HD100/HD200 Overscan Poll

[Taddeusz]

How many people out there in SageTV land have their TV's adding overscan to their HD100/HD200 video but have no option to disable it?

I am one who does. I have an Insignia 42" 1080p HDTV. Before I had my HD200 they made a firmware change to the HD100 which forces YUV HDMI output if your TV supports it. Otherwise it defaults to RGB output (more like a computer). The problem with this is that some TV's, notably mine, automatically apply overscan to a YUV input. The menus on my TV provide no way of disabling overscan. The HD100/HD200 provides no way of manually selecting YUV or RGB output, unlike my HDMI capable DVD player.

So I'm stuck between a TV that can't disable overscan and a media extender that I can't manually select RGB output on. I've contacted SageTV support and they don't feel the need to move on this very quickly because they say it's a problem with my TV and not with the HD200. I just want to get some feedback and find out how many people out there have the same problem. If you're not sure you should check it out. You may find you have the same problem.

[stanger89]

What's the problem? You can adjust the menus to fit any amount of overscan quite easily.

[gplasky]

I guess I'm not understanding the problem either. I use the HD200 menu to set the overscan for SageTV. After that my picture goes right up to the edge of the panel. I can set it to over or under the size of the actual screen. Whatever overscan my TV provides I can still adjust it with the Sage menu. I was able to have a full picture with hardly any overscan on both the HD100 that was connected and the HD200 that is currently connected to my HDTV.

Gerry

[Taddeusz]

This has nothing to do with menu overscan. This has to do with my TV cutting off the outside of the picture.

I would rather not have any overscan. When the HD100 and HD200 boot and detect that HDMI is connected they poll the device for display modes. If the device reports that it is capable of YUV video output it starts in that mode, otherwise it starts in RGB mode. The issue at hand is that different HDTV's may or may not treat YUV and RGB video the same. My TV does not. If it receives RGB video it assumes the source is like a computer and fits the video to the screen. However, if it receives YUV video it assumes that it is a television video source and automatically applies overscan to it. This wouldn't be a problem if the TV provided a way to enable/disable overscan but no such thing is available.

The result is that I can neither manually select the HD200 to output RGB or disable overscan through my TV. So I'm stuck with undesirable overscan that can not be changed due to lack of adjust-ability on both ends.

[festus]

Both my Panasonic V10 series plasma and cheap Panasonic LCD allow me to eliminate overscan for true 1:1 on source material. SageTV overscan settings only affect UI positioning, so overscanning can be doing unnecessary work to scale the image, reducing quality in the picture. For example, taking the center portion of a 1080p signal and scaling it to the 1080p screen.

[_Demo_]

Originally Posted by Taddeusz

How many people out there in SageTV land have their TV's adding overscan to their HD100/HD200 video but have no option to disable it?

I am one who does. I have an Insignia 42" 1080p HDTV. Before I had my HD200 they made a firmware change to the HD100 which forces YUV HDMI output if your TV supports it. Otherwise it defaults to RGB output (more like a computer). The problem with this is that some TV's, notably mine, automatically apply overscan to a YUV input. The menus on my TV provide no way of disabling overscan. The HD100/HD200 provides no way of manually selecting YUV or RGB output, unlike my HDMI capable DVD player.

So I'm stuck between a TV that can't disable overscan and a media extender that I can't manually select RGB output on. I've contacted SageTV support and they don't feel the need to move on this very quickly because they say it's a problem with my TV and not with the HD200. I just want to get some feedback and find out how many people out there have the same problem. If you're not sure you should check it out. You may find you have the same problem.

If you don't mind using a custom resolution I'll see if it we can add a forcergb flag.

_Demo_

[Taddeusz]

Originally Posted by _Demo_

If you don't mind using a custom resolution I'll see if it we can add a forcergb flag.

_Demo_

That would be acceptable for a short term solution. A selection in the GUI would be better for long term.

Last year I had been going back and forth on this with support for over a month after I noticed a display change from my HD100. The only reason I ever figured out what was causing my issue was because I have an HDMI capable DVD player that I just happened to be messing around with in the menu options at the time. I discovered that it has a selection for RGB or YUV HDMI output. After playing with that setting I noticed what was going on with the overscan on my HDTV and correlated that with my HD100. That's when I was told that a change was made to the firmware to automatically select YUV if it were available on the display device.

I realize YUV gives better color quality but I'd rather not have the overscan and I can't afford to buy a new TV right now.

[Fuzzy]

The thing to realize is, the overscan is SUPPOSED to be there. It seems you are wanting sage to scale the image to fit within the visible portion of your screen. (or, alternativly output "RGB mode" to trick the TV into doing this scaling for you). This would cause a loss of video information, and sharpness, and would NOT be ideal. You are much better off running the video at native resolution of your display (which would be partially outside the visible range), which would reduce in NO scaling of the image, and viewing of the image as it was originally intended.

[razrsharpe]

Originally Posted by Taddeusz

That would be acceptable for a short term solution. A selection in the GUI would be better for long term.

once you have the custom resolution defined you can use my Video Out Tools for the HD100/200 to switch between resolutions while playing a video.

[Taddeusz]

Originally Posted by Fuzzy

The thing to realize is, the overscan is SUPPOSED to be there. It seems you are wanting sage to scale the image to fit within the visible portion of your screen. (or, alternativly output "RGB mode" to trick the TV into doing this scaling for you). This would cause a loss of video information, and sharpness, and would NOT be ideal. You are much better off running the video at native resolution of your display (which would be partially outside the visible range), which would reduce in NO scaling of the image, and viewing of the image as it was originally intended.

