3 name = "Midi Passthru",
6 author = "Ardour Lua Task Force",
7 description = [[An Example Audio/MIDI Passthrough Plugin using Buffer Pointers]]
10 -- return possible audio i/o configurations
11 function dsp_ioconfig ()
12 -- -1, -1 = any number of channels as long as input and output count matches
13 -- require 1 MIDI in, 1 MIDI out.
14 return { { midi_in = 1, midi_out = 1, audio_in = -1, audio_out = -1}, }
17 -- "dsp_runmap" uses Ardour's internal processor API, eqivalent to
18 -- 'connect_and_run()". There is no overhead (mapping, translating buffers).
19 -- The lua implementation is responsible to map all the buffers directly.
20 function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
22 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:ChanMapping
24 local ib = in_map:get (ARDOUR.DataType ("midi"), 0) -- get index of the 1st mapped midi input buffer
26 if ib ~= ARDOUR.ChanMapping.Invalid then
27 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:MidiBuffer
28 local mb = bufs:get_midi (ib) -- get the mapped buffer
29 local events = mb:table () -- copy event list into a lua table
31 -- iterate over all MIDI events
32 for _, e in pairs (events) do
33 -- e is-a http://manual.ardour.org/lua-scripting/class_reference/#Evoral:MidiEvent
35 -- do something with the event e.g.
36 print (e:channel (), e:time (), e:size (), e:buffer ():array ()[1], e:buffer ():get_table (e:size ())[1])
41 -- The following code is needed with "dsp_runmap" to work for arbitrary pin connections
42 -- this passes though all audio/midi data unprocessed.
44 ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("audio"))
45 ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("midi"))
47 -- equivalent lua code.
48 -- NOTE: the lua implementation below is intended for io-config [-1,-1].
49 -- It only works for actually mapped channels due to in_map:count() out_map:count()
50 -- being identical to the i/o pin count in this case.
52 -- Plugins that have multiple possible configurations will need to implement
53 -- dsp_configure() and remember the actual channel count.
55 -- ARDOUR.DSP.process_map() does iterate over the mapping itself and works generally.
56 -- Still the lua code below does lend itself as elaborate example.
60 local audio_ins = in_map:count (): n_audio () -- number of mapped audio input buffers
61 local audio_outs = out_map:count (): n_audio () -- number of mapped audio output buffers
62 assert (audio_outs, audio_ins) -- ioconfig [-1, -1]: must match
64 -- copy audio data if any
65 for c = 1, audio_ins do
66 local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped input buffer
67 local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped output buffer
68 if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then
69 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP
70 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:AudioBuffer
71 ARDOUR.DSP.copy_vector (bufs:get_audio (ob):data (offset), bufs:get_audio (ib):data (offset), n_samples)
74 -- Clear unconnected output buffers.
75 -- In case we're processing in-place some buffers may be identical,
76 -- so this must be done *after* copying relvant data from that port.
77 for c = 1, audio_outs do
78 local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1)
79 local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1)
80 if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then
81 bufs:get_audio (ob):silence (n_samples, offset)
86 local midi_ins = in_map:count (): n_midi () -- number of midi input buffers
87 local midi_outs = out_map:count (): n_midi () -- number of midi input buffers
89 -- with midi_in=1, midi_out=1 in dsp_ioconfig
90 -- the following will always be true
91 assert (midi_ins == 1)
92 assert (midi_outs == 1)
94 for c = 1, midi_ins do
95 local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1)
96 local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1)
97 if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then
98 bufs:get_midi (ob):copy (bufs:get_midi (ib))
101 -- silence unused midi outputs
102 for c = 1, midi_outs do
103 local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1)
104 local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1)
105 if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then
106 bufs:get_midi (ob):silence (n_samples, offset)