(PHP 4 >= 4.0.1, PECL pdflib >= 1.0.0)
PDF_get_parameter — Ermittelt String-Parameter
Ermittelt den Inhalt eines PDFlib-Parameters vom Typ String.
The proper keys for pdf_get_parameter and pdf_get_value are under "Parameters and Values" under "A PDFlib Quick Reference" in the PDFlib reference manual (google is your friend).
To get the font name:
$fontname = pdf_get_parameter($pdf, "fontname", 0);
To get the font size:
$size = pdf_get_value($pdf, "fontsize", 0);