Aegisub/automation/autoload/kara-templater.lua

--[[
 Copyright (c) 2007, Niels Martin Hansen, Rodrigo Braz Monteiro
 All rights reserved.

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   * Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
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     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
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     may be used to endorse or promote products derived from this software
     without specific prior written permission.

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 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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-- Aegisub Automation 4 Lua karaoke templater tool
-- Parse and apply a karaoke effect written in ASS karaoke template language
-- See help file and wiki for more information on this

script_name = "Karaoke Templater"
script_description = "Macro and export filter to apply karaoke effects using the template language"
script_author = "Niels Martin Hansen"
script_version = "0.9 beta 1"


include("karaskel.lua")


-- Find and parse/prepare all karaoke template lines
function parse_templates(meta, styles, subs)
	local templates = { once = {}, line = {}, syl = {}, char = {}, furi = {}, styles = {} }
	local i = 1
	while i <= #subs do
		aegisub.progress.set((i-1) / #subs * 100)
		local l = subs[i]
		i = i + 1
		if l.class == "dialogue" and l.comment then
			local fx, mods = string.headtail(l.effect)
			fx = fx:lower()
			if fx == "code" then
				parse_code(meta, styles, l, templates, mods)
			elseif fx == "template" then
				parse_template(meta, styles, l, templates, mods)
			end
			templates.styles[l.style] = true
		elseif l.class == "dialogue" and l.effect == "fx" then
			-- this is a previously generated effect line, remove it
			i = i - 1
			subs.delete(i)
		end
	end
	aegisub.progress.set(100)
	return templates
end

function parse_code(meta, styles, line, templates, mods)
	local template = {
		code = line.text,
		loops = 1,
		style = line.style
	}
	local inserted = false

	local rest = mods
	while rest ~= "" do
		local m, t = string.headtail(rest)
		rest = t
		m = m:lower()
		if m == "once" then
			table.insert(templates.once, template)
			inserted = true
		elseif m == "line" then
			table.insert(templates.line, template)
			inserted = true
		elseif m == "syl" then
			table.insert(templates.syl, template)
			inserted = true
		elseif m == "furi" then
			table.insert(templates.furi, template)
			inserted = true
		elseif m == "all" then
			template.style = nil
		elseif m == "repeat" or m == "loop" then
			local times, t = string.headtail(rest)
			template.loops = tonumber(times)
			if not template.loops then
				aegisub.out(3, "Failed reading this repeat-count to a number: %s\nIn template code line: %s\nEffect field: %s\n\n", times, line.text, line.effect)
				template.loops = 1
			else
				rest = t
			end
		else
			aegisub.out(3, "Unknown modifier in code template: %s\nIn template code line: %s\nEffect field: %s\n\n", m, line.text, line.effect)
		end
	end
	
	if not inserted then
		table.insert(templates.once, template)
	end
end

template_modifiers = {
	"pre-line", "line", "syl", "furi", "char", "all", "repeat", "loop",
	"notext", "keeptags", "noblank", "multi", "fx", "fxgroup"
}

function parse_template(meta, styles, line, templates, mods)
	local template = {
		t = "",
		pre = "",
		style = line.style,
		loops = 1,
		layer = line.layer,
		addtext = true,
		keeptags = false,
		fxgroup = nil,
		inline_fx = nil,
		multi = false,
		isline = false,
		perchar = false,
		noblank = false
	}
	local inserted = false
	
