Place a video file in the Assets folder of your Unity project.
Keep the pixel size small such as 256x256.
Typically with 3D software, exponential square textures work better, if possible.
Keep the video duration short.
Use h.264 .mp4 (h.265 works)
These formats might work, depending on the codec: .mov .mpg .mpeg .mp4 .avi .asf
Select your object
Select Add Component in the Inspector
Choose Video->Video Player
Drag your video clip from the Assets tab onto Video Clip in the Video Player in the Inspector
If does not have have audio, turn off Audio Output Mode
Directions to use Adobe After Effects
Directions to use Adobe Media Encoder to make a H.264 movie