DVI vs. Component video cable

[gadget]

I just bought a Sony 42" Grand Wega LCD rear projection tv. As you know, it has 3 lcd chips, one for each component video. I have a pioneer dv275 dvd player using a very high quality component video cables. My question is, how much better or clearer is a dvi connection if I get a hd lg player over the one I have right now? Thanks.

[flaninacupboard]

component video can carry 1080i and 720p just the same as DVI or HDMI. should be little difference between the two, especially on a (relatively) small set like that.

[pyrate83]

How much does a dvd player with component out and 720p or 1080i cost though? Mine currently is only progressive at 480p. I just would like to experience true HD on my TV.

[flaninacupboard]

well TV's such as gadgets' with a 720p display obviously resize the DVD output before displaying it. in my eyes a DVD player with an upscaler is pointless, as any HD TV will have a scaler of it's own....

[pyrate83]

well TV's such as gadgets' with a 720p display obviously resize the DVD output before displaying it. in my eyes a DVD player with an upscaler is pointless, as any HD TV will have a scaler of it's own....

Well now you lost me to be honest...and this thread needs to be in the Digital TV forum but I can't move it since I'm not a mod.

[Capmaster]

pyrate - I can

Moving to Digital TV forum ...

[flaninacupboard]

i checked the sony site, and it says the grand wega 42" has a somethingx720 display, but will accept signals up to 1080i. if the display is physically 720 pixels high, the image -must- be scaled to fit....

[flaninacupboard]

Never mind, he fixed it.............

I can't trust you with that edit button cap.

[pyrate83]

So my tv will support up to 1080i with a 1280 x 768 resolution. If I understand correctly, I can't see this set in it's full glory unless I'm hooked up via a DVI cable.

[MOVIEGEEK]

www.crutchfield.com sells DVD players with DVI or HDMI output,some as low as $149US.

[pyrate83]

www.crutchfield.com sells DVD players with DVI or HDMI output,some as low as $149US.

Thanks Moviegeek.

[gadget]

Thank you all for your replies. Pyrate83, have you tried hooking up your tv via component and how much difference is there when watching between the two (dvi and component)?

[edDV]

So my tv will support up to 1080i with a 1280 x 768 resolution. If I understand correctly, I can't see this set in it's full glory unless I'm hooked up via a DVI cable.

DVI will make little or no difference* vs. analog componet cables for that set with few exceptions**.

Your set scales 480i, 480p and 1080i to your display's native 720p. 480i and 1080i are deinterlaced by the TV to 720p. All this happens for either type of cable connection.

All DVD discs are 720x480 by definition. They are formated for direct playback in 480i (interlace). A DVD disc containing 24fps movie material also contains the second field info on the disc so a progressive DVD player can convert the 2 fields first into 24fps and then into a 60fps progressive stream at 480p to the HDTV. Your TV will upscale this to 720p for display. The TV is designed to do this well since most people will be playing 480p DVDs on their HDTV. 480i DVD material is converted into progressive either in the player or by the HDTV if the input is 480i.

DVD players with HDMI outputs and internal scalers offer little or no advantage to you. You are betting the 480p to 720p scaler in the DVD player is somehow better than to one in your TV and my vote goes to the Sony engineers that designed your set.

These DVD players perform even worse for people who have only 1080i inputs for HDTV (the vast majority). These HDTV sets will take the 480p progressive DVD signal directly the same way yours does and display it at 720x480p or upscale it to the internal progressive display resolution. The picture will be as good as the HDTV set engineers could make it.

It you used an "upscaling" DVD player to convert the 480p 60fps progressive feed into an interlaced 30 or 60 fps 1080i feed and send it via HDMI to the TV, the TV would need to deinterlace the upscaled 1920x1080 input and scale that down to the HDTV's internal display resolution (typ ~1280x1080). The picture has to look far worse after all that.

* the only arguement for DVI/HDMI advantage in the "NTSC" world is digital vs analog connection performance. At the 42" size or less, few reviewers have seen a difference except for very cheap sets that skimp on the analog design quality. In the "PAL world" some component analog connections have been limited to 720x480 by Macrovision. An encrypted Digital connection is required to receive full 720x576 720p from a "PAL" DVD player.

