code: public byte[] GetFieldBinary(String pFieldName) throws IOException {
          if (!m_bAnalyzed)
              Analyze();
  
          APETagField pAPETagField = GetTagField(pFieldName);
          if (pAPETagField == null)
              return null;
          else
              return pAPETagField.GetFieldValue();
      }
docs: gets the value of a field (returns -1 and an empty buffer if the field doesn't exist)