CurtPalme.com Home Theater Forum

Moose · Joined: 09 Mar 2006 Posts: 788 Location: Minnesota

I used to read DVDFile everyday but now I go there only once in a while. I caught this statement in the article titled HD DVD Score A Big One (http://www.dvdfile.com/index.php?option=com_content&task=view&id=6228&Itemid=11):

**kal** · Posted: Wed Sep 05, 2007 6:52 pm Post subject:

This part is true:

BD storage is 50GB on 2 layers
HD-DVD storage is 30GB on 2 layers

BD max A/V bitrate: 48 mbit/sec
HD-DVD max A/V bitrate: 30.24 mbit/sec

Source: http://en.wikipedia.org/wiki/Blu-ray

However in practice, I've never heard anyone say that the bitrate difference makes a difference in quality when displaying real world material. Storage hasn't shown to be an issue... though I suppose a very long movie (3+ hours) could be compromized on HD-DVD if they tried to stuff it on only one disc. They *may* be cases in the future where HD-DVD may have to go to 2 discs where BD could stay with one. Some have said that the longer Lord of the Rings movies (especially the 3rd one) may be a problem on a single HD-DVD.

IMHO, I don't have problems with 3+ hour movies being split across 2 discs. Gives you a much needed stretch break.

I'm curious what HD-DVD and BD movies he's talking about. I'm hoping he's comparing the SAME title at least. How can you compare picture quality of completely different movies?

Kal

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

**IF** they used more storage on BD, so there was significantly less compression, then that might make a visible difference. But given that Hollywood seems much more interested in providing in-depth life histories of the pastry-cart lady on the movie set (and other thrilling "extra features") than in maximizing the image quality, I'd be amazed if they actually do devote any "unnecessary" space just to make the image look a tiny bit better -- especially since only about 0.1% of the viewers have displays that could show the difference. More than 0.1% of their viewers are probably interested in the pastry-cart lady. Rolling Eyes

**kal** · Posted: Wed Sep 05, 2007 7:08 pm Post subject:

Mmmm.... pastry-carts. I'm hungry now.

Kal

JustGreg · Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI

Mmmmmm....A Lady AND a pastry cart....mmmmmmm. I hope she's "Danish". badooom-chhh. Laughing

overclkr · Joined: 08 Mar 2006 Posts: 4227

Ridebreck · Posted: Wed Sep 05, 2007 7:38 pm Post subject:

I'm just curious if these jackasses who are constantly splitting hairs over infitesimal (sp?) differences in PQ in an effort to claim victory for one side or the other ever intends to actually WATCH a movie on either format. Maybe I'm just one of the weird people who actually buy a movie for entertainment value as opposed to critiquing every frame.

oliverg · Posted: Wed Sep 05, 2007 8:05 pm Post subject:

Same argument for 'superbit' DVDs really ..

I do find superbits are a little better though.

It really does depend on the codec

papalek · Joined: 08 Mar 2006 Posts: 1536 Location: Longs SC

It just seems to me that he is saying that the viewing angle is showing the faults. "Viewing angle of 42 degrees is mighty revealing" He must be using a very high gain screen. Mine is almost identical when you are WAY over to the side.
If his head moves just a few inches to the side subconsciously for the one that he prefers then it will be closer to the center and will be less distorted and look better to him.

Not exactly accurate if you ask me.

CRT_Ben · Joined: 28 Aug 2006 Posts: 1684 Location: Northern Virginia

ecrabb · Posted: Wed Sep 05, 2007 8:44 pm Post subject:

Kal posted a link awhile back to a site that compared still images of some titles on both BD and HD-DVD. The site also compares average bit-rate between the two on the same title. Assuming VC-1 is used on both, there should be little to no difference whatsoever between the two formats. If subtle differences do exist at comparable data rates, it will be from differences in the encoding process or something else in the production chain, NOT from any inherent quality difference between the two formats. As Cliff pointed out, it's the codec stupid... and with most of the newer releases, they're the SAME codec.

That said, I did notice when looking at the aforementioned site and comparing the still images, that several of the BD encodes had a little more detail in the background than did the HD-DVD example. I think it was "We Were Soldiers". There was a unit number painted on the noise of a Huey in the background; It was just readable with on BD and illegible on the HD-DVD. So, there are differences sometimes. At the same time, some of the BD images looked "artificially sharpened" - with more noise and grain, and even some edge enhancement-like , but not that bad. But, again - it depends on the encode and other production steps, NOT the media on which the material is stored.

