ardour { ["type"] = "dsp", name = "Simple Amp III", license = "MIT", author = "Robin Gareus", email = "robin@gareus.org", site = "http://gareus.org", description = [[ An Example DSP Plugin for processing audio, to be used with Ardour's Lua scripting facility.]] } function dsp_ioconfig () return { { audio_in = -1, audio_out = -1}, } end function dsp_params () return { { ["type"] = "input", name = "Gain", min = -20, max = 20, default = 6, unit="dB", scalepoints = { ["0"] = 0, ["twice as loud"] = 6 , ["half as loud"] = -6 } }, } end -- use ardour's vectorized functions -- -- This is as efficient as Ardour doing it itself in C++ -- Lua function overhead is negligible -- -- this also exemplifies the /simpler/ way of letting ardour to -- the channel and offset mapping. function dsp_run (ins, outs, n_samples) local ctrl = CtrlPorts:array() -- get control port array (read/write) local gain = ARDOUR.DSP.dB_to_coefficient (ctrl[1]) assert (#ins == #outs) -- ensure that we can run in-place for c = 1,#ins do --for c in pairs (ins) do -- also works, slightly less effective ARDOUR.DSP.apply_gain_to_buffer (ins[c], n_samples, gain); -- process in-place end end