I have an application which I would like to turn into a VAMP plugin for Sonic Visualiser, Audacity, and the like. I need the user to be able to select a section of audio, have the full audio and the selection limits sent to my app, and then have my app send back playable audio and some graphics (e.g., a spectrogram) for display to the user.
I cannot find in the VAMP API a way of creating new audio tracks. Is this possible with VAMP, or am I better off using VST or something else? Or am I missing the point entirely and this is host dependent?
Many thanks.
You've understood it correctly: Vamp plugins can't produce audio as output. Or at least, not in a form that any existing host will recognise as audio. They do analysis only, and the output is expected to be expressible as some set of structured features.
Note that Vamp plugins also don't generate the graphics -- the host does that. The plugin calculates only the structured features. They are quite low-level in that respect.