This should be straightforward for HP to support. I was able to test it out with good results on my printer by following these steps:
1. copy /usr/lib/cups/filter/hpps to hppdf
2. change ENTER LANGUAGE=POSTSCRIPT to ENTER LANGUAGE=PDF
3. edit the ppd and change cupsFilter to use pdf and the hppdf filter
This was only a proof of concept, but it did work. A proper implementation would need to add the proper cupsFilter lines to all the PPDs and also provide a better (non-duplicated) version of hppdf. But it is possible.
This should be straightforward for HP to support. I was able to test it out with good results on my printer by following these steps:
1. copy /usr/lib/ cups/filter/ hpps to hppdf
2. change ENTER LANGUAGE=POSTSCRIPT to ENTER LANGUAGE=PDF
3. edit the ppd and change cupsFilter to use pdf and the hppdf filter
This was only a proof of concept, but it did work. A proper implementation would need to add the proper cupsFilter lines to all the PPDs and also provide a better (non-duplicated) version of hppdf. But it is possible.