Ghostscript PDF Converter
PDF files need to be in PDF-Format 1.4 or below in order to be able to process those files using fpdf/tcpdf php libraries. As most customers are unaware of this and aren’t able to convert their files to this format, i had to do this on my own:
# apt-get install ghostscript
# gs -sPAPERSIZE=a4 \
-sDEVICE=pdfwrite \
-dPDFSETTINGS=/prepress \
-dEmbedAllFonts=true \
-dCompatibilityLevel="1.4" \
-dNOPAUSE \
-dBATCH \
-dSAFER \
-sOutputFile=output.pdf \
inputfile.pdf
This converts a given file “inputfile.pdf” from whatever PDF-version to version 1.4 as output.pdf.