[matroska-devel] OMF container format from AVID - the basis for AAF

Christian HJ Wiesner chris at matroska.org
Wed Jul 2 13:30:14 CEST 2003


certainly not a real competitor to matroska or MCF as OSS projects, just 
another closed source/open specs thinggie like Nullsoft's NSV and 
trolltech's MPX :



      The OMF Specification

OMF is an edit data interchange format introduced by Avid Technology in 
1990. OMF is a binary file format using object-oriented technology. It 
uses a ‘Bento’ object container (an Apple technology) into which data in 
the form of the 'OMF Object Model' is placed.

The use of the Bento container provides the foundation for building an 
extensible interchange format. The Avid OMF Object Model is an 
insightful design for capturing edit data. As a whole, the format 
provides the capability of interchanging very rich edit information 
about a project. This comes at the cost of abstraction and complexity – 
in other words, it is not so easy to understand.

Originally released as OMF1, OMF2 was introduced in 1996 to enhance the 
capabilities and efficiencies. While both formats share similar 
technologies, OMF2 is very different from OMF1 in terms of data types, 
properties, and semantics. This bifurcation of the formats caused even 
more complexity, but most applications will unfortunately need to 
support both.

The specification of both OMF1 and OMF2 are published by Avid.

It seems that this OMF container is used as the basis for this other 
thing we came across already, named AAF :


AAF metadata interchange will be based on Avid's Open Media Framework 
Interchange (OMFI). OMFI was previously implemented in Apple's Bento 
container architecture, now declared end-of-life by Apple. Its container 
architecture will be newly implemented in Microsoft's object-oriented 
COM-based Structured Storage. OMFI is widely used in the audio industry 
for exchange of audio files that must synchronize with edited video and 
film productions. It is also used by Heuris' MPEG Power Professional 
MPEG encoders to extract cut points from a production, which become 
I-frames in the Encoding Control List (ECL), and to locate SFX and TX 
that need special encoder handling. But Avid has only recently extended 
OMFI metadata and media interchange to its own line of video and film 
products, and not yet completely. Outside of Avid, only a few of Avid's 
NLE (nonlinear editing) competitors can exchange compositional metadata 
and Motion-JPEG video media via OMFI, notable Tektronix/Lightworks and 
Softimage (Microsoft). This is not entirely Avid's fault. Their partners 
have had the spec for years and not implemented it. Ironically, some 
OMFI media files can be interchanged using QuickTime 3. For example, 
Avid's entry-level nonlinear editor Cinema can use QuickTime 3 to open 
high-end Avid Media Composer files. At NAB'98 Discreet Logic showed 
their editing and effects workstations exchanging files between 
Macintosh and Windows.

A guy came to the Virtualdub support forum, claiming OMF/AAF superiority 
and 50+ years readability :

I flamed the heck out of him :D ...since then he didnt come back ( 
pretty stupid thing to claim something will work in 50+ years from now, 
especially in the world we are living in today ;-) ) ....

Just FYI, nothing we have to worry about, there are no open source 
libraries for any of them AFAIK ;) ...



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