Questions about 1080p

[shmokes]

I have heard a lot of people say that on screens about 42" and below nobody can tell the difference between 1080p and 720p.  I've never done any comparisons myself, but I don't see any reason to disbelieve this.  On the other hand, though, I've read a lot of reviews and such in which people people say that standard definition TV looks terrible on a 1080p screen compared to a 720p screen.  One part of my brain immediately starts putting things together and goes into skeptical mode.  I say, "Wait . . . if I can't tell the difference between 720p and 1080p on a 42" screen, why does this stuff look terrible on one, but passable on the other?"

I've come up a plausible answer for that, in that it must be excessive artifacting and ---Cleveland steamer--- that's introduced when the signal's resolution is upconverted that high, whereas there's much less data to add in order to upconvert only to 720p --- thus, 720p ends up with a superior picture.

Unfortunately, this begs another question.  Why, then, do DVDs look so great when upconverted to 1080p?  Can someone help me understand what I'm missing here?

[Dexter]

You can definitely tell the difference between 720p and 1080p depending on viewing distance. I've been looking at screens in both resolutions in stores and depending on screen size and viewing distance, theres a noticable difference depending on brand.

As for upscaling, I think different manufacturers use different chips, so results vary depending on algorithym used per mode.

Are you thinking of buying one? Theres good online reviews of pretty much everything out there, but before you part with your cash try viewing your perspective buy at the distance you'll be viewing it at home and see if it agrees with you.

Crap thing is, every retailer seems to have their sets adjusted differently so be sure to play around with the settings instore if you can.

[MaximRecoil]

Unfortunately, this begs another question.  Why, then, do DVDs look so great when upconverted to 1080p?  Can someone help me understand what I'm missing here?

DVD's are at the bottom end of "HD" (480p). This is quite a bit higher resolution than "standard definition TV" which translates digitally to about 320x240, plus it is interlaced, as per the NTSC standard for broadcast TV in the U.S. In PAL format, the resolution of DVD's is even higher (576p), which isn't all that far off from 720p.

Keep in mind that NTSC DVD's are also interlaced for compatibility with the NTSC video standard, but with DVD's that were sourced from film (e.g. a typical Hollywood movie) the progressive video is still there. "Progressive scan" DVD players can IVTC on the fly and only display the progressive frames.

The way this works is, when a film (~24 FPS) is transferred to NTSC DVD video, it is telecined. This adds 2 half (interlaced) frames for every 3 full frames (AKA: 3:2 pulldown). This results in a partially interlaced video of ~30 FPS (29.97 FPS). This is done for NTSC compatibility reasons. This was done long before DVD came out too. It was used for putting film-sourced movies onto e.g. VHS, and also for broadcasting film-sourced movies over the air.

So a "progressive scan" DVD player will IVTC (inverse telecine/3:2 pulldown removal) the DVD on the fly, i.e., it discards the 2 interlaced frames for every 3 full frames that were added during the telecine process, so you end up seeing only what was in the film in the first place at ~24 FPS.

If the DVD video was sourced from video in the first place (rather than film), then all of that is irrelevant. It will play the same on a "progressive scan" DVD player as on an older non-progressive scan DVD player—in other words, it will always be interlaced, because the source video itself was natively interlaced. You usually run into this with older TV shows, especially sitcoms, that are put onto DVD. Most of the sitcoms from the 80's for example, were shot on Betacam (video) rather than film. The bigger budget shows, e.g., Magnum P.I., were usually shot on film, thus you get a far better DVD transfer.

I got off on a tangent there, but the short answer is, DVD is of a substantially higher resolution than standard definition TV, so it looks better when "upconverted", because it doesn't have so far to go in order to get there.

[ahofle]

Interesting.  I thought all source material on DVD was 480i.

[Samstag]

I have heard a lot of people say that on screens about 42" and below nobody can tell the difference between 1080p and 720p.

There are any number of reasons this gets tossed around as "common wisdom":

A) People saying it are unaware that their 1080p TV is actually 720p resolution and just happens to accept a 1080p signal.
B) They may be unaware that the incoming signal can be in 1080p format but originate from a lower-quality source.  For example, a lot of recent Xbox/PS3 games render a resolution lower than 720p due to lack of processing power, then upscale each frame to either 720p or 1080i/p.  In that case you may not see a difference between two TVs.
C) They focus on the individual pixel size and don't notice the extra aliasing you'll get on a 720p when displaying a 1080i/p source.
D) They heard it from multiple sources on the internets, so it must be true.

[MaximRecoil]

Interesting.  I thought all source material on DVD was 480i.

