Most modern video projectors, at least the majority made since the early 90's, are designed to take higher resolution images from computers (1024x768 for example). The modern projector was designed to do computer presentations, so using them as strictly video projectors means a lot of usable resolution going to waste!
Many of the new digital projectors have built in scaler devices that process incoming low-resolution video signals and "scales" them up to the resolution that the projector wants them to be (called the projector's "native resolution"). However, many of these internal scaling devices are poor and introduce artifacts to the picture in the process of resampling the image... An outboard scaling device would be able to do a better job and create an image equal to the "native resolution" of the projector- but a good scaler costs thousands of dollars!
Someone somewhere got the bright idea that the mpeg decoding engine on a high buck PC video card coupled with a DVD-Rom drive might make a good dvd player to feed high resolution images to these compatible devices. By connecting a PC to the projector via the VGA connection you could scale the DVD playback to really high computer resolutions- exploiting the potential of these projector devices and avoiding the poor processing of internal scalers...
Turned out, they were right! The scaling possibilities of a computer coupled with high buck super-dooper video cards became serious competition for $10,000 video processors, all for less than $1500! This is the best way (in terms of value) to get to quality DVD images, if you have a projector or set that supports VGA or better resolutions...
The image is really good, much smoother and more film like than even a progressive scan DVD player can offer. The scaled output from decent HTPC even rivals majority of expensive scalers, up to and including systems costing $10,000+.
So, once it was started the quest began- the computer geekers and tweakers came out of the woodwork. Guys who were good with computers anyway saw the potential- and many specific applications have been written making computers the ideal player for DVD and so much more. There are applications (like Powerstrip) that let you dial in resolution to the pixel- meaning you can find the best possible "sweet spot" resolution for your projector or display device.
The HTPC craze has extended beyond the Front Projector users- now that rear projection HDTVs are becoming popular- many support higher resolution inputs, just like Front Projectors can, so a PC can be used to scale DVD to HD resolutions like 720p, 540p or 1080i to a HD compatible display! Some rear projection sets will even handle computer resolutions like 1024x768 and higher... Many RPTVs have a DB15 VGA style input or DVI- but even if not several manufacturers make a transcoder that will take computer input and output HD Component (expect to spend $300ish).
If you're interested in learning more about HTPC, you can read the HTPC/PC area here on the HTF.
Or the great (but very
advanced) HTPC area on AVS:
AV Sciences Forum HTPC Area
In addition to the appeal of excellent DVD playback, the HTPC concept has
hundreds of possibilities like:
- CD and mp3 playback in your HT, with visualizations and file controls.
- PVR functionality- basically a custom TIVO like machine that with the right
configuration can record HD programming as well!
- PC tasks like Websurfing and gaming in your HT on the big screen!
- You can use it to scale external sources (with the excellent, free
Dscaler).
- Completely custom resolutions for Projector/HDTV owners: dial the sweet spot
of your set
- Region free playback, PAL conversion, no layer changes.
- Custom preroll and intros for movie night. Compile your own theater intro-
and even play it back at full HIDEF resolutions direct from the PC (no need to
down convert it like DVD-R users do!)
- Neat add-on applications like
DVD subber allow you to
access subtitle streams from the internet (useful for anime fans or other
foreign films not subtitled for English!)
- DVD playback applications that allow you total control: have your movies play
as soon as you put them in with your preferred soundtrack and settings (skip
the warnings and the menus), automatic aspect ratio adjustments and more.
- See what others are doing with their HTPC here:
http://www.avsforum.com/avs-vb/show...&threadid=31877
Ive got a video card with a Svideo output on it, can I use this for HTPC?
Yes, although you miss a good deal of the point of HTPC,
in my honest opinion.
If you're coming from the PC via SVIDEO, you are getting a signal that has been
down converted to standard interlaced NTSC resolution not matter how high your
desktop resolution is set. The desktop setting is the VGA output resolution; as
long as you're using Svideo you're nowhere close to that.
The only way to get the actual full resolution from the PC to a TV set would
be to use the RGB (VGA 15 pin connector) output or DVI output from the card.
