xpdfSpliceGetPageWidth
Get the width of an input page.
double xpdfSpliceGetPageWidth(XpdfSpliceInputHandle in, int page)
This function returns the width of the specified page (crop box),
measured in points (1 point = 1/72 inch).
C:
XpdfSpliceInputHandle in;
double width, height;
in = xpdfSpliceOpenInput("c:/test/file.pdf");
width = xpdfSpliceGetPageWidth(in, 1);
height = xpdfSpliceGetPageWidth(in, 1);