ardour { ["type"] = "Snippet", name = "Vamp Onset Detection Example" } function factory () return function () -- get Editor selection -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Editor -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Selection local sel = Editor:get_selection () -- Instantiate a Vamp Plugin -- see http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:LuaAPI:Vamp -- -- here: the "Queen Mary Note Onset Detector" Vamp plugin (which comes with Ardour) -- http://vamp-plugins.org/plugin-doc/qm-vamp-plugins.html#qm-onsetdetector local vamp = ARDOUR.LuaAPI.Vamp("libardourvampplugins:qm-onsetdetector", Session:nominal_sample_rate()) -- prepare table to hold results local onsets = {} -- for each selected region -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:RegionSelection for r in sel.regions:regionlist ():iter () do -- "r" is-a http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Region -- prepare lua table to hold results for the given region (by name) onsets[r:name ()] = {} -- callback to handle Vamp-Plugin analysis results function callback (feats) -- "feats" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureSet -- get the first output. here: Detected note onset times local fl = feats:table()[0] -- "fl" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureList -- which may be empty or not nil if fl then -- iterate over returned features for f in fl:iter () do -- "f" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:Feature if f.hasTimestamp then local fn = Vamp.RealTime.realTime2Frame (f.timestamp, 48000) --print ("-", f.timestamp:toString(), fn) table.insert (onsets[r:name ()], fn) end end end return false -- continue, !cancel end -- Configure Vamp plugin -- -- One could query the Parameter and Program List: -- http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin -- but since the Plugin is known, we can directly refer to the plugin doc: -- http://vamp-plugins.org/plugin-doc/qm-vamp-plugins.html#qm-onsetdetector vamp:plugin ():setParameter ("dftype", 3); vamp:plugin ():setParameter ("sensitivity", 50); vamp:plugin ():setParameter ("whiten", 0); -- in this case the above (3, 50, 0) is equivalent to --vamp:plugin ():selectProgram ("General purpose"); -- run the plugin, analyze the first channel of the audio-region -- -- This uses a "high-level" convenience wrapper provided by Ardour -- which reads raw audio-data from the region and and calls -- f = vamp:plugin ():process (); callback (f) vamp:analyze (r:to_readable (), 0, callback) -- get remaining features (end of analysis) callback (vamp:plugin ():getRemainingFeatures ()) -- reset the plugin (prepare for next iteration) vamp:reset () end -- print results for n,o in pairs(onsets) do print ("Onset analysis for region:", n) for _,t in ipairs(o) do print ("-", t) end end end end