A Brief Look at De-Interlacing Modes

The process of taking interlaced content and displaying it in a non-interlaced form is often referred to as de-interlacing (for obvious reasons). There are two basic methods of de-interlacing, commonly known as "bob" and "weave."

Bob de-interlacing is more technically referred to as linear interpolation and it simply fills in the missing lines of resolution by interpolating between the resolution lines that are available. This interpolation form of de-interlacing is particularly useful if there are a lot of solid colors on the screen and if the decoder screws up and decides to combine two fields from different frames.

Weave de-interlacing, as the name implies, simply combines alternating lines of resolution from two separate interlaced fields. Using either method individually is generally not the best way of doing things, but thanks to the decent amount of power in today's PCs more sophisticated algorithms can be implemented to dynamically switch between bob and weave on a per pixel basis within a frame (usually referred to as adaptive per pixel de-interlacing).

NVIDIA's PureVideo supposedly takes adaptive per pixel de-interlacing one step further with what they call Spatial-Temporal de-interlacing. The idea here is that normal per pixel adaptive de-interlacing uses data from fields within a single frame to essentially fill in the blanks. NVIDIA's Spatial-Temporal de-interlacing can use data from fields in other frames to improve de-interlacing quality. We'll have to see if this ends up improving quality or not in our tests later in the article.

Frame Rate Conversion and You NVIDIA's PureVideo Driver and Encoder
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  • MDme - Monday, December 20, 2004 - link

    Hey Anand, why not suggest to nVidia that owners of 6800 series GPUs be able to download the codec and just have their serial #'s or proof of purchase? I mean, they shouldn't tout a feature that you need to pay extra for?

    They already screwed us 6800GT/U owners with a "broken" feature, now they wanna screw us 20$ more to get the "broken" feature?

    We need a petition site!!!!!
  • Guspaz - Monday, December 20, 2004 - link

    I was under the impression that the deinterlacing was done by the DVD decoder app itself. So would not the results differ from WinDVD to PowerDVD to Zoom? Also would have been nice to compare it to other modes of software deinterlacing such as motion compensated.

    Something that I didn't see mentioned in the article is that while the hardware deinterlacing is certainly a win for nVidia, ATI wins the WMV9 acceleration category, as I'm pretty sure that all R3x0 cards support it back to the 9500/9700. That means that ATI's WMV9 market penetration is way higher than nVidia's, since very few nVidia cards can do the acceleration.
  • Klaasman - Monday, December 20, 2004 - link

    Nevermind. Found info at Nvidia.

    "The new software will upgrade the decoders in ForceWare Multimedia 3.0 to access the new features in the NVIDIA DVD Decoder. The NVIDIA DVD Decoder will not upgrade NVDVD 2.0 as it was a separate application based upon an old architecture."

    They want me to pay twice for it I guess. Greedy bastards.
  • Klaasman - Monday, December 20, 2004 - link

    I got a copy of NVDVD with my eVGA 6800GT. How do I update the DVD codec? When I install the new version from Nvidia, it still asks for credit card info and stuff.
  • jonny13 - Monday, December 20, 2004 - link

    "NVIDIA's DVD decoder has always been $20, unfortunately I don't know of a single manufacturer that gives away their DVD decoders for free."

    I know that their DVD decoder has always been $20. But, they never specified that you would need to pay extra for a feature that they touted for months. Thats like making you pay for a special driver to get PS3.0 to work. If they advertise it as a feature on a card I am paying $500 for, it better damn well be free and not another 20 f'ing dollars.

    /rant
  • b3roldan - Monday, December 20, 2004 - link

    I'm really disappointed with the 6800s not having the wmv9 decoding... was gonna get myself a 6800U for xmas. I was reading on the X800XT-PE coz there's a Sapphire X800XT-PE relatively cheaper than most 6800Us in http://buycomp.hkgolden.com.

    Then I came accross this webpage that says the nv48 is still coming... http://www.digitimes.com/mobos/a20041220A7039.html

    hehe... I guess I can wait 3 months for the nv48, but then with the R520 just around the corner... man buying a card is starting to become a tough decision.

    neways... I was wonderin if neone could confirm this information on the hardware flaw...

    http://www.animenation.net/forums/archive/index.ph...
  • RCIEGR - Monday, December 20, 2004 - link

    You missed one very important feature to me.
    The 6800gt lacks the true hd output formats in component video output. I have a 6800gt and these card didn't include the special 10-pin din connector to the hd-component/s-video/composite adaptor plug. My freind at work bought a 6600gt(Chaintech) for his son for xmas, so I borrowed the card for a test this last weekend. Having a old school sony KDP-57XBR2 HDTV with only firewire and 2-hd component vidoe imputs. The true hd-output of the 6600gt is way more important of a feature to me then the wmv9 decoding.

    The output over component(both true 1080i & 720p; the sony can nativly handle both) looked very good, for both hd video(surferp****.com), hd tapestreams recorded from the firewire output of the mot-6208 hd-cable box and the latest games, once you figure out how n-view works and you get the game resolutions correct.

    anand, take a close look at the reference 6800gt cards and I think you will see the 10-pin din connector.

    I want a RMA for a 6800gt with the true hd-output with component video. eVGA does have a 90-day upgrade program. Maybe a 6900gt will show up quick?

    Thanks for you time
    Robert
  • MDme - Monday, December 20, 2004 - link

    Well, my XFX 6800GT didn't come with the NVDVD decoder. it's a shame nVidia sells a very expensive video card and tout's this feature but doesn't include the software to make it work.

    I think nvidia should know how it's customers feel. after all we were the early adopters. it's one thing to have a partially working feature but it's totally a rip-off not to have it at all!!!! $400 for a video card and you need to pay more for software to make it work? :(

    Hope Anand can be a voice for us.
  • ViRGE - Monday, December 20, 2004 - link

    Anand, check the final X800 press presentation slide-show/PDF, it was in there somewhere last time I read it.
  • sheik124 - Monday, December 20, 2004 - link

    nVIDIA has really done it this time. #29 mentioned ATI not doing their part, but at least the features they advertised and are slowly deploying work on ALL OF THE GPUs. nVIDIA owes us something for the false advertising, they've really wrecked my day, I paid for something, and I expect to have it, not half of it.

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