	local rest = mods
	while rest ~= "" do
		local m, t = string.headtail(rest)
		rest = t
		m = m:lower()
		if (m == "pre-line" or m == "line") and not inserted then
			aegisub.debug.out("Found line template '%s'\n", line.text)
			-- should really fail if already inserted
			local id, t = string.headtail(rest)
			id = id:lower()
			-- check that it really is an identifier and not a keyword
			for _, kw in pairs(template_modifiers) do
				if id == kw then
					id = nil
					break
				end
			end
			if id then
				rest = t
			end
			-- get old template if there is one
			if id and templates.line[id] then
				template = templates.line[id]
			elseif id then
				template.id = id
				templates.line[id] = template
			else
				table.insert(templates.line, template)
			end
			inserted = true
			template.isline = true
			-- apply text to correct string
			if m == "line" then
				template.t = template.t .. line.text
			else -- must be pre-line
				template.pre = template.pre .. line.text
			end
		elseif m == "syl" and not template.isline then
			table.insert(templates.syl, template)
			inserted = true
		elseif m == "furi" and not template.isline then
			table.insert(templates.furi, template)
			inserted = true
		elseif (m == "pre-line" or m == "line") and inserted then
			aegisub.out(2, "Unable to combine %s class templates with other template classes\n\n", m)
		elseif (m == "syl" or m == "furi") and template.isline then
			aegisub.out(2, "Unable to combine %s class template lines with line or pre-line classes\n\n", m)
		elseif m == "all" then
			template.style = nil
		elseif m == "repeat" or m == "loop" then
			local times, t = string.headtail(rest)
			template.loops = tonumber(times)
			if not template.loops then
				aegisub.out(3, "Failed reading this repeat-count to a number: %s\nIn template line: %s\nEffect field: %s\n\n", times, line.text, line.effect)
				template.loops = 1
			else
				rest = t
			end
		elseif m == "notext" then
			template.addtext = false
		elseif m == "keeptags" then
			template.keeptags = true
		elseif m == "multi" then
			template.multi = true
		elseif m == "char" then
			template.perchar = true
		elseif m == "noblank" then
			template.noblank = true
		elseif m == "fx" then
			local fx, t = string.headtail(rest)
			if fx ~= "" then
				template.fx = fx
				rest = t
			else
				aegisub.out(3, "No fx name following fx modifier\nIn template line: %s\nEffect field: %s\n\n", line.text, line.effect)
				template.fx = nil
			end
		elseif m == "fxgroup" then
			local fx, t = string.headtail(rest)
			if fx ~= "" then
				template.fxgroup = fx
				rest = t
			else
				aegisub.out(3, "No fxgroup name following fxgroup modifier\nIn template linee: %s\nEffect field: %s\n\n", line.text, line.effect)
				template.fxgroup = nil
			end
		else
			aegisub.out(3, "Unknown modifier in template: %s\nIn template line: %s\nEffect field: %s\n\n", m, line.text, line.effect)
		end
	end
	
	if not inserted then
		table.insert(templates.syl, template)
	end
	if not template.isline then
		template.t = line.text
	end
end

-- Iterator function, return all templates that apply to the given line
function matching_templates(templates, line, tenv)
	local lastkey = nil
	local function test_next()
		local k, t = next(templates, lastkey)
		lastkey = k
		if not t then
			return nil
		elseif (t.style == line.style or not t.style) and
				(not t.fxgroup or
				(t.fxgroup and tenv.fxgroup[t.fxgroup] ~= false)) then
			return t
		else
			return test_next()
		end
	end
	return test_next
end


-- Apply the templates
function apply_templates(meta, styles, subs, templates)
	-- the environment the templates will run in
	local tenv = {
		-- put in some standard libs
		string = string,
		math = math,
		_G = _G
	}
	tenv.tenv = tenv
	
