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Aspect Ratio & Native Resolution


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38 replies to this topic

#1 OFFLINE   georgemartin601

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Posted 25 March 2011 - 12:32 PM

Just had DirecTV installed last night. 3-room setup, one HDDVR (HR24), one HD (H24) and one standard box. I apologize if it's inappropriate to reference a link to another site here, but in an effort to possibly save time and explanation, here's my issue, may need to add "w" copy/paste:

ww.avsforum.com/avs-vb/showthread.php?t=1324280

Anyone know if my installer set the HD receivers up to automatically upconvert SD signals? If so, is this a setting I have access to? As you'll hopefully have read through the above link, my TV is set to NOT alter source content in any way. It can display any signal type. My receiver is set to "Native - On". "Formatting - Original". And each signal type is checked on in the receiver setup. I leave my "format" option (as set from the remote) to "Original/Unaltered".

I have changed these settings to troubleshoot, with no resolution to my problem. In short - I need to view content at its native resolution, native aspect ratio. SD content should appear as 4x3 on my HDTV, thus putting bars on both the left and right side of the screen. I would like to leave the "format" (as set on the remote) to "original". As doing this allows properly viewing HD content without making a change with each channel change.

Thanks

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#2 OFFLINE   veryoldschool

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Posted 25 March 2011 - 12:44 PM

Guess you need to understand what does what:
With "native on" and all resolutions selected, the DVR/receiver outputs the same resolution as the program is, so the receiver isn't scaling anything. Your TV will scale to fit your display size.
"Format" is another part of this. The DVR/receiver can/will change the format to stretch/crop/pillarbar, or your TV can do this. With "original format", the DVR/receiver also sends out the 4:3 format signal to your TV. You need to setup your TV to display this correctly.
In my case, I use original format for SD that is 16:9, and have my TV set to zoom 4:3. This gives me full screen undistorted and I use pillarbar for 4:3 SD, so the TV doesn't zoom.

Everyone needs to test/figure out which they like best, as both the DVR/receiver and TV have settings that make these changes, and you need to find which works best for you.


[edit] the short answer is: If SD is being distorted when you select original broadcast, it's your TV doing this and you need to look at your TV's menu for the change in setting.

Edited by veryoldschool, 25 March 2011 - 12:58 PM.

A.K.A VOS

#3 OFFLINE   e4123

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Posted 25 March 2011 - 12:57 PM

Welcome to DBSTALK:)
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#4 OFFLINE   georgemartin601

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Posted 25 March 2011 - 12:59 PM

I believe I understand perfectly what does what. My TV is set to display the signal/format/aspect ratio it receives. That is, it is not scaling or converting in any way. That is exactly my desire of the receiver as well. I want to view 4x3 SD/480i content in its native resolution, without altering the content in any way. In order to do that on a 16x9 HDTV, the receiver needs to add bars to the left/ride side of the image. This box is filling my 16x9 tv with a 4x3 image and calling it "480i+Original Format, Unaltered content". That is not possible, obviously. Obviously content that's 4x3 has to be "altered" to fill a 16x9 display. I've changed settings on my receiver to troubleshoot. I can indeed change from "original format" to "pillarbox" to see the 4x3 content. But making this change requires a change back to "original format" when switching back to HD signal content. So, the real question is, did my installer make some setting on this box during setup to upconvert SD content to 720p or higher? In some menu not accessed via the GUI?? If he didn't it appears DirecTV is calling clearly altered content, "unaltered". wow

#5 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:06 PM

Guess you need to understand what does what:
With "native on" and all resolutions selected, the DVR/receiver outputs the same resolution as the program is, so the receiver isn't scaling anything.


I'm saying that it appears to be doing exactly that, scaling that is. Native is on, all resolutions selected. My TV is doing NOTHING with the signal. Each and every SD broadcast FILLS my 16x9 tv. No bars, nothing. The "format" (as accessed on the remote format button) is set at "Original". Obviously I can change to "pillarbox". But again, obviously it is not showing me the "original" resolution/aspect. And leaving it at "pillarbox" forces me to change back to original when going back to HD broadcasts. Doable, yes, ideal no. Ideally, you'd leave it at original and everything would be displayed as intended. HD broadcasts look great by the way, and SD broadcasts are fine with the standard box on my SD CRT display.

