http: defines a port that normal web servers use to deliver content. Port 80, to be precise. Sometimes that content is .html, sometimes it is .jpg image files, sometimes it is mp3’s or video files. You want to know that your video is being served from a streaming server. At GravityLab, it is.
Your multimedia, when pushed through mms://, rstp:// or http://via the 554 port protocol, is being pushed through Windows Media Services 9, Helix Universal, or Quicktime Streaming Server respectively. What can, considering video MIME types with apache, is port 80. So if you link to video through http: but you specify the 554 port (ie:http://helix.gravlab.com:554/youraccount/yourfile.mov) http: loses all meaning in terms of defining a standard Port, because it is using the Quicktime Streaming Server 554 port.0