Hi Brooks
There is an extensive list of file types that are accepted by Totara under Site administration > Server > File Types - it is also possible to add file types to this list.
Are you having problems uploading a file type or playing a file type.
The default media player in Totara 12 is VideoJS which is capable of playing quite a few formats but not all. Have a look at Site admin > plugins > media player for formats that are supported.
regards