code: protected static void populateMetadataHeader(byte[] b, int type, int dataLength) {
          b[0] = IOUtils.fromInt(type);
          b[1] = (byte)'v';
          b[2] = (byte)'o';
          b[3] = (byte)'r';
          b[4] = (byte)'b';
          b[5] = (byte)'i';
          b[6] = (byte)'s';
      }
docs: Popupulates the metadata packet header,
  which is "#vorbis" where # is the type.