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William,

Now I don't claim to be an HTPC expert (actually, I am trying to build my first one right now), but I think the answer basically comes down to, do you want the projector's scaler (which is inferior) to do the scaling, or do you want the PC to do the scaling (much superior). One factor is the HTPC does the scaling all in the digital spectrum. The signal comes of the DVD, the computer scales it, then sends it out to the FP. If you used a prog scan DVD player, it would be converted to analog, then have to be converted back by the FP into digital to be scaled. This adds an unnecessary step.


Trust me, it must be better or else you wouldn't see so many testimonies about it. I haven't even seen one in real life yet and I am a believer. Partly because of the testimonies, and also because it makes sense. Common sense.

JD
 

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Trust me, it must be better or else you wouldn't see so many testimonies about it. I haven't even seen one in real life yet and I am a believer. Partly because of the testimonies, and also because it makes sense. Common sense.

JD

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While in this case I agree that HTPC's ARE better, I just want to point out I've read plenty of testimonies stating that green ink on the edge of a CD makes it sound better...


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All your bases are belonging to us since 1902...
 

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What is the obsession in using a computer to scale your video signal to a projectors native resolution? Why not feed the projector a 480P signal from a good progressive scan DVD player, and allow the projector to upconvert the signal to its native progressive resolution. My understanding is that once the video signal is in progressive form it is easy to convert it to 600P, 720P, or 768P without introducing artifacts. I would be afraid that my computer would sieze or crash right in the middle of a suspence film. Opinions Welcome - Thanks - William
 

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William,


The reason for using the HTPC is that, for the most part,

the internal scalers of the projectors are not that good.


There are two sources of artifacts - de-interlacing

artifacts, and scaling artifacts. The projector's internal

scaler can still introduce scaling artifacts.


A progressive scan DVD player is really just a DVD player

with a built-in line doubler to do the de-interlacing. As

pointed out in a recent issue of Stereophile's Guide to

Home Theater - not all of the progressive scan DVD players

on the market will recognize a signal with 3:2 pulldown

[ telecine ], and properly de-interlace this sequence by

skipping the repeated fields.


Additionally, since even a progressive scan DVD outputs an

analog signal - preferably PrPbY component - there is an

addition digital to analog back to digital conversion that

is done.


With an HTPC, the signal stays in the digital domain as long

as possible - and you can get near state-of-the-art scaling.


Also, when a video card manufacturer makes an advance in

scaling technology - like going from 8-bit video to 10-bit

video - you can upgrade to the newer technology for the

cost of a video card.


Sure the HTPC may require a bit of tweaking. However, a

lot of the proponents of HTPC are computer professionals

who are used to doing this type of thing.


Greg
 

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Don't forget the potential for higher refresh rates as well as aspect ratio manipulation.


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Sergio R.
 

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Quote:
While in this case I agree that HTPC's ARE better, I just want to point out I've read plenty of testimonies stating that green ink on the edge of a CD makes it sound better...
Good point - with the new lasers being used by DVD's, everybody knows that red ink is much superior to green ink. http://www.avsforum.com/ubb/smile.gif



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Brian
 

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The scalers in older business projectors are often an afterthought, and not too great for scaling 480i NTSC sources.


For a progressive scan DVD combined with a projector with a decent internal scaler the results can be much better (VPL10HT is a well-sited example), but it usually comes down to what you are willing to compromise on.


HTPCs are obviously more complex, and can potentially crash, and internal scalers are simple but almost uniformly inferior in quality.


Still, the internal scalers can look decent, and I wouldn't recommend getting a HTPC to someone who is uncomfortable with PCs in general, or expects a great deal of family usage.


I have a regular DVD player hooked up to my G15 so that my wife can press three buttons and watch a movie, but I'm much pickier about picture quality and always use my HTPC.


Also, there are higher-end scalers from the $1400 Quadscan to the more pricey Vigitec and Rock scalers that can get very close to HTPC quality combined with black box plug-and-play ease of use, but they cost much more money than a HTPC.


-Dean.
 

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William,


Keep in mind that the more you try to load into a PC, the more likely it is to become crash-prone and frustrating.


Also, cheaper components, especially bargain-basement memory and motherboards can be asking for trouble.


The good news is that it is not very expensive to build a dedicated HTPC these days. The hardware and software requirements are not that high. So by building a PC that does nothing besides DVD playback, for instance, you can build a great scaler -- for DVDs only -- for under $500. You can find actual shopping lists of exact components in the HTPC forum.


By contrast, building a new PC that covers all of a family's computing wants could run you $2000 easy. And the extra complexity might make it a failure for HTPC use.




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Kirk Ellis

G1000 D-ILA, HTPC, Panamorph (soon I hope),

Dish 6000 (HBOHD,SHOHD,CBS,NBC,ABC,WB,FOX,UPN, KCET -- does it get any better ?)
 

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Many people brought up very good points and the issue basically boils down to quality of scalers. Also, the VGA signal sent is not strictly digital but is rather just a high quality analog signal. It is subject to less loss because the colors and sync are seperated, but still lossy.


As mentioned, scalers are typically afterthoughts because most users send native resolution computer graphics to them. And those who use the tv inputs are used to lower quality, since its well, a TV!


Some newer projectors like Infocus LP340 and 350 use next-generation scalers. Many people hooking up an HTPC will report a downgrade in performance since you need a tuned HTPC with a Radeon to beat it. I think in the future this will become more and more mainstream as the chips for this become cheaper. Of course I believe the PC will keep up with using more professional VGA cards and better-developed, upgradeable deinterlacing and scaling routines.


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Cal Z.

Mits 65903 (65" widescreen HDTV)+ RCA DTC-100

and

Gateway Destination 27" (Princeton Arcadia based)+HTPC (Pentium II 400, 256mb, 20gb+9gb HD, Radeon LE, cybertainment tv tuner, asus dvd-rom, hercules game theater xp, Kenwood VR409 DTS receiver)

[email protected]
 

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While I think PC are great for film based DVDs they suck at video source. They fall back to bob/video mode which can leave rather blurred results - or aliasing (but clearer/sharper) if you use a Radeon. A progressive DVD player with adaptive de-interlacing and 3:2 pulldown removal will in most cases produce a much better picture for this kind of source material. I have DVDs encoded at 30fps interlaced (compared to 24fps progressive) that my Skyworth actually manages to do 3:2 pulldown removal on, leaving me with a picture quality the HTPC has no chance of matching with current hardware/software.


There's one other factor people neglected to mention - anamorphic downconversion. If your projector can't do the anamorphic strech you'll have to downconvert in the player - with a HTPC you can output at the native panel's resolution and thus avoid the downconversion and giving you a better picture.


So in the end it really comes down to watching habits, ease of use and projector limitations. If your projector has a good internal scaler that can do the anamorphic stretch then a HTPC is probably overkill compared to a progressive DVD player.


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/frode
 
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