.mpeg and .avi are inherently digital movie formats.
To read a digital movie as an analog signal, you would have to output it as an analog signal and then somehow input that signal.
HDMI cables use digital signals. SVGA cables use analog but they use multiple analog signals, as does S-VIDEO. You will, then, probably be wanting to output on to a coax connector using NTSC or PAL for the signal encoding.
You need to be careful in modulating NTSC and PAL, as those encodings include mechanisms for vertical retrace, horizontal and vertical blanking, interlace, horizontal sync, vertical sync, etc.. If you modulate away the control portions of the signal, your ability to recover per-pixel information will be compromised.