** exceptions may include unequalized long cable runs or connections to HDTV tuners. When the record block goes into effect, an HDCP encrypted connection will be required (DVI or HDMI with HDCP) to view record blocked material. Future HDTV DVD players will also require HDCP encrytion to view the HD-DVD in HD.

[gshelley61]

OK - I happen to own a 46" DLP HDTV with DVI input and a Bravo D1 upscaling DVD player. For larger fixed pixel displays like DLP, LCD, plasma, etc. with native HD resolution (not EDTV 853x480p panels) the all-digital signal from DVI does make a big difference. For smaller sized screens and CRT based displays (direct view and projection) the difference is less noticeable and probably not worth the expense.

The Bravo D1 has an excellent scaler (in the Sigma 8500 chip) that provides 480p, 720p, 1080i, and custom scaled resolutions through the DVI output. This is all done directly from the MPEG2 digital file, rather than from the analog 480i or 480p signal that a TV with a built in scaler would use. There are almost no scaling artifacts as a result, and the output can be 1:1 matched to the native resolution of your particular fixed pixel display. The idea is to bypass any scaling in the display altogether... if you have a 1280x720p display (like I do) it makes no sense to send it a 1920x1080i scaled signal, as it has to scale it down to 720p anyway.

My DLP has a built in Faroudja scaler, which is very good... but it still is no match for the Bravo when it comes to upscaling a DVD image.

I've tried a couple of upscaling players that can send the signal through the component analog HD outputs... the DVI definitely works better on a DLP display, and I suspect the same would be true of LCD and plasma screens.

[gshelley61]

edit (oops!)

[edDV]

Native display 720p (1280x720) or 1080p (1920x1080) HDTV sets are the cases where your argument directly holds. The competition is then between the DVD player scaler (720x480 even and odd fields to 720p) vs the HDTV set scaler (480p to 720p). In the second case the quality of the analog path influences performance.*

All other HDTV displays, including big plasmas, must go through an additional scaling at the TV end from 720p, 1080i or 1080p to the set's native resolution. Typical high end plasmas max out around 1440x1080, typical CRTs max around 1024x1080, sometimes 1280x1080.

I think most would agree that below 42" screen size you probably can't see a significant difference. Above 42", you may see a difference and if the set is very good, you may see a big difference if the DVD player scaler is very good as well.

All this will soon be mute as we buy scaling HD DVD players sometime next year that will all have HDMI outputs and scalers.

* analog quality can vary from very good to poor. It's not fair to compare a $350 scaling DVD player to a $40 K-mart brand analog DVD player. The test should be against a $200-350 analog player to be fair. Cheap DVD players have poor D/A low pass filters that limit luminance bandwidth. Likewise, expensive HDTV sets > 42" will also have high quality analog scalers in most cases.

[manono]

Hi-

In my opinion, the difference may be small, but it's definitely noticeable,and therefore significant. There are 2 reasons for this:

1. 1:1 pixel mapping. Upscaling to 720p to a 1280x720 HDTV minimizes any resizing artifacts. If your display isn't native 1280x720, then that point is negated.

2. No Analog to Digital conversions take place, as they do over component. Although some HDTVs do the conversions anyway (the Samsung DLPs don't), if you can get a straight digital connection, the picture is noticeably clearer and cleaner, with less visible noise.

I'm using a Samsung 42" DLP. I've had the Bravo D1 until it broke (power supply gave out). It was a revelation when I first saw the improvement in picture quality it gave. I now have an Oppo DV971H. It's still has "teething" problems, but it also has Faroudja "deinterlacing", PAL<->NTSC out of the box, as well as upscaling over DVI and MPEG-4 playback. It uses the Mediatek MT1389FE chipset. Both DVD/MPEG-4 players cost $200 plus shipping.

[edDV]

Another practical consideration is current HDTV sets are HDMI limited anyway. Most sets have only one HDMI input and that should be used with the HDTV tuner to prevent the record block from muting your display.

Soon we will have HD DVD players that will also require HDMI. I hope these models come with HDMI loop through or we will be forced to buy switchers. Those aren't cheap since they need to maintain HDCP encryption.

http://www.gefen.com/kvm/product.jsp?prod_id=2654
http://www.gefen.com/kvm/product.jsp?prod_id=2757
http://www.gefen.com/kvm/product.jsp?prod_id=2208

[gadget]

Very well explained. Thank you all.