The bottom line is that the TV (S-video) output on these cards provides a video
feed compatible with a standard TV- that is 480i- regardless of your desktop
settings.
Even if youre looking to just pass regular DVD playback to a standard TV, the
majority of these cards have a $2 circuit to handle this TV send- so most are
lower quality than even an entry-level DVD player. So if youre going Svideo,
chances are good even a $200 DVD player would be better for you than the HTPC
solution.
How can I get the HTPC to hook up to other sources besides DVD?
You need some sort of video input card to accept the
incoming video signal and display software to put it on screen..
Most people use an excellent free application called
Dscaler. This is an open
source PC based scaling engine that does amazing video processing. It does full
scaling to output resolutions, does 3:2 pulldown, aspect toggling and even has
built in TV tuner functions. It is free:
http://dscaler.org
The one hitch with Dscaler is that you have to use a particular type of input
card: any card based on the Brooktree (now Conexant) chipset. DO NOT PLAN TO
USE THE ATI INPUT ON THE ALL IN WONDER CARDS FOR INPUTTING VIDEO TO DSCALER.
These video inputs are mediocre at best, and will not work with Dscaler. You
can check the Dscaler FAQ for some specific cards, or just do a search on the
AVSforum and start
reading. I got an I/O Magic input card from Circuit City for like $35- it's a
little blown out on the whites- but for analog cable and a few Dreamcast games,
it's "good enough". Another hitch is that your OUPUT video card must be AGP, it
won't work with a PCI card (it will but you run a serious bandwidth risk to
doing decent resolutions).
If you're looking for top of the line input, a member on AVS (look for username
KBK) does a modification of the WinTV series card that is supposed to provide
the very best quality external input. Expect to spend a few hundred bucks to
get one however!
One extra note on the cutting edge: Some people have started using SDI input
Conexant cards with Dscaler, and have gotten their DVD player or DSS receiver
modified to put out a SDI digital output. This is really the cutting edge as
far as top quality processing goes- and it won't help you for analog sources
like VHS and is not yet available for any video game systems, but for DSS and
DVD provides Dscaler processing (which is great) with a direct digital path!
Also, you can read the
FAQ over at
http://www.dscaler.org/ which has plenty of details on how the software
works, what cards to look for, etc.
If you'd like to go beyond what Dscaler and these Conexant cards can offer,
some other popular solutions include pro input cards (like the Falcon) and a
new card (Holo3DGraph) which represent the most recent top of the line. The
Holo3DGraph also includes Faroudja HW deinterlacing, SDI, & component video
input.
Ok, Im sold- can I buy a HTPC somewhere or do I have to built one?
Several companies are now offering whats called TURN KEY HTPC configurations-
AVS and
Digital Connection both offer several excellent models of HTPC. However- it
is far more cost effective to build one yourself if you are even remotely
computer literate (or even if youre just brave!)
Like with any portion of PC use, what is a hot technology changes seemingly
everyday, but the basics for HTPC are:
Video- ATI Radeon based cards are the popular ones for HTPC output as they
usually exceed similarly priced cards in MPEG decoding.
Audio-
M-audio (aka Midiman)
cards are very popular in HTPC circles for offering bit for bit digital
transfer. Some people use
Soundblaster cards however.
Software-
TheaterTek is
very popular for HTPC, with the free ZOOM player also being a top choice!
As far as the rest of the hardware- Id point you to these FAQ documents on the
AVS forum. Happy hunting!:
http://www.avsforum.com/avs-vb/show...122&perpage=999
http://www.avsforum.com/avs-vb/show...314&perpage=999
http://www.avsforum.com/avs-vb/show...000&perpage=999
http://www.avsforum.com/avs-vb/show...237&perpage=999
http://www.avsforum.com/avs-vb/show...524&perpage=999
http://www.avsforum.com/avs-vb/show...307&perpage=999
Article written by Vince Maskeeper of www.musicianassist.com . Thanks also to www.HomeTheaterForum.com.
© Copyright 2002 Home Theater Forum. All rights reserved. Reprinted by permission.
