Hi Scott,
The WideView XLE does have an RCA input option, in addition to it’s built-in memory, Micro SD card slot and it’s own built-in media player.
The input is the standard RCA, (Red/white/yellow) plugs. It also supports 3.5mm A/V jack (used by devices such as portable DVD players etc)
If your main purpose is to use the goggles as a display device for another device, the WideView 3Dxi may be another good model to look at.