	tenv.retime = function(mode, addstart, addend)
		local line, syl = tenv.line, tenv.syl
		local newstart, newend = line.start_time, line.end_time
		addstart = addstart or 0
		addend = addend or 0
		if mode == "syl" then
			newstart = line.start_time + syl.start_time + addstart
			newend = line.start_time + syl.end_time + addend
		elseif mode == "presyl" then
			newstart = line.start_time + syl.start_time + addstart
			newend = line.start_time + syl.start_time + addend
		elseif mode == "postsyl" then
			newstart = line.start_time + syl.end_time + addstart
			newend = line.start_time + syl.end_time + addend
		elseif mode == "preline" then
			newstart = line.start_time + addstart
			newend = line.start_time + addend
		elseif mode == "postline" then
			newstart = line.end_time + addstart
			newend = line.end_time + addend
		elseif mode == "start2syl" then
			newstart = line.start_time + addstart
			newend = line.start_time + syl.start_time + addend
		elseif mode == "syl2end" then
			newstart = line.start_time + syl.end_time + addstart
			newend = line.end_time + addend
		elseif mode == "set" or mode == "abs" then
			newstart = addstart
			newend = addend
		elseif mode == "sylpct" then
			newstart = line.start_time + syl.start_time + addstart*syl.duration/100
			newend = line.start_time + syl.start_time + addend*syl.duration/100
		-- wishlist: something for fade-over effects,
		-- "time between previous line and this" and
		-- "time between this line and next"
		end
		line.start_time = newstart
		line.end_time = newend
		return ""
	end
	tenv.fxgroup = {}
	
	-- run all run-once code snippets
	for k, t in pairs(templates.once) do
		assert(t.code, "WTF, a 'once' template without code?")
		run_code_template(t, tenv)
	end
	
	-- start processing lines
	local i, n = 0, #subs
	while i < n do
		aegisub.progress.set(i/n*100)
		i = i + 1
		local l = subs[i]
		if l.class == "dialogue" and ((l.effect == "" and not l.comment) or (l.effect == "karaoke" and l.comment)) then
			l.i = i
			l.comment = false
			karaskel.preproc_line(subs, meta, styles, l)
			if apply_line(meta, styles, subs, l, templates, tenv) then
				-- Some templates were applied to this line, make a karaoke timing line of it
				l.comment = true
				l.effect = "karaoke"
				subs[i] = l
			end			
		end
	end
end

function set_ctx_syl(varctx, line, syl)
	varctx.sstart = syl.start_time
	varctx.send = syl.end_time
	varctx.sdur = syl.duration
	varctx.skdur = syl.duration / 10
	varctx.smid = syl.start_time + syl.duration / 2
	varctx["start"] = varctx.sstart
	varctx["end"] = varctx.send
	varctx.dur = varctx.sdur
	varctx.kdur = varctx.skdur
	varctx.mid = varctx.smid
	varctx.si = syl.i
	varctx.i = varctx.si
	varctx.sleft = math.floor(line.left + syl.left+0.5)
	varctx.scenter = math.floor(line.left + syl.center+0.5)
	varctx.sright = math.floor(line.left + syl.right+0.5)
	if syl.isfuri then
		varctx.sbottom = varctx.ltop
		varctx.stop = math.floor(varctx.ltop - syl.height + 0.5)
		varctx.smiddle = math.floor(varctx.ltop - syl.height/2 + 0.5)
	else
		varctx.stop = varctx.ltop
		varctx.smiddle = varctx.lmiddle
		varctx.sbottom = varctx.lbottom
	end
	if line.halign == "left" then
		varctx.sx = math.floor(line.left + syl.left + 0.5)
	elseif line.halign == "center" then
		varctx.sx = math.floor(line.left + syl.center + 0.5)
	elseif line.halign == "right" then
		varctx.sx = math.floor(line.left + syl.right + 0.5)
	end
	if line.valign == "top" then
		varctx.sy = varctx.stop
	elseif line.valign == "middle" then
		varctx.sy = varctx.smiddle
	elseif line.valign == "bottom" then
		varctx.sy = varctx.sbottom
	end
	varctx.left = varctx.sleft
	varctx.center = varctx.scenter
	varctx.right = varctx.sright
	varctx.top = varctx.stop
	varctx.middle = varctx.smiddle
	varctx.bottom = varctx.sbottom
	varctx.x = varctx.sx
	varctx.y = varctx.sy
end

function apply_line(meta, styles, subs, line, templates, tenv)
	-- Tell whether any templates were applied to this line, needed to know whether the original line should be removed from input
	local applied_templates = false
	
