[mythtv-users] overscan problems with nvidia 8400 GS

[Tortise]

Hi Todd et al

I made a subsequent post agreeing with you about SD sets and clarifying that I felt the threshold should be where a TV (and 
projector - really any relevant display device) manufacturer promoted a set could display a specific resolution then I cannot see it 
any other way than the set should display that resolution - including the full pixel count, and not an overscanned version of it - 
unless they specifically and clearly made sure the consumer understood they were getting a cut down overscanned version....something 
I have yet to see, has anyone seen that - or the option to turn it off to get the full resolution and pixel count as varying recent 
sets do.  Manufacturers have recognised the problem, but too late - and not done the backward fixes I believe they should.  If it 
were a US car safety issue would it have been done?

A great reference test site is http://www.w6rz.net/ - for example "Alternating black/white 1, 2, 3 and 4 pixel strips with moving 
bar 1920x1080" namely http://www.w6rz.net/vertrezivtc.zip is a great test to see if you are getting the resolution you understood in 
a 1080i/p display - the 1 width lines should be symmetrically discernable.  Similarly the degree of overscan can be measured with 
these files.

NVIDIA probably also see the overscanning as a legacy issue in their new HD cards, however as is well noted here the legacy issues 
will last much longer, (the life of the SD sets) I agree it would be nice if NVIDIA would continue that fix, however fundamentally I 
remain of the view the TV manufacturer should have delivered what they promoted - and that has priority when they promoted certain 
capabilities.  Did NVIDIA promote overscan correction, other than creating an expectation by providing it in their older cards?

I think you do have a point about having established the overscanning correction ability then NVIDIA probably has a responsibility 
to either make it clear it no longer is provided - or to continue it.  It is not hard to confirm Windows is supported for 
overscanning correction - just download a video card manual and confirmation is in many. It is hard to see why Windows is supported 
and Linux not.  Can anyone clarify?

In relevant cases I believe consumers are well entitled to demand it from the TV manufacturers - and less so NVIDIA.  If a TV is 
still in warranty - as many are, then the consumer has an even stronger case.

I note your point about "reasonable options".  Reasonableness from NVIDIA seems to me to be a secondary consideration here in 
comparison to display manufacturer obligations they created for themselves.

I think it is reasonable that where a TV is promoted to do something - it should do it, no matter how hard it is for the 
manufacturer, they have a duty to deliver what they promote.  Surely we consumers are entitled to have it corrected?



----- Original Message ----- 
From: "Todd Volz" <todd at stir.org>
To: "Discussion about mythtv" <mythtv-users at mythtv.org>
Sent: Sunday, July 12, 2009 3:05 AM
Subject: Re: [mythtv-users] overscan problems with nvidia 8400 GS


This is all well and good, however when I was working through this problem I found that my video card can fix the overscan in 
windows, but not linux.  I have learned to live with it for the last 1+ years, but it would be nice if NVidia would have as much 
feature compatibility as possible with their windows drivers as their linux drivers.

This isn't limited to just TV displays as my Sanyo projector does the same thing through it's component inputs...

Todd

----- Original Message -----
From: "Johnny" <jarpublic at gmail.com>
To: "Discussion about mythtv" <mythtv-users at mythtv.org>
Sent: Monday, July 6, 2009 8:52:25 AM GMT -06:00 US/Canada Central
Subject: Re: [mythtv-users] overscan problems with nvidia 8400 GS

> I've been studying this for some time now as I also enjoy the overscan problem. While mythtv can fix it for mythtv it does not fix
> it for the desktop.
>
> If consumer / users lobby their retailers and higher up the chain some more appropriate and permanent fixes might come our way.
>
> The question has been asked which NVIDIA cards have the problem e.g. the 8400 has been "named" in the subject. As best I can tell
> it is not a card model problem, they all share the same "problem" but not of their making. Lets get the root of the problem fixed.
>
> I look forward to hearing comments in response to the tortise's view of things.

It is true that overscan is caused by the TV and not the video card,
however, the problem of displaying stuff from a computer on a TV is
shared by the TV and the video card. In the case of SD TVs, they were
never intended to be hooked up to a computer and so it is unreasonable
to hope for them to fix this issue. So in my opinion, if Nvidia
provides a TV out option they do have some responsiblity to help me
display stuff correctly on that TV (especially since overscan is
standard in many many TVs).

Also for most older TVs it will be more than a firmware fix. The
overscan is probably set in hardware rather than software. Also the
reason people are focusing on Nvidia is that the ability to fix
overscan was available in all of their cards for many years. It is
only recently since 8xxxx and above that the overscan setting was
removed. I imagine the hardware that supported the feature changed and
they just haven't got around the rewriting the code for the newer
hardware, because as you mentioned there are other higher priority
things to be done first. However, a friend confirmed for me that he
can adjust overscan with his 8800 on Windows. So it seems that it is
only the Linux driver that hasn't been updated with this feature. It
seems much more likely that a single video card maker will re-enable a
feature in their new cards than getting a whole myriad of TV
manufacturers to redesign their hardware and provide firmware updates
for older sets. So for those of us with this issue on our existing
sets, Nvidia providing a fix is really the only reasonable option.
_______________________________________________