Edit Review — Matrox Parhelia-512

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Affordable graphics card opens wide real estate for NLEs.

Though designed with "immersive gaming" in mind, the MatroxParhelia-512 graphics board will appeal to editors outputting video todual computer displays and an NTSC monitor.

Every computer I've built has incorporated a Matrox graphics board— beginning with a G100. The reason is simple. They deliverhigh-performance, high-quality 2D graphics. But nowadays a lot more isrequired than good 2D graphics.

Today's NLEs, with their built-in composition and audio tools,require lots of screen real estate. Two or three 17in. LCD screens areperfect. And software-based, realtime NLEs often require an NTSCmonitor to display color-accurate images. The Matrox Parhelia-512delivers both of these capabilities — plus very high-performance2D and 3D graphics.

Let's start by looking at the Parhelia's graphics engine, which isbuilt on a 512-bit architecture. The Parhelia has a 256-bit DDR memoryinterface that delivers 20GBps of memory bandwidth. The memorybandwidth supports sustained performance by feeding the 512-bitGPU.

The card has four vertex shader units that support high-detail 3Dgeometry. They produce realistic lighting and animation effects.Parhelia-512 is optimized for OpenGL standard lighting models, handlingthese at accelerated rates.

Parhelia-512 also has quad texture-mapping units that simultaneouslysupport normal, specular, decal, and caustic attributes. With quadtexture mapping stages, plus five program-mable pixel shader stages oneach of the four vertex pipelines, Parhelia-512 has a 36-stage shaderarray. This shader array allows Parhelia-512 to render real-lifeeffects at high performance rates. Moreover, each stage maintains10-bit per-color precision.

Parhelia-512 provides hardware acceleration for antialiased text andfont rendering with full gamma correction — a feature currentlyavail-able in Microsoft operating systems, but only accelerated insoftware. Matrox supports hardware antialiasing under Windows XP andWindows 2000.

Matrox also offers a feature it calls Full Antialiasing (FAA-16x)that applies 16-sample antialiasing to objects. FAA-16x intelligentlyantialiases only the edge pixels of triangles and applies 16Xsupersampling to them, while leaving internal textures unblurred. Asedge pixels typically make up only a small fraction of the pixels in ascene, the board is able to offer this function with a smallperformance penalty. Parhelia also supports 4X Full Scene Antialiasing(4xFSAA).

All these technologies provide gamers and those working withgraphics applications a great image. I wonder when we'll see theseadvanced capabilities in the graphics engines of Matrox video products.These functions simply aren't going to be able to be executed by NLEsoftware-only applications.

Matrox introduced DualHead technology four years ago. Parhelia-512'sfully symmetric, multi-display support is contained on a singlegraphics chip. DualHead-HF is powered by two full-featured displaycontrollers with dual 400MHz 10-bit RAMDACs that can support dual2048×1536 (32-bit) analog outputs. (At right.)

Parhelia is also equipped with dual independent 165MHz DVI outputs.These DVI outputs have reduced blanking support for resolutions greaterthan 1600×1200 (16.8 million colors) at a 60Hz refresh rate.(Future LCD displays will support reduced blanking, thereby allowinggreater display resolution.) The DVI outputs support hardware overlays,hardware cursors, and gamma correction.

DualHead-HF's symmetric architecture includes two independentoverlay controllers and programmable mixing engines. Each overlaycontroller is equipped with a scalar unit and a look-up table (LUT) forgamma-corrected overlays. Video has a gamma curve different from RGBdata found on the desktop. Therefore, it needs to be correctedindependently of the primary display to produce an accurate coloroutput. Dual mixing engines enable various blending options of theprimary surface with the overlay surface. These mixing engines support256 levels of alpha-keying with per-pixel independent alpha support, aswell as chroma and color keying on a per-component range.

Parhelia-512 has a third, off-chip RAMDAC to support a rectangularWin-dows desktop stretched across three displays. This window's maximumresolution is 3840×1024 at 32 bits.

Parhelia-512 also provides DVD playback to RGB displays and NTSC/PALmonitors. DVD decoding, advanced video filtering, and scaling arecarried out with 10-bit precision. Matrox calls this functionDVDmax.