The source material will either be film or video. Once it is transferred to DVD in NTSC land, it all becomes 480i. However, due to the process (telecine) that converts film to NTSC video, it can be reversed (inverse telecine), leaving only the progressive frames from the film source. So if your playback hardware or software can IVTC ("progressive scan" DVD players can do this for example), and your display can support it, then you now have 480p.

If your DVD was sourced from video, then "progressive scan" doesn't do anything. It will always be 480i because the source was natively interlaced for every frame, i.e., there is no telecining to reverse.

Typically on film-source DVD video, the telecining is done by using pulldown flags to instruct the playback device to telecine the video during real-time playback. Since this method of telecining doesn't actually encode the extra interlaced frames into the video stream, it makes it that much easier to reverse it.

[ChadTower]

Keep in mind that a video mode doesn't necessarily say anything about source quality.  You can have a fullblown 1080p source that looks like total ass because the source is crap - and a 480p source that looks better for the same reason.  The video mode really only tells you what you might expect.  The rest is all up to source quality and the quality of whatever algorithms are coming into play in the firmware of each given device in the chain.

[Xiaou2]

The bigger the screen, the more you will notice the differences of resolution and
details.

 I have a 1080p  lcd.   I use it for my PC monitor - and occasionally watch movies on
it too     

 I can tell you that by changing the res lower,  you can clearly tell the differences.
Of course, it does not help that LCDs do not look good when not in their Native
resolutions.

 If your watching a lower res source on a high res TV,  then you will be displease at
the blocky blurry look.

[shmokes]

Well . . . it's just strange, I guess.  I'm under the impression that DVDs actually look better when upconverted to 1080p, while SD TV looks worse, but that SD looks worse when upconverted even to 720p.  I understand that SD has further to go, even to reach 720p, but why would DVD actually benefit from the conversion while SD looks worse?  Is it because an analog signal is being converted to digital before it can be upconverted, whereas a DVD is digital the whole time?

[MaximRecoil]

The bigger the screen, the more you will notice the differences of resolution and
details.

 I have a 1080p  lcd.   I use it for my PC monitor - and occasionally watch movies on
it too     

 I can tell you that by changing the res lower,  you can clearly tell the differences.
Of course, it does not help that LCDs do not look good when not in their Native
resolutions.

 If your watching a lower res source on a high res TV,  then you will be displease at
the blocky blurry look.

There is no noticeable difference between 720p and 1080p on my PC monitor (Mitsubishi Diamondtron 22" CRT). In fact, I'm satisfied with a good anamorphic DVD transfer on this size monitor.

[boykster]

I have heard a lot of people say that on screens about 42" and below nobody can tell the difference between 1080p and 720p.

There are any number of reasons this gets tossed around as "common wisdom":

The reality is that at "normal viewing distance", which for a 42" display is generally considered to be 6-8', your eye will not be able to distinguish the pixel structure of a 720p plasma, so the extra pixels of a 1080p plasma would add nothing additional to the image.  Of course this becomes irrelevant the MOMENT you move closer to the screen than the optimal viewing distance, as most displays are evaluated on showroom floors.  How often do you sit, with the set in the optimal position, 8' from a 42" display evaluating it's picture quality when at an electronics store.

I've not heard the 1080p looks worse than 720p when upscaling SD material, but I tend to trust my eyes when evaluating source material and displays so I dunno.  I think SD upscaled to 720p looks like garbage too.  I've had good success with upscaling my DVD's using my HTPC to 720p, but it pales when compared to native HD resolution source material. 

I suggest when demo'ing a display you go to a showroom that will allow you view lots of different source material: SD, DVD, HD, etc.  HD content may be spectacular, but those SD shows you watch may look like doody.

 

[Howard_Casto]

Keep in mind that a video mode doesn't necessarily say anything about source quality.  You can have a fullblown 1080p source that looks like total ass because the source is crap - and a 480p source that looks better for the same reason.  The video mode really only tells you what you might expect.  The rest is all up to source quality and the quality of whatever algorithms are coming into play in the firmware of each given device in the chain.

Dear god thank you!  Could you please go over to the daphne forums and explain this to them?  I got a lot of crap a few months back when I said digital leisure was ripping people off with their hd versions of the dragon's lair games.  I tried to explain that while technically the DL games were originally made on real, theater quality film, it was animated and colored with a crappy ntsc signal in mind as that is all the original cabient could display.  Also dolby 5.1 sound isn't particularly useful for a flim originally mastered in stereo.  Their reply was always "look at how nice the title screen looks and see how much more detail you can see"  My reply was "yeah the title looks good because it's static and thus was a capture of a hi-res background painting and I sure can see more detail, if by detail you mean film grain, scratches and poorly painted cells"  Eh but there's no accounting for common-sense. 

