PDFium: Chrome’s PDF rendering engine is now open-source
So it seems the SDK has the basic plumbing to make a commandline tool out of it: 
<a href="https://pdfium.googlesource.com/pdfium/+/master/fpdfsdk/src/fpdfview.cpp" rel="nofollow">https://pdfium.googlesource.com/pdfium/+/master/fpdfsdk/src/...</a><p>Anyone interested?