Does DVD Video from PC's DVI-out need deinterlacing?

Discussion in 'Computers' started by Will.MA, Dec 20, 2004.

  1. Will.MA

    Will.MA Stunt Coordinator

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    I'm not well versed on the many video concepts that surround the high definition format. In spite of much research on deinterlacing, 3:2 & 2:2 pulldown, scalers, etc. on this forum and others, I'm not sure I have it straight. It's a lot to process for the newly initiated.

    Well, I've begun to put together a modest system. The next purchase will be a new display device. While combing over the alternatives among DLP, LCD, RPTVs and plasmas, I was exposed to the idea of basing a HT system around the PC. As it turns out, I have a video card based on the Nvidia 5900XT engine with a DVI output that may be useful in this capacity. I'd like to use my PC instead of purchasing a progressive-scan DVD player if I can to minimize expense.

    Which brings me to my question: If I output video from the internal DVD player of the PC through the DVI output of my video card, is it progressive or is it still interlaced? If it is still interlaced, how can I change it to progressive without relying on my display's deinterlacer? It seems my PC should be able to do it better since it has more computing power on which to draw. And finally, how do you equate PC resolution to HD resolution? For instance, if I display a DVD from my PC at 1280 x 1024 resolution to a compatible front projector, is that considered HD, and if so, which setting (480p, 540p, 720p) is it equal to?
     
  2. Jesse Blacklow

    Jesse Blacklow Cinematographer

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    It's not technically considered HD unless it's actually using one of the HD resolutions (1280x720p, 1920x1080i, or 1920x1080p). Otherwise, it's just a computer resolution.

    The important thing to remember about post-processing is that it operates only within the image that is sent by the DVD. This is always either 480 (NTSC) or 576 (PAL) lines. They are usually progressive, but some of them aren't mastered or "flagged) correctly. On my system, the DVD is first decoded and deinterlaced. In this case, I'm using the nVidia decoders that came with TheaterTek 2, through a 3rd-party player (ZoomPlayer). PowerDVD and WinDVD both include proprietary decoders. There is also a freeware decoder from the DScaler folks. Next, a open-source program called ffdshow resizes (output is changed from 720x480 to 1440x960), denoises, and sharpens the image with a Lanczos algorithm. Finally, my video card scales the image to fit within the output specified (1024x768, for instance). All of this takes a significant amount of processing, so make sure your computer can handle it. My AMD64 3200+ and 6800GT are able to handle it, but there's not headroom for much else to be going on.
     
  3. Will.MA

    Will.MA Stunt Coordinator

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    I have:
    AMD XP 2900+
    Win_XP Pro SP2
    1 GB XMS Corsair PC3200 low latency
    Leadtek A350 (NVidia 5900XT)
    nForce2-based mainboard (DFI Lanparty II Ultra)

    I downloaded powerstrip and ffdshow. I also have PowerDVD, WinDVD, and NVDVD but I DON'T have zoomplayer. In your opinion, do I have enough power for post-processing? The signal will be sent DVI->HDMI to a digital projector.
     
  4. Jesse Blacklow

    Jesse Blacklow Cinematographer

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    Sure looks like it. A couple things:

    1) You don't really need Powerstrip with newer nVidia drivers. I'm using the 71.24 betas, but even the latest Microsoft-certified drivers (67.22, I think) have excellent control over resolutions and refresh rates.

    2) There's a guide at HTPCNews.comthat should get you started with post-processing. ZoomPlayer Pro (the full version) is quite cheap, and there's a couple other players out there that can take advantage of PP. One guy has an alpha player called "Mediator" which isn't fully functional, but plays DVDs just fine.

    3) The PQ of the various decoders can make a difference, especially on higher-rez displays. The best are either the newest nVidia decoders that can be had for $20 straight from nVidia or with the TheaterTek 2 player (which can also do PP with ffdshow), or the open-source and free DScaler 5 beta decoders. Both have positives and negatives, but few will argue that they're not, by far, the top two decoders.

    4) If you're having sync issues, check out a program called Reclock, it's helpful for when your displays refresh rate isn't a multiple of the media's framerate.

    Good luck! I guarentee you'll love the quality, but you'll find the need to tweak every so often. That's half the fun, IMHO.
     
