Bundle Audio to MIDI Lua script

scripts/vamp_audio_to_midi.lua

@@ -0,0 +1,70 @@
+ardour {
+	["type"] = "EditorAction",
+	name = "Polyphonic Audio to MIDI",
+	license     = "MIT",
+	author      = "Ardour Team",
+description = [[
+Analyze audio from the selected audio region to a selected MIDI region.
+
+A MIDI region on the target track will have to be created first (use the pen tool).
+
+This script uses the Polyphonic Transcription VAMP plugin from Queen Mary Univ, London.
+The plugin works best at 44.1KHz input sample rate, and is tuned for piano and guitar music. Velocity is not estimated.
+]]
+}
+
+function factory () return function ()
+	local sel = Editor:get_selection ()
+	local sr = Session:nominal_frame_rate ()
+	local tm = Session:tempo_map ()
+	local vamp = ARDOUR.LuaAPI.Vamp ("libardourvampplugins:qm-transcription", sr)
+	local midi_region
+	local audio_regions = {}
+	local start_time = Session:current_end_frame ()
+	local end_time = Session:current_start_frame ()
+	for r in sel.regions:regionlist ():iter () do
+		if r:to_midiregion():isnil() then
+			local st = r:position()
+			local ln = r:length()
+			local et = st + ln
+			if st < start_time then
+				start_time = st
+			end
+			if et > end_time then
+				end_time = et
+			end
+			table.insert(audio_regions, r)
+		else
+			midi_region = r:to_midiregion()
+		end
+	end
+	assert (audio_regions and midi_region)
+	midi_region:set_initial_position(start_time)
+	midi_region:set_length(end_time - start_time, 0)
+
+	for i,ar in pairs(audio_regions) do
+		local a_off = ar:position ()
+		local b_off = midi_region:quarter_note () - midi_region:start_beats ()
+
+		vamp:analyze (ar:to_readable (), 0, nil)
+		local fl = vamp:plugin ():getRemainingFeatures ():at (0)
+		if fl and fl:size() > 0 then
+			local mm = midi_region:midi_source(0):model()
+			local midi_command = mm:new_note_diff_command ("Audio2Midi")
+			for f in fl:iter () do
+				local ft = Vamp.RealTime.realTime2Frame (f.timestamp, sr)
+				local fd = Vamp.RealTime.realTime2Frame (f.duration, sr)
+				local fn = f.values:at (0)
+
+				local bs = tm:exact_qn_at_frame (a_off + ft, 0)
+				local be = tm:exact_qn_at_frame (a_off + ft + fd, 0)
+
+				local pos = Evoral.Beats (bs - b_off)
+				local len = Evoral.Beats (be - bs)
+				local note = ARDOUR.LuaAPI.new_noteptr (1, pos, len, fn + 1, 0x7f)
+				midi_command:add (note)
+			end
+			mm:apply_command (Session, midi_command)
+		end
+	end
+end end