Light (<50kB) and dependency-free javascript library for converting subtitles between different formats.
Download the file subtitleConverter.js and import its class.
<script type='module'>
import SubtitleConvertor from '/your-path/subtitleConverter.js';
</script>After thar, create an instance of subtitleConverter and save the subtitle text you want to convert into the instance property. Then just call a conversion function you want and set the output format as via parameter.
<script>
let converter = new SubtitleConvertor();
converter.subtitleText = assSubtitleText;
let convertedText = converter.convertFromAss('srt'); // 'srt' => SRT, 'vtt' => WebVTT
</script>Currently, it is only possible to convert from ASS format to SRT and WebVTT formats. In the future there may be a possibility to convert between SRT and WebVTT, conversion from SRT/WebVTT to ASS is not planned.
There are a few parameters that can be used to influence the conversion process.
| Parameter | Type (default) | Description |
|---|---|---|
| stripAssControlCodes | boolean (true) | Indicates if ASS control codes should be removed (they are not part of SRT/VTT standard, but some players support them). |
| convertCodesToTags | boolean (true) | Indicates whether ASS control codes that have an equivalent in SRT/VTT (namely B, I and U) should be converted to tags. (This option has effect only if stripAssControlCodes === true.) |
| minDuration | integer (300) | Minimum duration (in milliseconds) of subtitle line, shorter lines will be ignored. This is used to prevent flicking (very quick changing) of subtitle lines caused by animations used in ASS subtitles. |
| Parameter | Type (default) | Description |
|---|---|---|
| forceContrastOutline | boolean (true) | Indicates whether (regardless of subtitle styles) a contrasting text border should be enforced. (Due to some limitations of the WebVTT format, this is highly recommended for the sake of subtitle readability.) |
Example of using the parameter before starting the conversion:
<script>
let converter = new SubtitleConvertor();
converter.subtitleText = assSubtitleText;
converter.convertCodesToTags = false;
let convertedText = converter.convertFromAss('vtt');
</script>MIT Licence