75 lines
1.6 KiB
Lua
75 lines
1.6 KiB
Lua
ardour {
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["type"] = "dsp",
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name = "MIDI LFO",
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category = "Example", -- Utility
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license = "MIT",
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author = "Ardour Lua Task Force",
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description = [[MIDI CC LFO Example -- Triangle full scale CC Parameter automation]]
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}
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function dsp_ioconfig ()
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return { { midi_in = 1, midi_out = 1, audio_in = 0, audio_out = 0}, }
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end
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function dsp_params ()
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return
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{
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{ ["type"] = "input", name = "BPM", min = 40, max = 200, default = 60, unit="BPM"},
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{ ["type"] = "input", name = "CC", min = 0, max = 127, default = 1, integer = true },
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}
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end
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local samplerate
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local time = 0
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local step = 0
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function dsp_init (rate)
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samplerate = rate
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local bpm = 120
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spb = rate * 60 / bpm
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end
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function dsp_run (_, _, n_samples)
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assert (type(midiin) == "table")
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assert (type(midiout) == "table")
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local ctrl = CtrlPorts:array ()
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local bpm = ctrl[1]
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local cc = ctrl[2]
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local spb = samplerate * 60 / bpm -- samples per beat
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local sps = spb / 254 -- samples per step (0..127..1 = 254 steps)
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assert (sps > 1)
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local i = 1
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local m = 1
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for ts = 1, n_samples do
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time = time + 1
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-- forward incoming midi
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if i <= #midiin then
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while midiin[i]["time"] == ts do
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midiout[m] = midiin[i]
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i = i + 1
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m = m + 1
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if i > #midiin then break end
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end
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end
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-- inject LFO events
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if time >= spb then
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local val
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if step > 127 then val = 254 - step else val = step end
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midiout[m] = {}
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midiout[m]["time"] = ts
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midiout[m]["data"] = { 0xb0, cc, val }
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m = m + 1
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time = time - sps
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if step == 253 then step = 0 else step = step + 1 end
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end
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end
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end
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