[mythtv-users] moving tear line on HD image [was: Just let my TV de-interlace]

Brad DerManouelian myth at dermanouelian.com
Tue Oct 28 01:02:11 UTC 2008


On Oct 27, 2008, at 5:47 PM, Florin Andrei wrote:

> Brad DerManouelian wrote:
>> On Oct 27, 2008, at 3:58 PM, Florin Andrei wrote:
>>> case. I currently use 1080p for everything (it's fixed resolution
>>> for my
>>> myth system, and mythfrontend does all the scaling and  
>>> deinterlacing),
>>> and there's a tiny tear line that descends slowly over the screen,  
>>> and
>>> then there's a small jump (a single frame is maybe either lost or
>>> doubled, I'm not sure which) when the tear line reaches bottom. The
>>> jump
>>> occurs approx once every 30 seconds or so.
>>
>> Try a different connection. My PS3 did this over HDMI with 1080p and
>> stopped when I switched to 1080i. The my MythTV box did this with
>> 1080p over HDMI and doesn't any more now that I use DVI.
>
> You mean, a different type of input on the TV? OK, I guess I can try  
> it,
> but I can't imagine the reason why it should be so. The tear seems  
> like
> a small problem with the scan frequency of the source (or something  
> like
> that), but I totally wouldn't expect a high-quality player like the  
> PS3
> to exhibit problems of this sort.
> Did you just switch to the DVI input on the TV? Or did you use a
> DVI-to-HDMI adapter for MythTV?

The first HDMI standards did not accept 1080p throughput.
http://reviews.cnet.com/4520-11246_7-6388574-1.html

> By the way, there's a PS3 hooked up over HDMI to my TV, it's set to
> 1080p and it works very well.

My PS3 would black out for a couple of seconds when playing high- 
motion games (like a driving game) over HDMI 1080p. I believe this was  
fixed in an update.

> I have HDMI, component and VGA inputs on my TV, and the MythTV
> motherboard has HDMI and VGA outputs. The TV does not accept true HD
> signal (1080p, etc.) on VGA. So currently I must use HDMI (I keep VGA
> active and hooked up as well, as a secondary screen of different
> resolution, for quick troubleshooting in case HDMI goes bananas).
>
> I may install a separate graphics card on the myth appliance pretty
> soon, maybe with a DVI output, and try a DVI-to-HDMI adapter, but  
> isn't
> that "cheating"? (I mean, it's still the HDMI input on the TV)
> Or maybe a card with component out, I know there are some cards like
> that out there.
> Maybe just using a different graphics chip on the myth appliance will
> make a difference.
>
> I appreciate the tip, but it worries me a little. It seems to indicate
> this whole "HD from PC to TV" thing is somewhat of a crapshoot.

Your problem could also be due to a sub-standard HDMI cable. A more  
expensive cable just might do the trick for you.

-Brad



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