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

[Steven Adeff]

On 9/20/06, Isaac Richards <ijr at case.edu> wrote:
> On Wednesday 20 September 2006 5:24 pm, Jack Perveiler wrote:
> > <snip>
> >
> > > > It's not wrong.  It's reporting based off of what's in the video
> > > > headers.
> > >
> > > I see. And 0.19 did not look into the video headers?
> > >
> > > So, it's the fault of the channels or the provider.
> > >
> > > In that case, it would be extremely helpful to have a setting to force
> > > this always to "interlaced" (for 0.20 fixes branch).
> > >
> > > BTW, what's the negative effect, if I set a progressive recording to
> > > video scan "interlaced"?
> > > I can see no negative effect here, so maybe this means all my recordings
> > > really are interlaced, but some are wrongly marked in the video headers?
> >
> > Deinterlacing, at least with bob, can have some very undesirable side
> > effects when used with progressive content.  In my case I see two copies of
> > every image: one squished into the top half of the screen, the other
> > squished into the bottom half.  I don't know if that's what happens for
> > everyone, but that's what happend for me.
>
> Well, that shouldn't be happening.  Sounds like the bob filter's in place, but
> it's not doing the proper output..
>
> > Which is why I thought the ability to change the default away from "detect"
> > on a  per-channel basis sounded interesting.  Isaac, any comment on that?
> > If I coded it up, is the idea something that could be committed?  It sounds
> > like it won't fix everything for everybody, but could help some (myself,
> > anyways) and could still be overridable by the OSD selection.  I don't want
> > to waste my time on something non-commitable, though.
>
> I dunno if I like the idea of another setting for this.  Be better just to
> improve the handling of these situations.
>
> 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..
>
> Other thing to add would be automatic detection of telecined content (by the
> flag pattern, most likely), and automatically turning on the ivtc filter as
> necessary.
>
> Isaac

Isaac, I'm seeing on interlaced content (either my PVR-150 or 1080i)
that sometimes after the video is paused (either actually pausing, or
going to the edit menu) and rarely after skipping video, that the
video scan detection will "stop working", basically requiring me to go
into the menu and choose one of the options (any of them work, which
is also weird, I can even choose "progressive" and it works....). What
occurs is I get a skipping video, best I can describe it as is that
the frame rate slows down, or frames are "dropped".

Let me know what info I can get you to figure out whats going on.

Thanks!
-- 
Steve
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