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 return { { audio_in = -1, audio_out = -1}, }
16 -- require 1 MIDI in, 1 MIDI out.
17 function dsp_has_midi_input () return true end
18 function dsp_has_midi_output () return true end
21 -- "dsp_runmap" uses Ardour's internal processor API, eqivalent to
22 -- 'connect_and_run()". There is no overhead (mapping, translating buffers).
23 -- The lua implementation is responsible to map all the buffers directly.
24 function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
26 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:ChanMapping
28 local ib = in_map:get (ARDOUR.DataType ("midi"), 0) -- get index of the 1st mapped midi input buffer
29 assert (ib ~= ARDOUR.ChanMapping.Invalid)
31 if ib ~= ARDOUR.ChanMapping.Invalid then
32 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:MidiBuffer
33 local mb = bufs:get_midi (ib) -- get the mapped buffer
34 local events = mb:table () -- copy event list into a lua table
36 -- iterate over all MIDI events
37 for _, e in pairs (events) do
38 -- e is-a http://manual.ardour.org/lua-scripting/class_reference/#Evoral:MidiEvent
40 -- do something with the event e.g.
41 print (e:channel (), e:time (), e:size (), e:buffer ():array ()[1], e:buffer ():get_table (e:size ())[1])
46 -- The following code is needed with "dsp_runmap" to work for arbitrary pin connections
47 -- this passes though all audio/midi data unprocessed.
49 ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("audio"))
50 ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("midi"))
52 -- equivalent lua code.
53 -- NOTE: the lua implementation below is intended for io-config [-1,-1].
54 -- It only works for actually mapped channels due to in_map:count() out_map:count()
55 -- being identical to the i/o pin count in this case.
57 -- Plugins that have multiple possible configurations will need to implement
58 -- dsp_configure() and remember the actual channel count.
60 -- ARDOUR.DSP.process_map() does iterate over the mapping itself and works generally.
61 -- Still the lua code below does lend itself as elaborate example.
65 local audio_ins = in_map:count (): n_audio () -- number of mapped audio input buffers
66 local audio_outs = out_map:count (): n_audio () -- number of mapped audio output buffers
67 assert (audio_outs, audio_ins) -- ioconfig [-1, -1]: must match
69 -- copy audio data if any
70 for c = 1, audio_ins do
71 local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped input buffer
72 local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped output buffer
73 if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then
74 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP
75 -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:AudioBuffer
76 ARDOUR.DSP.copy_vector (bufs:get_audio (ob):data (offset), bufs:get_audio (ib):data (offset), n_samples)
79 -- Clear unconnected output buffers.
80 -- In case we're processing in-place some buffers may be identical,
81 -- so this must be done *after* copying relvant data from that port.
82 for c = 1, audio_outs do
83 local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1)
84 local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1)
85 if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then
86 bufs:get_audio (ob):silence (n_samples, offset)
91 local midi_ins = in_map:count (): n_midi () -- number of midi input buffers
92 local midi_outs = out_map:count (): n_midi () -- number of midi input buffers
94 -- with dsp_has_midi_in/out() the following will always be true
95 assert (midi_ins == 1)
96 assert (midi_outs == 1)
98 for c = 1, midi_ins do
99 local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1)
100 local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1)
101 if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then
102 bufs:get_midi (ob):copy (bufs:get_midi (ib))
105 -- silence unused midi outputs
106 for c = 1, midi_outs do
107 local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1)
108 local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1)
109 if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then
110 bufs:get_midi (ob):silence (n_samples, offset)