ardour { ["type"] = "dsp", name = "Simple Amp II", category = "Example", license = "MIT", author = "Ardour Lua Task Force", description = [[ An Example DSP Plugin for processing audio, to be used with Ardour's Lua scripting facility.]] } -- see amp1.lua function dsp_ioconfig () return { [1] = { audio_in = -1, audio_out = -1}, } end function dsp_configure (ins, outs) audio_ins = ins:n_audio(); local audio_outs = outs:n_audio() assert (audio_ins == audio_outs) end -- this variant modifies the audio data in-place -- in Ardour's buffer. -- -- It relies on the fact that by default Ardour requires -- plugins to process data in-place (zero copy). -- -- Every assignment directly calls a c-function behind -- the scenes to get/set the value. -- It's a bit more efficient than "Amp I" on most systems. function dsp_runmap (bufs, in_map, out_map, n_samples, offset) for c = 1,audio_ins do -- ensure that processing does happen in-place local ib = in_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of mapped input buffer for given cannel local ob = out_map:get(ARDOUR.DataType("audio"), c - 1); -- get id of mapped output buffer for given cannel assert (ib ~= ARDOUR.ChanMapping.Invalid); assert (ob ~= ARDOUR.ChanMapping.Invalid); local bi = bufs:get_audio(ib) local bo = bufs:get_audio(ob) assert (bi == bo) local a = bufs:get_audio(ib):data(offset):array() -- get a reference (pointer to array) for s = 1,n_samples do a[s] = a[s] * 2; -- modify data in-place (shared with ardour) end end end