overnight.lua

local reclen = 5 -- seconds

-- create a list of MIDI tracks to bounce
local mt = {}
for t in Session:get_tracks():iter() do -- for each track
	if not t:to_track():to_midi_track():isnil() then -- check if it's a MIDI track
		mt[t:name()] = t
	end
	-- mute *all* tracks (for now)
	t:mute_control():set_value(1, PBD.GroupControlDisposition.NoGroup);
end

-- now iterate over found MIDI tracked
for n,t in pairs (mt) do

	-- Assume all MIDI track outputs are connected, so simily un/mute as needed:

	t:mute_control():set_value(0, PBD.GroupControlDisposition.NoGroup); -- unmute MIDI track

	-- create one stereo Audio track, 2 in, 2 out, named after the midi track
	local tl = Session:new_audio_track (2, 2, nil, 1, n .. "-audio",  ARDOUR.PresentationInfo.max_order, ARDOUR.TrackMode.Normal)

	-- record-arm the created track
	for track in tl:iter() do
		track:rec_enable_control ():set_value (1, PBD.GroupControlDisposition.NoGroup)

		-- rely on auto-connect (for now) ; Preferences > Signal Flow
		--track:input():disconnect_all (nil)
		--track:input():audio(0):connect("system:capture_1")
		--track:input():audio(1):connect("system:capture_2")
	end

	-- rewind and record
	Session:goto_start()
	Session:maybe_enable_record()

	Session:request_transport_speed (1.0, true, 4)
	for i = 1, (10 * reclen) do
		ARDOUR.LuaAPI.usleep (100000) -- 100ms
		print() -- wake up main event loop
	end
	Session:request_transport_speed (0.0, false, 4)

	ARDOUR.LuaAPI.usleep (500000) -- wait for 1/2 sec

	-- disable record-arm
	for track in tl:iter() do
		track:rec_enable_control ():set_value (0, PBD.GroupControlDisposition.NoGroup)
	end
	-- mute the bounced MIDI track
	t:mute_control():set_value(1, PBD.GroupControlDisposition.NoGroup);

	-- clean up
	tl = nil
	collectgarbage()
	Session:save_state("")
end

mt = nil;
collectgarbage()