A—B

Active Streaming description (ASD) file

A file that describes the characteristics of a multimedia stream. It is read and written by the ASF Real-Time Encoder, and it is also read by the Channel service to define the multimedia stream format supported by a given channel.

Active Streaming format (ASF)

A low-overhead data format for multimedia streams, encapsulating images, audio, AVI, and so forth, as well as URLs, and allowing for the synchronization of these objects within the stream. A NetShow server can stream ASF formatted content and can store ASF streams as .asf files.

ActiveX

Microsoft ActiveX™ technologies are an open technology platform that extends the Windows architecture to include Internet and corporate intranet features and capabilities. ActiveX embraces both Java and Microsoft's Component Object Model (COM) technologies.

ActiveX controls

Embeddable controls written to the ActiveX specification. An ActiveX control can be embedded in a Visual Basic® form, a Visual C++® resource, or an HTML page.

aggregate output

A limit on the total amount of data that a NetShow server can stream to clients at any given time. The NetShow server will calculate its aggregate output, based on the sum of the bandwidth of each stream, and limit the bandwidth to the specified aggregate maximum.

announcement

Information for a client about a NetShow program and its associated channel. An announcement is stored in the form of an ASX file. NetShow uses announcements with ASF streams only.

ASFChop

A command-line utility for trimming the beginning or end of an ASF stream that has been stored by the Real-Time Encoder.

ASF Editor

A graphical tool that allows you to author, test, and generate an ASF file. The tool is designed to handle most of the issues of encoding and timing of low to mid bit-rate content. It allows the author to place objects—sounds, images, and URLs—so that they appear at the correct time during playback. It does not produce video files.

ASF Real-Time Encoder

An encoder used to author live ASF multimedia streams. It allows control of dynamic mixing of input media, and it outputs an ASF stream for distribution.

ASX file

A file quickly loaded by the client that contains information for the following purposes:

Transfer control from the HTTP browser to the NetShow Player control, so that streams can be directed to the player.
Represent an announcement of information necessary to access a program on a NetShow channel.
Provide a reference to a stored ASF stream.

bandwidth

In communications, the difference between the highest and lowest frequencies in a given range. For example, a telephone line accommodates a bandwidth of 3000 Hz, the difference between the lowest (300 Hz) and highest (3300 Hz) frequencies it can carry.

In computer networks, greater bandwidth networks indicate faster data-transfer capability. Bandwidth is expressed in bits per second (bps). In the NetShow environment, the NetShow Administrator can specify bandwidth constraints for a variety of functions, including maximum aggregate unicast bandwidth from the server, maximum bandwidth for a single unicast stream from the server, and the continuous bandwidth used by a multicast file transfer.