The downside to OMFI is that, because it was developed by Avid/Digidesign there has been a certain reluctance from some DAW manufacturers to accommodate what is essentially a proprietary format. And there have been certain reservations about OMFI’s timing resolution; dropped frames and off-sync layback may result if too many edits occur in given sequence, for example.

But the good news is that there is a non-proprietary standard that is just being completed, and which offers a great deal of promise as a universal “Rosetta Stone” for ensuring compatibility between media and projects from different DAW manufacturers. That august body, the Audio Engineering Society, recently unveiled “AES31: A Standard for Network and File Transfer of Audio.” AES31 defines three important parameters: firstly, how digitized files can be moved from one DAW or digital recorder to another, either via removable media or a high-speed network; secondly, how the digitized data should be arranged on the removable media or packaged for transfer via a LAN or WAN or The Internet; and, finally, how these files are related to one another at the sample level, so that sound elements can be accurately re-assembled, for example, to enable a multitrack remix session. (The fourth segment of AES31 could allow more additional data about a session – including mix automation, graphics and more complex metadata – to be included as part of the project files.)

AES31 specifies the use of the industry-standard FAT32 format for disk flies, while data is encoded in the familiar Broadcast Wave or BWAV format at up to 24-bit resolution and sampling rates to 96 kHz. (Useful for 24/96 DVD-Audio and other advanced mastering formats.)

FAT32 accommodates large numbers of files per volume, long filenames (useful for complete identification), large file sizes (essential for uncompressed audio), and uses disk space more efficiently. FAT32 is also implemented on the majority of computer platforms, including Macintosh, Unix/Linux and Windows systems. BWAV is based on the familiar .WAV file format, and includes additional data time-of-day and other important synchronization information. Basically, BWF adds extra data bits to each audio file that identifies its proper location in a project, plus other useful IDs.

As I have been discovering, one of the primary reasons why workstation and recorder manufacturers are anxious to implement an open standard like AES31 – as opposed to trying to emulate one another’s proprietary formats – is that the process only needs to be done once. As can be imagined, an “anything-to-anything” proposal would be extremely complex and costly to implement. AES31 compatibility is intended to dramatically reduce such efforts. Already, a number of firms have implemented AES31 compatibility, including Euphonix, Fairlight, SADiE, Steinberg and Waveframe; others are bound to follow in the near future.

And on the immediate horizon, but not yet available, is another, more complex data-exchange standard known as Advanced Authoring Format. AAF is a multimedia file format that enables content creators to exchange digital media and metadata between different systems and applications. But because AAF is being developed by a braod consortium (including Avid, BBC, CNN, Fox, Grass Valley Group, Liberty Livewire, Microsoft, Omneon, Panasonic, Philips, Pinnacle, Quantel, Sony and Warner Bros), it is not the work of an standards body such as AES. Despite this, sources at Digidesign have indicated that the current Pro Tools support for OMFI, in addition to OpenTL and other proprietary formats, in the long-term will be extended to involve AAF but not necessarily AES31, which has a lower priority.

And Digidesign’s reasons are not unreasonable. The firm considers that AES31 deals only with audio, whereas its customers are looking for integrated solutions that can handle video, graphics and other types of data. And it feels that AES31’s choice of FAT32 is inappropriate for manufacturers developing DAWs based on the Apple Macintosh. In summary, Digidesign concludes that OMFI and its successor AAF offer significant advantages for data interchange and incorporate several important metadata standards. For example, the firm thinks that OMFI and AAF can offer additional possibilities for data interchange that are not addressed by AES31, including routing, volume and multi-channel panning automation, plus even more advanced operations such as hardware and software plug-in processing.

All in all, the murky landscape of file exchange is clearing with the appearance of AES31 and, in the near future, AAF. Just so long as manufacturers remain up-to-date with the needs of the DAW marketplace, we can all benefit from a (relatively) more coherent approach to exchanging audio files and projects using industry-standard media and data formats. There’s no digital equivalent to analog 24-track on the horizon, but we’re getting closer. (And lest we pine too much for the good old days, remember the Scully 12-track and the Stephens 40-track machines.)

Next Time: “A Summary: Putting all the pieces together.”

©2001 Mel Lambert/Media&Marketing. All rights reserved