A couple of htpc questions (scaling, relative quality etc.)

Discussion in 'Desktop & Laptop Computers Forum' started by meoq, Oct 6, 2004.

  1. meoq

    meoq
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I've read a few articles about HTPCs at this stage, and a couple of FAQs, but I'm still left confused about a couple of issues.

    Basically, my main concern is that I want to play back DVDs using my PC, upscaled to 720p/1080i. Is this possible? I initially thought you had to use DScaler, but now I'm thinking it's more related to deinterlacing analog signals..? DScalar, at any rate, wouldn't work with my video card, so how can I upscale my output? Do you simply change the resolution using PowerStrip?

    Second question is: I will very likely be getting a LCD projector with HDMI inputs (probably the Panasonic AE700). Would my PC with DVI-I out drive a HDMI projector as well as a dedicated player with HDMI outputs? I heard somewhere that a DVI-to-HDMI cable would work as well as a HDMI-to-HDMI setup, since DVI is the exact same as far as video goes - is this true? I'm specifically thinking of the upcoming Panasonic S97 player which has HDMI output and upscaling capability..I previously was pretty much set on getting it, pending reviews, but I've since been looking at my PC as a cheaper and equivalent (PQ-wise) alternative. There seem to be so few direct comparisons between dedicated players and HTPCs, so I have lingering questions about how my PC would hold up. Can anyone provide advice?

    If it helps at all, I have a P4 2.53Ghz, 512MB RAM, ATi 9700 Pro..

    Cheers :thumbsup:
     
  2. KraGorn

    KraGorn
    Active Member

    Joined:
    Aug 30, 2003
    Messages:
    4,745
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    Warrington
    Ratings:
    +27
    Hi meoq,

    Re-scaling is inherent when you use a PC to generate the image for a projector. What happens is that you set the desktop size in the normal way and the projector 'sees' and image of the resolution and refresh rate you configure.

    When you select 'Full Screen' mode the projector 'sees' the DVD re-sized. The issue is which bit of software does this resizing. In lieu of anything else it's the DVD player, using hardware assistance if available (your ATI provides that), however better results can be achieved using a dedicated video processor.

    You're right that DScaler does this though its' main use is to act as a video processor for external signals like DVD players, TV tuners etc. The main application for processing internal video playback is FFDSHOW. It is NOT easy to get into its' full power, but getting started is easy enough.

    As for your question about cables. In principle yes, you can feed an HDMI display from a DVI source .. the other way round is NOT necessarily true BTW.

    Not sure quite what you're getting at by mentioning video games. A DVI output/input can be one of two types, DVI-D (digitial only) and DVI-I (digital and RGB analog, sometimes referred to as DVI-A), DVI-I is a DVI-D socket plus some pins, most video cards have DVI-I but a DVI-D cable works fine. HDMI is backward compatible with DVI-D which is why DVI->HDMI works. Note that it's because the video card has a DVI-I connector that you usually get an adaptor which you can plug into it to provide a second VGA output, VGA of course being analog.

    Your PC will be more than enough to run a DVD player like TheaterTek, probably the most commonly used player though WinDVD is also popular, however the process will not be sufficient to run FFDSHOW flat-out. You'll get some useful work out of it but not be able to use it to its' full potential. OTOH, FFDSHOW is NOT mandatory to get a PQ which exceeds most DVD players below £1000 IMX, all you need is a £50 DVD player.

    Your ATI video card is fine, though there's something of a stir in the HTPC world with the release of nVidia's 6800GT and soon-to-be-released 6600GT, though don't let that deflect you, it's still very early days yet and the 6600 isn't available yet anyway. :)

    HTH
     
  3. meoq

    meoq
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Hey KraGorn - thank you very much for your comprehensive reply, it is greatly appreciated!

    Just to clarify a couple of points - in terms of video alone, is DVI-to-HDMI the equivalent of HDMI-to-HDMI? I think I remember people saying that on boards before, but never got any confirmation. I'm just concerned that I could be getting a better picture from a dedicated player with HDMI-out if it does offer a step up in terms of signal quality.

    I will look into FFDShow, and see what is possible on my machine. Thanks for pointing me in its direction..

