# 720p broadcast on 1080i HD TV



## Rovingbar (Jan 25, 2005)

A few weeks ago I noticed that most Fox HD broadcasts have the Fox logo cut off in the bottom corner. I've read some refrences to 720p display problems early in 2004. Apparently the problem was resolved with a SW release, but I could not get a sens of what the problem actually was. I don't know if this is caused by my local broadcaster, if it is a 921 problem, or if it is a combination of the two. I'm fairly sure it is not my TV.

Problem Description: Basically the screen is partially zoomed when in normal display mode. (The 921s Zoom mode only makes it worse.) This only seems to be a problem with my local OTA Fox HD broadcasts. I've checked overscan, and various zoom settings on both the TV and the receiver. They are all correct. Even the 480p and 480i images are cut off roughly the same way. Other OTA HD and Dish HD channels display correctly. Here is a link to some photos of the problem,

Dish 921 Display Issue Photos

I noticed that the image displays properly in the Guide PIP and in the Menu-6-9 screen setup background. So this leads me to believe that it is somehow related to how the 921 displays the output. The signal processing must be correct, its just that the image gets cut off just before the final processing.

So what is the cause? My TV, the receiver, or the station? What can I do to fix it?

Thanks,
Jeff


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## dishbacker (Jun 15, 2004)

I've seen the same bug on my 42" Sony LCD RPTV... half cut-off (can see the same amount of the bug that you can see). I always assumed it was a Fox 4 issue and not my TV, even though I know my TV does have a bit of an overscan.

Hadn't notice that the bug will display correctly in the small window of the guide.


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## BobaBird (Mar 31, 2002)

Maybe the 921 thinks everyone is near-sighted. There is a similar problem with the Zoom mode being over-zoomed to the point that on 4:3 letterboxed material the station bug is barely visible. It's not that I want to see the bug :nono2: but it's a good static indicator of how much of the picture has been lost.

Send your description and link to your photos to [email protected]. The team is pretty responsive and, while I doubt they have anthing to do with the 921's on-going development, perhaps they can be enlisted as an "official" voice also saying this is not the way to display a picture.


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## dishbacker (Jun 15, 2004)

Here is something I found in the avsforum for the dallas local markets:

http://www.avsforum.com/avs-vb/showthread.php?postid=5077480#post5077480

To see the fox bug, you have to have the overscan set to 0....


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## invaliduser88 (Apr 23, 2002)

I haven't seen it as bad as that, but I did have to go into the maintenance menu and adjust the overscan on my mitsubishi.

One question, who do you have the TV type set to 4x3 #1?


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## Rovingbar (Jan 25, 2005)

Dishbacker, I knew Fox sets their bug righ at the edge of the broadcast, so I didn't really worry about it for a long while. I figured it was an overscan issue until I saw the entire logo on the Menu-6-9 screen. Then I started suspecting it was something in the signal processing, and not overscan. 


invaliduser88, normally I set HD to 1080i in 16x9 screen size. (For SD I use 480p and 4x3 #1). I've experimented with both the 4x3 TV types for HD. I get the same fit with 4x3 #1 in STRETCH display mode, and 4x3 #2 in NORMAL display mode. All three TV types have the same amount of screen cropping when I get the correct geometry, so it really doesn't matter which one I use.

Jeff


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## invaliduser88 (Apr 23, 2002)

You know what. I think your Fox station is just broadcasting the SD feed on their HD channel.

When I watch 24 in HD on the Houston Fox station, the Fox bug is positioned on the screen such that if you overlayed the 4x3 box on the HD image you would have the Fox bug right in the lower righthand corner of the 4x3 box. Then the local Fox Station (26) puts it's bug in the lower right hand corner of the 16x9 box.


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## Rovingbar (Jan 25, 2005)

Hmmm... I'll have to add the local analog signal so I can check that. Although I am pretty sure that the feed is not simply zoomed and croped. If it were, the Guide PIP would also be cropped. And the geometry is correct so the image is not stretched.

So you have 2 bugs running around on your 24! Someone should call the agency to exterminate at least one of them.  BTW, I think the local stations add the bug. We used to have multiple feeds for some of our syndicated channels, and the bug would vary slightly.


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## dishbacker (Jun 15, 2004)

Rovingbar, you might be on to something here... I need to look at it further, but was setting up a timer this morning for the masters coverage this afternoon and had on channel 8 SAT-SD. When watching the channel, the crawl going across the bottom of the newscast was right up against the bottom of my Sony LCD RPTV. When I went to the guide to setup my timer, there was significant black space at the bottom of the picture.

I have my output settings similar to yours, 1080i with 16x9 display type. Maybe conversion to 1080i is cutting off the bottom portion of the picture?

Definitely something that should warrant some investigation. Mark/Allen, have you noticed any of this?


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## Mark Lamutt (Mar 24, 2002)

I've been following this thread (well, loosely anyway), and I'm convinced that Rovingbar's problem is mostly one of overscan on his television, and very slightly what is being output by the 921. Fox places their HD logo (which is different than their SD logo) outside of the HD safe zone (the outside 5% of the picture). Sets with 0% overscan see the entire logo. Sets with 5% overscan see very little of the logo. My Sony RPTV falls in the middle - I see more of the logo that RB does, but I don't see the entire things either, and my Sony is set to about 4% overscan. I'd say RB's set is around 8%-10% overscanned right now just based on the pictures.

That's my opinion.


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## invaliduser88 (Apr 23, 2002)

I'll post a screen capture of a fox hd broadcast in Houston to compare to.


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## Rovingbar (Jan 25, 2005)

*Update:* I spent a lot of time working on overscan. It turns out that my TV has different geometry settings for 480p and 1080i. I had been judging overscan with my Avia disk in 480p, so it looked good (~4%) I guess the 1080i overscan was 5-8% or more. I've reduced it quite a bit. The logo is still cut-off, but it is not as bad. I'll try to post pictures when we get our camera back.

Thanks,
Jeff


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