The player below is a working demo of the Amazon S3 and CloudFront Video Player. It is a "Progressive Download" (aka non-streaming) player.
In the example, it is configured to securely play a MP4 video file that has been securely stored on Amazon S3, delivered through Amazon CloudFront, and the video will only play from this web site. Even if you do a view source of the file and try to grab the direct MP4 URL, that link will not work after 15 minutes from a different computer or device (email it to yourself and try to open the link after 15 minutes – it won't work).
The above video cannot be shared with unauthorized users, but it could be downloaded to the viewer's computer using third-party plugins like Video Downloader and Video DownloadHelper and Internet Download Manager (IDM).
So if you're looking to completely prevent even authorized users and members from being able to download the videos or audio they're watching and listening to (even for their own offline use), then check out the following streaming demos, which create impossible-to-download video and audio streams.
Read about the difference between Progressive Download Videos and Streaming Videos