def test_short(self):
        self.failUnlessEqual(cdata.short_le(self.ZERO(2)), 0)
        self.failUnlessEqual(cdata.short_le(self.LEONE(2)), 1)
        self.failUnlessEqual(cdata.short_le(self.BEONE(2)), 256)
        self.failUnlessEqual(cdata.short_le(self.NEGONE(2)), -1)
        self.assertTrue(cdata.short_le is cdata.int16_le)

        self.failUnlessEqual(cdata.short_be(self.ZERO(2)), 0)
        self.failUnlessEqual(cdata.short_be(self.LEONE(2)), 256)
        self.failUnlessEqual(cdata.short_be(self.BEONE(2)), 1)
        self.failUnlessEqual(cdata.short_be(self.NEGONE(2)), -1)
        self.assertTrue(cdata.short_be is cdata.int16_be)

 def __parse_genre(self, atom, data):
     # Translate to a freeform genre.
     genre = cdata.short_be(data[16:18])
     if b"\xa9gen" not in self:
         try:
             self[b"\xa9gen"] = [GENRES[genre - 1]]
         except IndexError:
             pass

 def __parse_replaygain_packet(self, fileobj, data_size):
     data = fileobj.read(data_size)
     if data_size != 9:
         raise MusepackHeaderError("Invalid RG packet size.")
     if len(data) != data_size:
         raise MusepackHeaderError("RG packet ended unexpectedly.")
     title_gain = cdata.short_be(data[1:3])
     title_peak = cdata.short_be(data[3:5])
     album_gain = cdata.short_be(data[5:7])
     album_peak = cdata.short_be(data[7:9])
     if title_gain:
         self.title_gain = _calc_sv8_gain(title_gain)
     if title_peak:
         self.title_peak = _calc_sv8_peak(title_peak)
     if album_gain:
         self.album_gain = _calc_sv8_gain(album_gain)
     if album_peak:
         self.album_peak = _calc_sv8_peak(album_peak)

 def __parse_genre(self, atom, data):
     values = []
     for version, flags, data in self.__parse_data(atom, data):
         # version = 0, flags = 0
         if len(data) != 2:
             raise MP4MetadataValueError("invalid genre")
         genre = cdata.short_be(data)
         # Translate to a freeform genre.
         try:
             genre = GENRES[genre - 1]
         except IndexError:
             # this will make us write it back at least
             raise MP4MetadataValueError("unknown genre")
         values.append(genre)
     key = _name2key(b"\xa9gen")
     self.__add(key, values)

 def __parse_tempo(self, atom, data):
     self[atom.name] = cdata.short_be(data[16:18])