Playtime

Try:

vlc --loop video.avi

Or:

vlc --repeat video.avi

You may also want:

--video-on-top and --fullscreen

Setup

The most practical solution I found to run GUI programs on startup is using Autostart. I created a .desktop file at /etc/xdg/autostart directory:

sudo nano /etc/xdg/autostart/display.desktop

when display would be a custom name for my script. I added following lines the display.desktop :

[Desktop Entry]
Name=Play a video
Exec=mpv --fs --start=00:00:00 path-to-my-video

Saved the file and reboot the Pi.

sudo reboot

sudo nano /etc/xdg/lxsession/LXDE-pi/autostart Add: @bash /home/pi/slide.sh

crontab -e add

Select quality: youtube-dl -F 'http://www.youtube.com/watch?v=P9pzm5b6FFY'