scripts/_vamp_tempomap_example.lua

   1 ardour { ["type"] = "Snippet", name = "Vamp TempoMap Test" }
   2
   3 function factory () return function ()
   4
   5         -- get Editor selection
   6         -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Editor
   7         -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Selection
   8         local sel = Editor:get_selection ()
   9
  10         -- Instantiate the QM BarBeat Tracker
  11         -- see http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:LuaAPI:Vamp
  12         -- http://vamp-plugins.org/plugin-doc/qm-vamp-plugins.html#qm-barbeattracker
  13         local vamp = ARDOUR.LuaAPI.Vamp("libardourvampplugins:qm-barbeattracker", Session:nominal_sample_rate())
  14
  15         -- prepare table to hold results
  16         local beats = {}
  17         local bars = {}
  18
  19         -- for each selected region
  20         -- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:RegionSelection
  21         for r in sel.regions:regionlist ():iter () do
  22                 -- "r" is-a http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Region
  23
  24                 -- prepare lua table to hold results for the given region (by name)
  25                 beats[r:name ()] = {}
  26                 bars[r:name ()] = {}
  27
  28                 -- callback to handle Vamp-Plugin analysis results
  29                 function callback (feats)
  30                         -- "feats" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureSet
  31
  32                         -- get the first output. here: Beats, estimated beat locations & beat-number
  33                         local fl = feats:table()[0]
  34                         -- "fl" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureList
  35                         -- which may be empty or not nil
  36                         if fl then
  37                                 -- iterate over returned features
  38                                 for f in fl:iter () do
  39                                         -- "f" is-a  http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:Feature
  40                                         if f.hasTimestamp then
  41                                                 local fn = Vamp.RealTime.realTime2Frame (f.timestamp, 48000)
  42                                                 table.insert (beats[r:name ()], {pos = fn, beat = f.label})
  43                                         end
  44                                 end
  45                         end
  46
  47                         -- get the 2nd output. here: estimated bar locations
  48                         local fl = feats:table()[1]
  49                         if fl then
  50                                 for f in fl:iter () do
  51                                         if f.hasTimestamp then
  52                                                 local fn = Vamp.RealTime.realTime2Frame (f.timestamp, 48000)
  53                                                 table.insert (bars[r:name ()],  fn)
  54                                         end
  55                                 end
  56                         end
  57                 end
  58
  59                 vamp:plugin ():setParameter ("Beats Per Bar", 4); -- TODO ask
  60
  61                 -- run the plugin, analyze the first channel of the audio-region
  62                 vamp:analyze (r:to_readable (), 0, callback)
  63                 -- get remaining features (end of analyis)
  64                 callback (vamp:plugin ():getRemainingFeatures ())
  65                 -- reset the plugin (prepare for next iteration)
  66                 vamp:reset ()
  67         end
  68
  69         -- print results (for now)
  70         -- TODO: calculate and set tempo-map
  71         for n,o in pairs(bars) do
  72                 print ("Bar analysis for region:", n)
  73                 for _,t in ipairs(o) do
  74                         print ("-", t)
  75                 end
  76         end
  77         for n,o in pairs(beats) do
  78                 print ("Beat analysis for region:", n)
  79                 for _,t in ipairs(o) do
  80                         print ("-", t['pos'], t['beat'])
  81                 end
  82         end
  83
  84 end end