Upscaling native dvd (480p) to 720p with DVI output

[JSMD]

I would like to upgrade my Home Theater mainly to watch 16:9 DVD (480p) on a 75" screen either with:

(a) 16:9 WSVGA (854x480):
InFocus ScreenPlay 4805 DLP with Faroudja DCDi and DVI, at Costco ($1,399) including 75" Screen.

or

(b) any of the following 16:9 WXGA (1280x720) LCD projectors:
Sanyo PVL Z3
Panasonic AE700U
InFocus ScreenPlay 5000

and consequently ugrading to a DVD Player with DVI output, Faroudja DCDi and 3-2 pulldownn: Denon 1910 or Zenith DVB318, to hook to any of the the above WXGA projector.

Reading different threads in several forums, I am confused:

The native resolution of DVD being 480p, how DVI output dvd players can "upscale" to higher resolution pixel formats like 720p (1280x720) or even 1080i?

[Brandon B]

They take the digital video signal direct from the DVD player's MPEG decoder, and scale it to 1280x720 resolution via a digital video processing chip. Same way any of the projectors do the same thing if they receive it at its original resolution of 480. They then output it at that resolution. Just like you can change resolutions on a computer before sending it to the monitor.

All digital PJs have a specific native resolution, the actual number of pixels on their imaging chips. In order to display the image from the chip, it MUST be scaled to fit into that number of pixels. That scaling can happen in either device though, as mos projectors are perfectly willing to accept signals in any standard format or in their own native resolution, which may also be a standard format.

BTW, 1280 x 720 is technically not WXGA, although many vendors call it that. WXGA is 1366x768, a data resolution. 720 is an ATSC (video) resolution.

[JSMD]

I understand the “no quality loss” transfer with DVI transfer process:
Native DVD (854x480) <== DVI out (DVD Player) == DVI in (Projector)==> Image (854x480)

However, still I do not understand in some threads and in some manufacturer brochures how the 480p (854x480) native (or maximum) resolution of DVD, could be "up-scaled" (in transfer trough DVI connection from DVD Player to Projector) to higher resolution pixel formats like 720p (1280x720) or even 1080i?

Native DVD (854x480) <== DVI out (DVD Player)== DVI in (Projector)==> "Upscaled or enhanced" Image (1280x720)?

Why to bother purchasing any 1280x720 projector for projecting DVD only, if anyway you have to set up both the DVD Player and the projector to 480p?

(Unless there are any other justification for this "up-scaling" or rather "no-quality-loss” with DVI transfer, like in 3-2 pull-down or 16:9 aspect ratio)

[JonMarsh]

Remember, there's lots of different kinds of gear out there. Digital projectors with a variety of fixed panel sizes (widescreen 854X480, widescreen 1024X576 (Matterhorn DLP chip), 1280 X 720, 1368X768, and even 1920X1080.

Digital projector ALL have to scale incoming signals in a variety of formats to fit the panel native resolution. Specialist companies like Genesis microchip make a variety of chipset for this purpose.

Standard video cards have multi-tap scaling hardware built in, and can do a pretty fair job of scaling video up or down with the right software- in fact, 3-5 years ago, the circuitry in a decent video card was typically better than that in projectors, which is a significant factor in HTPCs (Home Theater PC's) becoming popular with some folks.

Upscaling a video signal to a higher resolution can't create information that wasn't present in the original signal. But upscaling combined with oversampling and intelligent processing algorithms AND a higher resolution display may result in singificantly more pleasing display of that information.


Take a look at this image below- one is a "native DVD" respresentation of the pixel values in a small part of one frame in the DVD "The Fifth Element".

The other is the same section, upscaled and interpolated to 1080i.





Which would you rather see on your screen?

Now, also keep in mind, you have a wide VGA resolution projector- upscaling to it would be a waste of time, as it would just downconvert. Also, digital projectors are still mostly doing processing after A/D conversion of the digital signal to an 8 bit value. So, having 10 bit or 12 bit DACs in the output of a DVD player, as many of the current better ones do, doesn't really buy you anything with a digital display.

But throw that signal on an analog CRT, either direct view, rear projection, or front projection, and you can display the oversampling interpolation. As well as the higher resolution, as long as your projector supports it.

For example, in my system, I use a Zenith DVB318 on component output, through a component to RGBHV converter, into an NEC 9PG+ projector at 1080i. Works quite well; best picture I've ever hard. I have a HDCP compliant DVI to RGBHV converter, and will be trying another DVD player soon in that mode, but a lot depends on how well this DVI to RGB converter works. It's a crap shoot, I guess, but not that expensive a gamble. Basically I'm looking for alternatives for when the Zenith eventually wears out.

