[mythtv-users] tv-out quality problems

[Michael Bochynski]

On Mon, 2005-10-24 at 18:56 +0100, Nick wrote: 

> On 24/10/05, Michael Bochynski <mbochynski at audiumcorp.com> wrote:
> >  Hi All,
> >
> >  My setup is as follows - cable box, LeadTek WinFast TV Deluxe as tuner and
> > ATI Radeon 8500 as TV-Out.
> >
> >  However, My mythtv TV_OUT is significantly worse in terms of picture
> > quality than a direct cable out to TV. My question is whether it is due to
> > ATI card, not fully supported under Linux, or TV tuner, which does software
> > encoding?
> 
> I'm using ATI 9100IGP Radeon on-board video with no problems. Have you
> tried your card using the official drivers and also tried the GATOS
> OSS drivers? The cut-off for support of ATI cards in the official
> drivers is the Radeon 8500, so you should be OK. It's therefore likely
> you need to do some more tweaking (are you using S-Video to connect to
> the TV?).


I downloaded official ATI drivers most recently. Since without those
drivers I didn't have TV-OUT at all, I think my card is supported :)
BTW, I don't have monitor at all, my kudos to VNC ! I use MythTV as DVR
only, not as a linux box do do "stuff" and MythTV. It will be MythTV
only.

And yes, I am using s-video out, however not to TV, but to receiver. I
set up dual outs from my cable box. One directly to receiver and one to
mythtv->receiver. I was switching inputs on receiver to compare the
quality of TV using the same video source. The ranking is as follows,
form the best to the worst:

1. cable box
2. tv viewing program on Linux
3. myth tv

Note that while there is a giant difference between 1 and 2/3, the
difference bet 2 and 3 is small. Which leads me to believe that this si
more of ATI issue than mythTV.

Tweaking where? in MythTV? ATI Support Panel does not offer a lot of
options, besides positioning of the image, which doesn't help :) X
config files? 

> 
> >  I want to replace one of those components, by my question is whether it
> > makes more sense to get PVR-350 (I don't need dual tuners of 500, since I
> > use cable box)  or nice NVIDIA graphics card for better support for linux?
> 
> If you find you have a supported ATI card, I'd keep that, unless
> you're using some very low powered machine. I first got my PVR-350 and
> started using its beautiful TV out before ATI had fixed their drivers
> to get TV-out running on my Radeon 9100s. Once that support had
> stabilised, I've been using the ATI for TV-out via S-Video and have
> not looked back yet. The accelerated X driver for the 350 has come on
> in leaps and bounds, but still doesn't offer the range of tweaking
> that the regular ATI driver does, nor OpenGL support (the 9100 doesn't
> have 3D support unfortunately)


Does OpenGL matters for MythTV? As I mentioned earlier, this box is/will
be only DVR box. I do not plan do do anything on it. Maybe a little bit
of server side things, such as apache/php services, which need console
access only. 

> 
> In terms of watching standard def TV, the PVR-350 wins hands down
> against my ATI card (the difference is noticeable). However, for the
> extra functionality the ATI card provides in terms of MythVideo etc,
> and future HDTV support, I'd recommend exhausting this option first.
> I'm still happy to have my PVR-350 though, aside from a great encoder,
> the TV-Out is brilliant when required.


Yeah, that's what I am looking for brilliant TV-Out. As I mentioned in
my other response, I do not care about HDTV at this point, since I do
not plan to have it in the next 6 - 12 months. However, I do plan to
watch TV and use my MythTV box ...


> Nick


Michael
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