def x_comm(self):
        data = self.rawdata
        self.encoding = encodings[ord(data[0])]
        self.language = data[1:4]
        self.shortcomment = ''
        self.longcomment = ''

        if is_double_byte(self.encoding):
            for i in range(4,len(data)-1):
                if data[i:i+2] == '\x00\x00':
                    self.shortcomment = data[4:i].strip('\x00')
                    self.longcomment = data[i+2:].strip('\x00')
                    break
        else:
            for i in range(4,len(data)):
                if data[i] == '\x00':
                    self.shortcomment = data[4:i].strip('\x00')
                    self.longcomment = data[i+1:].strip('\x00')
                    break
                
        debug('Read Field: %s Len: %d Enc: %s Lang: %s Comm: %s' %
              (self.fid, self.length, self.encoding, self.language,
               str([self.shortcomment, self.longcomment])))
extract comment field
dataset/ETHPy150Open Ciantic/pytagger/tagger/id3v2frame.py/ID3v2BaseFrame.x_comm