[mythtv] Current DVB problems rundown

[John P Poet]

On 9/9/05, Kenneth Aafløy <lists at kenneth.aafloy.net> wrote:
> Lørdag 10 september 2005 03:40, skrev John P Poet:
> > On 9/9/05, Daniel Kristjansson <danielk at cuymedia.net> wrote:
> > > On Fri, 2005-09-09 at 17:33 +0100, John Pullan wrote:
> > > > I wonder if Daniel could provide us with a  new current list of
> > > > problems ?
> > >
> > > As far as I'm aware it's down to two:
> > >   Mysterious rec vs livetv problem (Adam Egger)
> > >     Need "mythbackend -v record,channel,siparser" output from
> > >     both on same channel with latest SVN.
> > >   DVB lock threshold (John Poet -- DVB driver issue)
> > >     Need to know driver + driver/kernel version used.
> >
> > I have tried the stock DVB drivers in the 2.6.12 and 2.6.13 kernels.
> > They behave the same.
> > I have just downloaded the latest DVB patch dated 05Sep05 from the
> > linuxtv site.  I will try patching a 2.6.13 kernel with it, and see if
> > that helps.
> 
> Please don't put driver issues onto the MythTV project, if it behaves the
> same, it should be a driver issue.


What is strange, is that this station was fine until I upgraded from
the 13Aug SVN to the 07Sep SVN.  I know that station is in the process
of installing a new transmitter antenna, so this might be coincidence,
but my TV still displays that station just fine.


> > Playing with azap, I have seen it take up to 20 seconds to get a lock
> > on that station (KOB-DT 4-1 or 26-3).
> >
> > Once it gets a lock, it holds it.  Once it gets a lock, I can stop
> > azap and restart it, and it immediately gets a lock.
> 
> It could be something related to zig-zag scanning, if atsc frontends
> permit that, since if you already have a lock it won't do it.
> It could also be related to an internal scanning routine (they do exist)
> which is not set up properly.
> 
> > If I use azap to tune another station, then try to tune KOB again, it
> > will once again take up to 20 seconds to get a lock.
> >
> > If I use azap to tune to another station, then tell it to tune KOB
> > again and let it try for a second, then *stop* azap and wait 20
> > seconds, then start azap again, it immediately gets a lock.  It is
> > like the actual "tuning" process takes a while on that station.
> >
> > If the latest DVB driver does not help, I am wondering if I can make
> > Myth retry for up to 20 seconds.  Where would I look in the Myth
> > source, if I want to play with this?
> 
> IMHO, nothing should be done to Myth because of this, only driver vs. api
> issues should be fixed in myth!

I have never touched a linux driver.  Myth I have a prayer of
tweaking, though ;)

> Kenneth

John