Streaming is the process used when a media file (for example: audio, video, or animation) is broken into smaller pieces so it can viewed or heard as the pieces are received rather than waiting for the whole file to be transferred before it is displayed. (This is similar to receiving and reading a book one page at a time instead of waiting for the whole book to arrive before starting to read it.)
Streaming allows you to view large data files without long delays, and to view live events in real time. In addition, RealOne Player can select the best available bandwidth of the provided media (some media is streamed at various bandwidths) so it matches the transfer/download speed available to you.
One of the protocols that can be used to optimize the bandwidth of a presentation is the Synchronized Multimedia Integration Language (SMIL). SMIL presentations send different steams for each of the components of a presentation (for example; a video stream, audio stream, and text stream). Each steam has a different optimum bit-rate associated with it, depending on the type of media that's being streamed. The results is that a complex multimedia presentation can be streamed with a much lower bandwidth then if the whole presentation was limited to the format and bandwidth of the largest media type.
The primary limiting factor for any Streaming Media is bandwidth. This is generally limited to the maximum speed (bandwidth) of your Internet connection, but it can also be limited by how many data streams a server can handle, and other network constraints. If the RealOne Player doesn't try to download data faster than you connection can handle, the presentation won't have to regularly pause to let the system catch up. To do this, a media provider will simultaneously stream the RealMedia in multiple bandwidths. RealOne Player will chose the data stream with a bandwidth that best matches your system. Of course, a narrower data stream will be of lower quality, but it is less likely to be interrupted then a wider data stream.
When media is being streamed, the bandwidth does not always remain constant. Often it will fall below what is required to continuously stream the presentation. To avoid pauses due to delays or slow transmissions, the RealOne Player will cache a portion of the media stream before beginning to play it. (This is evident by the " Loading nn%" shown in the content panel when starting a streaming media clip.) When the bandwidth is low, the RealOne Player takes data from the cache, and when bandwidth is high, the cache is refilled.
Generally speaking, Streaming Media refers to media information that is being presented on the Internet. The data stream originates on the Internet, is transferred by modem/data-line to your computer, is decoded by a player, and is viewed by the user. Recorded Media is a data file that is directly accessible from a users computer (such as a hard drive or network drive).
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From a purely technical standpoint, media that is being played from a local drive (recorded media) is still being streamed to the player software, but this process is much faster than media that is arriving from the Internet . For the purpose of this document, Streaming Media refers to media that is arriving from the Internet. |
When you play recorded media (such as an audio CD track on a CD, or an *.rm or *.mp3 file stored on a hard drive), the whole file is already present on your computer. When you play Streaming Media, you are receiving the information from the Internet.