thanks

#6 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:12 PM

I'm saying that it appears to be doing exactly that, scaling that is. Native is on, all resolutions selected. My TV is doing NOTHING with the signal. Each and every SD broadcast FILLS my 16x9 tv. No bars, nothing. The "format" (as accessed on the remote format button) is set at "Original". Obviously I can change to "pillarbox". But again, obviously it is not showing me the "original" resolution/aspect. And leaving it at "pillarbox" forces me to change back to original when going back to HD broadcasts. Doable, yes, ideal no. Ideally, you'd leave it at original and everything would be displayed as intended. HD broadcasts look great by the way, and SD broadcasts are fine with the standard box on my SD CRT display.

thanks

Format has no affect on HD resolutions, when the receiver has been set to 16:9 TV.
Format will affect HD resolutions when the receiver is set to a 4:3 TV.
If you've set your TV to display a "true 4:3 SD" signal/program when original format is selected, then changing to HD doesn't have any change with any format selection of the receiver.
A.K.A VOS

#7 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:16 PM

Are you saying if I want to view SD content in its native mode, to leave the "pillarbox" setting on? And doing so will allow me to switch back to HD content w/o making a change through the remote or receiver menu? And the HD content will be at its "native" resolution?

#8 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:24 PM

Are you saying if I want to view SD content in its native mode, to leave the "pillarbox" setting on? And doing so will allow me to switch back to HD content w/o making a change through the remote or receiver menu? And the HD content will be at its "native" resolution?

"Kind of"
Native means all your selected resolutions will be passed to the TV without any changes.
Format only works on SD, when the receiver is set to 16:9.
You can use pillarbox, as I do for full 4:3 SD. Changing to an HD channel doesn't require changing format, since it doesn't work on HD.
Now pillarbox/bar and original formats on SD can give different results, depending on how you've setup your TV. Pillarbox/bar will still send the 16:9 signal to the TV, where original format sends the 4:3 signal, so the TV will see this and can change to what you've set it up to do with 4:3.
"Now understand" when I say 4:3 & 16:9 "signal", I don't mean the picture, but the part of the signal that carries "the bit" defining what type the image is. Have I got you :confused: yet? :lol:
A.K.A VOS

#9 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:26 PM

Is there a channel or content/broadcast in any of DirecTV's service that will show me bars on the left/right side of my 16x9 TV, when (in menu) Native = On, Format = Original. And (via remote) Format = Original?

#10 OFFLINE   CCarncross

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Posted 25 March 2011 - 01:27 PM

I have all my HD boxes set to pillarbox, so 4:3 material(all SD channels) is set to be correct aspect ratio and all, no stretching at my house. When I change to any HD channel, it goes right back to normal HD....even with the pillarbox setting......

#11 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:33 PM

I just switched from Charter Cable. They offered SD and HD content. When I watched SD content, there were bars on the left right side of the screen. When I switched to HD content, it filled the screen. No change on the remote or menu. Receiver was set to display native resolutions, TV was set to display native resolutions. In no way am I proCharterCable, just stating a fact. Can I do the same with Directv's equipment? Can I have the box set to display native & original and switch from SD to HD content and make no changes on the remote, TV, or receiver menu?

It sounds like you're saying (I guess it sounds that way because you are, just need you to reiterate) to leave it on pillarbox mode to view SD at 4x3 and HD at 16x9 native. And I should forget that DirecTV lets you see a 4x3 picture that fills a 16x9 tv and calls it "original" and "unaltered". "thanks"

#12 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:34 PM

I think that answers my question CCarncross. thanks

#13 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:36 PM

Is there a channel or content/broadcast in any of DirecTV's service that will show me bars on the left/right side of my 16x9 TV, when (in menu) Native = On, Format = Original. And (via remote) Format = Original?

I think you're missing how this works.

"Original" is for when you want your TV to handle the format change. This was added for those that liked the TV doing the stretch, mostly where it varied from center to the sides.
Now "in my case" my TV can scale the image much better than the receiver's scaler does.
So "zoom" on my TV looks much better than "crop" on the receiver. Both fill the screen with the image, but my TV does it looking better.
I think you need to play with these and find what you like best, since you're the viewer and nobody can tell you which/what looks best to you.
A.K.A VOS

#14 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:40 PM

I just switched from Charter Cable. They offered SD and HD content. When I watched SD content, there were bars on the left right side of the screen. When I switched to HD content, it filled the screen. No change on the remote or menu. Receiver was set to display native resolutions, TV was set to display native resolutions.
And I should forget that DirecTV lets you see a 4x3 picture that fills a 16x9 tv and calls it "original" and "unaltered". "thanks"

You simply have more options with the DirecTV receivers than you had before. ;)
A.K.A VOS

#15 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:49 PM

I think you're missing how this works.

"Original" is for when you want your TV to handle the format change. This was added for those that liked the TV doing the stretch, mostly where it varied from center to the sides.


I don't want my TV to handle anything. I want it to only display what it is sent, no scaling, nothing. That's how it's set. I don't want the receiver to handle anything. I want it to display only what it is sent. No scaling, upconverting, stretching, nothing. It sounds like based on CCarncross reply, the only way to do that is to set it to "pillarbox". As long as that has no effect on altering the HD broadcast's native resolution, I suppose that's what I'll do, and just ignore the other (IMO) confusing verbiage.

It's not a matter of preference whatsoever. It's a matter of accuracy. Accurately displaying content as it was produced.

#16 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:54 PM

I don't want my TV to handle anything. I want it to only display what it is sent, no scaling, nothing. That's how it's set. I don't want the receiver to handle anything. I want it to display only what it is sent. No scaling, upconverting, stretching, nothing. It sounds like based on CCarncross reply, the only way to do that is to set it to "pillarbox". As long as that has no effect on altering the HD broadcast's native resolution, I suppose that's what I'll do, and just ignore the other (IMO) confusing verbiage.

It's not a matter of preference whatsoever. It's a matter of accuracy. Accurately displaying content as it was produced.

When you have an image size of less than 640x480, "something" needs to do the scaling, or it won't fit your screen.

If you're using native & pillarbox, the receiver is merely adding the bars, and your TV is scaling to fit your display size.

This setting may be what you've been used to so you don't realize this and now that you have more options, you're finding this hard.
A.K.A VOS

#17 OFFLINE   georgemartin601

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Posted 25 March 2011 - 01:56 PM

That's quite possible. I appreciate the info. I'll mess around with it tonight and probably report back, with either more questions born from confusion, or "I got it now" thanks

#18 OFFLINE   veryoldschool

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Posted 25 March 2011 - 01:59 PM

That's quite possible. I appreciate the info. I'll mess around with it tonight and probably report back, with either more questions born from confusion, or "I got it now" thanks

This always seems to take a while to "get it" [for me too at first], and these threads have been known to run to 200+ posts. :lol:
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#19 OFFLINE   Beerstalker

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Posted 25 March 2011 - 02:34 PM

I just switched from Charter Cable. They offered SD and HD content. When I watched SD content, there were bars on the left right side of the screen. When I switched to HD content, it filled the screen. No change on the remote or menu. Receiver was set to display native resolutions, TV was set to display native resolutions. In no way am I proCharterCable, just stating a fact. Can I do the same with Directv's equipment? Can I have the box set to display native & original and switch from SD to HD content and make no changes on the remote, TV, or receiver menu?


Yes you can get it set up to do this. That is pretty much how I have my TVs set up at home (except I have the DirecTV receiver upscale everything to 1080i, so I have native turned off).

First you need to make sure your receiver is set up for a 16:9 TV.

Then, in your case you want to have native turned on, and you want to check all of the formats that your TV supports (480i, 480p, 720p, 1080i, 1080p). Like I mentioned before 1080p is only 24 frames per second which not all 1080p TVs can accept. If you give us your TV's model number we can look up what all resolutions your TV can accept.

Then you need to set your receiver up to pillarbox 4:3 content, and tell it what color you want the pillar boxes to be (I think there is 3 choices, light grey, dark grey, and black, but I'm not sure).

After all this is done when you tune into a HD channel the picture should fill your entire screen (unless of course the channel is showing content that should be letterboxed or pillarboxed). When you change to an SD channel the picture should be 4:3 with pillarboxed sides (in whatever color your set). If not then you need to mess with the format button on the DirecTV remote and possibly the format button on your TV remote to get it set up correctly. Once it is set up correctly you should never have to hit the format button on the DirecTV remote again.

