[mythtv] [mythtv-commits] Ticket #6343: Problem with VDPAU and Temporal 2X deinterlacing

Yeechang Lee ylee at pobox.com
Sat Mar 14 18:44:36 UTC 2009


Mark Kendall <mark.kendall at gmail.com> says:
> Of that 1%, a certain amount is genuinely mixed
> progressive/interlaced.

Such content actually exists?!? My understanding, from reading
previous threads on the subject, was that no one had actually seen
genuinely mixed progressive/interlaced content in the wild.

> The balance of the 1% is genuinely interlaced material that has a
> mix of progressive and interlaced flags (I'm going to ignore for the
> time being telecined material). I have one dvb-t channel here that
> seems to flip between the 2 almost randomly. I know it's interlaced
> material (it's a news channel - the scrolling text is an easy
> giveaway) yet it sometimes flips 3 or 4 times a second and sometimes
> doesn't change for a couple of minutes.

Same here in the US; one OTA (the NBC affiliate) and several cable are
notorious for this. It even varies by program; for example, on NBC the
half hour-long _30 Rock_ and the hour-long _Chuck_ don't do this but
the hour-long _Friday Night Lights_ does. (_30 Rock_ used to do so,
but changed at some point.) The difference is visible in the displayed
recording times (yes, that longstanding cosmetic issue again); _30
Rock_ and _Chuck_'s recorded times are more or less accurate but
_Friday Night Lights_ displays ~53 minutes. These are all 1080i
broadcasts, by the way.

> I don't know. Clearly all televisions, set top boxes etc are happy
> with it because they display it properly.  But are they just
> assuming its interlaced because they never expect standard
> definition progressive material?

Here in the US standard-definition broadcasts, in my experience, are
interlaced when in analog format, whether over-the-air or via
cable. Digital standard-definition (whether via cable or over-the-air)
are progressive.

>  - whatever solution may be implemented in the future, I doubt it's
> going to appease everyone.

Apologizing ahead of time for my naivete, might the "staggered"
solution I suggest at
<URLhttp://www.gossamer-threads.com/lists/mythtv/users/373031#373031>
work? This is predicated on the assumption that there really is no
genuinely mixed progressive/interlaced content, but even if there is I
can't believe it's more than a tiny fraction of the problematic
streams out there.

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