~Jon

[JSMD]

Upscaling 480p to 720p or even 1080i?

Thank you for your detailed explanation, particularly the upscaling combined with oversampling and processing algorithms:

“Upscaling a video signal to a higher resolution cannot create information that was not present in the original signal; but upscaling combined with oversampling and intelligent processing algorithms AND a higher resolution display may result in significantly more pleasing display of that information.”

Now I am looking for the following combination:

DVD Player with DVI/HDMI output, Faroudja DCDi and 3-2 pulldown able to “upscale” to 1280x720 or 1080i, like Denon 1910, Zenith DVB318, Samsung HD841, Toshiba SD-5970

LCD Projector with 16:9, 1280x720 or 1080i, DVI/HDMI input, like Sanyo PVL Z3, Panasonic AE700U, InFocus ScreenPlay 5000

Draper Luma 106” Diagonal


Recently, I have seen detailed comparison (www.htguide.com/forum/archive/index.php4/t-9149) between the Denon 1920 and the Zenith DVB318 DVD Players. I understand they are the best in the US$200 price range.

I have seen also a recent detailed comparison (Projector Central, October 19, 2004) between the Panasonic AE700U and the Sanyo PVL Z3 and I understand they are the best projectors in the US$2,000 price range. However, I did not see any comparison with the InFocus SP5000

Did anyone tried or compared any combination between the above DVD Players and DVD Projectors?

[JonMarsh]

Let me just point out for the comparison you're making above, the Zenith is sort of a one trick Pony. It works VERY well going to 1080i, but it's performance at 480P and 720P suffers because of Y/C delay which manifests as Chroma bleed. I would NOT use it at those resolutions. ONLY 1080i output.

Now, that said, some folks are using with projectors in the class you describe, by using the 1080i output, and using the built in down conversion of the projector. Some projector chip sets do better with down converting 1080i to the native 720P set, than upconverting 480P.

This is a bit of a tightrope you're walking, between the scaling performance of different chip sets.

One point I definitely DO agree on is the desirability of DCDi processing in the DVD player. Some projectors have it, but then to take advantage, you have to feed it an interlaced 480i signal. Then, your DVD player selection would be pretty wide, just find one without the Chroma bug in the MPEG converter (See Secrets of High Fidelity and Home Theater DVD player comparisons).

I can't comment on the relative merits of the digitals you describe - hopefully some of the owners besides Dean can give you some additional insight- perhaps one who's compared them. The Z3 and the InFocus 5000 are newer models, and it will be harder to find comparisons and reviews. As always, it would be a very good idea to see the units for yourself before purchase.

~Jon

[Dean McManis]

The comparative pictures that Jon posted above are a good representation of the value of upconversion.

If you squint your eyes then the pictures look fairly close, otherwise you can clearly see the jaggies of the lower resolution rendered image.

And if you think that you are going to be watching HDTV material in the future, the 720p projectors are most likely worth the extra money spent. :T

One thing that I'll mention is that I bought a Samsung HD841 scaling DVD player, and it has some serious problems. It cannot produce a picture at 720p or 1080i that my projector can sync to via DVI. And there are periodic audio dropouts. ops:

Their tech support is aware of both problems, but they blame the Infocus SP5000 for not being compliant with the DHCP protocols, even though I just got a DHCP-enabled HD-PVR and it works fine, and the 720p PC input also works fine with the Infocus FPTV. And they have no solution for the audio issues yet.

So I pulled out the HD841 DVD player, and put back in my Panasonic RP91 which has no issues, and outputs 480p fine (which the projector scales up to 720p very well).

-Dean.

[JSMD]

DVD Players (16:9 and 4:3, 480p, 720p, 1080i, Faroudja, 3-2 pulldown, dvi/hdmi output

From Jon's and Dean's suggestions/comments (Zenith DVB318 and Samsung HD-931), only the Denon 1910 and the Toshiba SD-5970 remain from my list of DVD Players in the US$200 range

Any review/comment on the Toshiba SD-5970?

Any other DVD players with these specs (16:9 and 4:3, 480p, 720p, 1080i, Faroudja, 3-2 pulldown, dvi/hdmi output) in the $150-$400 bracket?

[JonMarsh]

Check out the newest release on DVD player shoot outs at Secrets of Home Theater and High Fidelity.

[JSMD]

DVD Player Benchmark

Thank you for the lead.

Impressive DVD Benchmark, although missing cheaper DVD Players like Denon-1910 and Zenith DVB318.

These benchmarks are very interesting. However, I like also forum discussions to check final user experience and suggestion especially regarding system integration.