ios - CGPDFStringGetBytePtr returning incorrect string while scanning pdf -

i have 1 pdf , trying scan pdf using cgpdfscanner. while scanning pdf, when word "file" encountered, cgpdfstringgetbyteptr api returns "\x02le". pdf having type1 font , no tounicodemapping(cmap). encoding dictionary not present in pdf hence using nsutf8string encoding. have tried nsmacosromanstringencoding, nsasciistringencoding had no luck. can problem?

thanks.

the code \x02 corresponds 'fi' string. 'fi' sequence drawn using ligature why have 1 character code.
correspondence between code , string done in font encoding. font encoding contains /differences array specifies mapping between code \x02 , sequence 'fi'