[mythtv-users] Correctly behaving 576i (or 480i) from vdpau-capable chip?

Paul Gardiner lists at glidos.net
Thu Jun 3 11:51:37 UTC 2010


Paul Gardiner wrote:
> Yeechang Lee wrote:
>> Paul Gardiner <lists at glidos.net> says:
>>> Ok. I finally got 1080p50 out of my ION board, and you are right;
>>> Advanced 2X vdpau is doing a brilliant job. I'm still using IFG, but
>>> that gives just as smooth results with Myth doing the
>>> deinterlacing. Possibly it's a little better - difficult to be
>>> sure. It's certainly good enough.  I don't need better than this.
>>
>> What happens when you use Advanced 2X but disable 600Hz mode?
> 
> Didn't get a chance to try this for a while: been upgrading to 0.23
> and fiddling with various things, but tried it again last night.
> If I disable IFG (Intelligent Frame Generation - which I've been wrongly
> calling 600Hz mode) then motion is like it was on my old CRT and
> how it is on this TV from sources other than MythTv when IFG
> is disabled: motion looks generally "hardened" (sorry best word
> I could come up with to describe it) rather than fluid; objects
> blur slightly when the camera pans, rather than holding a crisp
> image; and bright detail sort of vibrates.  With IFG on, during
> a pan, it is like the object is stationary and your view is
> moving.
> 
> On the other hand, I'm very pleased with vdpau and Advanced 2X
> because, it isn't defeating the TV's IFG, and it seems
> to be giving me the best quality I've seen from SD on the TV.
> I don't seem to be seeing so much posterization any longer. And
> I seem to be seeing less artefacts from IFG - although I guess
> that could be down to the content I've watched over the last
> day or two.

I tried IFG on v IFG off with a true 50i recording. I couldn't
really see any difference. So it looks like IFG is just what
you need if you live somewhere like the UK, where they starve
channels of bandwidth and send SD in 25p rather than 50i, but
if you're getting true 50i, then you don't really need IFG.

The test was with the credits of a program I used to watch
before buying the new TV. Strangely neither IFG on or off
was quite as fluid as I remember my old CRT when driven
directly with 576i.  I still haven't found a way to trick the
ION into outputting 576i, so I can't try it on the new set.

Paul.



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