How to convert PDF version 1.5 to version 1.4 in PHP

Question

How to convert PDF version 1.5 to version 1.4 in PHP? Can someone point me in the right direction?

Answer 1

I have a similar requirement, and I found that Ghostscript can change the version of PDF. The documentation is here: http://ghostscript.com/doc/current/Use.htm

However, I did not find anything specific about the dCompatibilityLevel parameter in the documentation. Rather, I found this article that demonstrated its use: http://rohieb.wordpress.com/2012/06/09/use-ghostscript-to-convert-pdf-files/

Here is the command:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dQUIET -dBATCH -sOutputFile=new-pdf1.5.pdf original.pdf 

Answer 2

You can easily convert PDF version 1.5 to 1.4. I am currently working in the same situation when I need to convert a PDF version. I noticed in my case that the PDF created from the dompdf library is version 1.3 and I use the latest mozilla firefox, but still mozilla shows a black screen when I try to read my PDF. (black screen on any page of my multi-page PDF file, not all).

so when my dompdf generates PDF version 1.3, I will convert it to version 1.4 because 1.4 is great for my Mozilla browser and indeed for all browsers.

You can convert the PDF version using 2 methods.

1) use ghostscript command line tool

 <?php exec('gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dBATCH -sOutputFile=new.pdf old.pdf') ?> 

2. using the PHP library specified in github. Download it from here.

I am currently working on this tool that encrypts a PDF file. It is almost ready and ready to use. Here

Answer 3

I had the same problem for many years, without reinstalling any things, there is an online converter: https://docupub.com/pdfconvert/

Answer 4

Here is a working full script, not perfect, but simple. The script reads all pdf from c: \ temp_in \, converts them and saves them as version 1.4 in the c: \ temp_done folder. There were problems with the paths to the ghost script, so the path is fully declared in shell_exec. Also added some debugging to the script by implementing "2> & 1". (Obviously, a ghost script requires installation.)

 <?php if ($handle = opendir("c:/temp_in/")) { while (false !== ($file = readdir($handle))) { if ('.' === $file) continue; if ('..' === $file) continue; $result = shell_exec('"C:\Program Files\gs\gs9.27\bin\gswin64c" -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dBATCH -sOutputFile="c:\temp_done\\'.$file.'" "c:\temp_in\\'.$file.'" 2>&1'); echo $result; } closedir($handle); } ?>