[ebenton]

Soon we will have HD DVD players that will also require HDMI. I hope these models come with HDMI loop through or we will be forced to buy switchers. Those aren't cheap since they need to maintain HDCP encryption.

By "HDMI loop through" I assume you mean the ability to "daisy chain" devices, similar to firewire?

[edDV]

Yes, so the HDTV tuner could connect to the HD DVD player and then the player connects to the TV.

[ebenton]

If they don't build them like that, they're stupid. Unless the technology doesn't support it, and if it doesn't, who's stupid idea was HDMI in the first place, anyway?

[edDV]

HDMI/HDCP is there to prevent digital copying. Blame Hollywood.

There will soon be a war over the record flag. I think Hollywood will back down when faced with the outcry.

[MOVIEGEEK]

If they don't build them like that, they're stupid. Unless the technology doesn't support it, and if it doesn't, who's stupid idea was HDMI in the first place, anyway?

I think Toshiba and Sony came up with it,HDMI combines the video and audio on one connector.I personally like DVI because all modern videocards have it.

[edDV]

If they don't build them like that, they're stupid. Unless the technology doesn't support it, and if it doesn't, who's stupid idea was HDMI in the first place, anyway?

I think Toshiba and Sony came up with it,HDMI combines the video and audio on one connector.I personally like DVI because all modern videocards have it.

There is no way to connect a videocard to a DVI or HDMI connector that supports HDCP encryption. HDCP is there to prevent that from being done.


http://www.pacificcable.com/HDMI_Tutorial.htm
http://www2.dvigear.com/hdcpfaq.html

[MOVIEGEEK]

edDV,
Are you saying current tv's with DVI input have HDCP?I thought HDCP wasn't being introduced in the US until 2006.I know HD-DVD/Blu-Ray will probably have it but what about video(non transmitted source) or DVD's I play on my PC?

[edDV]

Most DVI and HDMI equiped HDTVs have HDCP encryption. There may be a few older DVI ones out there that don't. Older VGA equiped HDTV ready sets do not have HDCP so these inputs can be used but the scan rates are custom requiring programs like Powerstrip to interface.

But remember, VGA is an analog interface.

HDCP is currently active and is a separate issue from the record flag. HDCP requires encryption at both ends. Only HDTV tuner/dvr type boxes and other approved products like HD DVD players will be able to connect.

Computer cards will not be able to connect.

[edDV]

The purpose of HDCP is to control which devices can "view" an encrypted digital source. HDCP encryption is present on digital sources with DVI/HDMI connections like tuners*(cable/satt/DTV) and can only be received by an HDCP equiped DVI or HDMI port (on a HDTV or approved DVR).

From the computer geeks viewpoint, this prevents computer connection to these ports on an HDTV or DVR (or tuner/dvd). The only options left are VGA (now obsolete) or component analog wideband inputs on the HDTV, plus of course low bandwidth NTSC/PAL S-Video and composite.

* the only exception currently is the IEEE-1394 port on some HDTV tuners and cable boxes that pass unencrypted DTV ATSC TS streams (as mandated by the FCC). The cable company has the right to encrypt its channels on the IEEE-1394 connector.

[MOVIEGEEK]

I see,thanks for the info.

[manono]

Hi edDV-

I may be misunderstanding you on this (or maybe not). You seem to be saying that you can't connect a player without HDCP to a display with HDCP. But in my experience that's not true. My Samsung DLP with a DVI connector supports HDCP. The Bravo D1 DVD/MPEG-4 player I had (before it broke) didn't support HDCP, but played fine to the Samsung HDTV over DVI. It's been said over at the AVS Forums that people with older HDTVs with DVI and no HDCP had better get one of the Bravo units, or one of the very few others without HDCP, before they disappear, if they wish to use the DVI connector.

By extension, although I've never tried it, people running HTPCs over DVI to an HDCP compliant display shouldn't have any problems either. There are certainly plenty of people running such setups, I think.

Yes, if the "player" (set top box, DVD player, and eventually video cards) are HDCP compliant, then the display must be also, but not the other way around.