Learn how to provide seamless quality switching in this guide - Setting Up Video Quality Switching
The above player plays mobile (480x272), standard (640x360) and high resolution (940x544) MP4 and WebM videos (for best browser compatibility).
Following player uses quality switching for video hosted on CloudFront with signed URL (download protection):
Missing quality file
The mobile quality for the following player is missing, however switching to it won't break the playback: