FileMaker will not allow you to have multiple people opening a file from a container and editing it simultaneously by default. The Export Field Contents (usually to the Temporary Path) is a standard way to open and view a file. It is even possible to script a reinsert of a modified file (after export), but still may not work well for a multi-user solution.
Videos may be inserted using External Container Storage and should play properly in an interactive container field.
For more information on using External Container Storage you might check Knowledge Base Article #10244.
I hope this information is of use!
Yep, figured as much. Thanks.