# BUG REPORT: Grey Bar mode is flawed



## bytre (Sep 10, 2003)

Model: DishDVR 921
Card Revision: DNASP103 Rev300
Boot version: 120B
Flash Version: F051
SW Version: L145HECD-N

Observation: When 4:3 material is displayed in grey bar mode on satellite channels, there is a narrow black bar between the grey area and the actual picture. See attached image with red outlines around problem.

Expectation: The grey bars should come up right to the edge of the picture.

Reasoning: Grey bars are designed to give "average" exposure to the phosphors on the rest of the screen that is not being used while a 4:3 picture is displayed in the center, giving them the chance to "burn in" at approximately the same rate as the rest of your set. By leaving a column of black between the actual picture and the grey bars, users who watch a lot of 4:3 material will end up with these two columns of phosphors which are underutilized, and can then make burn in apparent on the set.

The current implementation may be visually more appealing, but it misses the point of having grey bars in the first place.

To be researched: Whether this affects the OTA tuner as well (I expect it will, but I have not been able to test that yet).


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## bytre (Sep 10, 2003)

Another observation regarding the grey bars - they are much brighter than the grey bars my TV (mitsubishi 55857) uses on its stretch mode. As I am unable to calculate the "average" grey, I don't know which machine has the wrong brightness.


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## Mark Lamutt (Mar 24, 2002)

Part of this issue lies in the fact that not every 4x3 channel is the same width, and sometimes different programs on the same channel have slightly different widths. It looks to me like the Gray Bars are located so that they extend to the edge of the 4x3 frame considering 0% overscan in the 4x3 frame. Most 4x3 programs are framed to account for roughly 5% overscan. So, there may not be picture data in the 4x3 frame in the area from 5% overscan back to the edge. 

I believe what the 6000 Gray Bars mode did was to place the gray bars 5% into the 4x3 frame to solve this issue.


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## 928gt (Dec 17, 2003)

> I believe what the 6000 Gray Bars mode did was to place the gray bars 5% into the 4x3 frame to solve this issue.


True, but what I don't understand is why the heck doesn't the 921 do this since Dish obviously already knew this was neccassary ! Shouldn't lessons learned on previous receivers become part of the base software on new receivers instead of having to rehash the same old problems over and over again.

An example of this is obvious with the 6000, aspect modes were finally working correctly, YET the 811 and 921 aspect modes are a joke. Don't they have enough common sense to have these adjustments already corrected on newer models. Sometimes I wonder if the 921/811 team has ever even looked at a 6000......

Dave


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## Mark Lamutt (Mar 24, 2002)

Dave - they probably haven't. The 921 software came directly from the 721 software, and I don't know where the 811 software started out, but it certainly doesn't look like it started with the 6000 code.

The 6000 also didn't offer a 16x9 anamorphic enhanced mode. That's new with the 921 (and maybe the 811) and is what's causing the AR problems for the 921.


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## 928gt (Dec 17, 2003)

> The 6000 also didn't offer a 16x9 anamorphic enhanced mode. That's new with the 921 (and maybe the 811) and is what's causing the AR problems for the 921.


Hi Mark,

Can you explain the advantage of this "New" anamorphic enhanced mode in relation to any feeds we get from Dish ?

I sort of understand the anamorphic aspect control that happens with DVDs, but I don't see the advantage of this with current satellite feeds. Call me lost or stupid, but did I miss that day in class or what ?

FYI, I am using a full digital 16 by 9 display so if you can relate the advantage of this new technology to that I would appreciate it.

Dave


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## Mark Lamutt (Mar 24, 2002)

I don't have a fully digital display, so I don't have much intelligent to say about that. My sony's coming up on 3 years old.

I don't know what the advantage is. I'm sure one of the other users around here that is more technically inclined in this area can provide a much better explanation that I can. All that I really know at this point is the list of bugs that have been caused by it.


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## bytre (Sep 10, 2003)

Mark Lamutt said:


> Part of this issue lies in the fact that not every 4x3 channel is the same width, and sometimes different programs on the same channel have slightly different widths. It looks to me like the Gray Bars are located so that they extend to the edge of the 4x3 frame considering 0% overscan in the 4x3 frame. Most 4x3 programs are framed to account for roughly 5% overscan. So, there may not be picture data in the 4x3 frame in the area from 5% overscan back to the edge.
> 
> I believe what the 6000 Gray Bars mode did was to place the gray bars 5% into the 4x3 frame to solve this issue.


