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

Stuart Auchterlonie stuarta at squashedfrog.net
Sat Sep 30 08:59:29 UTC 2006

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.


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