[mythtv] Video as time base stopped working on EPIA with recent CVS

[Darren]

Henk and Steve,

I should have mentioned that I am not the only EPIA user running this
way, there is a thread on viaarena about this.

http://forums.viaarena.com/messageview.cfm?catid=28&threadid=52109

Steve, maybe you could comment on the NuppelVideoPlayer::VTAVSync Patch
suggested there that is required to stop the frontend getting stuck. 

The patch is to remove 

 
if (diverge > MAXDIVERGE) 
{ 
// Audio is way ahead of the video - cut the frame rate 
// until it's almost in sync 
cerr << "A/V diverged by " << diverge 
<< " frames, extending frame to keep audio in sync" << endl; 
nexttrigger.tv_usec += (frame_interval * ((int)diverge / MAXDIVERGE)); 
}

It seems to work nicely.

Regards,

Darren

On Sun, 2004-04-11 at 16:49, Darren wrote:
> Henk and Steve,
> 
> Yes I run the frontend as root, in fact the distro I use is a diskless
> version of gentoo that I modded myself and that doesn't have anything
> other than root.
> 
> I have solved the problem I was having, after reading the comments Henk
> wrote about process priorities being boosted I removed some "nice"
> script commands that I had put in myself when trying to get smooth
> video. Now the frontend is working again.
> 
> As to whether the video as timebase is actually working for me. I think
> it must be, I guess I'm not using the nvidea timebase though as the
> video is provided from the northbridge chipset which I think is S3
> based. Anyway the reason I think its working is that when I start
> viewing a channel, I can see the audio is out of sync and hear it warp
> into sync (it sounds quite funny on a music channel). The main thing for
> me is that the video is smooth.  
> 
> I would like to know more about how this mechanism works, so Steve, if
> you have some time can you contact me off list to discuss it. Failing
> that, can you point me to the significant section of code.
> 
> Thanks to both of you for replying,
> 
> Regards,
> 
> Darren
> 
> On Sun, 2004-04-11 at 16:06, Henk Poley wrote:
> > Op zondag 11 april 2004 16:38, schreef steve at nexusuk.org:
> > > -----BEGIN PGP SIGNED MESSAGE-----
> > > Hash: SHA1
> > >
> > > On Fri, 9 Apr 2004, Henk Poley wrote:
> > > > 1) Sure it really worked before? The dev of this thing told me it only
> > > > works with nVidia cards. Possinly you ran it on it's primary fallback
> > > > method.
> > >
> > > Oops, yes I forgot to point this out in my previous mail - the option uses
> > > the /dev/nvidia device.  If you don't have that device then it will fall
> > > back to /dev/rtc and as a last resort, usleep().  But generally if you
> > > don't have /dev/nvidia it's not worth using it instead of the normal
> > > experimental AV sync option.
> > 
> > What about showing this info (needs nvidia, and root) in the 'tooltip' at the 
> > bottom of the settings screen? Might reduce the number of people who report 
> > errors when using it.
> > 
> > > > 2) You still run the frontend as root? As since the thing can only acces
> > > > the vsync info as root, and can only relyably fall-back to precise
> > > > timeing information by the kernel as root. As a normal user it will fall
> > > > back to using usleep(), which would be (and is) crap.
> > >
> > > AFAIK running the frontend as root is recommended anyway isn't it?  Since
> > > the frontend likes to increase it's process priority on some threads
> > > (which only root can do).
> > 
> > I think I heard that somewhere before, but I never seen these 'higher' threads 
> > nor seen any better behaviour. And doesn't Jarods guide use GDM? That login 
> > manager doesn't do root auto-login (at least my mine doesn't). So I think an 
> > awfull lot of people run their frontend as a normal user. (Unless Jarod bases 
> > it on an SElinux kernel...)
> > 
> > 	Henk Poley <><
> > _______________________________________________
> > mythtv-dev mailing list
> > mythtv-dev at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
> 
> 
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