Fix animation detection

[dmitrylyzo]

This is a version of the upstream maintainer - a simplified parser (without analyzing no-op move).
libass#111 (comment)
libass#111 (comment)

New parser in action

// clear - dropAllAnimations disabled
// drop - dropAllAnimations enabled
// -> 1/0 - animated or not

clear: Move (with tabulator) {\move	(50,50,1230,670)} -> 1
drop:  Move (with tabulator) {                      } -> 0
clear: {\c1&H000000&\alpha&HAA}Move (with unclosed block) {\move(50,50,1230,670) -> 0
drop:  {\c1&H000000&\alpha&HAA}Move (with unclosed block) {\move(50,50,1230,670) -> 0
clear: {\notatag \fs50 \t     (\frz180}Transform (with space) -> 1
drop:  {\notatag \fs50         \frz180}Transform (with space) -> 0
clear: {\frz30 aa \fad(100,500) \fs120}Fad simple -> 1
drop:  {\frz30 aa               \fs120}Fad simple -> 0
clear: {\frz-30 b \fade(50,255,0,10,300,700,900) \fs121}Fade complex -> 1
drop:  {\frz-30 b                                \fs121}Fade complex -> 0
clear: いろは{\kf128}笑{\kf47}え{\kf24}ば {\kf91}空{\kf58}ま{\kf27}で -> 1
drop:  いろは{      }笑{     }え{     }ば {     }空{     }ま{     }で -> 0
clear: にほえと{\ko128}笑{\ko47}え{\ko24}ば {\ko91}空{\ko58}ま{\ko27}で -> 1
drop:  にほえと{      }笑{     }え{     }ば {     }空{     }ま{     }で -> 0
clear: ちりぬるを{\K128}笑{\k47}え{\K24}ば {\k91}空{\K58}ま{\k27}で -> 1
drop:  ちりぬるを{     }笑{    }え{    }ば {    }空{    }ま{    }で -> 0
clear: {\shad5\bord5\fnIPAMincho}週間 -> 0
drop:  {\shad5\bord5\fnIPAMincho}週間 -> 0
clear: {\an2}Not animated due to libass ext \{\move(1,1,500,500)} -> 0
drop:  {\an2}Not animated due to libass ext \{\move(1,1,500,500)} -> 0
clear: {\an8}{\bord3}Animated {\move(1,1,500,500)} with unusual{\1c&H00FF00&}ly placed {\r}tags -> 1
drop:  {\an8}{\bord3}Animated {                  } with unusual{\1c&H00FF00&}ly placed {\r}tags -> 0
clear: {\notatag \fs50 \t     (\frz180)}Transform 2 (with space) -> 1
drop:  {\notatag \fs50         \frz180)}Transform 2 (with space) -> 0
clear: {\notatag \fs50 \t     ((\frz180)}Transform 3 (with space) -> 1
drop:  {\notatag \fs50          \frz180)}Transform 3 (with space) -> 0
clear: {\notatag \fs50 \t (500, 2000, \frz180)}Transform 4 (with space) -> 1
drop:  {\notatag \fs50                \frz180)}Transform 4 (with space) -> 0
clear: {\t(0,130,\1c&HFFFFFF&\t(65,565,\fscy0)}Transform 5 -> 1
drop:  {         \1c&HFFFFFF&          \fscy0)}Transform 5 -> 0
clear: {\t(0,120,\1c&H00FFFF&\t\frz180)}Transform 6 -> 1
drop:  {         \1c&H00FFFF&\t\frz180)}Transform 6 -> 0
clear: {\move	(50,50,1230,670\t(\1c&H00FFFF&\frz180)}Transform 7 -> 1
drop:  {                        \1c&H00FFFF&\frz180)}Transform 7 -> 0
clear: {\t(\1c&H00FFFF&\t(\frz180)}Transform 8 -> 1
drop:  {   \1c&H00FFFF&   \frz180)}Transform 8 -> 0

In my version I kept the in-depth analysis of the move tag (to skip no-op \move(1,2,1,2)), but my parser has parsing mistakes.

Looking at the revised “Fix event tag parsing” I can again see more parsing mistakes in the newly touched code (eg using locale-dependent functions, assuming parentheses can be nested, and more).

Therefore, simpler is more reliable.

Changes

• Simplified event parser.
• No in-depth analysis of the move tag.

Issues
jellyfin/jellyfin-web#2291
Due to incorrect parsing \fad and \fade are not considered animated and are displayed in a semi-transparent state.