[Howard_Casto]

I have heard a lot of people say that on screens about 42" and below nobody can tell the difference between 1080p and 720p.  I've never done any comparisons myself, but I don't see any reason to disbelieve this.  On the other hand, though, I've read a lot of reviews and such in which people people say that standard definition TV looks terrible on a 1080p screen compared to a 720p screen.  One part of my brain immediately starts putting things together and goes into skeptical mode.  I say, "Wait . . . if I can't tell the difference between 720p and 1080p on a 42" screen, why does this stuff look terrible on one, but passable on the other?"

I've come up a plausible answer for that, in that it must be excessive artifacting and ---Cleveland steamer--- that's introduced when the signal's resolution is upconverted that high, whereas there's much less data to add in order to upconvert only to 720p --- thus, 720p ends up with a superior picture.

Unfortunately, this begs another question.  Why, then, do DVDs look so great when upconverted to 1080p?  Can someone help me understand what I'm missing here?

It's real simple actually, and it's stuff we know from mame. 

A ntsc signal, even one from your cable provider is analog.  That means colors and such aren't uniform even if they are supposed to be and there's a ton of noise on all but the cleanest of dgital cable/sat signals.  Even assuming it's 100% clear and untouched, it's still conveted to analog so it can connect to your tv and it gets ruined anyway.  In other words, much like old-school web graphics, the image is dithered.  Take a 256 gif and upscale it and it looks terrible, but take an image the exact same resolution, only a bitmap or a 24 bit jpeg and it looks pasable, mainly because all the color information is there and the image editor can put a nice blur on it and smooth things out.  A hd set has great precision in color and sharpness, so any of these minor flaws on a sd signal, that would normally just not be significant enough to show up on a analog tv shows up like a target on a digital display.  Also remember that unless you have a fancy hdmi-enabed cable box, there's no upconversion and thus nothing is filtered. 

Think of spyhunter in mame, with the filters turned off on a lcd monitor.  Looks like crap doesn't it?  The road is speckeled with dots and everything is blocky.  Well the source used dithering to make the road and the superior precision and color range of a lcd monitor removes this natural blending.  It's basically the same deal. 

Now dvd's are totally different.  First off it's a pure digital signal and your have component out or better, meaning even though it's converted to analog, the source is purely digital and your monitor gets sent a greater color range with a sharper contrast.  Up-converting does quite well with this type of source material as well, because again, the image is un-dithered and there is more color information to work with.  Going back to our jpeg example... ever notice how a 800x600 wallpaper still looks ok on a 1024x768 screen?  Well it's the same exact image color-wise, only some detail is lost between a 1024x768 version of the same image so scaling it only blurrs the sharpness a tad. 

I can tell you right now, you CAN tell the diff between 720p and 1080p, I think it's just that there is so little true 1080p video out there people don't realize they've probably never seen it before.  First off, unless you are using hdmi then you can't get a 1080p signal, rather you get 1080i, which is only just a shade larger than 720p in the vertical, which is the part of a digital image we can notice artifacts in the most.  Secondly, I'm not aware of ANY hd broadcasts that use 1080p.  Sure some broadcast it out at that size, but either the cable box degrades it back to 1080i, the source material was only filmed in 720p, or the signal is compressed (think divx rips) to get it down the line.  Streaming 1080p to the 360 or teh ps3's blueray player is about the only way I know to watch real 1080p at this point, and that includes hd-dvd and blueray players as even though they are currently expensive, they are also currently very crappy when it comes to decoding the discs. 

With that being said, the same pure or almost pure digital connections, the same high quality color values and the same display hardware is used for both 720p and 1080p media so there isn't THAT much difference.  On your pc, aside from a larger desktop space of course, can you really tell THAT much difference between a computer running a pc game at 1024x768 and one running it and 1280?

So to sum up, a sd ntsc signal looks crappy not because of it's poor resolution, but it's poor quality.  If it were a pure digital signal coming out a higher end connector then it'd look fine, which is essentially why dvds look ok since they are glorified ntsc without all the crap. 

Hope that helps!

[ChadTower]

I got a lot of crap a few months back when I said digital leisure was ripping people off with their hd versions of the dragon's lair games.

Did they remaster based on the original cels or did they just upconvert the original master footage?

[ahofle]

Remaster from original cells.

