[mythtv-users] Deinterlace stopped working in latest SVN trunk

[Brad Templeton]

On Thu, May 31, 2007 at 03:17:11PM +1000, Matt Doran wrote:
> 
> Brad Templeton wrote:
> > On Wed, May 30, 2007 at 05:21:38PM +1000, Matt Doran wrote:
> >   
> >> Brad Templeton wrote:
> >>     
> >>> I decided to upgrade to the lastest SVN trunk after about 6 months
> >>> from the last one (also a .21 but protocol 32) and now I find
> >>> my deinterlace is not operating, no matter whether I set it to bob,
> >>> linear blend or kernel.   It was bob before and worked.  No error message
> >>> (on the system in question) about not having enough framerate for bob,
> >>> or any other diagnostic.
> >>>
> >>> This is on 1080i content being sent to a 720p screen.
> >>>
> >>> Don't see anything about deinterlace in the change logs -- did something
> >>> change recently regarding this?
> >>> _______________________________________________
> >>>
> >>>   
> >>>       
> >> I recently got this working.  It's a bit tricky.  I don't know what has 
> >> changed, because I've only tried to get bob working since using trunk.
> >>
> >> It's worth running your frontend with verbose playback logging (e.g. 
> >> mythfrontend -v playback).  This should give you information about why 
> >> bob deinterlacing isn't working.
> >>     
> >
> > It's all deinterlacing.   Debug tracks indicate Myth is getting
> > confused by the streams (which I think are ordinary) and deciding
> > there are progressive frames in the middle and turns off the deinterlacer.
> >
> >
> >   
> I wonder if this is telecining.  I'm not expert, but when I had a DVD 
> that was incorrectly detecting progressive scan, someone suggested 
> adding the inverse telecine filter.  I'm not sure if this happens in 
> broadcasts, but you can give it a try.  
> 
> Just add "ivtc" to your custom filters in Setup->TV->Playback.

Alas, no joy.   The Chicago recording seems particularly bad.  Some
recordings are not doing it at all (SNL for example) while others do it
to differing degrees.  (Most of my 1080i are from NBC)  No sign of it
on a cbs program though.

Even a year old NBC program has these constant disablings of deinterlace.

So it is something about how NBC is encoding the programs that is
confusing Myth.  I don't think they would send actual 1080 line progressive
frames in the stream -- that would confuse most TVs.