Be aware that sometimes SD channels will show a movie in letterbox form. Since you have your receiver set up to pillarobox you will end up with what is called windowboxing. This is where you have the black letterbox bars on top and bottom, and then the grey/black pillarbox bars on the side. When this happens you can just watch it like this, or you can use either the DirecTV remote format button, or your TVs format button (if you TV supports it) to zoom the picture in. This will allow the pillarbox bars on the sides to go away, and it will cut off most if not all of the letterbox bars on the top. However the picture will probably look pretty bad because you are in effect zooming in an already low quality SD picture and making it bigger which will magnify the flaws in the picture.

Edited by Beerstalker, 25 March 2011 - 02:39 PM.


#20 OFFLINE   TomCat

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Posted 25 March 2011 - 07:11 PM

Is there a channel or content/broadcast in any of DirecTV's service that will show me bars on the left/right side of my 16x9 TV, when (in menu) Native = On, Format = Original. And (via remote) Format = Original?

There are a couple of channels that still use wings on 4:3 content that they upconvert to HD. TNT is one of them. Often when they have a 4:3 commercial, they will display the wings with the TNT logo. Also, a lot of local stations do the same thing.

Since the analog shutoff, there are no sources for true 4:3 other than low-power stations OTA. The HD stations on cable or sat that have SD equivalents for their legacy SD customers actually derive those SD equivalents from the HD feeds by centercutting the video and downscaling it back to 480i. The advantages for them (and us) are having to deal with only a single feed for both services and much higher SD quality.

Video channels stay on their resolution at all times; if they didn't, it would make for nasty burps in the video (and the audio) every time they changed resolution, so to avoid that they crossconvert everything to the same resolution.

As far as striving for accuracy by avoiding rescaling, that is not really possible. If your set is 1080p, then 720p content from FX or ABC or FOX or ESPN will have to be rescaled. If you use "native on", all scaling will happen in your TV. If you instead match your 1080p set with a 1080i resolution output (the pixel map is then 1:1 even if there is deinterlace involved in the set) then the only scaling will be in your DVR, and only for non-1080 content.

Modern scalers are pretty close to perfect anyway. The level of quantization error is negligible, as scaling one format to another involves simple math using integers. It used to be only a few years ago that we needed high-end consumer black boxes to do this that cost $10K or more to do it without artifacts (which were mostly due to the inability to keep up with the sheer number of calculations per second needed), but a $199 20" Vizio can do that today without even breaking a sweat. Now that proc power can handle the needed number of calculations per second, it is pretty easy to do that math quickly enough to avoid any errors at all, and human vision is not good enough to even distinguish whatever remaining artifacts it may create.
It's usually safe to talk honestly and openly with people because they typically are not really listening anyway.

#21 OFFLINE   georgemartin601

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Posted 26 March 2011 - 08:26 AM

Haven't been able to put anything to the test yet, but all sounds like very good relevant info . . . thanks to everyone.

If this helps, here's my equipment:

- Panasonic TC-P54VT25 Plasma
- DirecTV HR24-100 (& H24-200)
- Not really relevant - Panny bluray and sound

Sounds like everyone knows what I'm after and I'm probably trying to simplify something that really isn't simple at all. I'll re-state my goal based on the above info - I want to do as little content altering as possible, unless the altering can actually provide a better picture while maintaining the original aspect ratio.

I'm going to start by testing with Native On, Format Original, and Pillarbox and have my TV use the Full picture setting.

Thanks much to all

#22 OFFLINE   veryoldschool

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Posted 26 March 2011 - 09:41 AM

Haven't been able to put anything to the test yet, but all sounds like very good relevant info . . . thanks to everyone.

If this helps, here's my equipment:

- Panasonic TC-P54VT25 Plasma
- DirecTV HR24-100 (& H24-200)
- Not really relevant - Panny bluray and sound

Sounds like everyone knows what I'm after and I'm probably trying to simplify something that really isn't simple at all. I'll re-state my goal based on the above info - I want to do as little content altering as possible, unless the altering can actually provide a better picture while maintaining the original aspect ratio.

I'm going to start by testing with Native On, Format Original, and Pillarbox and have my TV use the Full picture setting.