	-- General variable replacement context
	local varctx = {
		layer = line.layer,
		lstart = line.start_time,
		lend = line.end_time,
		ldur = line.duration,
		lmid = line.start_time + line.duration/2,
		style = line.style,
		actor = line.actor,
		margin_l = ((line.margin_l > 0) and line.margin_l) or line.styleref.margin_l,
		margin_r = ((line.margin_r > 0) and line.margin_r) or line.styleref.margin_r,
		margin_t = ((line.margin_t > 0) and line.margin_t) or line.styleref.margin_t,
		margin_b = ((line.margin_b > 0) and line.margin_b) or line.styleref.margin_b,
		margin_v = ((line.margin_t > 0) and line.margin_t) or line.styleref.margin_t,
		syln = line.kara.n,
		li = line.i,
		lleft = math.floor(line.left+0.5),
		lcenter = math.floor(line.left + line.width/2 + 0.5),
		lright = math.floor(line.left + line.width + 0.5),
		ltop = math.floor(line.top + 0.5),
		lmiddle = math.floor(line.middle + 0.5),
		lbottom = math.floor(line.bottom + 0.5),
		lx = math.floor(line.x+0.5),
		ly = math.floor(line.y+0.5)
	}
	
	-- Specific for whole-line processing
	varctx["start"] = varctx.lstart
	varctx["end"] = varctx.lend
	varctx.dur = varctx.ldur
	varctx.kdur = math.floor(varctx.dur / 10)
	varctx.mid = varctx.lmid
	varctx.i = varctx.li
	varctx.left = varctx.lleft
	varctx.center = varctx.lcenter
	varctx.right = varctx.lright
	varctx.top = varctx.ltop
	varctx.middle = varctx.lmiddle
	varctx.bottom = varctx.lbottom
	varctx.x = varctx.lx
	varctx.y = varctx.ly
	
	tenv.orgline = line
	tenv.line = nil
	tenv.syl = nil
	tenv.basesyl = nil

	-- Apply all line templates
	aegisub.debug.out(5, "Running line templates\n")
	for t in matching_templates(templates.line, line, tenv) do
		if t.code then
			aegisub.debug.out(5, "Code template, %s\n", t.code)
			tenv.line = line
			run_code_template(t, tenv)
		else
			aegisub.debug.out(5, "Line template, pre = '%s', t = '%s'\n", t.pre, t.t)
			applied_templates = true
			local newline = table.copy(line)
			tenv.line = newline
			newline.layer = t.layer
			newline.text = ""
			if t.pre ~= "" then
				newline.text = newline.text .. run_text_template(t.pre, tenv, varctx)
			end
			if t.t ~= "" then
				for i = 1, line.kara.n do
					local syl = line.kara[i]
					tenv.syl = syl
					set_ctx_syl(varctx, line, syl)
					newline.text = newline.text .. run_text_template(t.t, tenv, varctx)
					if t.addtext then
						if t.keeptags then
							newline.text = newline.text .. syl.text
						else
							newline.text = newline.text .. syl.text_stripped
						end
					end
				end
			else
				-- hmm, no main template for the line... put original text in
				if t.keeptags then
					newline.text = newline.text .. line.text
				else
					newline.text = newline.text .. line.text_stripped
				end
			end
			newline.effect = "fx"
			subs.append(newline)
		end
	end
	aegisub.debug.out(5, "Done running line templates\n\n")
	
	-- Loop over syllables
	for i = 0, line.kara.n do
		local syl = line.kara[i]
		
		aegisub.debug.out(5, "Applying templates to syllable: %s\n", syl.text)
		if apply_syllable_templates(syl, line, templates.syl, tenv, varctx, subs) then
			applied_templates = true
		end
	end
	
