add vamp-plugin example lua script

diff --git a/scripts/_vamp_example.lua b/scripts/_vamp_example.lua
new file mode 100644 (file)
index 0000000..da40026
--- /dev/null
+++ b/scripts/_vamp_example.lua
@@ -0,0 +1,49 @@
+ardour { ["type"] = "Snippet", name = "Vamp Plugin Example" }
+
+function factory () return function ()
+       local sel = Editor:get_selection ()
+
+       local vamp = ARDOUR.LuaAPI.Vamp("libardourvampplugins:dBTP", Session:nominal_frame_rate())
+       print (vamp:plugin():getName())
+
+       -- for each selected region
+       for r in sel.regions:regionlist ():iter () do
+               print ("Region:", r:name ())
+
+               -- run the plugin, analyze the first channel of the audio-region
+               vamp:analyze (r:to_readable (), 0, nil)
+
+               -- get analysis results
+               local f = vamp:plugin ():getRemainingFeatures ()
+
+               -- f is-a Vamp::Plugin::FeatureSet  aka  std::map<int, Vamp::Plugin::FeatureList>
+               for id, featlist in f:iter () do
+                       print (id, featlist)
+               end
+
+               -- get the first FeatureList
+               local featurelist = f:table()[0]
+               -- Vamp::Plugin::FeatureList is a typedef for std::vector<Feature>
+               for feat in featurelist:iter () do
+                       print ("-", feat.label)
+               end
+
+               -- get the first feature..
+               local feature = featurelist:at(0)
+               -- ..and the values of the feature, which is-a std::vector<float>
+               local values = feature.values
+               -- iterate over the std::vector<float>
+               for val in values:iter () do
+                       print ("*", val)
+               end
+
+               -- access the first element of Vamp::Plugin::Feature's "values" vector
+               local value = values:at(0)
+               -- in case of libardourvampplugins:dBTP that's the true-peak
+               local dbtp = 20 * math.log (value) / math.log(10)
+               print (string.format ("Region '%s': %.2f dBTP", r:name (), dbtp))
+
+               -- reset the plugin
+               vamp:reset ()
+       end
+end end