Download and prepare a Raspbian Lite Image
Install the desktop environment:
sudo apt-get install lightdm
Next run the following commands:
sudo apt–get update
sudo apt–get install –y git
git clone https://github.com/adafruit/pi_video_looper.git
cd pi_video_looper
sudo ./install.sh
Next edit /boot/video_looper.ini
Change the configuration to look in the pi folder for the video isntead of the USB drive. Like so:
#file_reader = usb_drive
file_reader = directory
Be sure to change the default password then you are done as long as you copied a video into /home/pi
Reference: https://learn.adafruit.com/raspberry-pi-video-looper/installation