Here is a piece of code that will playback a MP4 file.
import direct.directbase.DirectStart
from pandac.PandaModules import CardMaker
from pandac.PandaModules import NodePath
from pandac.PandaModules import TextureStage
myMovieTexture=loader.loadTexture("test.mp4")
myObject = loader.loadModel("plane")
myObject.setTexture(myMovieTexture, True)
myObject.reparentTo(render)
myMovieTexture.play()
cm = CardMaker("My Fullscreen Card");
cm.setFrameFullscreenQuad()
cm.setUvRange(myMovieTexture)
card = NodePath(cm.generate())
card.reparentTo(render2d)
card.setTexture(myMovieTexture)
card.setScale(card, 1.0)
run()