HDTV - HDMI audio Issues and grainy/cropped image
I have seen so many threads all over the net discussing this, so I have attempted to complile here.


HDTV monitors have an issue with the electronic display idendification data [url="http://en.wikipedia.org/wiki/Extended_display_identification_data"](EDID)[/url] which leads to:

Bad image quality when connected via a HDMI/DVI cable and/or problems setting the correct resolution called [url="http://en.wikipedia.org/wiki/Overscan"]overscan[/url].


My research leads me to think the problem comes from Microsoft demanding certain settings in the EDID of HDTV monitors (I think to avoid copying).

[url="http://us.download.nvidia.com/Windows/260.99/260.99_Win7_WinVista_Desktop_Release_Notes.pdf"]Page 31 Nvidia 260.99 release notes[/url]
[quote]However, Microsoft requires that certain TV/HDTV modes be available for all digital
displays, including DVI and HDMI, even if they are not HDTV.
[/quote]

The problems could be resolved by monitor consructors (if they are permitted by Microsoft), or possibly by the video card drivers.

Anyway the results of days of research/surfing:

This is a known problem which has been around for a long time.

Using an HDTV plugged in with a DVI/HDMI cable, the monitors do not communicate as a monitor but as a TV leading to a grainy image, although I've read some monitors have a [url="http://forums.nvidia.com/index.php?showtopic=189529"]1:1 pixel setting that forces the issue.[/url]

If you use a VGA/D-Sub connection you will get a cropped/overscanned image, [url="http://forums.nvidia.com/index.php?showtopic=184286"]discussed here[/url].

The fact that using HDMI cables also carries audio seems a [url="http://forums.nvidia.com/index.php?showtopic=189704&st=0&p=1170727&hl=HDMI%20grainy%20&fromsearch=1&#entry1170727"]problem for some too[/url].

[url="http://forums.nvidia.com/index.php?showtopic=99932"]Illustrated guide: getting back analog audio input on the TV with a HDMI PC-to-TV connection - NVIDIA Forums[/url]

The problems stem from the EDID in the monitors which tell the computer info about the monitor.

While I have been trying to repair this problem on my monitor I have found these workrounds, none of which I have managed to make work for me. [u]DO NOT TRY AN EDID MOD IF IT'S NOT FOR YOUR MONITOR MAKE AND MODEL[/u]


[url="http://vip.asus.com/forum/view.aspx?board_id=13&model=24T1E&id=20100504050118781&page=1&SLanguage=en-us"]Asus thread relative to MY monitor 24T1E.[/url]

[url="http://www.overclock.net/nvidia/332266-9800-gx2-hdmi-display-issue-fix.html"]9800 gx2 HDMI display issue Fix - Overclock.net - Overclocking.net[/url]

[url="http://forums.nvidia.com/index.php?showtopic=58483&st=0"]Discussing changing EDID to sort out both issues[/url]

[url="http://forums.nvidia.com/index.php?showtopic=184286"]Resolution problems on latest Nvidia driver (260.99)[/url]

[url="http://us.download.nvidia.com/Windows/260.99/260.99_Win7_WinVista_Desktop_Release_Notes.pdf"]From 260.99 changelog page 31[/url]

[quote]Flat Panel Scaling Controls are Non-functional for Some TV
Modes for Some Displays
The NVIDIA Control Panel flat panel scaling controls on the ʺAdjust Desktop Size &
Positionʺ page are not intended to be used for TV modes, and normally the controls are
not available for TV or HDTV displays.
However, Microsoft requires that certain TV/HDTV modes be available for all digital
displays, including DVI and HDMI, even if they are not HDTV.
While the NVIDIA flat panel scaling controls are available for those displays, they will
not be functional for the TV modes that appear in compliance with the Microsoft
requierements. The affected modes are as follows:
 1920x1080i @50/59.94/60 Hz
 1280x720p @50/59.94/60 Hz
Release 260 Graphics Drivers for Windows - Version 260.99 RN-W26099-01v01 | 32
Known Product Limitations
 720x480p @ 59.94/60 Hz
 720x576p @ 50 Hz
[/quote]


Conclusions:

Nvidia are aware and working on this.

This problem is EDID based....

This problem could be from from a variety of sources:

Microsoft requirements obliging certain EDID settings by manufacturers
VGA drivers unadapted to this problem

In the meantime don't buy a HDTV and wait nicely for a fix....
I have seen so many threads all over the net discussing this, so I have attempted to complile here.





HDTV monitors have an issue with the electronic display idendification data (EDID) which leads to:



Bad image quality when connected via a HDMI/DVI cable and/or problems setting the correct resolution called overscan.





My research leads me to think the problem comes from Microsoft demanding certain settings in the EDID of HDTV monitors (I think to avoid copying).



Page 31 Nvidia 260.99 release notes

However, Microsoft requires that certain TV/HDTV modes be available for all digital

displays, including DVI and HDMI, even if they are not HDTV.





The problems could be resolved by monitor consructors (if they are permitted by Microsoft), or possibly by the video card drivers.



Anyway the results of days of research/surfing:



This is a known problem which has been around for a long time.



Using an HDTV plugged in with a DVI/HDMI cable, the monitors do not communicate as a monitor but as a TV leading to a grainy image, although I've read some monitors have a 1:1 pixel setting that forces the issue.



If you use a VGA/D-Sub connection you will get a cropped/overscanned image, discussed here.



The fact that using HDMI cables also carries audio seems a problem for some too.



Illustrated guide: getting back analog audio input on the TV with a HDMI PC-to-TV connection - NVIDIA Forums



The problems stem from the EDID in the monitors which tell the computer info about the monitor.



While I have been trying to repair this problem on my monitor I have found these workrounds, none of which I have managed to make work for me. DO NOT TRY AN EDID MOD IF IT'S NOT FOR YOUR MONITOR MAKE AND MODEL





Asus thread relative to MY monitor 24T1E.



9800 gx2 HDMI display issue Fix - Overclock.net - Overclocking.net



Discussing changing EDID to sort out both issues



Resolution problems on latest Nvidia driver (260.99)



From 260.99 changelog page 31



Flat Panel Scaling Controls are Non-functional for Some TV

Modes for Some Displays

The NVIDIA Control Panel flat panel scaling controls on the ʺAdjust Desktop Size &

Positionʺ page are not intended to be used for TV modes, and normally the controls are

not available for TV or HDTV displays.

However, Microsoft requires that certain TV/HDTV modes be available for all digital

displays, including DVI and HDMI, even if they are not HDTV.

While the NVIDIA flat panel scaling controls are available for those displays, they will

not be functional for the TV modes that appear in compliance with the Microsoft

requierements. The affected modes are as follows:

 1920x1080i @50/59.94/60 Hz

 1280x720p @50/59.94/60 Hz

Release 260 Graphics Drivers for Windows - Version 260.99 RN-W26099-01v01 | 32

Known Product Limitations

 720x480p @ 59.94/60 Hz

 720x576p @ 50 Hz







Conclusions:



Nvidia are aware and working on this.



This problem is EDID based....



This problem could be from from a variety of sources:



Microsoft requirements obliging certain EDID settings by manufacturers

VGA drivers unadapted to this problem



In the meantime don't buy a HDTV and wait nicely for a fix....

#1
Posted 01/04/2011 09:36 AM   
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