[mythtv-users] 720p HD content from WPVI in Philly periodic a/v sync issues

[Andrew Gallatin]

Taylor Ralph [tralph11 at yahoo.com] wrote:
> --- On Fri, 12/11/09, Andrew Gallatin <gallatin at cs.duke.edu> wrote:
> 
> > From: Andrew Gallatin <gallatin at cs.duke.edu>
> > Subject: Re: [mythtv-users] 720p HD content from WPVI in Philly periodic a/v sync issues
> > To: "Discussion about mythtv" <mythtv-users at mythtv.org>
> > Date: Friday, December 11, 2009, 10:54 AM
> > Byron Poland [wpoland at gmail.com]
> > wrote:
> > > for the past couple of months anything I record from
> > WPVI in Philadelphia
> > > (delivered via clear qam from Verizon FIOS in
> > Wilmington, DE), has had
> > > playback problems where the video and audio fall out
> > of sync, and myth then
> > > speeds up the video and/or drops frames for a second
> > or 2 to catch up.? I've
> > > read the list and seen other threads describing a
> > similar phenomenon,
> > > including being isolated to one channel.? All
> > other 720p and 1080 recordings
> > 
> > <..>
> > 
> > I think this is the same problem as reported here, nearly
> > 2 years ago:
> > ? http://www.gossamer-threads.com/lists/mythtv/dev/317736
> > 
> > As DanielK said "they are just using an encoding extension
> > we don't
> > support very well.....I believe they are broadcasting about
> > 40 fps on
> > a 60fps stream and marking some of the frames as
> > repeatable"
> > If this is true, you may have luck complaining to the
> > broadcaster like
> > the people in that thread did.? Unfortunately, that's
> > not much of an
> > option for me, as multiple broadcasters in my market have
> > their
> > encoders setup this way.? The only way I was able to
> > play back these
> > sorts of streams was by using a non-MythTV front end (sigma
> > based
> > SageTV HD100).
> > 
> > I'd love to come back to MythTV, and I'm eagerly looking
> > forward to a
> > fix to this.? I have a mythbox setup running trunk,
> > and I'm happy to
> > test patches, make snippets of these streams available to
> > the devs,
> > etc.
> > 
> > Drew
> 
> I've got a couple patches attached that might help. They are both based on 0.22-fixes but the latest av-sync changes to trunk will probably break the repeat_pict patch. Let us know if these help at all.

I checked out a fresh 22-fixes and applied the patch.
Unfortunately, it actually seemed to make things worse.
I've attached -v playback from a problematic file.
This is using an Ion 330 using VDPAU, displaying to
a 1080p panel.

> Also, if you provide samples then I'll have a look.

I'll email you a link to a snippet off-list.

Thanks,

Drew

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