No, that's not it at all. What I really want is for my TV to NOT apply overscan so I don't lose the outside edge of the image. SageTV isn't doing anything to the image but sending it to the TV. But I didn't really have a choice in the matter as I won the TV in a contest.

This doesn't really matter for TV broadcasts that are assumed to have overscan applied as the graphics are usually away from the edges of the screen and there is often CC garbage on the top edge when SD broadcasts are being inserted into HD.

But for Blu-ray sources the video would be better served if it didn't have overscan applied. As the 1080p source would fit the 1080p resolution of my screen. That is how the image was intended to be viewed. Not being chopped, no matter how little, on the edges.

[Taddeusz]

Originally Posted by razrsharpe

once you have the custom resolution defined you can use my Video Out Tools for the HD100/200 to switch between resolutions while playing a video.

That would be handy as I'd actually prefer to watch TV broadcasts with overscan but everything else without.

[Fuzzy]

My point was that you do NOT have 1920x1080 VISIBLE pixels on your screen. So making the image fit within the visible portion would NOT be 1:1 pixel mapping, and WOULD result in scaling. The tv is not 'applying overscan' to anything, it is simply painting a 1920x1080 image on it's 1920x1080 array (you just can't see all of the array - which is by design, and part of the 1080p specs).

[Taddeusz]

Originally Posted by Fuzzy

My point was that you do NOT have 1920x1080 VISIBLE pixels on your screen. So making the image fit within the visible portion would NOT be 1:1 pixel mapping, and WOULD result in scaling. The tv is not 'applying overscan' to anything, it is simply painting a 1920x1080 image on it's 1920x1080 array (you just can't see all of the array - which is by design, and part of the 1080p specs).

Then that's false advertising. A screen that is advertised as having a vertical resolution of 1080 lines better dang well have 1080 lines. I've hooked a computer up to my TV and run it at 1920x1080 and it displays quite sharply with 1:1 pixel mapping. And, BTW, 1:1 pixel mapping means that the image fits the display without overscan.

If you show me some sources I might believe you but right now what you say is just hogwash and doesn't make any sense.

[Fuzzy]

1:1 pixel mapping does NOT mean the image fits the screen perfectly. 1:1 mapping means that one pixel of the computer desktop shows as one pixel on the display. HD Guidelines recommend at least a 3.5% overscan, meaning of the 1920x1080 screen, you can expect to be able to see 1852x1042, though even that much isn't guaranteed. This is there to ENSURE you don't see the edge of the video, which, in older transmission systems, included blanking info, and sometimes embedded data (CC, Teletext, Datacasting). Newer systems, this would be edge compression artifacts in the digital stream. Either way, accept that it is there, and will remain an industry standard. This is the reason any self-respecting video camera contains 'safe area' boundaries in the viewfinder, so you know where to keep the action to prevent it from being shown in overscan.

To test what your set is doing, connect your PC in 1920x1080 mode, and use the attacted BMP as your desktop background, in tile mode. Looking closely, you should be able to see the alternating white and black pixels. If instead, the background is a even gray, or shows moirre lines, then your image is being scaled, and you are NOT showing 1:1 mapping. (my guess is, if you are set at a 1920x1080 desktop resolution, and can see the edges of the desktop, you are NOT 1:1).

[cncb]

Originally Posted by Fuzzy

My point was that you do NOT have 1920x1080 VISIBLE pixels on your screen. So making the image fit within the visible portion would NOT be 1:1 pixel mapping, and WOULD result in scaling. The tv is not 'applying overscan' to anything, it is simply painting a 1920x1080 image on it's 1920x1080 array (you just can't see all of the array - which is by design, and part of the 1080p specs).

According to this Engadget article the tv crops the overscan area and then scales it up to fit the 1080p resolution of the display.

[Taddeusz]

Ok, regardess of whether the image is really 1:1 pixel mapped, a 1080p display should be able to display 1080 lines of resolution edge to edge. Period.

As I said before, I have no problem with TV broadcasts being overscanned. They are supposed to be. But films are not meant to be overscanned, they should be displayed edge-to-edge.

[GKusnick]

Originally Posted by Taddeusz

But films are not meant to be overscanned, they should be displayed edge-to-edge.

Not sure I really want to get in the middle of this, but if you look carefully the next time you're at the movies, you'll see that the image is typically projected slightly larger than the screen, spilling over a bit into the black border to ensure that the entire white reflective area is filled.

[Fuzzy]

And action is still kept well within the 'safe zones' in any cinematic piece. They simply HAVE to work with an overscan region, because of the many variances between theaters, projection angles, etc.

[Taddeusz]

Anyway, this has gotten a bit off topic. Suffice it to say I would prefer there be no overscan in certain situations. The only way that can be accomplished with my TV is for the HD200 to output an RGB signal.

[Taddeusz]

Just thought I'd add that the latest beta update for the HD200 added an option to the custom resolutions. Adding something like this:

1920x1080p@59.94RGB|standard=HDMI_1080p59|forcergb

will force the HD200 into RGB mode at 1080p. Adjusting the overscan I noticed that my TV was cutting off approximately 2in on the top and bottom and 3in on the sides on a 42in TV.