prototype lua midi generators & filters and port event-rewrite

1 files changed, 52 insertions, 0 deletions

diff --git a/scripts/midigenerator.lua b/scripts/midigenerator.lua
new file mode 100644
index 0000000000..e9aa55d280
--- /dev/null
+++ b/scripts/midigenerator.lua
@@ -0,0 +1,52 @@
+ardour {
+	["type"]    = "dsp",
+	name        = "Midi Generator",
+	category    = "Utility",
+	license     = "MIT",
+	author      = "Robin Gareus",
+	email       = "robin@gareus.org",
+	site        = "http://gareus.org",
+	description = [[An Example Midi Generator for prototyping.]]
+}
+
+function dsp_ioconfig ()
+	return { { audio_in = 0, audio_out = 0}, }
+end
+
+function dsp_has_midi_output () return true end
+
+local tme = 0 -- sample-counter
+local seq = 1 -- sequence-step
+local spb = 0 -- samples per beat
+
+local midi_sequence = {
+	{ 0x90, 64, 127 },
+	{ 0x80, 64,   0 },
+}
+
+function dsp_init (rate)
+	local bpm = 120
+	spb = rate * 60 / bpm
+	if spb < 2 then spb = 2 end
+end
+
+function dsp_run (_, _, n_samples)
+	assert (type(midiout) == "table")
+	assert (spb > 1)
+	local m = 1
+
+	for time = 1,n_samples do -- not very efficient
+		-- TODO, timestamp the sequence in beats, calc/skip to next event
+		tme = tme + 1
+
+		if tme >= spb then
+			midiout[m] = {}
+			midiout[m]["time"] = time
+			midiout[m]["data"] = midi_sequence[seq]
+
+			tme = 0
+			m = m + 1
+			if seq == #midi_sequence then seq = 1 else seq = seq + 1 end
+		end
+	end
+end