some ideas on how templated karaoke could work in auto4/lua
for notext syl and char templates there are also variables $pretext and $posttext which hold the text before and after the syllable/character, to be able to create "build up" style effects
template line timing doesn't matter but layer does (layer is copied directly to the output lines)
style is used for matching again the text
it's not possible to do furigana per-character
templates are applied first in order of class, then in order of appearance
class order: pre-line/line, syl, char, furi
ie. first all pre-line/line templates are applied for a karaoke line, then all syl templates are, then all char templates, then all furi templates, then proceed to next karaoke line
code and template lines within same class are executed intermixed as they appear
(code lines are like template lines, they just don't generate any output)
the 'all' modifier should be used carefully, it will catch *any* line, even those without karaoke tags in them