1 files changed, 95 insertions, 0 deletions
diff --git a/share/scripts/amp5.lua b/share/scripts/amp5.lua
new file mode 100644
index 0000000000..f992d0d029
--- /dev/null
+++ b/share/scripts/amp5.lua
@@ -0,0 +1,95 @@
+ardour {
+	["type"]    = "dsp",
+	name        = "a-Amplifier",
+	category    = "Amplifier",
+	license     = "MIT",
+	author      = "Ardour Team",
+	description = [[Versatile +/- 20dB multichannel amplifier]]
+}
+
+function dsp_ioconfig ()
+	return
+	{
+		-- -1, -1 = any number of channels as long as input and output count matches
+		{ audio_in = -1, audio_out = -1},
+	}
+end
+
+
+function dsp_params ()
+	return
+	{
+		{ ["type"] = "input", name = "Gain", min = -20, max = 20, default = 0, unit="dB"},
+	}
+end
+
+local sr = 48000
+local cur_gain = 1
+
+function dsp_init (rate)
+	sr = rate
+end
+
+function dsp_configure (ins, outs)
+	n_out   = outs
+	n_audio = outs:n_audio ()
+	assert (outs:n_midi () == 0)
+end
+
+-- the DSP callback function
+function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
+	-- apply I/O map
+	ARDOUR.DSP.process_map (bufs, n_out, in_map, out_map, n_samples, offset)
+
+	local ctrl = CtrlPorts:array() -- get control port array
+	local target_gain  = ARDOUR.DSP.dB_to_coefficient (ctrl[1]) -- 10 ^ (0.05 * ctrl[1])
+	local current_gain = cur_gain -- start with the same for all channels
+
+	for c = 1, n_audio do
+		local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1); -- get id of mapped output buffer for given cannel
+		if (ob ~= ARDOUR.ChanMapping.Invalid) then
+			cur_gain = ARDOUR.Amp.apply_gain (bufs:get_audio(ob), sr, n_samples, current_gain, target_gain, offset)
+		end
+	end
+
+--[[
+	if current_gain ~= cur_gain then
+		self:queue_draw () -- notify display
+	end
+--]]
+end
+
+-------------------------------------------------------------------------------
+--- inline display + text example
+
+--[[
+local txt = nil -- cache pango context globally
+
+function render_inline (ctx, w, max_h)
+	local ctrl = CtrlPorts:array () -- get control ports
+
+	if not txt then
+		-- allocate PangoLayout and set font
+		--http://manual.ardour.org/lua-scripting/class_reference/#Cairo:PangoLayout
+		txt = Cairo.PangoLayout (ctx, "Mono 8px")
+	end
+
+	txt:set_text (string.format ("%+.2f dB", ctrl[1]));
+	tw, th = txt:get_pixel_size ()
+
+	local h = th + 4 -- use text-height with 4px padding
+	if (h > max_h) then h = max_h end -- but at most max-height
+
+	-- clear background
+	ctx:rectangle (0, 0, w, h)
+	ctx:set_source_rgba (.2, .2, .2, 1.0)
+	ctx:fill ()
+
+	-- center text
+	ctx:set_source_rgba (.8, .8, .8, 1.0)
+	ctx:move_to (.5 * (w - tw), .5 * (h - th))
+	txt:show_in_cairo_context (ctx)
+
+	return {w, h}
+end
+--]]