	-- Loop over furigana
	for i = 1, line.furi.n do
		local furi = line.furi[i]
		
		aegisub.debug.out(5, "Applying templates to furigana: %s\n", furi.text)
		if apply_syllable_templates(furi, line, templates.furi, tenv, varctx, subs) then
			applied_templates = true
		end
	end
	
	return applied_templates
end

function run_code_template(template, tenv)
	local f, err = loadstring(template.code, "template code")
	if not f then
		aegisub.debug.out(2, "Failed to parse Lua code: %s\nCode that failed to parse: %s\n\n", err, template.code)
	else
		local pcall = pcall
		setfenv(f, tenv)
		for j = 1, template.loops do
			tenv.j = j
			local res, err = pcall(f)
			if not res then
				aegisub.debug.out(2, "Runtime error in template code: %s\nCode producing error: %s\n\n", err, template.code)
			end
		end
	end
end

function run_text_template(template, tenv, varctx)
	local res = template
	aegisub.debug.out(5, "Running text template '%s'\n", res)
	
	-- Replace the variables in the string (this is probably faster than using a custom function, but doesn't provide error reporting)
	if varctx then
		aegisub.debug.out(5, "Has varctx, replacing variables\n")
		local function var_replacer(varname)
			varname = string.lower(varname)
			aegisub.debug.out(5, "Found variable named '%s', ", varname)
			if varctx[varname] ~= nil then
				aegisub.debug.out(5, "it exists, value is '%s'\n", varctx[varname])
				return varctx[varname]
			else
				aegisub.debug.out(5, "doesn't exist\n")
				aegisub.debug.out(2, "Unknown variable name: %s\nIn karaoke template: %s\n\n", varname, template)
				return "$" .. varname
			end
		end
		res = string.gsub(res, "$([%a_]+)", var_replacer)
		aegisub.debug.out(5, "Done replacing variables, new template string is '%s'\n", res)
	end
	
	-- Function for evaluating expressions
	local function expression_evaluator(expression)
		f, err = loadstring(string.format("return (%s)", expression))
		if (err) ~= nil then
			aegisub.debug.out(2, "Error parsing expression: %s\nExpression producing error: %s\nTemplate with expression: %s\n\n", err, expression, template)
			return "!" .. expression .. "!"
		else
			setfenv(f, tenv)
			local res, val = pcall(f)
			if res then
				return val
			else
				aegisub.debug.out(2, "Runtime error in template expression: %s\nExpression producing error: %s\nTemplate with expression: %s\n\n", val, expression, template)
				return "!" .. expression .. "!"
			end
		end
	end
	-- Find and evaluate expressions
	aegisub.debug.out(5, "Now evaluating expressions\n")
	res = string.gsub(res , "!(.-)!", expression_evaluator)
	aegisub.debug.out(5, "After evaluation: %s\nDone handling template\n\n", res)
	
	return res
end

function apply_syllable_templates(syl, line, templates, tenv, varctx, subs)
	local applied_templates = false
	
	-- Loop over all templates matching the line style
	for t in matching_templates(templates, line, tenv) do
		tenv.syl = syl
		set_ctx_syl(varctx, line, syl)
		
		if apply_one_syllable_template(syl, line, t, tenv, varctx, subs, false, false) then
			applied_templates = true
		end
	end
	
	return applied_templates
end

function is_syl_blank(syl)
	if syl.duration <= 0 then
		return true
	end
	
	-- try to remove common spacing characters
	local t = syl.text_stripped
	if t:len() <= 0 then return true end
	t = t:gsub("[ \t\n\r]", "") -- regular ASCII space characters
	t = t:gsub("　", "") -- fullwidth space
	return t:len() <= 0
end

function apply_one_syllable_template(syl, line, template, tenv, varctx, subs, skip_perchar, skip_multi)
	local t = template
	
	aegisub.debug.out(5, "Applying template to one syllable with text: %s\n", syl.text)
	
	-- Check for right inline_fx
	if t.inline_fx and t.inline_fx ~= syl.inline_fx then
		aegisub.debug.out(5, "Syllable has wrong inline-fx (wanted '%s', got '%s'), skipping.\n", t.inline_fx, syl.inline_fx)
		return false
	end
	
	if t.noblank and is_syl_blank(syl) then
		aegisub.debug.out(5, "Syllable is blank, skipping.\n")
		return false
	end
	