[ChadTower]

Then it should be dramatically better than the original release if they did it competently, yes?

[MaximRecoil]

So to sum up, a sd ntsc signal looks crappy not because of it's poor resolution, but it's poor quality.

They are both to blame. If you were to approximate the resolution of an SD NTSC signal (320x240) with a purely digital video, it will look bad displayed full-screen on an HD display, regardless of the quality of the video's encoding.

[ChadTower]

Should we all be afraid of the prospect of a Maxim-HC argument?  Or should we just move aside and let it ride?

[Jouster]

Ok...I'm all about dumb when it comes to TV's...someone please learn me good.

Tv, in order of resolution go:
SD
720p
1080i
1080p
?? ?

I'm guessing from this thread that the i is interlaced and the p is progressive.

Does any of this change if you are looking at getting a projector?  I realize there are other factors to consider in getting a projector (lumens, contrast...blah, blah, blah), but what of resolution?

Jouster

[Hoopz]

Should we all be afraid of the prospect of a Maxim-HC argument?  Or should we just move aside and let it ride?

It happened before in Arcade Misc.  Fairly boring....

[Howard_Casto]

Remaster from original cells.

No... they re-scanned the original film from the archives, the original cells weren't touched, nor do they exist anymore. 

[MaximRecoil]

Ok...I'm all about dumb when it comes to TV's...someone please learn me good.

Tv, in order of resolution go:
SD
720p
1080i
1080p
?? ?

SD
480i
480p
720p
1080i
1080p
2K
4K

I'm guessing from this thread that the i is interlaced and the p is progressive.

Yes.

Does any of this change if you are looking at getting a projector?  I realize there are other factors to consider in getting a projector (lumens, contrast...blah, blah, blah), but what of resolution?

Jouster

Resolution is important for projectors as well. Higher resolution is better, all else being equal.

[shmokes]

Does any of this change if you are looking at getting a projector?  I realize there are other factors to consider in getting a projector (lumens, contrast...blah, blah, blah), but what of resolution?

Jouster

It all works the same with a projector.  However, resolution is probably especially important with a projector for no other reason than screen size.  Just as people say that you can't tell the difference between 1080p and 720p with a 40" screen or less (notwithstanding Howard's opinion), 1080p is going to be more important at 120" than it is at 50".  Larger screens need higher resolutions or the pixels are big and the images are blocky.

[Howard_Casto]

So to sum up, a sd ntsc signal looks crappy not because of it's poor resolution, but it's poor quality.

They are both to blame. If you were to approximate the resolution of an SD NTSC signal (320x240) with a purely digital video, it will look bad displayed full-screen on an HD display, regardless of the quality of the video's encoding.

"Bad" is subjective... yes it'll look like a low resolution picture, because... well it is a low resolution picture (duh!) but a pure digital 320x240 will look dramatically better than a crappy degraded 320x240.  On top of that, NTSC is much higher resolution than you think (unless we are talking rabbit ears).  I'll just refer you to this link:

http://www.strata.com/support/3dmanual/ch13/ch13_7.html

Now with that being said, yes... sd signals are interlaced, but that only effects vertical resolution, not horizontal, so taking into account the extra border the actual resolution of your typical ntsc signal is 640x324, that's still a pretty low resolution, but interlacing (gasp!) actually does a good job of doubling the vertical res on lower end signals like ntsc, so unless we are looking at a static image, it still seems like a 640x480 image.  But wait, to confuse things even more, the type of tv plays a part again.  Analog tvs do interlaced just fine, they were designed to, digital tvs vary.  Your comb filter on your dtv may or may not be able to "de-interlace" a ntsc signal, making it look similar (but still not quite as good) as it would on an analog tv.  

Regardless, our main issue is still quality, it's just in this case were are also talking about loss of quality via interlacing/dinterlacing and filtering processes done to the image.  640x480i isn't THAT bad, and that becomes evident if you see it on a large screen projection tv, even if it supports hi-def, compared to a similar sized lcd tv.

So as I stated in my original post, it is partly to blame, but my guess is you just glanced at what I said and only read the last sentence.  

[MaximRecoil]

"Bad" is subjective... yes it'll look like a low resolution picture, because... well it is a low resolution picture (duh!) but a pure digital 320x240 will look dramatically better than a crappy degraded 320x240.  On top of that, NTSC is much higher resolution than you think (unless we are talking rabbit ears).  I'll just refer you to this link:

http://www.strata.com/support/3dmanual/ch13/ch13_7.html

A typical over-the-air NTSC TV broadcast will only yield about 330 lines of horizontal resolution. You will always have 485 lines of visible vertical resolution, interlaced, which gives you 242.5. This roughly translates to a 320x240 digital resolution. Now if we are talking direct broadcast feed, then the resolution would be improved. 

