simple-subtitle-parser/source/Parsers/WebVttParser/index.ts

_(previously, subtitle-parsing-tool)_

import { Cue } from "../../types";
import Parser from "../Parser/index";

export default class WebVttParser extends Parser {
  public timeStampMarker = "-->";

  parse(string: string): Cue[] {
    const multiline = Parser.processStringToArray(string);
    const allRawCueData = Parser.processArrayToArrayBlocks(multiline);
    const rawCueData = Parser.dropEmptyArrayBlocks(allRawCueData);
    const filteredCueData = this.dropNonCueData(rawCueData);

    return Parser.processArrayBlocksToCues(
      filteredCueData,
      this.timeStampMarker,
    );
  }

  dropNonCueData(rawCueData: string[][]): string[][] {
    return rawCueData.filter((cueData) => {
      const [header] = cueData;
      const isValidData = !(
        header.startsWith("WEBVTT") ||
        header.startsWith("NOTE") ||
        header.startsWith("STYLE")
      );

      return isValidData;
    });
  }
}