scripts/faders_to_trims.lua

   1 ardour {
   2         ["type"]    = "EditorAction",
   3         name        = "Faders to Trims",
   4         license     = "MIT",
   5         author      = "PSmith",
   6         description = [[Add 'Trim' plugins to all tracks.  Move the fader value into the trim.]]
   7 }
   8
   9 function action_params ()
  10         return
  11         {
  12         }
  13 end
  14
  15
  16 function factory (params)
  17         return function ()
  18                 -- loop over all tracks
  19                 for t in Session:get_tracks():iter() do
  20
  21                         fader_value = t:gain_control():get_value()
  22                         if fader_value == 1 then
  23                                 goto skip
  24                         end
  25                         if t:gain_control():automation_state() ~= ARDOUR.AutoState.Off then
  26                                 goto skip
  27                         end
  28
  29                         -- TODO: skip MIDI tracks without or with a post-fader synth
  30                         -- (fader is MIDI-velocity)
  31
  32                         v = math.log(fader_value, 10)
  33                         trim_gain = 20*v
  34                         fader_pos = 0
  35                         local proc;
  36                         local i = 0;
  37
  38                         repeat
  39                                 -- find the fader proc
  40                                 proc = t:nth_processor (i)
  41                                 if (not proc:isnil() and proc:display_name () == "Fader") then
  42                                         fader_pos = i
  43                                 end
  44                                 i = i + 1
  45                         until proc:isnil()
  46
  47                         -- apply the trim
  48                         trim = t:nth_processor (fader_pos+1)
  49                         if (not trim:isnil() and trim:display_name () == "a-Amplifier") then
  50                                 --existing trim found; sum the trim and the fader gain, and set the trim to that value
  51                                 cur_gain = ARDOUR.LuaAPI.get_processor_param (trim, 0)
  52                                 ARDOUR.LuaAPI.set_processor_param (trim, 0, trim_gain+cur_gain)
  53                         else
  54                                 --create a new Trim processor, and set its value to match the fader
  55                                 local a = ARDOUR.LuaAPI.new_luaproc(Session, "a-Amplifier");
  56                                 if (not a:isnil()) then
  57                                         t:add_processor_by_index(a, fader_pos-1, nil, true)
  58                                         ARDOUR.LuaAPI.set_processor_param (a, 0, trim_gain)
  59                                         a = nil -- explicitly drop shared-ptr reference
  60                                 end
  61                         end
  62
  63                         --zero the fader gain
  64                         t:gain_control():set_value(1, PBD.GroupControlDisposition.NoGroup)
  65
  66                         ::skip::
  67
  68                 end --foreach track
  69
  70         end  --function
  71
  72 end --factory