I have some pdf in which 'ligature' font chars are missing: I can see correctly 'ff' and 'ffi' chars displaying the pdf, but If I copy and paste text (or extract text using SDK) there are no 'ffi', 'ff' chars (with copy-paste a see a square instead of that chars).
I don't generate this pdfs by myself, so I don't know the generation process.
My doubt is: I can see correct chars even if embedded text is bad, why? Is there a way to extract good text?
If I do a pdf->ps->pdf conversion, the missing chars problem is fixed. I can copy and paste text and I see correct ligature font chars. How this could be possible?
Thanks in advance