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livetrax/scripts/midi_remap.lua
2019-02-19 15:38:10 +01:00

98 lines
2.9 KiB
Lua

ardour {
["type"] = "dsp",
name = "MIDI Note Mapper",
category = "Utility",
license = "MIT",
author = "Alby Musaelian",
description = [[Map arbitrary MIDI notes to others. Affects Note On/Off and polyphonic key pressure. Note that if a single note is mapped multiple times, the last mapping wins -- MIDI events are never duplicated.]]
}
-- The number of remapping pairs to allow. Increasing this (at least in theory)
-- decreases performace, so it's set fairly low as a default. The user can
-- increase this if they have a need to.
N_REMAPINGS = 10
OFF_NOTE = -1
function dsp_ioconfig ()
return { { midi_in = 1, midi_out = 1, audio_in = 0, audio_out = 0}, }
end
function dsp_params ()
local map_scalepoints = {}
map_scalepoints["None"] = OFF_NOTE
for note=0,127 do
local name = ARDOUR.ParameterDescriptor.midi_note_name(note)
map_scalepoints[string.format("%03d (%s)", note, name)] = note
end
local map_params = {}
i = 1
for mapnum = 1,N_REMAPINGS do
-- From and to
for _,name in pairs({"| #" .. mapnum .. " Map note", "|__ to"}) do
map_params[i] = {
["type"] = "input",
name = name,
min = -1,
max = 127,
default = OFF_NOTE,
integer = true,
enum = true,
scalepoints = map_scalepoints
}
i = i + 1
end
end
return map_params
end
function dsp_run (_, _, n_samples)
assert (type(midiin) == "table")
assert (type(midiout) == "table")
local cnt = 1;
function tx_midi (time, data)
midiout[cnt] = {}
midiout[cnt]["time"] = time;
midiout[cnt]["data"] = data;
cnt = cnt + 1;
end
-- We build the translation table every buffer because, as far as I can tell,
-- there's no way to only rebuild it when the parameters have changed.
-- As a result, it has to be updated every buffer for the parameters to have
-- any effect.
-- Restore translation table
local translation_table = {}
local ctrl = CtrlPorts:array()
for i=1,N_REMAPINGS*2,2 do
if not (ctrl[i] == OFF_NOTE) then
translation_table[ctrl[i]] = ctrl[i + 1]
end
end
-- for each incoming midi event
for _,b in pairs (midiin) do
local t = b["time"] -- t = [ 1 .. n_samples ]
local d = b["data"] -- get midi-event
local event_type
if #d == 0 then event_type = -1 else event_type = d[1] >> 4 end
if (#d == 3) and (event_type == 9 or event_type == 8 or event_type == 10) then -- note on, note off, poly. afterpressure
-- Do the mapping - 2 is note byte for these types
d[2] = translation_table[d[2]] or d[2]
if not (d[2] == OFF_NOTE) then
tx_midi (t, d)
end
else
tx_midi (t, d)
end
end
end