[mythtv-users] Best way to Send Video via DVI

[George Mari]

Nathan A. Smith wrote:
> On Sun, 2007-12-23 at 20:07 -0600, George Mari wrote:
>> Nathan A. Smith wrote:
>>> Hi,
>>>
>>> I am trying to tweek my mythbox to get 2 problems solved....
>>>
>> [deleted]
>>
>>> 2. While all the tv shows (both HD & SD) display pretty close to correct
>>> -- I can't get any other screen to fill my Mitushbishi TV fully.  This
>>> is partially the TV's fault, to see the problem see this pdf file (page
>>> 78). 
>>>
>>> http://download.jazel.net/misc/filecache/0b/0b6d644186a1fc48fe0f8d84d3ad4b36_V33(631-731)%20OG.pdf
>>>
>>> Does anyone know how to over come that?
>>>
>> [deleted]
>>
>> You may want to try a DVI-to-HDMI adapter if you do not get satisfactory 
>> results with your DVI input.  I don't have your model TV, but I do have 
>> a Mitsubishi LCD panel, and says the same thing in my manual as in yours 
>> - don't connect a computer to the HDMI input.  I tried it anyway, for a 
>> while, and it worked just fine - TV did not blow up, etc.  It did 
>> overscan the image a bit, so the edges of the MythTV menus were off the 
>> screen on all 4 sides, but it was certainly usable.  This may fill the 
>> screen in your case, with your particular TV.
>>
>> I switched it back to DVI after a few days, though, as the HDMI input 
>> did not produce improved interlaced output as I was hoping.
> Hmmm...
> 
> So If I read you correctly, there isn't a really good way to get a
> picture that fits right for both TV & Computer images?  

I'm just saying that the problem might be with your particular TV.  :-(

 From what I read in your TV's manual, a 720P or 1080P resolution sent 
to the TV on it's DVI port will not fill the entire screen.  That's what 
I saw on page 78 that you pointed to.

My TV has a similar chart as yours, but it shows the image filling the 
entire screen when using a 720P or 1080P resolution over DVI, where 
yours does not.

If in fact, this is how it appears to you when you use that resolution, 
i.e., your image doesn't fill the entire screen, what I was trying to 
explain was that most modern TV's seem to treat a signal coming into one 
of its HDMI ports as a "television" signal, and not a "computer" signal, 
and will usually fill the entire screen with a 720P or 1080I/P signal, 
where it may not fill the screen on it's DVI port.  So, if you really 
want to have it fill the whole screen, you can buy a DVI-HDMI adapter 
and see if that does the trick, and fills your screen with the image 
coming from your computer.

 > I see you ended
> up with DVI - why did you switch back if both were of equal image
> quality?  

On my TV, the image over DVI was not overscanned, whereas on HDMI, it 
was overscanned, so I could not see the very edges of the MythTV menus. 
  The recordings were fine during playback over HDMI - no difference in 
quality, and I didn't really notice the overscan - it wasn't too much. 
But for me it was more important to see the entire menu.

I could have looked up how to change the overscan via the TV's service 
menu, or adjust the mythfrontend GUI width and height, but I just didn't 
feel like doing that.

Plus, as I mentioned, the real reason I experimented with HDMI was to 
see if I could get the TV to do the de-interlacing for playback. 
(Didn't work - later on discovered it's mostly an issue with Nvidia's 
drivers.)

> Just trying to figure out if it's a good bet to go and buy a
> new connector.
> 

I think the DVI-HDMI adapter cost me about US$25.  I guess it depends on 
how badly you want your image to fill your screen.

Good luck.