[mythtv-users] deinterlacing and non-smooth playback at 1080i

Mark Kendall mark.kendall at gmail.com
Wed May 23 07:56:43 UTC 2007

On 5/22/07, Seth Daniel <mythtv.org at sethdaniel.org> wrote:
> I'd expect it not to work.  All the evidence I've gathered from reading
> nvnews has led me to believe that the nvidia driver (since at least the
> 9xxx version) is broken for 1080i output with a 1080i source.  Hey, I
> hope I'm wrong and you can tell me what the heck is going on.
> > This will probably sound like a really stupid question - but are you
> > sure your tv is displaying at 1080i? Can you post your full xorg.conf
> > and the xorg.0.log.
> Sure I'm sure. :o)  I have a number of devices that require a switch
> (generally on the back of the device) to be set to 1080i/720p/480p/480i.
> If you get it wrong it doesn't work.  And you can tell when it's set at
> 1080i.  When I watch a station that broadcasts at 1080i and I'm using my
> Saumsung OTA receiver it looks wonderful.  When I'm using Myth it looks
> less wonderful b/c I'm watching it at 720p and the scaled down 1080i
> doesn't look nearly so good (if I set the same receiver to 720p I get the
> same 'scaled down' shimmering and jagginess etc... that I get with myth).


Impossible to tell for sure, but my guess is that the custom modeline
that you are using to compensate for the broken interlaced output in
the 9 series drivers is having other side effects. The fact that it is
picked up as a 30Hz output in xorg.0.log suggests you are effectively
halving the datarate somewhere to compensate for the line doubling the
driver is delivering by default. Your tv is probably only getting one
field or something to that effect.

Your best bet is probably to try and get 8776 installed. Xvideo should
work if you disable xvideo sync to vblank.



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