Create Lua script to create a playlist on selected audio tracks with only audible contents

share/scripts/new_clean_playlists.lua

@@ -0,0 +1,261 @@
+ardour { ["type"] = "EditorAction", name = "New clean playlists",
+	license     = "MIT",
+	author      = "Mathieu Picot (Houston4444)",
+	description = [[Copy the current playlist of selected audio tracks to a new playlist with audible regions only.]]
+}
+
+function factory (params) return function ()
+
+	-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Selection
+	local sel = Editor:get_selection ()
+
+	-- Track/Bus Selection -- iterate over all Editor-GUI selected tracks
+	-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:TrackSelection
+	for route in sel.tracks:routelist():iter() do
+
+		-- each of the items 'route' is-a
+		-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Route
+		local track = route:to_track() -- see if it's a track
+		if track:isnil() then
+			-- if not, skip it
+			goto next_route
+		end
+
+		local is_audio = false
+		if track:data_type():to_string() == "audio" then
+			is_audio = true
+		end
+
+		local main_pl_name = track:name() .. "._MAIN_"
+		local main_pl_ex_name = track:name() .. "_ExMAIN_"
+
+		-- find the playlist name track_name._MAIN_
+		for pl in Session:playlists():playlists_for_track (track):iter() do
+			if pl:name() == main_pl_name then
+				pl:set_name(main_pl_ex_name)
+				break
+			end
+		end
+
+		-- copy current playlist, get new playlist and rename it
+		-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Playlist
+        track:use_copy_playlist()
+		local playlist = track:playlist()
+		playlist:set_name(track:name() .. "._MAIN_")
+
+		-- we will stock here the values needed to modify/remove regions
+		local regions_to_modify = {}
+        local point_b = 0
+        local point_c = 0
+
+		for r in playlist:region_list():iter() do
+			local r_front = r:position():samples()
+			local r_end = r_front + r:length():samples()
+
+			-- region can be finally splited into many segments
+			-- 'segments' is a table containing segments with the form
+			-- {{seg1_start, seg1_end}, {seg2_start, seg2_finish}...}
+			-- segments will finally be regions
+			local segments = {{r_front, r_end}}
+
+			-- values used for audio tracks to prevent cut during an audible fade
+			local r_no_cut_before = r_front
+			local r_no_cut_after = r_end
+
+			if is_audio then
+				local ra = r:to_audioregion()
+				if ra:fade_in_active() then
+					r_no_cut_before = r_front + ra:fade_in_length():samples() + 64
+				end
+
+				if ra:fade_out_active() then
+					r_no_cut_after = r_end - ra:fade_out_length():samples() - 64
+				end
+			end
+
+			for rg in playlist:region_list():iter() do
+				-- ignore regions equal or above this one
+				if rg:layer() <= r:layer() then
+					goto next_rg
+				end
+
+				-- get points between which lower regions can be cut
+				local cut_point_left = rg:position():samples()
+				local cut_point_right = cut_point_left + rg:length():samples()
+
+				if is_audio then
+					rga = rg:to_audioregion()
+
+					cut_point_left  = cut_point_left + 64
+					cut_point_right = cut_point_right - 64
+
+					if rga:fade_in_active() then
+						cut_point_left = cut_point_left + rga:fade_in_length():samples()
+					end
+
+					if rga:fade_out_active() then
+						cut_point_right = cut_point_right - rga:fade_out_length():samples()
+					end
+				end
+
+				-- ignore regions with no overlap with this one
+				if cut_point_left >= segments[#segments][2]
+						or cut_point_right <= segments[1][1] then
+					goto next_rg
+				end
+
+				-- stock here the segments ids we should remove
+				local remove_id_list = {}
+
+				-- iterate segments
+				for i, s in pairs(segments) do
+					if cut_point_right <= s[1] or cut_point_left >= s[2] then
+						-- rg:  ___      or      ____
+						-- s :      ___      ____
+
+						-- compared region doesn't overlap this segment
+						goto next_segment
+
