On my Raspberry Pi 2 running Wheezy, I have a php if statement that if true
echo exec('/usr/bin/X11/omxplayer -o local --win "0 0 1680 1080" /var/www/xxx/thisvideo.mp4 > /dev/null 2>/dev/null');
I also have OMXPlayer running a startup movie, both run fine. But I on my Raspberry Pi 3 running Jessie, I have the same statement, but it won't run the video, the screen flashes like it is trying to start but just goes back to what it was doing. On this Pi I also have the startup movie running with OMXPlayer and it runs fine. Is there something that has changed from Wheezy to Jessie that I'm overlooking?