Video::Info::ASF is a Perl module for ASF files for attributes like:
$video = Video::Info::ASF->new(-file=>$filename); #like this
$video->vcodec; #video codec
$video->acodec; #audio codec
ASF stands for Advanced Systems Format, in case you were wondering. It used to stand for Active Streaming Format, but Microsoft decided to change it. This type of file is primarily used to store audio & video data for local or streaming playback. It can also be embedded with commands (to launch a web browser, for instance), for an "immersive" experience. ASF is similar in structure to RIFF. (See RIFF::Info). The morbidly curious can find out more below in REFERENCES.