MXF Technology

Linux Media Arts has been working on MXF technology and systems since 2001 and continues to offer consulting and design services on Linux based MXF. We first exhibited MXF technology at NAB in 2003 and now offer MXF as an option on L-SERVER, CINELERRA, and ENSANTRA.   Please ask how we can help you with your MXF consulting needs and on your system deployment.

MXF (Material eXchange Format): MXF is an object subset of AAF and is on the verge of becoming an SMPTE standard. MXF was designed for less complex (less vertically rich) metadata applications, such as news editing and video streaming from servers. Because of its flatter metadata structure, it is better suited to be used as a metadata wrapper within a video signal or a TCP/IP stream. It offers performance benefits over the more complex AAF file structure because of its streamable nature.

For postproduction, one of the most important points about MXF video and metadata is that MXF will seamlessly interoperate with AAF-based postproduction environments. The less extensive MXF metadata can be accepted in full by AAF-based workstations, and AAF metadata can be flattened out to become the sleeker MXF metadata.

Thanks to the zero-divergence policy of the AAF and MXF proponents, the formats are fully interoperable with one another. All MXF metadata is understood by AAF, but if some AAF-specific metadata is not defined within the MXF standard, the non-MXF compliant metadata will be filtered and flattened out when being encoded as MXF.

What is MXF ?

The Material eXchange Format (MXF) is an open file format targeted at the interchange of audio-visual material with associated data and metadata. It has been designed and implemented with the aim of improving file based interoperability between servers, workstations and other content creation devices. These improvements should result in improved workflows and result in more efficient working than is possible with today’s mixed and proprietary file formats.

MXF has been designed by the leading players in the broadcast industry with an enormous amount of input from the user community to ensure that the format really meets their demands. It is being put forward as an Open Standard which means it is a file transfer format openly available to all interested parties. It is not compression-scheme specific and simplifies the integration of systems using MPEG and DV as well as future, as yet unspecified, compression strategies. This means the transportation of these different files will be independent of content, not dictating the use of specific manufacturers’ equipment. Any required processing can simply be achieved by automatically invoking the appropriate hardware or software codec. However, MXF is designed for operational use and so all handling processes are seamless to the user. It just works.

Besides offering better interoperability - working with video and audio between different equipment and different applications - the other major contribution is the transport of metadata. By developing MXF from the beginning as a new file format, considerable thought has gone into the implementation and use of metadata. Not only is this important for the proper functioning of MXF files, it will also enable powerful new tools for media management as well as improving content creation workflows by eliminating repetitive metadata reentry.

The changing technology of television production and digital services to viewers means the ways for moving content – programme video and audio – in studios is changing too. Not only is there far greater use of computers and IT-related products, such as servers, but also reliance on automation and the re-use of material have expanded. Besides the need to carry metadata, file transfers are needed to fit with computer operations and streamed for real-time operations.

The development of the Material Exchange Format (MXF) is a remarkable achievement of collaboration between manufacturers and between major organisations such as Pro-MPEG, the EBU and the AAF Association. It establishes interoperability of content between various applications used in the television production chain. This leads to operational efficiency and creative freedom through a unified networked environment.

How does MXF improve my workflow?

The existence of an open, industry-wide metadata aware file format will have a big impact on the way in which material is handled. The typical stages in creating a TV program are shown opposite. At present the hand off between each stage comprises a mix of video tape, proprietary multimedia files, Word documents, Excel spreadsheets, faxes, sticky labels, Post-It™ notes and word of mouth metadata transfer. In fact the only metadata which is handled in a reasonable universal way is Timecode. Experienced professionals will know, however, that even Timecode handling is not “clean” throughout many workflows and often much time is wasted working around Timecode metadata problems rather than reaping the benefits of a clean metadata chain.

As MXF gets adopted by more manufacturers, more and more of the transfer stages in the figure will allow a rich variety of metadata to be transferred to the next production stage allowing media professionals to concentrate on using the multimedia content and metadata rather than hunting the information they need. This can be demonstrated with a simple example. Imagine that some wildlife footage is shot on location in Africa. GPS metadata (i.e. the geographical coordinates of the camera) is added to each camera shot as an annotation. This metadata will stay with the essence inside the MXF file while the program is being created. An automatic production process could then convert GPS coordinate information into additional human readable metadata such as “Masai Mara”. This workflow automation reduces mundane human chores and improves the accuracy of the stored data.