You may want to play your video directly from your computer. You could also use a standard DVD player, but the resolution will not be very good. We highly recommend using a little digital media player like the ones listed below. They are relatively inexpensive and you can load your video file onto an SD card or USB thumb drive for playback. The HD video quality is excellent. The products are linked below so that you can conveniently purchase on Amazon.
Micca Speck 1080p Full-HD Ultra Portable Digital Media Player For USB Drives and SD/SDHC Cards
This little box will provide HD quality video through an HDMI cable to your projector. You will need a thumb drive or SD card loaded with your video file which you plug into the box. It comes with a remote control. It supports a wide variety of video file formats. This goes for about $40 (I recently switched to this player and I love it! It’s a lot easier to just save the video file to an SD card than to have to burn a disc every time I want to make a change)
Media Player, Keedox Digital Media Player HD Media Player HDMI FULL HD 1080P for USB Drivers, SD Cards, HDD, External Devices
Similar to the model above but a little less expensive at about $30.