Video compositing is moving off the big-iron systems and becoming a desktop art

By Bill Ferster

Digital image compositing has been a mainstay of high-end commercial and motion-pictureproduction since Quantel released the first Harry in 1985. But compositing tools are no longer the exclusive province of well-heeled facilities. In terms of features, desktop systems are doing the job of million-dollar equipment, but for a fraction of the price.

Digital video is the great equalizer in the compositing field, at least in terms of image quality. A workstation-based system may process frames faster, but it offers no inherent advantages when it comes to how the image will look. A 32-bit pixel, after all, is the same on a PC and an SGI.

In addition, PC-based systems can share the array of scanners, graphics tablets, printers, storage devices and other peripheral devices that are available, as well as an active base of inexpensive software tools. A number of packages for Mac and Windows computers provide extensive feature sets, letting desktop compositors perform a wide range of tasks, from wire removal to complex high-resolution effects compositing for film.

The Software

Adobe's After Effects. The venerable After Effects is the hands-down leader in desktop compositing systems in terms of features, stability, units in the field and loyal users. It is extremely well designed and relatively easy to use, and it offers an incredible amount of control over complex compositing tasks via motion tracking, splined motion paths and a seemingly unlimited number of image layers.

Adobe has fostered very tight integration of After Effects with the other members of its production stable, including Photoshop and Illustrator, the dominant programs in their respective fields. Taken as a group, these packages represent a complete and powerful set of tools for videographics production.

After Effects runs equally well on the Mac and Windows NT/95 platforms and supports multiprocessor systems for increased speed. In addition, a number of add-on hardware-accelerator cards are available that can make an After Effects-based system outperform FLINT running on SGI's O2 workstation.

Alias/Wavefront's Composer. Among the software available from SGI's Alias/Wavefront subsidiary is the high-end Composer 4.5. Long a staple of motion-picture-effects production, Composer is now also being positioned as a tool for creating CD-ROM- and Web-bound composited video. The downside for interactive-content developers is that the package is not available for Mac and Windows; to use it, you'll need an O2 or OCTANE.

Composer comes with an extensive tool set for animated color correction and film-grain addition. It also provides such powerful features as motion blur, time warp, lens distortion, Z-depth compositing (for 3D-animation work), traveling mattes and "True Track," a predictive motion-tracking scheme that lets users match computer-generated effects and live action to the motion of an object in a sequence.

Composer 4.5 supports multiple-processor distributed rendering. Its price starts at $9,995.

Avid's Media Illusion. Also at the high end of desktop compositing systems, Media Illusion 4.5 is widely used by film and television effects artists. The package has, however, found a following among producers in other application areas. Psygnosis, the games and interactive division of Sony, for example, uses Media Illusion to create effects not only for its Playstation games, which include Formula One 97, Wipeout 2097 and G-Police, but also for the games' promotional video pieces, according to Avid.

Media Illusion provides a full range of powerful compositing features and uses a process-tree structure that offers an unlimited number of layers. The software integrates seamlessly with Avid's Media Composer nonlinear-editing systems and runs on a range of SGI workstations, including the O2 and OCTANE.

Media Illusion starts at $24,800 for the O2 version and $31,000 for the OCTANE version. It supports multiple-CPU distributed background rendering.

Chyron's Concerto. Recently acquired from Axis Software of Los Angeles, Concerto forms the backbone of a new division of Chyron that aims to expand the company's presence in the Windows NT graphics market. Concerto is a timeline-based, resolution-independent compositing system that can handle an unlimited number of layers of audio and imagery.

Concerto has the ability to use "proxy" images-that is, low-resolution images that stand in for high-resolution picture elements. This proxy system is somewhat similar to offline editing, in which low-res representations are used to increase compositing speed. When all decisions are final, the system automatically re-renders the show using the real high-res elements.

Chyron provides native effects with Concerto. The package also supports a variety of third-party plug-ins, including MetaCreations' Final Effects, Ultimatte, BorisFX, the WAVES Power Pack and Synergy International's Hollywood FX.

Discreet Logic's FLINT and Illuminaire. In the past two years, Discreet Logic has acquired D-Vision Systems, Denim Software and Lightscape Technologies. In March, the company announced a major integration of all of its native and purchased product lines-and a systematic renaming of the products themselves. In the compositing category, FLINT has become Discreet Logic EFFECT for the SGI O2 platform, and Illuminaire Composition has become EFFECT for Windows 95, Windows NT (Intel and Alpha) and Mac/Power Mac.

Discreet describes FLINT 5.0 as an "online desktop system for creating visual effects, multilayer compositing, editing, paint and graphics." It is resolution-independent and performs in real time. (For more on FLINT 5.0's capabilities, see our Test Patterns review in March.)

Illuminaire, developed by Denim, was introduced to great fanfare at NAB '97. The package is divided into two parts: Paint, an object-oriented painting tool, and Composition, which offers traditional image-compositing tools coupled with capabilities for manipulating objects in 3D space and casting shadows from them. Discreet has said that it plans to merge the painting and compositing components into one tight package and that it will incorporate new features, including motion tracking and advanced keying, into the software. Composition will also be getting a facelift to make it look more like FLAME and FLINT, as well as the ability to read and write those systems' native file formats. This will position Composition as an inexpensive feeder system to Discreet's pricier workstation packages.

eyeon Software's Digital Fusion. Developed by the Australian special-effects designer Steve Roberts, Digital Fusion is also a resolution-independent compositing system. The package takes an interesting "Lego blocks" approach to compositing, allowing users to plug together a range of effects. Each effect is represented visually as a box in a diagram that is not unlike a standard schematic; complex effects are built by connecting a series of these boxes within the diagram. Placing a "monitor" icon at any point in the path gives the user a view of the composited imagery that will result.