That does sound like an explanation, albeit not one I agree with. I will view some other 4x3 material to see if I can find any variation in them.


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## SimpleSimon (Jan 15, 2004)

So far, I see the black lines on every 4:3 program.


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## 928gt (Dec 17, 2003)

Here are some photos that better describe the flawed grey bars and aspect modes concerning HD channels.

Please note I purposely used CBS-HD channel with a 4.3 format image as I feel it shows the issues better. Also note I am using DVI-D so some of this may not be apparent on the "over" overscanned Component output.

First photo - "Stretch Mode" - You can still see the CBS generated grey bars on each side. ( If feel this is mainly on DVI-D output since it seems to be slightly "underscanned")

Second Photo - "Zoom Modes" - All the 921 does is zoom the picture vertically and not horizonally which makes everything "skinny". Note cutoff PGA logo

Third Photo - "Gray Bar mode" - Identical vertical squeeze issue as with Zoom mode, but then squeezes even farther AND adds the grey bars on the outside of the vertically distorted image so you have 2 sets of gray bars, then a skinny picture.

Next time one of the HD channels is sending a 4.3 format try your aspect modes and you will see what I mean.

Dave


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## DonLandis (Dec 17, 2003)

_"Part of this issue lies in the fact that not every 4x3 channel is the same width, and sometimes different programs on the same channel have slightly different widths."_

Mark- Considering that most 4:3 broadcast is derived from NTSC program sources, the picture width is related to the NTSC regulated horizontal blanking period of 11.44 us. This is one spec that has survived the deregulation. I really don't know why you may be obseving different full active picture widths in Denver but all my 4:3 channels here are identical on a display that has no protection for overscan. I have also examined most of the video from the local stations here on a calibrtated WFM and all seem to be in compliance with the 11.44 us maximum HB.


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## SoCalStev1 (Jan 10, 2004)

I too see black bars inside the grey bars on every 4:3 station I watch. I have a feeling this is probably not so great for my TV as its a RPTV. I hope there is a remedy for this soon.

Thanks

S/W L145


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## tnsprin (Mar 16, 2003)

928gt said:


> Here are some photos that better describe the flawed grey bars and aspect modes concerning HD channels.
> 
> ...


?? what settings on tv and on STB.

The pictures you are showing look like the improper setting of you STB and your TV set. In particular the last picture looks like the setting for a STB at 480I/P 16x9 picture where your tv set is not set on FULL (widescreen) mode.


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## 928gt (Dec 17, 2003)

> The pictures you are showing look like the improper setting of you STB and your TV set. In particular the last picture looks like the setting for a STB at 480I/P 16x9 picture where your tv set is not set on FULL (widescreen) mode.


Display Settings on the 921 are set to "16.9" and "720p" and are output to a 16.9 plasma via DVI-D.

My plasma doesn't have "display modes" like "widescreen" etc, when using the DVI-D input. The only choices when using DVI-D are "One to One" (pixel mapping) or "Fill screen"

BTW, see my photo in this thread http://www.dbstalk.com/showthread.php?t=23699
showing the recent HD NET test pattern using the same 921/TV settings as in the other photos. My plasma is properly displaying this info correctly, the "double gray" bar issue is coming from the 921 and not from incorrect settings.

Dave


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## tnsprin (Mar 16, 2003)

928gt said:



> Display Settings on the 921 are set to "16.9" and "720p" and are output to a 16.9 plasma via DVI-D.
> 
> My plasma doesn't have "display modes" like "widescreen" etc, when using the DVI-D input. The only choices when using DVI-D are "One to One" (pixel mapping) or "Fill screen"
> 
> ...


Certainly strange. The Double gray bars are not from the 921. WCBS-HD normally broadcasts a set of gray bars on its 4x3 pictures. So one set is coming from the 921 the other from the CBS channel. But this picture is broadcast as a full screen 16x9 1080i so, based on your pictures showing no overscan, should have came out correctly even after conversion to 720p.


