getDefaultOutputOptions(configs) {
    const { merge, options = [] } = configs || {};
    const { conf } = this;
    const vb = conf.getVal('vb');
    const fps = conf.getVal('fps');
    const crf = conf.getVal('crf');
    const preset = conf.getVal('preset');

    let opts = []
      // misc
      .concat([
        '-hide_banner', // hide_banner - parameter, you can display only meta information
        '-map_metadata',
        '-1',
        '-map_chapters',
        '-1',
      ])

      // video
      .concat([
        '-c:v',
        'libx264', // c:v - H.264
        '-profile:v',
        'main', // profile:v - main profile: mainstream image quality. Provide I / P / B frames
        '-preset',
        preset, // preset - compromised encoding speed
        '-crf',
        crf, // crf - The range of quantization ratio is 0 ~ 51, where 0 is lossless mode, 23 is the default value, 51 may be the worst
        '-movflags',
        'faststart',
        '-pix_fmt',
        'yuv420p',
        '-r',
        fps,
      ]);

    //---- vb -----
    if (vb) {
      opts = opts.concat(['-vb', vb]);
    }
    if (merge) {
      opts = opts.concat(options);
    } else {
      opts = options;
    }

    return opts;
  }
Get default ffmpeg output configuration
@private