Where Shall We Go Next? - A Practical Guide to Video and Audio Compression - page 622

and likely replaced by H.264, as the open standard is more attractive. Some satellite TV
services have already declared that VC-1 is not under consideration. We will have to wait
and see how this plays out.

39.4 W3C Baseline Formats

The W3C baseline formats describe the variety of media types that are used within a SMIL
container. This accomplishes many things that Flash and MPEG-4 might do with interac-
tive presentations but lacks the capability of packaging the entire presentation into a single
container.
There appears to still be much work to do on this W3C standard but it is certainly
worth watching. SMIL provides some rapid-previewing mechanisms and for simple pre-
sentations, it is remarkably easy to publish using existing frameworks and workflow sys-
tems that are already deployed for publishing dynamically generated web sites, XML, and
RSS feeds.

39.5 Multimedia with MPEG-4

An important distinction of MPEG-4 is that it addresses topics well outside the boundaries
of video compression. Modeling in 2D or 3D come into play and there is much in MPEG-4
that is designed to be of use for interactive- and multimedia-content developers.
Multimedia authoring tools will use compressed video as an asset object to be aggre-
gated with other assets in a composite application that is played back on a suitable target
device.
Much more information about MPEG-4 and the other related standards such as
MPEG-7 and -21 is available at the MPEG Industry Forum web site.

39.5.1 Why Is MPEG-4 Different from the Other Video Formats?

Because MPEG-4 is so much more than a video standard, it is differentiated somewhat from
the previous MPEG standards. Advances in video compression that correspond to MPEG-1
and MPEG-2 form only a small part of the MPEG-4 specification. The other parts describe
structured audio, 3D scenes, meshes, and all manner of object-based constructions.

39.5.2 MPEG-4 Systems-Layer Framework

The MPEG-4 systems layer provides a much more sophisticated scene-construction envi-
ronment, allowing for structured audio and video and even 3-dimensional scenes.

W3C baseline formats: http://www.w3.org/TR/2000/WD-smil-boston-20000622/baseline_formats.html
MPEG-4 Net: http://www.mpeg4.net/resources/
MPEGIF: http://www.mpegif.org/