Material Exchange Format is a container format for professional digital video and audio media defined by a set of SMPTE standards. A typical example of its use is for delivering advertisements to TV stations and tapeless archiving of broadcast TV programs.
Summary
MXF when used in form of "Operational Pattern OP1A or OPAtom" be used as a "container" or "wrapper" or "reference file" format which supports a number of different streams of coded "essence", encoded in any of a variety of video and audio compression formats, together with a metadata wrapper which describes the material contained within the MXF file. Other "Operational Patterns" can contain or reference multiple materials just like a simple timeline of a video editing program. MXF has full timecode and metadata support, and is intended as a platform-agnostic stable standard for future professional video and audio applications. MXF was developed to carry a subset of the Advanced Authoring Format data model, under a policy known as the Zero Divergence Directive. This theoretically enables MXF/AAF workflows between non-linear editing systems using AAF and cameras, servers, and other devices using MXF.
Usage
From the year 2004, MXF was in the process of evolving from standard to deployment. The breadth of the standard was subject to lead to interoperability problems as vendors implement different parts of the standard or interpret misleading parts of the standard differently. MXF is fairly effective at the interchange of D10 material, mainly because of the success of the Sony eVTR and Sony's eVTR RDD to SMPTE. Workflows combining the eVTR, Avid NLE systems, and broadcast servers using MXF in coordination with AAF are now possible. Long-GOP MPEG-2 material interchange between video servers is possible, as broadcasters develop application specifications they expect their vendors to implement. As of Autumn 2005, there were major interoperability problems with MXF in broadcast post-production use. The two data-recording camera systems which produced MXF at that time, Sony's XDCAM and Panasonic's DVCPRO P2, produced mutually incompatible files due to opaque subformat options obscured behind the MXF file extension. Without advanced tools, it was impossible to distinguish these incompatible formats. Additionally, many MXF systems produce split-file A/V, and use a file naming convention which relies on randomly generated filenames to link them. Not only does this exacerbate the issue of knowing exactly what is in an MXF file without specialized tools, but it breaks the functionality of standard desktop computer techniques which are generally used to manipulate data on a level as fundamental as moving, copying, renaming, and deleting. Using a randomly generated filename is uninformative to the user, but changing the name breaks the loose database structure between files. One example problem that caused interopability problems in 2004: Some of the in 2004 popular MXF export tools will not allow the user to create a stereo AES file within the MXF wrapper, nor will they allow the user to add free-text annotation to the MXF file so created. Thus, an MXF file received & unwrapped may reveal SMPTE D10 compliant essence with eight mono AES audio components; the recipient has no way of knowing whether these components are multiple stereo pairs, 5.1 or serve some other purpose. Some of the incompatibilities were addressed and ratified in the 2009 version of the standard. MXF is used as the audio and video packaging format for Digital Cinema Package. It is also used in the STANAG specification documents. The file extension for MXF files is ".mxf". The Macintosh File Type Code registered with Apple for MXF files is "mxf ", including a trailing space.
Tools
MXF converters
This list represents some examples of free and Open-source products that support the MXF standard in a way that the reading and writing is compatible to professional products.
FFmpeg, an open source project added support for muxing and demuxing of MXF and MXF D-10 in FFmpeg 0.5, released in March 2009.
XMedia Recodeis an freeware converter tool that support MXF files.
Ingex is an open-source suite of software for the digital capture of audio and video data, developed and heavily used by the BBC. SDI capture is supported, as well as real-time transcoding. Portions of the suite also act as a network file server for media files, as well as archiving to LTO-3 data tape.
SMPTE's has information, for the ordering of CD-ROMs, which would hold formal copy of the SMPTE standards. Judging by SMPTE's index, all of the standards, referenced above, would be contained on those CD-ROMs, as available from . contains up-to-date information on the status of the SMPTE documents.
