Reading PDF Bookmarks from PHP

[Deane Barker]

I'd like to open an existing PDF and read out the bookmarks present in
the document.

Using PDFLib (http://www.pdflib.com/), I managed to get the page count
out thusly:

$pdf = pdf_new();
pdf_open_file($pdf);
$pdi = pdf_open_pdi($pdf,'x.pdf',NULL,0);
$numPages=pdf_get_pdi_value($pdf,"/Root/Pages/Count",$pdi,0,0);

However, I can't even see an interface for getting the bookmarks out.
I'm not married to PDFLib -- anything will do.

Deane