[mythtv-users] OT - MX4000 to FX5200

Kevin Kuphal kuphal at dls.net
Thu May 4 11:18:44 EDT 2006


Brad Fuller wrote:
> Brian Wood wrote:
>   
>> On May 4, 2006, at 8:46 AM, Kevin Kuphal wrote:
>>
>>   
>>     
>>> Brad Fuller wrote:
>>>     
>>>       
>>>> I'm going to swap out the cable. The first thing I thought of when  
>>>> the
>>>> B&W popped up was that since the MX4000 works and the FX5200 doesn't,
>>>> maybe the S-Video out voltage level is flaky and maybe at the edge.
>>>> Since I'm running a long cable (10ft of S-Video going to a
>>>> S-Video<->Composite converter and about 20ft of RG6) that maybe it's
>>>> just not making it somehow. I realize that this is no where near the
>>>> length limit, but what the heck.
>>>>
>>>>       
>>>>         
>>> If you're plugging the S-VIDEO output into a Composite input you  
>>> need to
>>> change the TV-OUT format line in your xorg.conf from "S-VIDEO" to
>>> "COMPOSITE".  That controls the color signalling that the card sends,
>>> not the type of connector that it uses.  Having this set wrong will
>>> result in B&W picture.
>>>     
>>>       
>> Depends on what type of "converter" he is using, but I agree this is  
>> the root of the problem.
>>
>> Be aware that the adapter supplied with nVidia cards is *not* a  
>> converter, it is simply ti allow you to access the composite signal  
>> from the S-Video-type connector.
>>
>> But like I said, if his target is a composite input, there is no  
>> reason to fool with S-Video at all.
>>   
>>     
> The only difference between composite and S-Video is that luminance and
> chroma are separated on S-Video.
> Unless the driver can tell the video board to combine Y and C and send
> it out on a single pin (and indicate what pin it's sending the combined
> signal on) then signifying "SVIDEO" or "COMPOSITE" in xorg.conf works
> equally. I doubt that there is any difference between using "SVIDEO" or
> "COMPOSITE" on a board that has only SVIDEO out.
>
> Do you have a different explanation?
>   
I don't have an explanation other than that it works.  I have more than 
one nvidia board with only S-VIDEO out where if I do not set the tv-out 
format to COMPOSITE, I get a B&W signal when using an s-video to 
composite cable connected to it.

Kevin


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