[mythtv] AVSync2 Improvements

[David Engel]

On Thu, Feb 14, 2019 at 10:15:50AM -0500, Peter Bennett wrote:
> 
> 
> On 2/13/19 12:56 PM, Peter Bennett wrote:
> > 
> > 
> > On 2/13/19 11:26 AM, David Engel wrote:
> > > Recordings worked fine with the new patch.  Live TV was also better in
> > > that it did sync up.  I think we can and should do better, though.
> > > Several seconds before the big stuttering settles down 60+ seconds for
> > > the little, jerkiness to go away is too long, IMO.  I know most of us
> > > either don't use live TV or don't mind pausing briefly when we do.
> > > However, some of us have family members who do use live TV and, at
> > > least in my case, it has been a point of contention.
> > > 
> > > My hope is that we can find a good, deterministic way to handle the
> > > live TV case better.  Failing that, we might need to capitulate add a
> > > delay.  I know someone objected to that recently.  Perhaps we could
> > > make such a delay configurable with the default being 0.
> > > 
> > I think that now it is working the same as in v29.
> > 
> > It pauses one frame at a time until playback is 3 seconds behind the
> > recording. The problem is that after that it gets slightly ahead of the
> > 3 seconds again from time to time and does more pauses. I will need to
> > change it so that it pauses a bit longer than the amount it uses for
> > subsequent checks. Alternatively, only pause once and never check again.
> > The reason I have subsequent checks is in case you hit jump forward and
> > get into the stuttering situation again. I am not sure if this is
> > possible.
> > 
> > Another thing I want to do is reduce the excessive number of messages it
> > puts in the verbose playback during Live TV startup.
> > 
> > I will get another patch for it.
> > 
> > Peter
> I was not able to easily change the logic, so I have added a setting for a
> delay at the start of Live TV that defaults to zero and is configurable.
> Setting 4000 ms seems to eliminate the stuttering. Setting zero will still
> recover over approximately a minute.
> Updated patch:
> 
> https://code.mythtv.org/trac/attachment/ticket/13383/20190213_1544_catchup_plus.patch

I saw the new patch and tried it briefly last night.  Setting a wait
of 1000ms helped sometimes and not others when entering live TV.  I
need to test more with longer waits.  One thing I noticed was that no
value seemed to have any effect on channel changes.  They were always
very stuttery.  Is the new setting even used when changing channels?

David
-- 
David Engel
david at istwok.net