wranglebot/src/core/transcode/TranscodeSetFactory.ts

open source media asset management

import { EventEmitter } from "events";

export default class TranscodeSetFactory extends EventEmitter {
  private transcodes: any;
  constructor(transcodes) {
    super();
    this.transcodes = transcodes;
    this.transcodes.forEach((transcode) => {
      transcode.on("progress", (progress) => {
        this.emit("progress", progress);
      });
    });
  }

  runOne(transcode) {
    return new Promise((resolve, reject) => {
      transcode.on("error", (err) => {
        this.emit("error", err);
        reject(err);
      });
      transcode.on("end", (type) => {
        resolve(type);
      });
      transcode.run();
    });
  }

  run() {
    return new Promise((resolve, reject) => {
      let i = 0;
      const tick = () => {
        if (i >= this.transcodes.length) {
          resolve(true);
        } else {
          this.runOne(this.transcodes[i]).then(() => {
            i++;
            tick();
          });
        }
      };
      tick();
    });
  }
}