[mythtv] what does "DVBRec(1): PID 0x840 discontinuity detected" mean?

Steven Adeff adeffs.mythtv at gmail.com
Sat Sep 30 19:05:15 UTC 2006


On 9/30/06, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> On 9/30/06, Stuart Auchterlonie <stuarta at squashedfrog.net> wrote:
> > On Fri, Sep 29, 2006 at 07:19:02PM -0400, Steven Adeff wrote:
> > > On 9/29/06, Stuart Auchterlonie <stuarta at squashedfrog.net> wrote:
> > > >
> > > > These are caused by the next packet being recieved on that pid,
> > > > not being the one that is expected.
> > > >
> > > > The main cause is bad signal, but you've had that sorted.
> > > > It can also caused by things like power spikes, or other
> > > > intermittant interferance.
> > > >
> > > > However, looking at this i've noticed something interesting.
> > > > We don't throw away the packet if we detect a discontinuity.
> > > > This would be okay if the new packet CC = last seen CC, as this
> > > > would possibly be a duplicate packet. But if the new packet CC
> > > > is > last seen CC + 1 (modulo 0xf) then the full TS packet is
> > > > broken and should be thrown away....
> > > >
> > > > I'll whip up a quick patch for that...
> > >
> > > thanks, let me know if I can provide any more information. I do know
> > > that my HD3000 is more prone to this error than either of my Aver
> > > A180's (which 95% of the time show the problem at the same time).
> > >
> >
> > That is to be expected, since some form of electrical interference
> > would hit the input and all cards equally. It looks like the HD3000
> > is more sensitive to this noise..
> >
> > The patch has gone in in changeset 11334.
>
> Is it safe to apply the diff for 11334 to 0-20-fixes or will it need
> other patches to work?

well, I did that anyway, and it seems as though only my HD3000 card
has issues (perhaps moving it to another pci slot?), as the A180's
recorded together fine, and only showed any problems once the HD3000
started recording.

any way, let me know about how exactly I should test the patch (I'll
guess I did it wrong) and I'll try that...

-- 
Steve
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