Streaming Media Basics

Streaming Media is media (audio, video, or graphics) that is delivered as a stream of data and played as it is received. It allows you to view large data files without long delays and minimal data loss, or to view live events in real time.

On Demand vs. Live Steaming Media

On-Demand Media: A media file that is available on the internet and is streamed to your computer. Typically it is an audio or video clip that you can select and listen to from start to finish.

Live Streaming Media: An audio or video stream that is presented live and is available continuously. Typically these are internet radio or TV stations.

Streaming Media vs. Recorded Media 

Streaming Media: Media that is being presented on the internet. The stream originates on the internet, is transferred to your computer, is decoded by a media player, and is then viewed.

Recorded Media: Data files that are directly accessible from your computer (on a hard drive or network drive) such as audio CD tracks on a CD, or downloaded video files.

Bandwidth

The property that most affects your experience playing any type of streaming media over the internet is bandwidth. Usually this means the maximum speed (Kbps) of your internet connection, but it can also refer to capacity of the media server (how many data streams the server can provide), as well as other network constraints.

RealPlayer can select a media stream that best matches your available bandwidth, so the media stream matches your Preferences and your available download speed.

More about bandwidth

RealPlayer can also display media created in Synchronized Multimedia Integration Language (SMIL) protocol, which optimizes the bandwidth of a presentation. SMIL presentations send different streams for each of the components of a presentation (for example: a video stream, audio stream, and text stream). Each stream has a different optimum bitrate associated with it.

The result is that a complex presentation can be streamed with a much lower bandwidth than if the whole presentation were limited to the format and bandwidth of the largest media type.

Buffering

When media is being streamed, the bandwidth does not always remain constant. Often it will fall below what is required to stream the presentation smoothly. To avoid pauses because of delays or slow transmissions, RealPlayer will cache, or buffer, a portion of the media stream before beginning to play it. This is indicated by "Loading xx%" in the Status Display when you start playing a clip.

When the bandwidth through your connection is low, or data dropsa term describing bad data transfers that must be re-transmitted, RealPlayer takes data from the buffer. When bandwidth returns to normal, RealPlayer puts data into the buffer until the cache is refilled. When you attempt to view a high-bandwidth clip over a low-bandwidth connection, RealPlayer will create as large a buffer as possible before beginning playback.