+					elseif cut_point_left <= s[1] and cut_point_right >= s[2] then
+						-- rg:  ________
+						-- s :    ____
+						
+						-- compared region exceed both front and end
+						-- this segment will be removed
+						table.insert(remove_id_list, i)
+						goto next_segment
+
+					elseif cut_point_left <= s[1] then
+						-- rg:  ____
+						-- s :    _____
+
+						if is_audio then
+							-- audio segment is cut 64 samples before compared region fade out
+							-- in the limit of the original segment
+							-- it also do not cut during the region fades
+							if cut_point_right > r_no_cut_before then
+								s[1] = math.min(cut_point_right,
+								                r_no_cut_after)
+							end
+						else
+							s[1] = cut_point_right
+						end
+
+					elseif cut_point_right >= s[2] then
+						-- rg:     _____
+						-- s :  _____
+
+						if is_audio then
+							-- audio segment is cut 64 samples after compared region fade in
+							-- in the limit of the original segment
+							if cut_point_left < r_no_cut_after then
+								s[2] = math.max(cut_point_left,
+								                r_no_cut_before)
+							end
+						else
+							s[2] = cut_point_left
+						end
+
+					else
+						-- rg:      B___C
+						-- s :  A___________D
+
+						-- worst case, compared region rg is above r,
+                        -- rg starts after and finish before r.
+
+						point_b = cut_point_left
+						point_c = cut_point_right
+
+						if is_audio then
+							point_b = math.max(point_b, r_no_cut_before)
+							point_c = math.min(point_c, r_no_cut_after)
+
+							if point_b > r_no_cut_after or point_c < r_no_cut_before then
+								-- we must keep the fade integrity
+								goto next_segment
+							end
+						end
+
+						-- we can modify the table now because
+						-- we break the iteration loop just after.
+						-- add the new segment C->D
+						table.insert(segments, i + 1, {point_c, s[2]})
+
+						-- reduce the original segment (from A->D to A->B)
+						s[2] = point_b
+						break
+					end
+					::next_segment::
+				end
+
+				-- remove segments that need to be removed
+				for i=1, #remove_id_list do
+					table.remove(
+						segments, remove_id_list[#remove_id_list +1 -i])
+				end
+
+				-- if all segments are removed, region will be deleted
+				if segments[1] == nil then break end
+
+				::next_rg::
+			end
+
+			-- security check
+			-- prevent segments and gaps shorter than 128
+			-- and overlap segments from the same region
+			local last_end = -1
+			local new_segments = {}
+
+			for i, s in pairs(segments) do
+				if s[2] - s[1] > 128 then
+					if s[1] > last_end + 128 then
+						table.insert(new_segments, s)
+					else
+						new_segments[#new_segments][2] = s[2]
+					end
+				end 
+				last_end = s[2]
+			end
+
+			-- remember the regions we have to delete or modify
+			table.insert(regions_to_modify, {r, new_segments})
+        end
+
+		-- Remove, split or cut needed regions
+		for i=1, #regions_to_modify do
+			r = regions_to_modify[i][1]
+			segments = regions_to_modify[i][2]
+
+			if #segments == 0 then
+				playlist:remove_region(r)
+			else
+				for j=1, #segments do
+					if j == #segments then
+						-- last segment, cut directly this region
+						rg = r
+					else
+						-- 2 segments or more for this region
+						-- So we need to clone the region before to cut it
+						rg = ARDOUR.RegionFactory.clone_region(r, true, false)
+						playlist:add_region(rg, rg:position(), 1, false, 0, 0, false)
+						
+						while rg:layer() > r:layer()
+						do
+							rg:lower()
+						end
+					end
+
+					-- finally cut the region if needed
+					if segments[j][1] ~= rg:position():samples() then
+						rg:cut_front(Temporal.timepos_t(segments[j][1]), 0)
+					end
+
+					if segments[j][2] ~= rg:position():samples() + rg:length():samples() then
+						rg:cut_end(Temporal.timepos_t(segments[j][2]), 0)
+					end
+				end
+			end
+		end
+		::next_route::
+	end
+end end