Software support for the Parhelia is provided by the version 1.03driver I obtained at the Matrox website. Once the driver's loaded, youcan use Matrox PowerDesk to set up and optimize your graphicsconfiguration.

The key operating settings are made with the Multi-Display plus theQuality and Performance tools. I set the Parhelia for one analog RGBLCD display and one analog NTSC LCD projector. If I had two RGBmonitors, I would have been able to choose where pop-up menus appear.For me the obvious choice would be the monitor in which the mousecursor is resting. As I expected, the Parhelia's RGB performance wassuperb. I was able to see a three-monitor configuration at the New YorkDV Show this winter. A three-monitor setup provides a very realisticimmersive experience — sudden movements can make you dizzy! Ifyou go this way, choose LCD monitors that have thin black bezels.

I must confess that my real interest in the Parhelia-512 was not its3D graphics capabilities. My focus was on the Parhelia's NTSC output.The first thing I noted was that the board has independent proc-ampcontrols for the video overlay and TV output. This means you canoptimize the look of video that appears on an RGB monitor as an overlay— and optimize the look of video output from the encoder to anNTSC monitor. You make these adjustments using the Monitor and TVAdjustments tool.

The NTSC encoder output is obtained in either of two ways. When anapplication requests that an overlay be placed over one of the RGBdisplays, the contents of the overlay can be NTSC-encoded. Applicationssuch as Premiere and Xpress DV use overlays to display motion videowindows. However, applications use overlays in different ways.

Adobe Premiere 6.5 supports realtime effects. Unfortunately, whenplaying back realtime effects, it does not update the overlay surface.Therefore, realtime video cannot be displayed on your NTSC monitor.When not in realtime mode, Avid's Xpress DV is able to DV-compressplayback. The compressed data is sent via IEEE 1394 to a DV camcorderor DV deck, where it is converted to NTSC. Once you engage realtime,however, that image is no longer updated. Xpress DV, however, is ableto play realtime effects to an overlay.

Therefore, Parhelia provides a great solution for Xpress DV editors.But other questions remain. How good is the quality of the output toyour NTSC monitor? Overlays containing YUV data require no color-spaceconversion. However, if the overlay is RGB it must be converted to YUV.Parhelia-512 features a 10-bit NTSC encoder for DVD-quality images.

The inherent resolution of the overlay is dependent on the NLEapplication. If your NLE supports a 720×480 overlay, your NTSCmonitor will show full DV resolution. Premiere supports a full-sizedbuffer for non-realtime preview and playback. However, if your NLEstores only one field's worth of data, then effective verticalresolution will be halved. Avid Xpress DV uses a full-sized buffer, butit contains only one field.

Matrox ships a WYSIWYG plug-in that can be used with After Effects,3ds Max, and Softimage XSI 3.0. This plug-in enables an applicationthat does not use an overlay to output an image to your NTSC monitor.The Matrox plug-in accesses the RGB buffer and converts it to YUV videofor NTSC output. I used the plug-in with After Effects and it workedwell.

In fact, everything about the Parhelia-512 worked well. If you needmultiple RGB display support plus output to an NTSC monitor, this isthe graphics board to buy.

Contributing editor Steve Mullen is owner of Digital VideoConsulting, which provides consulting and conducts seminars on digitalvideo technology. Mullen can be reached at d-v-c@mindspring.com. His website is www.mindspring.com/~d-v-c.

Company: Matrox
Dorval, Quebec; www.matrox.com

Product: Parhelia-512 graphics card

Assets: Supports up to three monitors; high-quality NTSCoutput; dual independent 165MHz DVI outputs; independent proc-ampcontrols for the video overlay and TV output.

Caveats: Make sure your NLE supports an RGB overlay whenplaying video in realtime.

Demographic: Editors who use multiple RGB displays and alsoneed output to an NTSC monitor.

Price: $599 for 256MB of DDR memory; $399 for 128MB.

To comment on this article, email the Video Systems editorialstaff at vsfeedback@primediabusiness.com.