These are ports to be opened on your firewall to allow WA video call or voice call: WHATSAPP Call: TCP: 4244,5222,5223,5228,5242 UDP: 3478,45395 Reference: http://kaa.kiev.ua/blog/whatsapp-voice-calls-firewall-ports/ LINE call: TCP: 443 UDP: 2675
We can use ghostscript or ps2pdf: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=outputA.pdf input.pdf ps2pdf -dPDFSETTINGS=/screen input.pdf output.pdf Ghostscript should produce more compatible output.pdf by running twice: gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output-Final.pdf outputA.pdf > Reference
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