    I have heard about the NVidia cards, specifically the 32-bit per component color reproduction, which is indeed interesting. It's strange, because with regard to games, most people think the ATi cards have better IQ (though that's possibly because of AA and AF which wouldn't have much/any role in movie playing). I don't think I can afford to shell out for a 6800 at the moment, though I'll keep an eye on them for the future..

    Thanks again for your help! :clap:
     
  4. KraGorn

    KraGorn
    Active Member

    Joined:
    Aug 30, 2003
    Messages:
    4,745
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    Warrington
    Ratings:
    +27
    Since TheaterTek 2.0 is still unreleased the only people who know the difference a 6800GT makes over an ATI are the beta testers .. there's no doubt the 6800GT is better it's a question of how much.

    As far as DVI/HDMI is concerned, you may like to take a look at this detailed description of DVI/HDCP/HDMI for the full details, but in a nutshell:

    1) DVI is the specification of the electronic signals transferring the digital data which describes image.
    2) HDCP (High Definition Content Protection) is the specification of the encryption and other Digital Restrictions Management which tries to prevent that digital data being 'pirated'.
    3) HDMI is a combination of DVI + HDCP + other goodies.

    Thus, where the sending device doesn't implement HDCP (which no PC hardware does at this point in time AFAIK) then the HDMI receiver simply 'sees' the un-protected digital data and processes it.

    The main difference between DVI and HDMI (ignoring the content protection [email protected]) is that HDMI also includes digital audio, whereas DVI is solely video as you point out.

    Bottom line: AFAIK, there's no difference whatsoever in PQ simply by using an HDMI connection as opposed to a DVI one, any PQ difference would be down to the processing done by one of the connected devices. Whether that will change when the HDMI Version 2 spec is implemented I don't know, currently all HDMI-equipped devices are Version 1, I've read nothing which indicates the new spec will allow for a better PQ in a like-for-like comparison.
     
  5. meoq

    meoq
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Cool stuff, that all makes sense.

    One further question arising from your post: the supposed advantages of NVidia's 6800 series only become apparent when using TheaterTek 2.0? Does the software need to specifically take advantage of the higher colour precision, or are there other issues?

    Thanks, and sorry for all the Qs.

    Thanks :beer:
     
  6. KraGorn

    KraGorn
    Active Member

    Joined:
    Aug 30, 2003
    Messages:
    4,745
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    Warrington
    Ratings:
    +27
    Well that's not strictly true, the 6800 also reportedly produces a better PQ than an ATI 9800 using the current version. The main thing about TT 2 is that they're switching to the nVidia MPEG decoder which in turn makes better use of the 6800 hardware than the current Sonic decoder.

    I really have little idea about graphics chipsets these days so I've no idea how big a part features like pixel shaders, the number of pipelines, AA & AF etc. etc. play in DVD playback quality.

    Note that the 6600GT is supposedly better again due to having more video processing ... search back on here for recent posts mentioning the 6800, in one thread I asked about the 6600 vs. 9800 with respect to gaming and someone posted a link to a review which basically says the 6600 beats the 9800 hands-down.

    [edit]

    This is the thread, look towards the end.
     
  7. meoq

    meoq
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Cheers for all your help KraGorn, lots to consider, as always!
     
  8. KraGorn

    KraGorn
    Active Member

    Joined:
    Aug 30, 2003
    Messages:
    4,745
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    Warrington
    Ratings:
    +27
    My pleasure :) I'm waiting for the 6600GT since it means I can replace my 9800 Pro and use just one PC for games and HTPC duties.

    If I may suggest, ignore FFDSHOW for the time being and just get a decent DVD player (TT) and decent graphics card, then worry about twiddling and tweaking. If you worry about FFDSHOW at the outset you'll never make a buying decision. :D
     
  9. meoq

    meoq
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Yeah, I plan to this incrementally. Asides from biting off more than I can chew starting off, I'd like to see the improvements these things make - if I start off trying everything at once, I may never appreciate what I'm seeing or how different it could be without any improvements! :suicide:

    So, I'll probably stick with my current set up and card, DVI-out to my projector (looking likely to be an AE700), probably using TheaterTek, and then see what that's like. I imagine it'll look pretty good. Then tweak from there. The only change I might make to my PC now is a quieter DVD drive (the current one whips up quite a storm when in full use!). Thanks again..
     

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice