[mythtv-users] playback not smooth regardless of source

Seth Daniel mythtv.org at sethdaniel.org
Wed Feb 28 05:54:00 UTC 2007

On Tue, Feb 27, 2007 at 05:03:25PM +0000, Mark Kendall wrote:
> On 2/27/07, Seth Daniel <mythtv.org at sethdaniel.org> wrote:
> > Isn't one of the advantages of using something like MythTV the ability
> > to 'upscale' video?  When I watch a DVD on my Zenith DVD player it can
> > upscale to 1080i.  People on this list have talked about upscaling *all*
> > of their video.  To put it mildly it would be extraordinarily
> > disappointing if I could only watch DVDs at 480p or SD at 480i.  I will
> > wonder why I even bothered to build a myth box when I could have just
> > bought a DVR.
> I wasn't necessarily assuming you'd use it on a day to day basis -
> just trying to find out what does work for you as a starting point.

Sorry, I didn't mean to be petulant.  Regardless of the conclusion I
really do appreciate you helping me out.  

> It's worth pointing out that it probably doesn't matter whether you're
> display using 480 or 720p/1080i. With the former the tv does the
> scaling, with the latter your video drivers/card do it. In fact, if
> your tv isn't 720p/1080i native resolution it will do additional
> scaling anyway (but probably OT).
> The GUI does look much better in 720p though!

You think so? :o)   I once went to a presentation put on by a fairly
well known A/V magazine/webzine where the presenter tried to convince us
of the superiority of 720p over 1080i.  I remain not entirely convinced.

> > I'll happily send over more logs.
> Can you post some using 1080i, no deinterlacing and openglvsync and
> 720p, bobdeint and openglvsync.


A few observations:

- 1080i w/o deint is awful.  No jitter as far as I can tell but other
  problems that I don't really know how to describe.

- surprisingly to me 720p with Bob seems to work w/o issue.  I recall
  watching a ripped DVD at 720p a few weeks back (before I figured out
  how to get my TV to 1080i) and it had the same jitter issues I have
  seen recently.  Now it seems to be fine.  This time I tried a ripped
  DVD and then watched some HD.  No problems in the short time I watched
  either of those.

- all tests were with openglsync enabled in the frontend.

seth / @sethdaniel.org
Q:  What's the difference between a Mac and an Etch-a-Sketch?
A:  You don't have to shake the Mac to clear the screen.

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