|There are literally dozens of different codecs that movies can be encoded in. You need to know what video format your Emerson can play, the instruction manual can tell you all you need to know.|
If the video you are trying to play isn't working, you can download video converters that can convert it to a format your Emerson can play. Handbrake is one such converter that can convert your video into something more compatible.
Handbrake converter - http://handbrake.fr/