[mythtv-users] Fuzz in my video output

[Brian Wood]

On Jun 19, 2006, at 2:34 PM, Nathan Smith wrote:

> On Mon, 19 Jun 2006, Brian Wood wrote:
>
>>
>> On Jun 19, 2006, at 2:01 PM, Nathan Smith wrote:
>>
>>> Hey list,
>>>
>>> When I view TV (it is a QAM signal) in MythTV, at the top of the
>>> screen
>>> there is a thin line of noise (it's about half an inch wide and
>>> covers the
>>> entire top part of the screen, and it looks almost like a static
>>> channel
>>> on a TV), and no configuration options that I've tried can get rid
>>> of it.
>>> If I record shows, the noise even shows up on the recorded version.
>>> The
>>> rest of the TV signal looks great, and channel browsing works
>>> perfectly
>>> (the noise also shows up on every channel).
>>>
>>> I'm using an HD-5500 with the 2.6.16.20 kernel running Ubuntu 6.06/
>>> AMD64.
>>>
>>> Any ideas?
>>
>> Just guessing, but:
>>
>> It's probably being transmitted intentionally, it is data, in the
>> digital equivalent of the vertical blanking interval.
>>
>> Usually most TVs overscan just a bit to prevent this showing up in
>> the picture.
>
> I'm viewing this on my monitor (Dell 24 inch 2405FPW LCD).. have  
> you heard
> of it happening on monitors as well?


Especially on monitors, because they normally do not overscan at all.

I think Myth has some overscan settings in it, I'm not by my machine  
at the moment and so can't check.

But I want to be sure this is what the problem is, I've never watched  
QAM channels enough to notice if there is usually a bunch of data at  
the top.

Can anybody else confirm this ? The description certainly sounds like  
what data would look like in that position.