Advanced Systems Format

What Does Advanced Systems Format Mean?

Advanced systems format (ASF) is a universal format developed by Microsoft for storing and streaming media. ASF is a digital audio/video container format developed from 1995-1998.


ASF can act as a container for many media formats; popular types include WMA, WMV and MPEG4 video.

ASF supports data transfer over a wide range of networks and protocols while still extending its support for audio and video playback from a number of sources such as local playback and Internet delivery. ASF enables playback to start even if a complete file is not available, which makes it ideal for Internet use. The ASF container is most widely used for Windows Media video and audio codecs, although it can be used to hold a variety of other video and audio codecs.

Advanced Systems Format was previously known as Advanced Streaming Format or Active Streaming Format.

Techopedia Explains Advanced Systems Format

ASF is based on serialized objects that are nothing but byte sequences defined by a globally unique identifier marker. Although ASF does not define how the video or audio should be encoded with the codec, it defines the structure of the video/audio stream. This is identical to the function performed by the QuickTime, AVI and Ogg container formats.

ASF files can also contain metadata objects, which might include artist, title, album and genre for an audio track. Because ASF is a format designed especially for streaming, it supports scalable media types and stream prioritization.

The ASF specification can be downloaded from the Microsoft website but is not available on an open source license.


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Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…