Then, look at something like the comparison of The Prestige. The BD version is AVC (h.264) at 20.99GB, while the HD-DVD is VC-1 at 16.33GB. From the file size, you'd assume the BD would look better, right? It's a good thing they mark the images, because they look nearly identical - as in practically indistinguishable.

Here's the comparison site - check it out (warning - large images, German server:

High Definition Media Mouseover Comparisons

SC

EDIT - OK, I just went back and looked at a few of those comparison images. Anybody that gives BD some general edge in image quality based on watching some material at 1080p from a 42-deg viewing angle is full of sh*t. Looking at a lot of those images with my nose practically jammed up against my Apple Cinema HD Display, I can't tell the difference between the newer AVC/VC-1 encodes. If he's seeing a difference, it's either psychological, because of differences in the boxes themselves, differences in his signal chain, or all of the above. I call bull****.

Take a look at the Happy Feet encodes. Both VC-1... identical. Look at "Flags of our Fathers"... in spite of the BD/AVC encode being a full 50% larger than the HD/VC-1 encode(!!!) - 32.9GB vs. 20.8 GB - they're IDENTICAL.

My conclusion: HD-DVD and BD are both awesome. People need to STFU about which one is better, buy the one they like and watch some movies. There... I feel better, now. Wink

ecrabb · Posted: Wed Sep 05, 2007 8:48 pm Post subject:

By quoting the 42-deg viewing angle, I think he's trying to say he sits close to the screen. Too bad that isn't that close - especially for 1080p.

THX MINIMUM spec for the WORST seat in the house is 35-degrees. At close to 1.2x screen widths, I'm probably around to 75-degrees. I don't remember, though.

SC

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

Well, lessee here. 42° viewing angle means the half-angle is 21°. That gives you a right triangle from your eye, to the center of the screen, to the edge of the screen, and back. If the screen is 1 unit wide, the half-screen is 0.5 wide. Distance to the screen is X. 0.5 / X = tan(21°), so X = 0.5/tan(21°) = 1.3. 42° field of view means you're sitting at 1.3x screen width. That's pretty close.

SC, at 1.2 screen widths, 0.5 / 1.2 = tan(θ). atan(.5/1.2) = θ = 22.62°, so your viewing angle is 2*22.62 = 45.24°. To get a 75° field of view you'd have to sit at 0.5/tan(75°/2) = 0.65x screen width.

That comparison site shows that for many movies, the images are nearly identical. Maybe not pixel-for-pixel identical, but you wouldn't be able to say one is better than the other. Remember also that you're looking at still images there. When you view them at 24 frames per second, your eye averages out a massive amount of information. You'd never see those minor differences if you're actually watching the movie as opposed to viewing a still screen shot with a magnifying glass.

wkomassa · Joined: 21 Aug 2007 Posts: 101 Location: Brookfield, WI

That site was great, and really cements in my mind that people who take sides for picture quality reasons are just fooling themselves. That proves with lots of examples that it is a push. It comes back to hardware... quality and cost, and software availability.

FWIW, Best Buy (in-store only) seems to be running a $299 special on the HD-A20... and you still get the 5 discs by mail. Three stores by me was already sold out, but there are still at least 2 or 3 other stores in the area that appear to have them in stock. I'm guessing this is the beginning of the phase-out of the A20s before the A30s start coming in.

Blu-Ray prices seem to be remaining steady. Man, Toshiba is really going all-out. 1080p for under $300. It's getting VERY hard to resist! VERY hard!

Gino · Posted: Thu Sep 06, 2007 3:50 am Post subject:

he is definitely smoking something.

naturally higher bit rates mean more information/less compression if using the same codec, but the point is they don't bother using all the space available. i think they even have a problem with too high a bitrate and couldn't fill the whole disc if they wanted to unless it was an extra long feature.

overclkr · Joined: 08 Mar 2006 Posts: 4227

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Knew this was just a problem concerning space ? Shocked

ecrabb · Posted: Thu Sep 06, 2007 5:40 am Post subject: