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Which will have higher resolution?

post #1 of 43
Thread Starter 
A movie on an upconverting DVD player or an HD movie off cable from, say, TNT HD?
post #2 of 43
All HDTV channels networks are 1080i except ABC, FOX and ESPN plus Nat Geo and some other independents which are 720p.

ALL SD-DVD are 480i - no matter what "upconversion" is done - the original image is still 480i !!

READ the link in my sig to learn about "upconverting".
post #3 of 43
No brainer...

SD DVD = 720x480 max
HD cable (should) = 1920x1080i or 1280x720p
even sat. HD

Now, which will look better in motion?

err... ummm... It depends on the provider, the channel, the movie, the bitrates, etc., etc.

I've found upconverted SD DVD's via my Toshiba A20 to look better than some HD movies (1440x1080) on Dish Network. Other times, I've found the HD broadcasts to look better.

HD OTA (ABC, Fox, CW, CBS, NBC, etc.) to me always looks better than upconverted SD DVD unless I have bad reception.

Blu-Ray/HD DVD (and probably HD VMD) generally look better than upconverted SD DVD except for bad transfers.

One more thing--for smaller screens (<37"), the differences between all the above are negligible from normal (>6 ft.) viewing distances.
post #4 of 43
Thread Starter 
Cavu, that link looks VERY informative, thanks for linking it.

Allargon, that is very interesting about the various contingencies. But, your last comment was most important, since I have a 32 inch! Thanks
post #5 of 43
This message is not intended to confuse the OP ... it is a nitpick.

Quote:
Originally Posted by allargon View Post

SD DVD = 720x480 max

It's neither a min nor a max It is what it is but there is more to the story:

SD-DVDs are recorded on the media as 720x480 but they are NEVER displayed that way.

the 720x480 SD-DVD pixels are not square - they are rectangular.

On 4:3 content, the 720x480 pixels are narrower than they are tall and are converted to 640x480 square pixels.

On 16:9 content, the 720x480 pixels are taller than they are wide and are converted to 854x480 square pixels.

The native output of a SD-DVD player is 480i
post #6 of 43
He's talking about TNT, which means you're usually watched a cropped AND upconverted movie. In that case I'd take upconverted any day.
post #7 of 43
Thread Starter 
Quote:
Originally Posted by sirjonsnow View Post

He's talking about TNT, which means you're usually watched a cropped AND upconverted movie. In that case I'd take upconverted any day.

Right, what brought it up was that TNT was showing Lord of the Rings recently and it looked great, but I have the DVD's already and was wondering which was supposed to be better. When I played the DVD to compare, I could not really tell much of a difference (supporting Allargon's point). Also, I did realize that it was cropped all to heck, which would be a drawback in a movie like that.
post #8 of 43
Quote:
Originally Posted by Vance14 View Post

I have a 32 inch!

You could save a LOT of money and buy a 32" 480p display since from that distance you will NOT be able to tell any difference between 480p and 720p and 1080p !!

post #9 of 43
Quote:
Originally Posted by cavu View Post

This message is not intended to confuse the OP ... it is a nitpick.

And I'm going to correct your nitpick.

Quote:
SD-DVDs are recorded on the media as 720x480 but they are NEVER displayed that way.

This is true for NTSC. It is 720x576 for PAL.

Quote:
the 720x480 SD-DVD pixels are not square - they are rectangular.

Yep, this is also true.

Quote:
On 4:3 content, the 720x480 pixels are narrower than they are tall and are converted to 640x480 square pixels.

Here is where the correcting starts. The 720 pixels are not "converted" to 640 pixels. Under normal operation the 704 center pixels are DtoA (digital to analog) converted to the NTSC active video area of the 63.5 microsec NTSC analog scan line. Some players might do all 720, but various things I've read point to it being the center 704 or all 720. Keep in mind that the DVD standard even supports 544 pixels (or some value in that range) width DVDs. Whatever it is, it is just DtoA'd to fit in the NTSC (or PAL) active video area of the scan line.

Quote:
On 16:9 content, the 720x480 pixels are taller than they are wide and are converted to 854x480 square pixels.

Again, no conversion. Because NTSC/PAL widescreen is really anamorphic widescreen, the same 720/704 pixels are DtoA'd to the NTSC/PAL active video area of the scan line. The widescreen display, does the stretching to fill the width of the screen.

Quote:
The native output of a SD-DVD player is 480i

True.
post #10 of 43
Quote:
Originally Posted by cavu View Post

You could save a LOT of money and buy a 32" 480p display since from that distance you will NOT be able to tell any difference between 480p and 720p and 1080p !!


I wouldn't go that far. The difference is certainly less, but to say you can't tell any difference is pushing the envelope of reality a bit.

I have a friend with a 32" LCD and I can clearly see the difference in image quality if the sources are good.

DVD lacks sharpness and detail compared to a good HD transfer. With DVD, everything appears to be just a slight bit out of focus. Skin detail is a bit more muddy.

I'll grant you, it can be hard to tell the difference between a well mastered DVD and an average HD broadcast on a smaller TV, but the difference is certainly there. Despite not being the best broadcast, the transfer of "Lawrence of Arabia" on HDNet via D* was clearly better than my superbit DVD - and the TV we used has an excellent scaler in it.
post #11 of 43
Based on the context of the OP, I'd say that what he is really asking is "which should look better?". Resolution is something that's measured easily, "what looks better" is not. IMHO, the only semi-reliable measure of what looks best is bitrate, since 1080 at a low bitrate can easily look worse than an upscaled 480, or even native 480 at a high bitrate. As mentioned already, the size of the screen matters too.

People that sell TVs and sat/cable service would love us all to believe that 1080 is the "best looking". I wish that were true. It's pretty rare to see anything on sat or cable that looks better than a well-upscaled DVD. There are exceptions, but too damn few. OTA HD channels typically look pretty good, better than DVD.

GIGO.
post #12 of 43
Quote:
Originally Posted by rdgrimes View Post

People that sell TVs and sat/cable service would love us all to believe that 1080 is the "best looking". I wish that were true. It's pretty rare to see anything on sat or cable that looks better than a well-upscaled DVD. There are exceptions, but too damn few. OTA HD channels typically look pretty good, better than DVD.

GIGO.

You need a better programming provider - or you need to calibrate your TV. While HD quality is still a 50/50 proposition with some channels, that's significantly more than "damn few".
post #13 of 43
Quote:
Originally Posted by mrvideo View Post

Here is where the correcting starts. The 720 pixels are not "converted" to 640 pixels. Under normal operation the 704 center pixels are DtoA (digital to analog) converted to the NTSC active video area of the 63.5 microsec NTSC analog scan line.

On digital displays, with digital connections, there is no analog conversion. It's simply resized by the scaler.

And most DVDs today are anamorphic, meaning if you have a 16:9 display, the pixels are already matched to your aspect ratio.

When talking about resolution over broadcast, let's also not forget multiple generations of overcompression, softening filters (to increase compressibility), and downresing, all of which make HD broadcast movies look far worse than HD/BD discs.
post #14 of 43
Quote:
Originally Posted by mrvideo View Post

And I'm going to correct your nitpick.

To nit your nit of my nit:

You are talking d/a analog and are very likely correct.

I am referring to straight digital pixels. All 720 are used.
post #15 of 43
Quote:
Originally Posted by nm88 View Post

When talking about resolution over broadcast, let's also not forget multiple generations of overcompression, softening filters (to increase compressibility), and downresing, all of which make HD broadcast movies look far worse than HD/BD discs.

We're not talking about HD/BD discs. The comparison is to SD DVD.

HD/BD Discs will ALWAYS look better than cable, OTA or satellite unless someone really screws up the mastering. Just the bit rate alone assures those other sources can't compete.
post #16 of 43
Quote:
Originally Posted by cavu View Post

All HDTV channels are 1080i except ABC, FOX, ESPN and Nat Geo which are 720p.

ALL SD-DVD are 480i - no matter what "upconversion" is done - the original image is still 480i !!

READ the link in my sig to learn about "upconverting".

There are a lot more 720p channels than you list, like Speed HD, History HD, Bio HD, A&E HD, Disney HD, Toon Disney HD, Fox Business HD. Also most Fox owned regional sports networks are 720p.
post #17 of 43
Quote:
Originally Posted by CKNA View Post

There are a lot more 720p channels than you list, like Speed HD, History HD, Bio HD, A&E HD, Disney HD, Toon Disney HD,

You are right; I said channels when I meant networks.

IAC, for full details, check the Official AVS HDTVsummary.
Quote:


Fox Business HD. Also most Fox owned regional sports networks are 720p.

I did say FOX was 720p.
post #18 of 43
Thread Starter 
With my 32 inch LG, I can see a VERY big difference between a HD channel and a standard definition channel at 10 feet. Now, it is true that some of the SD channels seem much better than others, even the best (like the History Channel or Discovery, neither in HD in my area) look much closer to the HD, but I can still tell the difference.
post #19 of 43
Quote:
Originally Posted by Vance14 View Post

With my 32 inch LG, I can see a VERY big difference between a HD channel and a standard definition channel at 10 feet.

And you would see EXACTLY the same difference on a 480p display.

You are talking about differences in the source programming.

HD programming has more color depth, less noise, less compression, etc. than typical SD programming. That is what you are seeing.

I am referring to the resolution of the display itself. If you were to connect the same input signal to otherwise identical 480p, 720p and 1080p 32" displays, side-by-side, you would not be able to distinguish one from the other at 11 feet.

Some of you seem to think this is an "opinion". It is not. It is scientific proven fact and is based on the acuity of human vision. Do some Googling to get up to speed on the facts.

Start here ...Visual Acuity Viewing Distance: Test It for Yourself
post #20 of 43
Thread Starter 
Oh, I see what you are saying. So, if I attached a 480p display and a 720p display to identical HD DVR's and identical inputs, the picture would look exactly the same.
post #21 of 43
Quote:
Originally Posted by Vance14 View Post

if I attached a 480p display and a 720p display to identical HD DVR's and identical inputs, the picture would look exactly the same.

EXACTLY!
post #22 of 43
Quote:
Originally Posted by nm88 View Post

On digital displays, with digital connections, there is no analog conversion. It's simply resized by the scaler.

That is correct, but the topic was about SD DVD players, which are 480i analog out. I totally did not broach the subject of digitally displaying DVD output because of the main question/topic.

Quote:


And most DVDs today are anamorphic, meaning if you have a 16:9 display, the pixels are already matched to your aspect ratio.

I'm not sure what you are saying here. It makes no difference if the video is 16:9 or 4:3, the 720 pixels are DtoA output to the same NTSC/PAL active video area. If the DVD player is configured for its output going to a widescreen display, then it will just dump the video out raw. If not, then of course other options come into play; letterbox or pan and scan, which again was over and above the original topic.

Quote:


When talking about resolution over broadcast, let's also not forget multiple generations of overcompression, softening filters (to increase compressibility), and downresing, all of which make HD broadcast movies look far worse than HD/BD discs.

Oh so true. That doesn't just pertain to movies over OTA HD, it pertains to any program broadcast OTA.
post #23 of 43
Quote:
Originally Posted by cavu View Post

am referring to straight digital pixels. All 720 are used.

The point was that you were saying that the 720 pixels was digitally converted to other pixel resolutions before being output and that is not the case for playing DVD output over an analog circuit.

There are front and back porch issues with NTSC/PAL analog that comes into play when dealing with digital video. I won't go into those issues here, as that would be way off topic.
post #24 of 43
Quote:
Originally Posted by CKNA View Post

There are a lot more 720p channels than you list, like Speed HD, History HD, Bio HD, A&E HD, Disney HD, Toon Disney HD, Fox Business HD. Also most Fox owned regional sports networks are 720p.

Not only that, SD-DVD is 720x480 and 720x576 (NTSC/PAL), not just 720x480. The DVD standard also supports other sub-pixel resolutions, with 720 being the max horizontally.
post #25 of 43
Quote:
Originally Posted by cavu View Post

I did say FOX was 720p.

For most readers, FOX means the broadcast, i.e., OTA, network, not any of the other properties that 20th Century Fox owns. If you also mean to include those properties, you need to explicitly say that.
post #26 of 43
Quote:
Originally Posted by mrvideo View Post

That is correct, but the topic was about SD DVD players, which are 480i analog out.

No. They are 480i digital !! DVDs are digital media, not analog.
Quote:
Originally Posted by mrvideo View Post

that is not the case for playing DVD output over an analog circuit.

You are the one who introduced "analog" to this discussion. I don't believe anyone else is discussing analog outputs.

All of my DVD and HD-DVD players have digital outputs connected to my digital displays.

Why, in this day and age, would I even be thinking about analog devices??
post #27 of 43
Quote:
Originally Posted by cavu View Post

I am referring to the resolution of the display itself. If you were to connect the same input signal to otherwise identical 480p, 720p and 1080p 32" displays, side-by-side, you would not be able to distinguish one from the other at 11 feet.

Good luck finding a 32" 480p television, that isn't a CRT. No one makes 480p EDTVs anymore.

The solution to the problem of not being able to see the difference between 480p and 720p is to sit closer or get a bigger TV.

BTW, I personally don't believe in that chart that you posted earlier. While for most material (TV Shows, Movies), that distance chart is pretty accurate, it fails when you're dealing with high detail sources like a computer display.

I can see the difference between a 720p and a 1080p TV of the same size when viewing a 1920x1080 screen at distances exceeding those listed on the chart.

But to each their own.

ft
post #28 of 43
Quote:
Originally Posted by ftaok View Post

Good luck finding a 32" 480p television, that isn't a CRT. No one makes 480p EDTVs anymore.

That may be true in that size range. I really wouldn't know - I usually deal with 100"+ FP displays.
post #29 of 43
Quote:
Originally Posted by ftaok View Post

BTW, I personally don't believe in that chart that you posted earlier. While for most material (TV Shows, Movies), that distance chart is pretty accurate, it fails when you're dealing with high detail sources like a computer display.

I don't necessarily like that chart either. Even if it were accurate, it would have to assume a certain level of eyesight. I have 20/10 vision and can detect the differences at further distances than the chart indicates. Someone with 20/40 or 20/100 vision obviously would have trouble detecting differences at closer distances. The chart is OK as a general guide but is not in any way reliable for individual results.
post #30 of 43
Quote:
Originally Posted by jimp2244 View Post

The chart is OK as a general guide but is not in any way reliable for individual results.

The chart is completely accurate for 20/20 vision.

You guys slay me! Whether you like the chart or believe the chart is completely irrelevant. Who cares!

Facts are facts.

The smallest element discernible by someone with 20/20 vision is 1 minute of arc. Period. That's the way the human optic system works.:

Quote:


The standard definition of normal visual acuity (20/20 vision) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc. Since one degree contains sixty minutes, a visual angle of one minute of arc is 1/60 of a degree. The spatial resolution limit is derived from the fact that one degree of a scene is projected across 288µm of the retina by the eye's lens.

In this 288µm, there are 120 color sensing cone cells packed. Thus, if more than 120 alternating white and black lines are crowded side-by-side in a single degree of viewing space, they will appear as a single gray mass to the human eye. With a little trigonometry, it is possible to calculate the resolution of the eye at a specific distance away from the lens of the eye.



For the case of normal visual acuity the angle Theta is 1/60 of a degree. By bisecting this angle we have a right triangle with angle Theta/2 that is 1/120 of a degree. Using this right triangle it is easy to calculate the distance X/2 for a given distance d.

X/2 = d (tan Theta/2)

When visually inspecting an object for a defect such as a crack, the distance (d) might be around 12 inches. This would be a comfortable viewing distance. At 12 inches, the normal visual acuity of the human eye is 0.00349 inch. What this means is that if you had alternating black and white lines that were all 0.00349 inch wide, it would appear to most people as a mass of solid gray.
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