Lua Script Example for Audio to Midi Transcription (work in progress)

diff --git a/scripts/_vamp_note_example.lua b/scripts/_vamp_note_example.lua
new file mode 100644 (file)
index 0000000..df42104
--- /dev/null
+++ b/scripts/_vamp_note_example.lua
@@ -0,0 +1,57 @@
+ardour { ["type"] = "Snippet", name = "Vamp Audio Transcription Example" }
+
+function factory () return function ()
+
+       -- simple progress information print()ing
+       --[[
+       local progress_total;
+       local progress_last;
+       function cb (_f, pos)
+               local progress = 100 * pos / progress_total;
+               if progress - progress_last > 5 then
+                       progress_last = progress;
+                       print ("Progress: ", progress)
+               end
+       end
+       --]]
+
+       -- 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 ()
+       local sr = Session:nominal_frame_rate ()
+
+       -- Instantiate a Vamp Plugin
+       -- see http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:LuaAPI:Vamp
+       local vamp = ARDOUR.LuaAPI.Vamp ("libardourvampplugins:qm-transcription", sr)
+
+       -- 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
+
+               --[[
+               progress_total = r:to_readable ():readable_length ()
+               progress_last = 0
+               --]]
+               vamp:analyze (r:to_readable (), 0, nil --[[cb--]])
+               print ("-- Post Processing: ", r:name ())
+
+               -- post-processing takes longer than actually parsing the data :(
+               local f = vamp:plugin ():getRemainingFeatures ()
+
+               local fl = f:table ()[0]
+               print (" Time (sample) |  Len  | Midi-Note");
+               if fl then for f in fl:iter () do
+                       assert (f.hasTimestamp and f.hasDuration);
+                       local ft = Vamp.RealTime.realTime2Frame (f.timestamp, sr)
+                       local fd = Vamp.RealTime.realTime2Frame (f.duration, sr)
+                       local fn = f.values:at (0) -- midi note number
+                       print (string.format (" %14d %7d %d", ft, fd, fn))
+               end end
+
+               -- reset the plugin (prepare for next iteration)
+               vamp:reset ()
+       end
+
+end end