Thanks much to all

With HD, there is either no scaling or very little [720p needs some for a 1080 display], so SD should really be the only one that this would be noticeable.
Perhaps the thing to do is to turn native off and then select an SD channel that is showing a show in 16:9, where it has boarders on all sides.
With native off, the format button will cycle through all formats & resolutions. This will show how well the receiver scales, as you cycle through them.
Then I'd stop with the receiver on 480i/p and original format, and use the TV remote to change the TV format to zoom.
This will have the TV doing the most scaling.
Compare the TV scaling and the receiver with crop should give you the best idea of which works better, if there is a difference.
Some can't see any, while others can. The receivers are the same so this comes down to whether the TV is better at this or not.
A.K.A VOS

#23 OFFLINE   BattleZone

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Posted 26 March 2011 - 09:56 AM

Okay, your Panasonic has a 1920x1080 panel. The ONLY signals that will not need to be scaled are "1080" source signals. All signals that are either "480" (720x480) or "720" (1280x720) MUST be scaled up by either the TV set or the DVR if they are to fit the screen. Without scaling, SD signals (480) would be postage-stamp sized in the middle of your TV screen with huge black bars on all sides.

So, you have to figure out which scaler does a better job: the one in the TV set, or the one in the DVR. If the DVR is set to "Native: On", then the TV set is doing the scaling. If "Native: Off", then the DVR is doing the scaling.

For SD content, "Pillar Box" is what will give you the "most correct" aspect ratio. MOST TVs can't handle "original" format SD signals automatically, so you'd need to "ride" your TV's "format" or "aspect ratio" button as you changed channels in that mode.

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#24 OFFLINE   veryoldschool

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Posted 26 March 2011 - 10:06 AM

For SD content, "Pillar Box" is what will give you the "most correct" aspect ratio. MOST TVs can't handle "original" format SD signals automatically, so you'd need to "ride" your TV's "format" or "aspect ratio" button as you changed channels in that mode.

You see many more TVs than I do, so this may be true, "but" the TVs that I've have/had, a setting for 4:3 480.
"for instance", I set my Sony for zoom with 4:3. The windowboxed SD programing has me change the receiver to original and the TV zooms it. After I'm done watching, I change the receiver to pillarbox, and the TV changes from zoom to full, which is the 16:9 setting for it.
This means I only need one remote and just a few presses of format to cycle into and out of the TV's zoom mode.
A.K.A VOS

#25 OFFLINE   TomCat

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Posted 27 March 2011 - 12:44 AM

...Compare the TV scaling and the receiver with crop should give you the best idea of which works better, if there is a difference.
Some can't see any, while others can. The receivers are the same so this comes down to whether the TV is better at this or not.

Some may think they can see a difference, but that is only because they think they can. The differences between modern scalers are virtually negligible. They all use the same algorithm to do the job. Human vision, even from golden trained eyeballs, is as incapable of seeing the difference as humans are of following a scent trail like a bloodhound. Bloodhounds, like sharks, have finely developed senses. We don't.

We are simply not equipped to distinguish the difference, which is also why we can regularly compress HD video 100:1 before it begins to become noticeable. There has never been anyone who could distinguish scaling artifacts from modern scalers in a double-blind study. In fact, no one can really look at video and tell you if it is 1080i or 720p, either. Well, they maybe can tell you, but they don't really know, even if they think they do.

Much more visible (and still mostly not noticeable) are deinterlace errors. Pre-2005 sets often did not do this well (which is why deinterlace in the DVR may be better for them). Even that cheap Vizio doesn't deinterlace all that well; the one I am familiar with does it well 99.99% of the time, but certain sorts of motion or picture changes will make it burp and line dice noticeably for a split second. And it is not the smooth normal interlace artifacts you see on motion, it varies very widely and quickly; perfect for a split second, widely line-diced for the next, which is annoying.

Bottom line, it is worth experimenting to see whether the DVR or TV itself does a better job of both, even though the scaling is rarely if ever different for modern sets. Sadly, deinterlace is not so ubiquitously perfect.

+++++++++++++++++++++++++++++++++++++++++++

But I digress. Back to scaling. Scaling is very simple math, done very quickly: For instance, to scale 1080 to 720, if you overlay the pixel grid map of 1280x720 over the pixel map of 1920x1080, you can see and measure exactly where each 720 pixel falls in physical relationship to teach 1080 pixel. Only four pixels on the source map are relevant to each new pixel location. Assuming you were trying to find just the new value in the H dimension, if the first 720-map pixel of line 1 falls 66.67% on pixel 1 and 33.33% on pixel 2 of line 1 of the 1080 map, then you can multiply the binary coefficient representing the first pixel on the 1080 map by 0.666, and the second value (of the second pixel) by 0.333, then add the two together.

