ardour { ["type"] = "dsp", name = "Inline Spectrogram", category = "Visualization", license = "GPLv2", author = "Robin Gareus", email = "robin@gareus.org", site = "http://gareus.org", description = [[An Example DSP Plugin to display a spectrom on the mixer strip]] } -- return possible i/o configurations function dsp_ioconfig () -- -1, -1 = any number of channels as long as input and output count matches return { [1] = { audio_in = -1, audio_out = -1}, } end function dsp_params () return { { ["type"] = "input", name = "Logscale", min = 0, max = 1, default = 0, toggled = true }, { ["type"] = "input", name = "1/f scale", min = 0, max = 1, default = 1, toggled = true }, { ["type"] = "input", name = "FFT Size", min = 0, max = 4, default = 3, enum = true, scalepoints = { ["512"] = 0, ["1024"] = 1, ["2048"] = 2, ["4096"] = 3, ["8192"] = 4, } }, { ["type"] = "input", name = "Height (Aspect)", min = 0, max = 3, default = 1, enum = true, scalepoints = { ["Min"] = 0, ["16:10"] = 1, ["1:1"] = 2, ["Max"] = 3 } }, { ["type"] = "input", name = "Range", min = 20, max = 160, default = 60, unit="dB"}, { ["type"] = "input", name = "Offset", min = -40, max = 40, default = 0, unit="dB"}, } end -- a C memory area. -- It needs to be in global scope. -- When the variable is set to nil, the allocated memory -- is free()ed local cmem = nil function dsp_init (rate) -- global variables (DSP part only) dpy_hz = rate / 25 dpy_wr = 0 -- create a ringbuffer to hold (float) audio-data rb = PBD.RingBufferF (2 * rate) -- allocate memory, local mix buffer cmem = ARDOUR.DSP.DspShm (8192) -- create a table of objects to share with the GUI local tbl = {} tbl['rb'] = rb; tbl['samplerate'] = rate -- "self" is a special DSP variable referring -- to the plugin instance itself. -- -- "table()" is-a http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR.LuaTableRef -- which allows to store/retrieve lua-tables to share them other interpreters self:table ():set (tbl); end function dsp_runmap (bufs, in_map, out_map, n_samples, offset) -- here we sum all audio input channels channels and then copy the data to a ringbuffer -- for the GUI to process later local audio_ins = in_map:count (): n_audio () -- number of audio input buffers local ccnt = 0 -- processed channel count local mem = cmem:to_float(0) -- a "FloatArray", float* for direct C API usage from the previously allocated buffer for c = 1,audio_ins do -- Note: lua starts counting at 1, ardour's ChanMapping::get() at 0 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 if (ib ~= ARDOUR.ChanMapping.Invalid) then if c == 1 then -- first channel, copy as-is ARDOUR.DSP.copy_vector (mem, bufs:get_audio (ib):data (offset), n_samples) else -- all other channels, add to existing data. ARDOUR.DSP.mix_buffers_no_gain (mem, bufs:get_audio (ib):data (offset), n_samples) end ccnt = ccnt + 1; -- copy data to output (if not processing in-place) if (ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob) then ARDOUR.DSP.copy_vector (bufs:get_audio (ob):data (offset), bufs:get_audio (ib):data (offset), n_samples) end end end -- Clear unconnected output buffers. -- In case we're processing in-place some buffers may be identical, -- so this must be done *after processing*. for c = 1,audio_ins do 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 if (ib == ARDOUR.ChanMapping.Invalid and ob ~= ARDOUR.ChanMapping.Invalid) then bufs:get_audio (ob):silence (n_samples, offset) end end -- Normalize gain (1 / channel-count) if ccnt > 1 then ARDOUR.DSP.apply_gain_to_buffer (mem, n_samples, 1 / ccnt) end -- if no channels were processed, feed silence. if ccnt == 0 then ARDOUR.DSP.memset (mem, 0, n_samples) end -- write data to the ringbuffer rb:write (mem, n_samples) -- emit QueueDraw every FPS -- TODO: call every FFT window-size worth of samples, at most every FPS dpy_wr = dpy_wr + n_samples if (dpy_wr > dpy_hz) then dpy_wr = dpy_wr % dpy_hz self:queue_draw () end end ---------------------------------------------------------------- -- GUI local fft = nil local read_ptr = 0 local line = 0 local img = nil local fft_size = 0 local last_log = false function render_inline (ctx, w, max_h) local ctrl = CtrlPorts:array () -- get control port array (read/write) local tbl = self:table ():get () -- get shared memory table local rate = tbl['samplerate'] if not cmem then cmem = ARDOUR.DSP.DspShm (0) end -- get settings local logscale = ctrl[1] or 0; logscale = logscale > 0 -- x-axis logscale local pink = ctrl[2] or 0; pink = pink > 0 -- 1/f scale local fftsizeenum = ctrl[3] or 3 -- fft-size enum local hmode = ctrl[4] or 1 -- height mode enum local dbrange = ctrl[5] or 60 local gaindb = ctrl[6] or 0 local fftsize if fftsizeenum == 0 then fftsize = 512 elseif fftsizeenum == 1 then fftsize = 1024 elseif fftsizeenum == 2 then fftsize = 2048 elseif fftsizeenum == 4 then fftsize = 8192 else fftsize = 4096 end if fftsize ~= fft_size then fft_size = fftsize fft = nil end if dbrange < 20 then dbrange = 20; end if dbrange > 160 then dbrange = 160; end if gaindb < -40 then dbrange = -40; end if gaindb > 40 then dbrange = 40; end if not fft then fft = ARDOUR.DSP.FFTSpectrum (fft_size, rate) cmem:allocate (fft_size) end if last_log ~= logscale then last_log = logscale img = nil line = 0 end -- calc height if hmode == 0 then h = math.ceil (w * 10 / 16) if (h > 44) then h = 44 end elseif (hmode == 2) then h = w elseif (hmode == 3) then h = max_h else h = math.ceil (w * 10 / 16) end if (h > max_h) then h = max_h end -- re-create image surface if not img or img:get_width() ~= w or img:get_height () ~= h then img = Cairo.ImageSurface (Cairo.Format.ARGB32, w, h) line = 0 end local ictx = img:context () local bins = fft_size / 2 - 1 -- fft bin count local bpx = bins / w -- bins per x-pixel (linear) local fpb = rate / fft_size -- freq-step per bin local f_e = rate / 2 / fpb -- log-scale exponent local f_b = w / math.log (fft_size / 2) -- inverse log-scale base local f_l = math.log (fft_size / rate) * f_b -- inverse logscale lower-bound local rb = tbl['rb']; local mem = cmem:to_float (0) while (rb:read_space() >= fft_size) do -- process one line / buffer rb:read (mem, fft_size) fft:set_data_hann (mem, fft_size, 0) fft:execute () -- draw spectrum assert (bpx >= 1) -- scroll if line == 0 then line = h - 1; else line = line - 1; end -- clear this line ictx:set_source_rgba (0, 0, 0, 1) ictx:rectangle (0, line, w, 1) ictx:fill () for x = 0, w - 1 do local pk = 0 local b0, b1 if logscale then -- 20 .. 20k b0 = math.floor (f_e ^ (x / w)) b1 = math.floor (f_e ^ ((x + 1) / w)) else b0 = math.floor (x * bpx) b1 = math.floor ((x + 1) * bpx) end if b1 >= b0 and b1 <= bins and b0 >= 0 then for i = b0, b1 do local level = gaindb + fft:power_at_bin (i, pink and i or 1) -- pink ? i : 1 if level > -dbrange then local p = (dbrange + level) / dbrange if p > pk then pk = p; end end end end if pk > 0.0 then if pk > 1.0 then pk = 1.0; end ictx:set_source_rgba (ARDOUR.LuaAPI.hsla_to_rgba (.70 - .72 * pk, .9, .3 + pk * .4)); ictx:rectangle (x, line, 1, 1) ictx:fill () end end end -- copy image surface if line == 0 then img:set_as_source (ctx, 0, 0) ctx:rectangle (0, 0, w, h) ctx:fill () else local yp = h - line - 1; img:set_as_source (ctx, 0, yp) ctx:rectangle (0, yp, w, line) ctx:fill () img:set_as_source (ctx, 0, -line) ctx:rectangle (0, 0, w, yp) ctx:fill () end -- draw grid on top function x_at_freq (f) if logscale then return f_l + f_b * math.log (f) else return 2 * w * f / rate; end end function grid_freq (f) -- draw vertical grid line local x = .5 + math.floor (x_at_freq (f)) ctx:move_to (x, 0) ctx:line_to (x, h) ctx:stroke () end -- draw grid on top local dash3 = C.DoubleVector () dash3:add ({1, 3}) ctx:set_line_width (1.0) ctx:set_dash (dash3, 2) -- dotted line ctx:set_source_rgba (.5, .5, .5, .8) grid_freq (100) grid_freq (1000) grid_freq (10000) ctx:unset_dash () return {w, h} end