ešte som našiel toto:
$content = shell_exec('/usr/local/bin/pdftotext '.$filename.' -'); //dash at the end to output c
alebo<iframe src="http://docs.google.com/gview?url=http://path.com/to/your/pdf.pdf&embedded=true"
style="width:600px; height:500px;" frameborder="0"></iframe>