Videos are embedded in a survey through a HTML element. You will need to post the video to a VOD service such as YouTube. Then, you can use a HTML element with content:

<iframe width="640" height="315" src="https://www.youtube.com/embed/KXdUNp_9oHs" frameborder="0" ></iframe>

where you need to adjust the src URL for the iframe tag to point to your video.

Note that embedding of video is not supported for installs that are configured for the highest level of XSS protection.

For an example of embedded video, see:

http://novisurvey.net/n/videocontent.aspx