Open System Nonlinear Editing

By Robert Lamm

Until now, nonlinear software has required specialized boards to digitize and compress the video onto disk. These boards werenít cheap, and they generally only worked with the specific software they come with. So, if you bought, say, a Data Translation system, you could only run Data Translation software on Data Translation hardware and vice versa. This locked you into Data Translation for the rest of your life unless you were willing to chuck everything and start over from scratch.

There has always been one program that refused to tie itself to a single hardware supplier: Adobe Premiere. But Premiere needs to render out a complete file of the production before it can play it back, and this can take hours for even a short video. This, we were told, was the price we paid for 'open-system' flexibility.

Enter D-Vision, a company that got burned by locking their D-Vision PRO nonlinear editor to the Intel ActionMedia card. The ActionMedia card was soon surpassed by other hardware, and the D-Vision software, although highly praised, suffered because the hardware it ran on didnít have very good image quality.

Most software manufacturers in this situation just port their application to a new board and start the cycle again. But D-Vision decided to take a bold step: They would write their software with sufficient flexibility to run on any hardware using standard Windows protocal. Software users would be able to run it on any card, from the $300 hobbyist special to the $7000 component digital card. And you can upgrade your system by buying a better card without having to get different software. This concept of interchangeable software/hardware is what 'open system' design is all about.

True, it also means that users can move away from D-Vision without replacing their hardware, but the D-Vision people think their new package screams anyway...

Nobody thought it could be done. But just about a week before NAB, D-Vision contacted SMPTE/NE member Wilson Chao at Cambridge TV Productions (Newton, MA), and asked him to digitize a D-Beta tape they sent him with his Avidsí AVR-27 highest image quality. Wilson sent the best version back and D-Vision put it on a monitor at NAB, next to their own systemís output. The comparison was there for all to see: The D-Vision AVI-file video, using an off-the-shelf Matrox card under Windows NT for capture and playback was sharper and had less artifacts than the closed-system, proprietary-hardware Avid footage. The booth was mobbed for the entire show.

Unfortunately, there's still some work to be done: D-Vision needs to port over the functions from their older products onto this new platform. (It should be done by fall.)

As the current leader in open system Windows nonlinear solutions, D-Vision is starting up a group to enhance the Video-For-WIndows format to optimize it for professional production: Among the group's stated goals:

-Improvements to Video-for-Windows for greater interoperability between different vendorsí codecs. This will allow video to be played back with any card, regardless of what card it was digitized with.

-Increases in maximum throughput, maximum file sizes, lower overhead and greater editing and random-access capabilities. This will improve image quality and enhance capabilities generally. Right now, VFW file size is limited to 4GB, which puts a hard limit on program length.

-Real-time multi-stream effects: Simultaneous playback of multiple video channels into an outboard real-time DVE (such as the Aladdin). The group plans to develop a standard driver format for these DVEís so that different cards can be used interchangeably.

-Real-time alpha channel/keying capability so that overlaid subtitles and graphics don't need to be rendered out.

-Standard driver formats for VTRís, routers. switchers, DVEís, video servers, audio devices, external knobs/sliders, display acceleration cards, software/hardware plugins and more. These drivers will allow control of MIDI musical equipment, VTR's and other external gear from within the nonlinear application. Eventually, you may be able to transfer compressed video directly from a digital VCR at high speed without any decompression/recompression artifacts.

The group, tentatively called the Open DML group, held a press conference at NAB (hosted by our very own Bob Turner, nonlinear columnist for Videography), at which they spelled out these goals and invited anyone who wanted to participate. So far, the member/observer list includes ACCOM, Adobe, C-Cube, CBS, Diaquest, D-Vision, EMC, Fast, Image North, Intergraph, Leitch, Matrox, Micropolis, Microsoft, Pinnacle, Play, SoftImage, Tektronix, Truevision, and (gasp!) AVID! Avidís new Windows-based nonlinear system isnít open system, but maybe they think it ought to be...

Anyone can join the new consortium, just contact Janet Matey at Matrox, 514-969-6037, fax 514-685-2853,

Robert Lamm is Manager at CYNC Corp., a video dealership in Brookline, MA. He can be reached at (617) 277-4317,