We've been hearing details about NVIDIA's on-chip programmable video processor ever since the NV40 originally launched about eight months ago. Back then NVIDIA had stated that the NV40's on-chip video processor incorporated a high-quality adaptive de-interlacing engine, along with better filtering and scaling techniques, video de-blocking logic and an integrated TV-encoder. The NV40's on-chip video processor was also to be a complete HDTV solution as well, with the ability to output HDTV streams in all of the popular formats (720P, 1080i, 480P, CGMS). It also had integrated PVR (Personal Video Recorder) functionality, with hardware audio / video synchronization, hardware MPEG 1 / 2 / 4 encoding and decoding, and WMV9 decode acceleration.

It has since become known that the original NV40 chip used on AGP GeForce 6800 class cards didn't accelerate WMV9 content at quite the level NVIDIA would have liked, but newer derivatives of the chip with an updated video engine are much better performers in this respect.  The GeForce 6600 GT, for example, is equipped with the updated on-chip programmable video processor, which gets a new name today.  At 9:00AM EST NVIDIA's PureVideo technology, not to be confused with Matrox's brand of the same name, was officially unveiled.  The combination of a GeForce 6 Series graphics card, with new decoder software that should be available on NVIDIA's site shortly, finally make PureVideo a reality. And video on the PC now comes a step closer, and perhaps even surpasses, the quality available from most Consumer Electronics devices. The key features of NVIDIA's PureVideo technology include:

• High-definition MPEG-2 Hardware Acceleration.  A dedicated 16-way vector processor enables smooth playback of HD video with minimal CPU usage.
• WMV High-definition Hardware Acceleration.  Programmable support of the newest format enabled by Microsoft Windows Media Player and Windows XP Media Center Edition 2005 for fluid playback of WMV and WMV HD content.
• High-quality Real-time Video Recording.  An advanced motion-estimation engine makes it possible to record in real-time without a loss in quality.
• Spatial / Temporal Adaptive De-Interlacing.  Experience interlaced content from satellite, cable, and DVD feeds in full detail and without jagged edges or artifacts.
• 3:2 Pull-down Correction and "Bad Edit" Correction.  Restore video to its original 24fps film format to experience a crystal clear picture, frame after frame.
• Flicker-free Multi-Stream Scaling.  High-quality 4-tap by 5-tap scaling maintains image detail, even when scaling a small video to a large area of the screen.
• Display Gamma Correction.  Automatic format detection adjusts the color quality of video playback so that it is not too dark, overly bright or washed out, regardless of the display.

To give you some examples of how PureVideo affects video playback on the PC, we installed a GeForce 6600 GT into one of our test systems and compared its video playback quality to an ATI Radeon X700. ATI has long been regarded as having the best video engine available on the PC.  Their popular All-In-Wonder line of cards is a testament to this fact.  But NVIDIA isn't the type of company to just sit back and let a competitor dominate a particular market segment unchallenged. Which is where PureVideo comes in...

The HotHardware Test System Intel-Powered Screamer

HOW WE CONFIGURED THE TEST SYSTEM: We tested the ATi Radeon X800 XL on a DFI LANPARTY 925X-T2 Intel i925X chipset-based motherboard, powered by an Intel Pentium 4 560 3.6GHz CPU. The first thing we did when configuring this test system was enter the BIOS and loaded the "High Performance Defaults."  The hard drive was then formatted, and Windows XP Professional with SP2 was installed. When the installation was complete, we installed the latest Intel chipset drivers, installed all of the necessary drivers for the rest of our components, and then we removed Windows Messenger from the system. Auto-Updating, System Restore, and Drive Indexing were then disabled, the hard drive was defragmented, and a 768MB permanent page file was created on the same partition as the Windows installation. Windows XP's Visual Effects were set to "best performance" and all playback tests were performed in VMR mode.

The see the benefits of NVIDIA's PureVideo technology, we occasionally had to alter one of the settings available in their new Decoder Properties menu.  In the "Inverse Telecine" tests you'll see on the next page, we had to change the Deinterlace Mode to "Smart" from "Automatic".  We had to do this because it's possible to "fool" the algorithm with content that has bad edit detection that's too good. Most high end projectors and plasma televisions from companies like Samsung, Marantz, among others, all have the ability to turn off the inverse telecine algorithms to ensure accurate results. For the ATI powered card, we left all drivers and software at their default settings except for one. We had to manually edit a registry key to enable WMV9 acceleration with the Radeon X700. This is due to the fact that Microsoft has yet to release an update to Media Player 10 that'll enable this functionality by default.  We should also note that we used an updated set of DLL files for a portion of the tests presented here to demonstrate the benefits of WMV9 acceleration. When using the updated DLL files, CPU utilization dropped dramatically while playing back some WMV HD content.

Spatial-Temporal De-Interlacing
Explanation - Content that comes over satellite, cable, and from DVD is interlaced data, targeted for TVs, that uses two pictures to provide full picture detail. Since the pictures are taken at different times and then are weaved (interlaced) together, feathering can appear along the moving edges. Many consumer progressive scan TVs and most PCs demonstrate this annoying video problem. PureVideo technology uses the PC industry's most advanced algorithm to remove motion artifacts and maintain full image detail providing a smooth video.

