[mythtv] [mythtv-commits] Ticket #2429: Autodetect video scan is confused by 1080i recordings

Thomas Börkel thomas at boerkel.de
Thu Sep 21 05:45:43 UTC 2006


Isaac Richards wrote:

> For instance, see NVP::AutoDeint(VideoFrame *frame)..  It's only going to flip 
> between interlaced/progressive after a couple frames of the opposite type to 
> what's current have been seen, instead of on the actual frame that needs it.  
> That'll lead to a couple frames of interlaced content being displayed as 
> progressive, etc..

I have identified 4 cases here (Bob deinterlacer, DVB-C, SD, PAL, Germany):

1. Autodetect says "I"
Everything's fine, like in 0.19.

2a. Autodetect says "P"
Forcing to "I" seems not to improve the picture, but it does not hurt 

2b. Autodetect says "P"
Scrolling text looks bad. Forcing to "I" fixes this.

3. Autodetect switches between "I" and "P"
Every couple of seconds(!), it switches between "I" and "P". In the 
moment of "I", scrolling text looks OK, in the moment of "P", it looks 
bad. Forcing to "I" fixes this.

I have to investigate 2a further, but it looks like (at least in my case 
and one other with DVB-S that I know of) even a global force to "I" 
setting (like force aspect ratio) would improve things.


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