[mythtv] [mythtv-commits] Ticket #3035: 1080i source material playback results in solid blue video with Via-XvMC

R. G. Newbury newbury at mandamus.org
Wed Feb 7 03:49:33 UTC 2007

Peter Schade wrote:
> I think i readed somewhere the unichrome chipset only supports up to 
> 1024x1024. Perhaps thats the problem?
> ----- Original Message ----- 
> From: "MythTV" <mythtv at cvs.mythtv.org>
> To: <mythtv-commits at mythtv.org>
> Sent: Tuesday, February 06, 2007 10:47 PM
> Subject: Re: [mythtv-commits] Ticket #3035: 1080i source material playback 
> results in solid blue video with Via-XvMC
> #3035: 1080i source material playback results in solid blue video with 
> Via-XvMC
> --------------------------------+-------------------------------------------
>  Reporter:  midl_man at yahoo.com  |        Owner:  ijr
>      Type:  defect              |       Status:  new
>  Priority:  minor               |    Milestone:  unknown
> Component:  mythtv              |      Version:  0.20
>  Severity:  medium              |   Resolution:
> --------------------------------+-------------------------------------------
> Changes (by midl_man at yahoo.com):
>   * keywords:  => 1080i via xvmc blue
> Comment:
>  The same problem occurs when using minimyth (linpvr.org) on this hardware
>  so it's not a FC6 specific issue either.
>  If it would help, I can get provide a small 1080i source clip (although
>  even a short 5 second clip will be about 10MB).

Going from memory as I'm typing this lying in bed..

Since the OP is using via-xvmc, he has a via chipset, and that is the 

The CN400/VT6123 chipset can do 1024x1024 TV out. But most boards with 
the VT6123 such as the SP13000 only have S-video out and may not 
properly do even that. I forget what the limit of S-video is. 720x480 is 
The CN400 chipset (VGA) out can do much better. Exactly what I do not 
recall, but iirc, 1920x1080 is possible, although possibly frame rate 
I do know that the SP13000 can drive a 1920x1080 native resolution LCD 
(Dell 2407FPW..just received ..awesome!) but I have not yet figured out 
how to play my 3 bits of HD content: SD only. OTOH, I can report that 
the scaling circuitry works fine.

The VT6125 TV encoder chip is supposed to do HD levels...But so far 
there are no drivers capable of dealing with it. Openchrome is working 
on that, The CN700 series chipset may also be crippled in other ways 
too, and it is unlikely that such a board will ever do HD.

Moreover, the LVDS/DVI daughterboard available for some of the Via 
motherboards, may not reach HD resolutions either, as it does not have 
the bandwidth capability needed.

All of these facts are disclosed on the Via website. Unfortunately, not 
in any easy to find and easily comprehensible manner.

So this is an invalid myth bug. As the actress said to the drunken 
sailor, 'that's a real hardware problem'.


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