NVIDIA GeForce 6600 GT

ATI Radeon X700

In the above example, NVIDIA's spacial-temporal de-interlacing algorithm is used to eliminate the feathering that sometimes appears along the edge of a moving object when playing back interlaced video on the PC.  When comparing the same frame from the test video, one captured using a GeForce 6600 GT and the other captured with a Radeon X700, the image produced on the 6600 seems to have the better quality.  The jaggies in the arm of the pendulum are less pronounced, and the ball appears well rounded with minimal stair-stepping.

Inverse Telecine (3:2 pulldown)
Explanation - Most high-quality content starts out as film that is shot at 24 frames per second. When it is broadcast as TV programs or saved on DVD it is converted to 30 frames per second to conform to broadcast standards. This conversion process is called telecine (3:2 pull-down). Since the additional frames are simply made up from fields in the original content when converting back to progress frames, this simple conversion can yield images that are blurry. NVIDIA PureVideo technology recovers the original film content to show a clear picture frame after frame and provides hardware acceleration on GeForce 6 Series GPUs in a process called inverse telecine (3:2 pulldown correction).

NVIDIA GeForce 6600 GT

ATI Radeon X700

This next pair of images clearly demonstrate the difference in image quality between a GeForce 6600 GT with PureVideo Technology and an ATI Radeon X700.  Pay special attention to the tracks in the lower-right portion of the frame, and the lines along the roof of the trolley.  The NVIDIA powered card cleans up the artifacts that are visible when watching this particular clip on the Radeon.

We would like to mention that for the majority of the clip, these artifacts are barely visible with either card, and it's only in a sampling of frames that there is a clearly noticeable difference between the two cards' output. And after spending a few hours experimenting with a collection of DVDs, we weren't able to find any better examples of these artifacts with any "real world" content.

Bad Edit Detection (3:2 Correction)
Explanation - A further problem with video in 3:2 pull-down format is that post-conversion video editing can disrupt the normal 3:2 cadence. Basic inverse telecine solutions do not affect the deviation form. The resulting fields are used out of order so that every video frame displayed has jagged edge artifacts. NVIDIA PureVideo technology uses advanced processing to overcome the disrupted field sequence to display perfect picture detail frame after frame for smooth, natural looking video.

NVIDIA GeForce 6600 GT

ATI Radeon X700

This pair of images also show a clear difference in each card's output.  If you look closely at the truck's grill, between the '2' and the headlight, and along the edge of the windshield wipers, jaggies and feathering are visible in the frame captured with the Radeon that simply aren't there when using the GeForce 6600 GT with PureVideo. In conversations with representatives from ATI, however, they stated a software update would be able to address this issue.

Windows Media Video 9 Acceleration
Explanation - Microsoft's Windows Media Video 9 (WMV9) HD format was recently accepted by the SMPTE HD-DVD consortium as a new HD format. Windows Movie Maker software comes bundled with Windows XP to make it easy for consumers to edit and save their favorite videos. These videos are saved in the .WMV format. NVIDIA GeForce 6 Series GPUs is the first family of GPUs to include dedicated hardware to accelerate playback of WMV and WMV-HD content for fluid full frame rate video even on systems with entry-level CPUs. Previous generations of NVIDIA GPUs were not able to support WMV9 decode acceleration and often times HD WMV9 content would drop frames.

NVIDIA GeForce 6600 GT

ATI Radeon X700

NVIDIA GeForce 6600 GT (Patched)

To document CPU utilization when playing back WMV HD content, we used the performance monitor built-into Windows XP.  Using performance monitor, we created a log file that sampled the percent of CPU utilization every second, while playing back the 1080p version of the "Step Into Liquid" video available on Microsoft's WMVHD site. That data was then imported into Excel to create the graph above.  The graph shows the CPU utilization for each card in an un-patched environment, as your system at home would be configured right now, and patched using a pair of DLLs supplied by NVIDIA.  The updated files will be available in a patch to Windows Media Player 10, that should be released shortly.

With an un-patched system, CPU utilization was much higher during WMV HD playback.  The Radeon had the overall advantage in the initial tests, but the GeForce 6600 was close behind.  With the system patched, however, CPU utilization dropped significantly.  This time around, the NVIDIA powered card had the slight advantage overall. Looking at the statistics below the graph, you can also see that each card performed similarly.  In one instance, the 6600 dropped a single frame, but other than that there isn't much to point out.  (Note: There is only one ATI statistics image, because the stats were identical in the patched and un-patched environments.)

Summary: In the examples we have shown here today, the NVIDIA GeForce 6600 GT with PureVideo Technology had better image quality than the Radeon X700.  The NVIDIA powered card also had lower CPU utilization when playing back WMV HD content when hardware acceleration was enabled using a pair of beta DLL files.  However, the ATI powered card had a slight advantage in CPU utilization in the default configuration.

NVIDIA's PureVideo Technology is a definite step in the right direction. The video quality produced on the GeForce 6 Series of graphics cards with PureVideo technology was excellent, and rivaled that of most consumer electronics devices.  When compared to ATI, NVIDIA also seems to have gained ground, or even surpassed ATI in some respects.  We won't dwell on this point though, because ATI also has some updates in the works that will likely render the comparisons made here somewhat out-dated in a few short weeks. We'll have to revisit the topic of image quality during video playback at a later date, using real world content to make any final conclusions. Regardless, NVIDIA's PureVideo Technology and new decoder software dramatically improve video playback on the PC, and further blurs the lines between the PC and a Home Entertainment Center. More information on NVIDIA's PureVideo Technology is available on their website in this press release, and in this comparison chart that illustrates the specific features available in the GeForce 6 Series of cards.

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