[ahofle]

Remaster from original cells.

No... they re-scanned the original film from the archives, the original cells weren't touched, nor do they exist anymore. 

I wasn't aware there was a difference.  Isn't a cell just a frame from the original film?
Anyway, I think the point is that they sampled the original film instead of just upconverting the laserdisc source (at least that was Chad's question).
http://www.digitalleisure.com/contents/DVDRom_games.htm
"Fully interactive gameplay digitally remastered from the original film"

[MaximRecoil]

Remaster from original cells.

No... they re-scanned the original film from the archives, the original cells weren't touched, nor do they exist anymore. 

I wasn't aware there was a difference.  Isn't a cell just a frame from the original film?
Anyway, I think the point is that they sampled the original film instead of just upconverting the laserdisc source (at least that was Chad's question).
http://www.digitalleisure.com/contents/DVDRom_games.htm
"Fully interactive gameplay digitally remastered from the original film"

No, the animation cells are the hand drawn/painted clear sheets of "paper". These are photographed in a certain order to make the film.

In any event, if they scanned the original film to make a new digital master, and then made an HD encode from that; it would definitely be an improvement over the laserdiscs (especially if they restored/cleaned the film [if necessary]). This is the same process used to make HD movies from live-action films.

[ChadTower]

I wasn't aware there was a difference.  Isn't a cell just a frame from the original film?

This is a case where animation differs from live action.  Obviously in live action you can't reshoot the footage so the film is as far back as you go... with animation, if the original hand drawn cels still exist, you can remaster from those and essentially recreate the footage in a pure manner.

[Jouster]

It all works the same with a projector.  However, resolution is probably especially important with a projector for no other reason than screen size.  Just as people say that you can't tell the difference between 1080p and 720p with a 40" screen or less (notwithstanding Howard's opinion), 1080p is going to be more important at 120" than it is at 50".  Larger screens need higher resolutions or the pixels are big and the images are blocky.

That is an excellent point, and one I had not really thought through.  A woman may look hot from a far...but as you get closer, you can see the effects from the ugly stick...but if you look at her with a magnifying glass...you can see the backward 'Made in China' indentations on her from the stick.

Jouster

[patrickl]

A woman may look hot from a far...but as you get closer, you can see the effects from the ugly stick...but if you look at her with a magnifying glass...you can see the backward 'Made in China' indentations on her from the stick.

Ehm ... a chinese woman was recently voted miss world 

[ChadTower]

Ehm ... a chinese woman was recently voted miss world 

He was talking about the ugly stick being made in China.   

[MaximRecoil]

I wasn't aware there was a difference.  Isn't a cell just a frame from the original film?

This is a case where animation differs from live action.  Obviously in live action you can't reshoot the footage so the film is as far back as you go... with animation, if the original hand drawn cels still exist, you can remaster from those and essentially recreate the footage in a pure manner.

Yes, but film is still a very high quality source, more than enough for an HD transfer, which is actually low resolution compared to what film is capable of (assuming at least 35mm film, which is the most common format for Hollywood-type movies).

[patrickl]

Ehm ... a chinese woman was recently voted miss world 

He was talking about the ugly stick being made in China.   

Lol, ok. I stand corrected 

[boykster]

I wasn't aware there was a difference.  Isn't a cell just a frame from the original film?

This is a case where animation differs from live action.  Obviously in live action you can't reshoot the footage so the film is as far back as you go... with animation, if the original hand drawn cels still exist, you can remaster from those and essentially recreate the footage in a pure manner.

Yes, but film is still a very high quality source, more than enough for an HD transfer, which is actually low resolution compared to what film is capable of (assuming at least 35mm film, which is the most common format for Hollywood-type movies).

Yep.  Some of the most impressive HD transfers I've ever seen are of old(er) film movies.  Sure, the 'all digital' stuff that's been coming out lately is very sharp - sometimes overly so - but it's amazing how well a well maintained or cleaned film master can transfer to HD.

Re: projectors - another yep.  when you're talking about increasing the screen size by a factor of 4 or more (area), you want as much resolution as possible.  The terminology is different, but the effect is the same: seeing the "pixel structure" of the image.  Many pj manufacturers use techniques to blend the pixels while preserving sharpness to try to reduce the "screen door effect" (SDE).  I have a 720p projector and an 85" screen that looks very nice at 8', and spectacular at 12'.