getMetadata() {
    const timescale = shaka.util.TsParser.Timescale;
    const metadata = [];
    for (const id3DataArray of this.id3Data_) {
      const id3Data = shaka.util.Uint8ArrayUtils.concat(...id3DataArray);
      const pes = this.parsePES_(id3Data);
      if (pes) {
        metadata.push({
          cueTime: pes.pts ? pes.pts / timescale : null,
          data: pes.data,
          frames: shaka.util.Id3Utils.getID3Frames(pes.data),
          dts: pes.dts,
          pts: pes.pts,
        });
      }
    }
    return metadata;
  }
Return the ID3 metadata

@return {!Array<shaka.extern.ID3Metadata>}
@export