[mythtv-users] OT - MX4000 to FX5200

[Brad Fuller]

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?