ardour { ["type"] = "dsp", name = "Midi Passthru", category = "Example", license = "MIT", author = "Ardour Team", description = [[An Example Audio/MIDI Passthrough Plugin using Buffer Pointers]] } -- return possible audio i/o configurations function dsp_ioconfig () -- -1, -1 = any number of channels as long as input and output count matches return { { audio_in = -1, audio_out = -1}, } end -- require 1 MIDI in, 1 MIDI out. function dsp_has_midi_input () return true end function dsp_has_midi_output () return true end -- "dsp_runmap" uses Ardour's internal processor API, eqivalent to -- 'connect_and_run()". There is no overhead (mapping, translating buffers). -- The lua implementation is responsible to map all the buffers directly. function dsp_runmap (bufs, in_map, out_map, n_samples, offset) -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:ChanMapping local ib = in_map:get (ARDOUR.DataType ("midi"), 0) -- get index of the 1st mapped midi input buffer assert (ib ~= ARDOUR.ChanMapping.Invalid) if ib ~= ARDOUR.ChanMapping.Invalid then -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:MidiBuffer local mb = bufs:get_midi (ib) -- get the mapped buffer events = mb:table () -- copy event list into a lua table -- iterate over all MIDI events for _, e in pairs (events) do -- e is-a http://manual.ardour.org/lua-scripting/class_reference/#Evoral:MidiEvent -- do something with the event --print (e:channel ()) end end ---- -- The following code is needed with "dsp_runmap" to work for arbitrary pin connections -- this passes though all audio/midi data unprocessed. ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("audio")) ARDOUR.DSP.process_map (bufs, in_map, out_map, n_samples, offset, ARDOUR.DataType ("midi")) -- equivalent lua code. -- NOTE: the lua implementation below is intended for io-config [-1,-1]. -- It only works for actually mapped channels due to in_map:count() out_map:count() -- being identical to the i/o pin count in this case. -- -- Plugins that have multiple possible configurations will need to implement -- dsp_configure() and remember the actual channel count. -- -- ARDOUR.DSP.process_map() does iterate over the mapping itself and works generally. -- Still the lua code below does lend itself as elaborate example. -- --[[ local audio_ins = in_map:count (): n_audio () -- number of mapped audio input buffers local audio_outs = out_map:count (): n_audio () -- number of mapped audio output buffers assert (audio_outs, audio_ins) -- ioconfig [-1, -1]: must match -- copy audio data if any for c = 1, audio_ins do local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped input buffer local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) -- get index of mapped output buffer if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:DSP -- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:AudioBuffer ARDOUR.DSP.copy_vector (bufs:get_audio (ob):data (offset), bufs:get_audio (ib):data (offset), n_samples) end end -- Clear unconnected output buffers. -- In case we're processing in-place some buffers may be identical, -- so this must be done *after* copying relvant data from that port. for c = 1, audio_outs do local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then bufs:get_audio (ob):silence (n_samples, offset) end end -- copy midi data local midi_ins = in_map:count (): n_midi () -- number of midi input buffers local midi_outs = out_map:count (): n_midi () -- number of midi input buffers -- with dsp_has_midi_in/out() the following will always be true assert (midi_ins == 1) assert (midi_outs == 1) for c = 1, midi_ins do local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1) local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1) if ib ~= ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob then bufs:get_midi (ob):copy (bufs:get_midi (ib)) end end -- silence unused midi outputs for c = 1, midi_outs do local ib = in_map:get (ARDOUR.DataType ("midi"), c - 1) local ob = out_map:get (ARDOUR.DataType ("midi"), c - 1) if ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid then bufs:get_midi (ob):silence (n_samples, offset) end end --]] end