static filterDuplicateCodecs_(codecs) {
    // Filter out duplicate codecs.
    const seen = new Set();
    const ret = [];
    for (const codec of codecs) {
      const shortCodec = shaka.util.MimeUtils.getCodecBase(codec);
      if (!seen.has(shortCodec)) {
        ret.push(codec);
        seen.add(shortCodec);
      } else {
        shaka.log.debug('Ignoring duplicate codec');
      }
    }
    return ret;
  }
@param {!Array<string>} codecs
@return {!Array<string>} codecs
@private