Although it does not support Adobe's ubiquitous plug-ins, Digital Fusion does support the 5D Monster plug-ins used by Jaleo and Discreet Logic and Ultimatte's keying technology. The company has formed an alliance with Digital Processing Systems, maker of the well-regarded Perception disk recorder, with which eyeon's Digital Fusion software directly interfaces. DPS is also distributing the Digital Fusion package.

Digital Fusion lists for $2,495. In addition to the standard package, an advanced version of the software, called Digital Fusion Post, is available for $4,995. It offers Cineon file support, 64-bit color and the Ultimatte keying plug-in. Digital Fusion fully supports NT's multithreaded design for significantly faster rendering. Each rendering operation initiates an individual thread, a technique that eyeon claims can speed rendering by up to 400 percent.

n Puffin Designs' Commotion. Commotion is a product that defies easy pigeon-holing. It was developed by Scott Squires, a visual-effects supervisor at ILM, to solve common production problems for which there was no software-fast wire removal, for example, and successive retouching of portions of frames. It was not intended to be a comprehensive image-composition package. Puffin portrays Commotion as a complement to After Effects and other compositing packages, which it clearly can be. But positioning it that way diminishes the incredible power of this production-oriented Mac-based program.

The heart of Commotion is its ability to work quickly on full-resolution video in real time. It can access and manipulate all images instantly, with no need for rendering. To accomplish this, Commotion takes full advantage of the plummeting prices of memory chips, storing uncompressed video frames in the Mac's DRAM. Each full-resolution frame occupies about 1 MB, so three seconds' worth of D1 video can be stored on a 96 MB system.

Frames are typically loaded as QuickTime files from the system's hard disk. Commotion also offers ways to increase the number of images the artist can work with. One is a "virtual-memory" scheme in which a sliding group of frames is ferried to and from the disk as needed. Another lets users load cropped sections of a frame to save space.

Finally, Commotion provides powerful tools for retouching image sequences (as opposed to individual images), including spline-based rotoscoping, difference matting and onion-skinning. The most powerful of these features is the "Super-Clone," which lets artists interactively paint areas using a brush from another area or from another frame in the sequence. This feature makes removing wires on complicated backgrounds very fast.

Puffin recently released a $399 plug-in Commotion component for After Effects. The company expected to have a Windows NT version of Commotion at NAB when this issue went to press.

n Videonics' Effetto Pronto. This new compositing hardware-and-software combination is the result of Videonics' acquisition of CUB Systems, the manufacturer of the Zydeco dedicated compositing system. As we went to press, Effetto Pronto was scheduled to start shipping at NAB-which I'm sure will cause more than a few glasses of Chianti to be raised.

The Effetto Pronto system has three main components: the stand-alone, Mac-based Effetto compositing software, which offers resolution-independent compositing, 3D DVEs, character generation, texture and bump mapping, and color correction; the Pronto plug-in PCI card, which gives the system real-time compositing functions; and the Rapido interface card, which provides a direct connection to codec boards, such as those made by Truevision, via an over-the-top video bus and Matrox's Movie-2 bus.

It is the Pronto PCI card that makes the Effetto Pronto system unique. To create it, Videonics shrank the impressive functionality of CUB's Zydeco compositing system into three custom ASICs that perform digital magic. The result is a real-time 3D compositing and effects system capable of unlimited channels, color correction, mixing, keying and title generation. Effetto Pronto is priced at $4,995 and available for the Mac only.

The Hardware

In terms of image quality, ease of use and overall capabilities, desktop compositing systems hold their own quite well. Where the big-iron systems still have an edge is in rendering speed: A FLAME or Quantel Henry runs circles around a basic desktop system in that area.

There are a few ways to close the gap. The first is simply to wait. Faster microprocessors seem to be coming to market every day, and it is not unreasonable to expect CPU clock speeds to exceed 1,000 MHz by next year. (Other enhancements, such as integrated math processing and MMX, are also increasingly common.) The custom graphics chips found on inexpensive graphics adapters can achieve truly impressive performance when working with large 2D and 3D images. In addition, arcane memory paths, such as Intel's AGP, will hasten the arrival of dedicated-workstation performance on desktop PCs.

If you can't wait, there are things you can do now to speed your system. Just as many hands make light work, adding processors offers huge improvements in rendering speed-provided that your compositing software is optimized to take advantage of multiple processors.

n Integrated Computing Engines. After Effects users can gain a further edge by plugging ICE's ICEfx card into their PCI Mac or Windows systems. The $4,995 ICEfx card contains 16 high-speed digital signal processors that speed rendering of certain After Effects filters and other processes by a magnitude of five to 12. Unfortunately, the operative word here is "certain." According to ICE, "only processes that have had drivers expressly written for them will be accelerated." ICE has worked closely with Adobe to gain access to "hooks" within After Effects to pass off the processing of functions to the ICEfx card. Another limitation is that ICEfx's acceleration is limited to the 720 x 484/525 video resolutions. This means that it can't provide the much-needed performance improvement for film images.

ICE offers a number of effects with the card, and they run quite quickly. In addition, ICE has accelerated the Ultimatte and CineLook plug-ins. CineLook makes scenes shot on video look as if they originated on film.

n Total Impact. A new contender in the add-in compositing-acceleration arena is Total Impact's Total Express MP, a $4,995 (seems to be the magic number here) accelerator card for the Power Mac versions of After Effects. The card adds four 604e PowerPC chips to the system.

Unlike ICE, Total Impact has nestled closely to the After Effects core libraries. As a result, Total Express MP accelerates most of the software's internal functions, providing a 400 percent increase in speed. Further, certain functions have been hand-coded to offer speed increases of more than 1,500 percent. Finally, Total Express MP is completely resolution-independent, making it attractive to those working in film.n