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Rough-in an qm-barbeattracker Lua example

This commit is contained in:
Robin Gareus 2017-08-04 01:56:50 +02:00
parent 9036f89311
commit ceb31ff683

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ardour { ["type"] = "Snippet", name = "Vamp TempoMap Test" }
function factory () return function ()
-- get Editor selection
-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Editor
-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Selection
local sel = Editor:get_selection ()
-- Instantiate the QM BarBeat Tracker
-- see http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:LuaAPI:Vamp
-- http://vamp-plugins.org/plugin-doc/qm-vamp-plugins.html#qm-barbeattracker
local vamp = ARDOUR.LuaAPI.Vamp("libardourvampplugins:qm-barbeattracker", Session:nominal_frame_rate())
-- prepare table to hold results
local beats = {}
local bars = {}
-- for each selected region
-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:RegionSelection
for r in sel.regions:regionlist ():iter () do
-- "r" is-a http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Region
-- prepare lua table to hold results for the given region (by name)
beats[r:name ()] = {}
bars[r:name ()] = {}
-- callback to handle Vamp-Plugin analysis results
function callback (feats)
-- "feats" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureSet
-- get the first output. here: Beats, estimated beat locations & beat-number
local fl = feats:table()[0]
-- "fl" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:FeatureList
-- which may be empty or not nil
if fl then
-- iterate over returned features
for f in fl:iter () do
-- "f" is-a http://manual.ardour.org/lua-scripting/class_reference/#Vamp:Plugin:Feature
if f.hasTimestamp then
local fn = Vamp.RealTime.realTime2Frame (f.timestamp, 48000)
table.insert (beats[r:name ()], {pos = fn, beat = f.label})
end
end
end
-- get the 2nd output. here: estimated bar locations
local fl = feats:table()[1]
if fl then
for f in fl:iter () do
if f.hasTimestamp then
local fn = Vamp.RealTime.realTime2Frame (f.timestamp, 48000)
table.insert (bars[r:name ()], fn)
end
end
end
end
vamp:plugin ():setParameter ("Beats Per Bar", 4); -- TODO ask
-- run the plugin, analyze the first channel of the audio-region
vamp:analyze (r:to_readable (), 0, callback)
-- get remaining features (end of analyis)
callback (vamp:plugin ():getRemainingFeatures ())
-- reset the plugin (prepare for next iteration)
vamp:reset ()
end
-- print results (for now)
-- TODO: calculate and set tempo-map
for n,o in pairs(bars) do
print ("Bar analysis for region:", n)
for _,t in ipairs(o) do
print ("-", t)
end
end
for n,o in pairs(beats) do
print ("Beat analysis for region:", n)
for _,t in ipairs(o) do
print ("-", t['pos'], t['beat'])
end
end
end end