Parses and compiles ASS subtitle format to easy-to-use data structure.
npm install ass-compilerUse parse or compile as needed.
import { parse, stringify, compile, decompile } from 'ass-compiler';
// ASS file content
const text = `
[Script Info]
; ...
`;
// parse just turn ASS text into JSON
const parsedASS = parse(text);
const stringifiedText = stringify(parsedASS, options);
// compile will get rid of invalid tags, merge duplicated tags, transform drawings, etc.
const compiledASS = compile(text, options);
const decompiledText = decompile(compiledASS, options);{
// A Style named `Default` will be automatic generated by options.defaultStyle
// if it is not exists in `[V4+ Style]` section.
defaultStyle: {
Name: 'Default',
Fontname: 'Arial',
Fontsize: '20',
PrimaryColour: '&H00FFFFFF&',
SecondaryColour: '&H000000FF&',
OutlineColour: '&H00000000&',
BackColour: '&H00000000&',
Bold: '0',
Italic: '0',
Underline: '0',
StrikeOut: '0',
ScaleX: '100',
ScaleY: '100',
Spacing: '0',
Angle: '0',
BorderStyle: '1',
Outline: '2',
Shadow: '2',
Alignment: '2',
MarginL: '10',
MarginR: '10',
MarginV: '10',
Encoding: '1',
},
}{
defaultMargin: '0000',
processText: (inpText) => inpText,
skipEmptyEvent: false,
skipUnusedStyle: false,
}Default value: 0000
Default margin value for margins in event comments and dialogues.
Based on the spec it should be 4-digit long. But this adds up quite a bit to the subtitle file size and there is no problem with video players if this is only one digit. So override this to reduce subtitle file size.
Sample input
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0,0,0,,This is a test of the ASS format and some basic features in it.
Default output
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,This is a test of the ASS format and some basic features in it.
Output with defaultMargin = '0'
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0,0,0,,This is a test of the ASS format and some basic features in it.
Default value: (inpText) => inpText
Function for processing style. Can be used for updating styles.
Sample input
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Default output
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Output with (inpStyle) => { inpStyle.Fontname = 'Open Sans'; return inpStyle; }
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Open Sans,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Default value: (inpText) => inpText
Function for processing event texts. Useful for things like applying smart quotes with smartypants.
Sample input
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0,0,0,,This is a test of the ASS format and some basic features in it.
Default output
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,This is a test of the ASS format and some basic features in it.
Output with (inpText) => inpText.toUppercase()
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,THIS IS A TEST OF THE ASS FORMAT AND SOME BASIC FEATURES IN IT.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,THIS IS A TEST OF THE ASS FORMAT AND SOME BASIC FEATURES IN IT.
Default value: false
Skip yielding events with empty text. Useful for cleaning up subtitle file.
Sample input
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0,0,0,,
Default output
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,
Output with skipEmptyEvent = true
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Default value: false
Skip yielding styles that are not used in any event. Useful for cleaning up subtitle file.
Sample input
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Style: Alt,Times New Roman,40,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,8,10,10,10,0
Style: Unused,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0,0,0,,
Default output
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Style: Alt,Times New Roman,40,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,8,10,10,10,0
Style: Unused,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,
Output with skipUnusedStyle = true
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,0
Style: Alt,Times New Roman,40,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,8,10,10,10,0
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.00,Default,,1,2,3,,This is a test of the ASS format and some basic features in it.
Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,
For details of data structure, please use the online viewer.