Autodesk 64006-051108-9001 User Guide - Page 14

6 Chapter 1: Introduction data rate that is appropriate for their connection. If the Internet connection slows down, the server can also deliver a slower data rate stream until the transfer speed returns to normal. The streaming server and the player communicate constantly to determine which data stream to use and switch streams as needed. Buffering Buffering is a technique used by media players to ensure that the movie plays smoothly. It does this by saving a specified amount of movie data in the player's internal memory, which allows for smooth playback even when the network gets congested. For example, a typical buffer stores about 10 seconds in its memory before the stream starts playing. When you watch streaming movies on the Internet, you will typically see a "Buffering" message displayed by the player, and you must wait until buffering is complete before you can see the movie. If network congestion causes incomplete buffering, the player rebuffers the file and begins playing as soon as it can store 10 seconds. Streaming Architectures QuickTime QuickTime scalability is accomplished through the use of alternates. You can create alternate versions for various connection speeds and other criteria. You can intermix real-time streaming and progressive-streaming alternates within the same alternate group to provide the optimal experience for a range of viewers. Often, it works well to make alternates for modems as progressive-streaming movies and the higher bandwidth alternates (ISDN and above) for realtime streaming. Real 10 Real 10 offers scalability through its SureStream feature™. With Cleaner, you can create up to six different audio and video tracks that are encoded for the most common user connections. In addition to SureStream, RealPlayer™ can drop frames/degrade the image quality to maintain real-time playback over slower connections. Windows Media Using a Windows Media Server, the Windows Media Intelligent Streaming has bandwidth scalability to support up to five alternate video streams and one audio stream. Cleaner currently supports only a single video stream per Windows Media file. The Windows Media Player can also drop frames to maintain real-time playback over slower connections.