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## 928gt (Dec 17, 2003)

>Certainly strange. 

Yes, that is why I posted pics, much easier than trying to explain it.

>The Double gray bars are not from the 921. WCBS-HD >normally broadcasts a set of gray bars on its 4x3 >pictures. So one set is coming from the 921 the other >from the CBS channel. 

Correct, I purposely used the "gray bar'd" CBS broadcast to illustrate this. I never meant to imply the 921 was doing 2 sets of gray bars. Had I waited for CBS to switch to not using gray bars you would see the 921 gray bars, then equal sized black bars then a skinny video image.

>But this picture is broadcast as a full screen 16x9 1080i >so, based on your pictures showing no overscan, should >have came out correctly even after conversion to 720p.

Yes, another tidbit is if I put up a full 16.9 image like Dish HD demo channel and select gray bars (no real reason to do this normally, but for sake of discussion) the 921 will "Squeeze" the 16.9 image to a 4.3 image picture AND add gray bars to the outside... In reality when on an HD channel the 921 should simply overlay the gray bars on the sides of the image to simulate a 4.3 image and NOT change or "squeeze" the original image format. 

Of course if all the HD channels would stop using 4.3 images completely this would be mute, BUT I feel it will be a long time before this happens, especially with broadcast HD channels. Plus it will be even longer until all advertisers start making all commercials in true HD format.

Dave


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## Slordak (Dec 17, 2003)

928gt said:


> Yes, another tidbit is if I put up a full 16.9 image like Dish HD demo channel and select gray bars (no real reason to do this normally, but for sake of discussion) the 921 will "Squeeze" the 16.9 image to a 4.3 image picture AND add gray bars to the outside... In reality when on an HD channel the 921 should simply overlay the gray bars on the sides of the image to simulate a 4.3 image and NOT change or "squeeze" the original image format.
> 
> Of course if all the HD channels would stop using 4.3 images completely this would be mute, BUT I feel it will be a long time before this happens, especially with broadcast HD channels. Plus it will be even longer until all advertisers start making all commercials in true HD format.
> 
> Dave


As you noted, you can currently use gray bar mode when on an HD channel to do an "unstretch", effectively doing the inverse operation of a normal "stretch 4:3 content to a 16:9 screen". The interesting and useful thing about this is you can unstretch channels which are broadcasting nasty 4:3 content stretched (rather than with black or gray bars)!

For example, ESPNHD (which should be free for anyone who has ESPN, since it has more or less no HD content to speak of) frequently takes 4:3 content, stretches it to 16:9, and broadcasts this as their "high definition" image. It looks like crap, but with the gray bar mode, you can do an "unstretch" and the image reverts back to being (almost) normal.

This is kind of a bug that becomes a feature, in my opinion!


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## 928gt (Dec 17, 2003)

>This is kind of a bug that becomes a feature, in my opinion!

Maybe in the next software release they should rename the "Gray Bar" mode to "Unstretch Mode" AND then add a PROPER "Gray Bar" mode


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## 928gt (Dec 17, 2003)

Slordak,

Couldn't resist testing your theory when I got home tonight. Tuned to ESPN-HD, selected Gray Bar mode and viola... it transformed the over-stretched ESPN feed to a perfect 4.3 image with gray bars. ESPN-"HD" never looked better and all the players now looked like normal people instead of trolls 

BTW, I think we should all petetion Dish to change the name of the HD Gray Bar mode to the "Slordak UN-Stretch" mode... in your honor !!!

Dave


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## Slordak (Dec 17, 2003)

Laugh. Thanks! Actually someone in another thread first alerted me to the fact that the 921 was doing this, and I too was confused as to why it would do such a thing, since it doesn't make a whole lot of sense. However, it does seem to prove useful for the ESPN-HD case, so it's a happily unintended consequence (unless you actually need gray bars mode for your TV set, in which case it's not as happy).


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## 4HiMarks (Jan 21, 2004)

928gt said:


> Tuned to ESPN-HD, selected Gray Bar mode and viola... it transformed the over-stretched ESPN feed to a perfect 4.3 image with gray bars.


I did the same thing on the Pro Bowl. It made watching it semi-bearable. That is the only thing I have found the Gray Bar mode useful for.

-Chris


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