[mythtv] sync & bob changes in the last month

[Hamish Moffatt]

On Thu, Sep 16, 2004 at 08:11:16PM -0400, Doug Larrick wrote:
> Hamish Moffatt wrote:
> >I've just upgraded to the latest CVS; until now I was running code from
> >about a month ago. I've noticed two changes immediately:
> >
> >1. bob now displays flickering blue lines along the top and bottom of
> >   the picture area. (My sources are all 16:9 and my TV 4:3, so the
> >   top and bottom of the picture are very visible.) None of the
> >   other filters do this, and it didn't happen a month ago.
> >   Can anyone confirm?
> 
> This is due to the code that's shifting the second field down by 1/2 a 
> line so it's offset properly.  Bob should probably paint the first/last 
> line black so it's not so noticeable.  You could set a tiny bit of 
> overscan to compensate.

Actually, overscan won't help me. Because I'm displaying a 16:9 image in
4:3, it's letterboxed and so there's big black bars above/below the
flickering top/bottom line.

Is the 1/2 line offset new(ish)? As I said I didn't see this issue with
the code about a month ago.

> >2. It seems to take longer to acquire A/V sync after fast forwarding.
> >   I've been using USleep (on kernel 2.6) for ages and it's been pretty
> >   quick (though sync hasn't always been perfect), though I just tried RTC
> >   as well and also saw slow sync. Will rebuild with OpenGL support.
> >   Is this a known change?
> 
> This effect would go away if we properly flushed the audio card's 
> buffers when coming out of pause.  I'd do it if I knew how.  See the 
> thread "Reasonable a/v sync at startup" from the end of August.

I see. Thanks for the explanation. (Actually my original post was
slightly wrong; I was using OpenGL before.)


Hamish
-- 
Hamish Moffatt VK3SB <hamish at debian.org> <hamish at cloud.net.au>