	-- Recurse to per-char if required
	if not skip_perchar and t.perchar then
		aegisub.debug.out(5, "Doing per-character effects...\n")
		local charsyl = table.copy(syl)
		tenv.basesyl = tenv.basesyl or syl
		tenv.syl = charsyl
		
		local left, width = syl.left, 0
		for c in unicode.chars(syl.text_stripped) do
			charsyl.text = c
			charsyl.text_stripped = c
			charsyl.text_spacestripped = c
			charsyl.prespace, charsyl.postspace = "", "" -- for whatever anyone might use these for
			width = aegisub.text_extents(syl.style, c)
			charsyl.left = left
			charsyl.center = left + width/2
			charsyl.right = left + width
			charsyl.prespacewidth, charsyl.postspacewidth = 0, 0 -- whatever...
			left = left + width
			set_ctx_syl(varctx, line, charsyl)
			
			apply_one_syllable_template(charsyl, line, t, tenv, varctx, subs, true, false)
		end
	
		return true
	end
	
	-- Recurse to multi-hl if required
	if not skip_multi and t.multi then
		aegisub.debug.out(5, "Doing multi-highlight effects...\n")
		local hlsyl = table.copy(syl)
		tenv.basesyl = tenv.basesyl or syl
		tenv.syl = hlsyl
		
		for hl = 1, syl.highlights.n do
			local hldata = syl.highlights[hl]
			hlsyl.start_time = hldata.start_time
			hlsyl.end_time = hldata.end_time
			hlsyl.duration = hldata.duration
			set_ctx_syl(varctx, line, hlsyl)
			
			apply_one_syllable_template(hlsyl, line, t, tenv, varctx, subs, true, true)
		end
	
		return true
	end

	-- Regular processing
	if t.code then
		aegisub.debug.out(5, "Running code line\n")
		tenv.line = line
		run_code_template(t, tenv)
	else
		aegisub.debug.out(5, "Running %d effect loops\n", t.loops)
		for j = 1, t.loops do
			tenv.j = j
			local newline = table.copy(line)
			newline.styleref = syl.style
			newline.style = syl.style.name
			newline.layer = t.layer
			tenv.line = newline
			newline.text = run_text_template(t.t, tenv, varctx)
			if t.addtext then
				newline.text = newline.text .. syl.text_stripped
			end
			newline.effect = "fx"
			aegisub.debug.out(5, "Generated line with text: %s\n", newline.text)
			subs.append(newline)
		end
	end
	
	return true
end


-- Main function to do the templating
function filter_apply_templates(subs, config)
	aegisub.progress.task("Collecting header data...")
	local meta, styles = karaskel.collect_head(subs, true)
	
	aegisub.progress.task("Parsing templates...")
	local templates = parse_templates(meta, styles, subs)
	
	aegisub.progress.task("Applying templates...")
	apply_templates(meta, styles, subs, templates)
end

function macro_apply_templates(subs, sel)
	filter_apply_templates(subs, {ismacro=true, sel=sel})
	aegisub.set_undo_point("apply karaoke template")
end

function macro_can_template(subs)
	-- check if this file has templates in it, don't allow running the macro if it hasn't
	local num_dia = 0
	for i = 1, #subs do
		local l = subs[i]
		if l.class == "dialogue" then
			num_dia = num_dia + 1
			-- test if the line is a template
			if (string.headtail(l.effect)):lower() == "template" then
				return true
			end
			-- don't try forever, this has to be fast
			if num_dia > 50 then
				return false
			end
		end
	end
	return false
end

aegisub.register_macro("Apply karaoke template", "Applies karaoke effects from templates", macro_apply_templates, macro_can_template)
aegisub.register_filter("Karaoke template", "Apply karaoke effect templates to the subtitles.\n\nSee the help file for information on how to use this.", 2000, filter_apply_templates)