  5. Scott L

    Scott L Producer

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    Excellent advice Jesse! Can I ask what kind of display you're working with? I'm on a modest infocus 4805 and even though the native resolution is 854x480 I see a huge improvement in scaling to 1440x960.

    Will- it looks like you have enough power. The big hit on the CPU is Lanczos or Spline resize. Most do 4-tap but others can get away with a higher number, along with increasing the sharpening levels. Denoise3d is another popular algorithm and it takes some muscle to process that. Good news is that you can configure and tweak to high heaven on what suits you and your setup.
     
  6. Jesse Blacklow

    Jesse Blacklow Cinematographer

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    Scott, I'm currently using my parent's Infocus X1, which is IIRC basically the business version of the 4805, although I have a Z1 (960x540) in storage for a couple months. My full settings are as follows:

    Athlon64 3200+
    DFI LanParty UT nForce3-250 (w/onboard SPDIF and 8-channel analog)
    1GB PC3200 RAM
    eVGA 6800GT with Arctic Silencer NV5
    XP Pro SP2

    I use either ZoomPlayer (VMR9 Windowless) or Mediator (VMR9 Renderless*) as a media player, with the nVidia decoders via TT2, which I bought before I knew the decoders would be sold separately. At least we get some of the decoder updates early. I use the NVVPP, along with Smart deinterlace and "Best available". I also use Reclock because 48hz and 72hz settings (multiples of NTSC film rez) don't look right on the X1. My ffdshow version is not from the main guys, but from a recompiler (Andy) who has made some great optimizations for SSE and SSE2. I think the latest version is an alpha from August 1, 2004.

    I don't have my exact ffdshow settings here at work, but here's what I think they are (in this order):
    Output is set to "Raw video"
    aWarpSharp (no chroma sharpening, no blur, depth 64, threshold 0.80)
    Lanczos4 resize to 2x (i.e. 1440x960), resize Chroma @ 0.4
    aSharp (unsharp masking threshold 0.4, adaptive sharpening strenght 10, block adaptive sharpening 4)

    I've heard that higher than 4 introduces some nasty ringing (kind of like edge enhancement). For better PQ, I'd go for Lanczos4, but Lanczos2 is almost as good and will free up some CPU. On Will's system, if you want to use Denoise3D (Andy's alpha has a HQ option that should be checked), you have to engage another filter--say, Levels at default--before it*.

    * For more information, check out the threads labeled "Very early alpha of my dvd player" and "Ffdshow FAQ" over at AVS Forum.
     
  7. Scott L

    Scott L Producer

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    Sounds almost exactly like mine, down to the graphics card + NV5. [​IMG] Just fyi the X1 is the business version of the 4800 though. The 4805 and 4800 have different DMD chips and resolutions.

    My setup is Levels > denoise3d+HQ > Lanczos4 > output YV12. I use Lanczos4, I swear the Spline can look better but I get more stable playback with the other method. If you need to free up some CPU cycles you can convert the colorspace to YV12 by adding the simple Picture Properties/Levels filter first and turning it down just 1 notch. This colorspace is easier to work with than YUY2 and it doesn't degrade the colors.
     
  8. Will.MA

    Will.MA Stunt Coordinator

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    I've now purchased ZoomPlayer Pro and will soon need decoders. I read somewhere that Sonic DVD package contains the easiest decoder to use with ZP. Folks here seem to prefer the TTK decoders or NVidia likely for good reason. I don't want to go with the easiest system to manage but for the best PQ. Is it then the best advice to invest in the Theatertek or NVidia decoders instead of Sonic?

    I will also take a look at the DeNoise algorithm. I want to make sure the picture I project is so sweet that it makes my wife whose ambivalent about most things technical forget about the $$$ invested in the gear.

    Thanks you all for your input. Keep it coming guys. Sharing what you know about these programs makes it easier for new gusy like me to quickly get a good picture up and running.
     
  9. Jesse Blacklow

    Jesse Blacklow Cinematographer

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    Yes and no. If you're willing to go without subtitles and use beta software, you can use the DScaler 5 decoders. You may need a program such as AnyDVD to use them, though. Otherwise, the nVidia decoders are the way to go. For all intents and purposes, the decoders that come with TheaterTek are the same decoders that you can get from nVidia. They just have different upgrade rates. For instance, I think the current TheaterTek decoders are 1.00.67, whereas the ones on nVidia's site are 1.00.65, but the differences are slight.
     

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