Real Networks are one of the market leaders in streaming technology, as of October 1997 commanding up to 85% of the market share, competing against other providers of media plug-ins and players such as Microsoft NetShow, Macromedia Shockwave, Xing Streamworks, VXtreme and Vivo. During the last eight months since RealPlayer 5.0 was released, use of streaming media on the Web has tripled, from about 100,000 sites offering content to just over 300,000. Accounting for all versions up through 5.0 (the current standard since the G2 player pictured below is promoted from its "free demo" beta status), 48 million players have been downloaded, at an approximate rate of 100,000 players per day. [29]

Real Networks logo, September 1998

A typical streaming media system such as the Real System consists of five elements - encoders and content creation tools (1) which are used to create or capture and then edit sound and/video data types (2), which are stored in centrally-located servers (3), to be transmitted over networks (4) to be received and decoded by client-side players (5) for live or on-demand playback.

Figure 12: A typical streaming media system, as used by Real Networks .
 

The Real System contains three main software applications

1. Servers - purchased from Real Networks to store their coded media files. These files are connected to Web pages by metafiles - addresses that download the files from the media server rather than the web server. This allows users to continue navigating the site, moving from one document to another without interrupting the data stream from the media server. A real Server will store, download and stream both live and on-demand audio and video clips, offering companies and bands a wide range of ways to present their music to the public - singles, album preview clips, live audio broadcasts, interviews, live concerts, promotional video clips and much more.
   
   
2. Encoders - after the video or audio has been digitised, the data is compressed into smaller files which can only be read by a RealPlayer at the user-end of the process. These files carry a .ra (Real audio) or .rm (Real media) extension, and vary in size depending on the method of encoding used. Real Networks offer a range of encoding technology designed for various computer platforms and modem speeds, the resulting file sizes from which are represented in the table below.
   
   
   

Relative file sizes for Real Audio- encoded sound files.

Unencoded	size	encoder version (bandwidth )	size
.wav file, 44.1kHz, 16-bit stereo	10.1Mb	RA dual ISDN mono/stereo	586 Kb
.wav file, 22kHz, 16-bit stereo	5Mb	RA single ISDN mono/stereo	296 Kb
.wav file, 8kHz, 8-bit mono	938Kb	RA 3.0 (28.8) mono	117 Kb
		RA 2.0 (28.8)	113 Kb
		RA 1.0 (14.4)	60 Kb
		RA 4.0 (8.5)	64 Kb
		RA 4.0 (6.5)	42 Kb

The different levels of encoding are known as codecs (coder/decoder) and offer varying quality of sound, e.g. the higher the codec (14.4, 28.8, 56, ISDN ) the larger the resulting file and therefore the better the sound quality. The lower-bitrate codecs (6.5, 8.5 and 14.4) offer a sound quality equal to a clear, strong AM radio station, with slightly reduced frequency and dynamic range. The medium-range codecs (RA 2.0 and RA 3.0, both at 28.8) offer a sound quality equal to a clear FM mono radio station, with a slightly reduced frequency and dynamic range, while the higher codecs (ISDN and above) offer near-CD sound quality with a slight reduction in frequency and dynamic range. [30]

As with other types of compression, Real Encoder works by selecting and storing only the most relevant data and discarding the rest. Moving images are stored as frames relative to each other, so that the only information stored about two virtually identical frames is the actual variation in movement between the two. This cuts down considerably the amount of storage space needed to digitise film, and similarly music is compressed by recording the data in relative sound data.

The Real Encoder will encode files stored on computer disk or other medium, will encode directly from CD or other media devices and also supports live encoding - a signal can be programmed to broadcast at a specific time, or a live feed can be encoded and broadcast instantaneously, while being archived for future on-demand requests.

3. Players - These are decoders that are downloaded from Real Networks " web-site onto an individual's computer, enabling the user to hear/see the encoded data. Real Players will play both audio and video, and can be downloaded free. Once the player is installed, the user's web browser has to be adjusted to identify Real Media files and the application that will decode them.

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