set of audio files as input, one per channel -- there are other plugins that would benefit from this, such as the MATCH alignment plugin. But that isn't possible now.
Chris
