ardour {
["type"] = "dsp",
name = "Voice/Level Activate",
+ category = "Utility",
+ author = "Ardour Lua Task Force",
license = "MIT",
- author = "Robin Gareus",
- authoremail = "robin@gareus.org",
- site = "http://gareus.org",
- description = [[
- An Example Audio Plugin that rolls the transport
- when the signal level on the plugin's input a given threshold.]]
+ description = [[Roll the transport when the signal level on the plugin's input exceeds a given threshold.]]
}
function dsp_ioconfig ()
return
{
+ -- support all in/out as long as input port count equals output port count
{ audio_in = -1, audio_out = -1},
}
end
end
function dsp_configure (ins, outs)
- n_channels = ins:n_audio();
+ n_channels = ins:n_audio()
end
--- use ardour's vectorized functions
function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
local ctrl = CtrlPorts:array() -- get control port array (read/write)
- if Session:transport_rolling() then ctrl[2] = -math.huge return end
+
+ if Session:transport_rolling() then
+ -- don't do anything if the transport is already rolling
+ ctrl[2] = -math.huge -- set control output port value
+ return
+ end
+
local threshold = 10 ^ (.05 * ctrl[1]) -- dBFS to coefficient
local level = -math.huge
+
for c = 1,n_channels do
- local b = in_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of buffer for given cannel
- if b ~= ARDOUR.ChanMapping.Invalid then
- local a = ARDOUR.DSP.compute_peak(bufs:get_audio(b):data(offset), n_samples, 0)
+ local b = in_map:get(ARDOUR.DataType("audio"), c - 1) -- get id of audio-buffer for the given channel
+ if b ~= ARDOUR.ChanMapping.Invalid then -- check if channel is mapped
+ local a = ARDOUR.DSP.compute_peak(bufs:get_audio(b):data(offset), n_samples, 0) -- compute digital peak
if a > threshold then
Session:request_transport_speed(1.0, true)
end
- if a > level then level = a end
+ if a > level then level = a end -- max level of all channels
end
end
- ctrl[2] = ARDOUR.DSP.accurate_coefficient_to_dB (level)
+ ctrl[2] = ARDOUR.DSP.accurate_coefficient_to_dB (level) -- set control output port value
end