That gives the value that the first 720-map pixel should be in the H dimension, which is somewhat of an average of what the luminance would be on the 1080 map at that 720 map pixel's physical location for the two 1080 pixels that "share", or more accurately are adjacent to that same point of real estate. Of course you have to do this in the vertical dimension as well, so actually four pixels and four constants are involved in calculating each new pixel value for every pixel, two in the H dimension and two in the V dimension. That is basic math a fourth grader can understand.

There is rounding involved, but it is negligible; at the worst case, since there are 219 possible values for luminance in 8 bit 4:2:0, the error would be less than half of one IRE in brightness (in analog terms) which is not distinguishable at any grey level, and the error is on average half that (the rounding drags the calculated value either to the quantum level above or below it, whichever is closer). For scaling between 480, 720, 768, and 1080, the rounding errors are even much lower than that; often there is no rounding error at all for most pixels, meaning the scaling is completely or at least virtually transparent. Certainly not even approaching visible.

If there would be rounding (which really only exists in scaling done between uncommon formats) it could result in banding, but nearly or totally invisible banding. If you see banding it is due to compression, not scaling, because that sort of artifact is much more severe when compression is high (as it is for ATSC, DVB, and QAM delivered to consumers), and common scaling has very little rounding errors. Oversampling could eliminate the errors, but is not needed since there really are no visible errors when scaling common formats in the first place.

Since the map never changes, the values of those multipliers are constants, That means they can be written into the formula, burned into the silicon as a lookup table, and do not have to be recomputed each time. And since pixels for 720p, for example, are 1.5 times as wide and 1.5 times as tall as 1080p pixels, there are only three constants needed, 4, 2, and 1 (so really, just two, as the 1 can be ignored and 2 is used twice). Since the math is done in integers this reduces the rounding error possibility to almost zero.

If you look at the attached diagram, it shows the first 5 pixels of the first 3 lines of the 1080 luminance pixel map in black and white. Overlayed over that is the first 3 pixels of the first 2 lines of the 720 pixel map, in blue. Note that this represents the top-left corner of an HD display.

To calculate the luminance value of pixel 1 line 1 of the 720 map, take the luminance value of pixel 1 line 1 of the 1080 map and multiply it by 4. Take the value of pixel 2 line 1 of the 1080 map and multiply it by 2. Take the value of pixel 1 line 2 of the 1080 map and multiply it by 2. Take the value of pixel 2 line 2 of the 1080 map and multiply it by 1 (simply use the whole value of pixel 2 line 2 in this case).

Notice that these constants directly represent the amount of area (divided by 9) that the new 720 pixel overlays for each of the four 1080 pixels (each 720 pixel always overlays either 4/9ths, 2/9ths, or 1/9th of each corresponding 1080 pixel).

Add these four new values (the binary coefficients representing the 1080 pixel times their constants) together and divide by 9, and that gives the luminance value to assign to the new 720 pixel, for line 1 row 1. Now repeat the process for each remaining 720 pixel.

Congratulations, you have just rescaled 1080p to 720p.

Thats a total of 6 (really 5) simple calculations per pixel: multiply each of the coefficients representing 4 pixels (those from the source map overlayed or adjacent to the new pixel location on the target or destination pixel map) by its lookup table constant, add those values together then divide by 9 to resolve each new coefficient representing each new pixel (the "9" is where the tiny amount of rounding error creeps in).

Now that we have what is a very simple formula, all we have to do is crunch the numbers of the new pixels fast enough, which even for for 1080p60 is just over 18 million calculations per field, (12+ million for luminance, 3+ mill for Cr, and 3+ mill for Cb) or just over 1 billion calcs per second, give or take, even including the phantom 6th calculation, a speed any modern dedicated microprocessor can handle without even breathing hard. Resolutions lower than 1080p60 are even easier, because there are fewer pixels, meaning fewer calcs per second.

Attached Thumbnails

  • pixel map scaling.png

Edited by TomCat, 27 March 2011 - 05:09 AM.

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