@Scott is correct. It sounds like they are sending you full spreads rather than the single page PDFs, and that should be very easy for them to fix.
However, for the "programmer/designers" among us, I thought I would share another solution. This requires:
pdfinfo from xpdf to identify the bounding box of the page in points
gs from Ghostscript to split the left and right pages
pdftk from the PDF Toolkit to put the PDF back together again.
Once these are all installed and in your PATH, you should be able to do the following.
Imagine you are dealing with a file named
Example.pdf. You first run:
pdfinfo -f 1 -l 1000 -box Example.pdf
This will give you a lot of info about your PDF, including, for each page, the size in points as
Page 1 size: 595 x 842 pts (A4). We need this information for our
gs command. Specifically, each page (after being split) is 421 points wide by 595 points high. Since Ghostscript's
pdfwrite's resolution is 720 dpi and 1 inch is 72 points in PDF, we'll multiply those values by 10 in the
pdfwrite step below.
-o out%03d_A.pdf \
-c "<</PageOffset [0 0]>> setpagedevice" \
-o out%03d_B.pdf \
-c "<</PageOffset [-421 0]>> setpagedevice" \
If you are using Windows, replace the "
\" with "
The above commands will create a bunch of files named something like "out001_A.pdf", "out001_B.pdf" and so on. Notice for the right pages, we use a negative page offset.
pdftk to put it all back together again.
pdftk out*_?.pdf cat output combined.pdf
This worked like a charm for me ;)