ardour { ["type"] = "dsp", name = "Voice/Level Activate", category = "Utility", author = "Ardour Lua Task Force", license = "MIT", 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 function dsp_params () return { { ["type"] = "input", name = "Threshold", min = -20, max = 0, default = -6, doc = "Threshold in dBFS for all channels" }, { ["type"] = "output", name = "Level", min = -120, max = 0 }, } end function dsp_configure (ins, outs) n_channels = ins:n_audio() end 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 -- 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 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 -- max level of all channels end end ctrl[2] = ARDOUR.DSP.accurate_coefficient_to_dB (level) -- set control output port value end