[mythtv] [mythtv-commits] Ticket #1768: Fix off by one error in assembly of PSIP

Janne Grunau janne-mythtv at grunau.be
Wed May 3 22:42:24 UTC 2006


On Thursday 04 May 2006 00:28, Daniel Kristjansson wrote:
> On Wed, 2006-05-03 at 22:14 +0000, MythTV wrote:
> > #1768: Fix off by one error in assembly of PSIP
> >
> >  attached patch fixes an of by one error in assembly of PSIP from
> > ts packets. It is only triggered if the PSIP ends at the end of one
> > tspacket.
> >
> >  I see that bug only after the removal of the sectionreader in
> > DVBSiparser in [9816].
> >
> >  Is there a reason why the real data starts at PSIOffset()+1? I
> > think I remember it makes sense if you look at the mpeg standard.
> > But it confuses me everytime I look at it. So we should at least
> > add a big red blinking comment stating the reason.
>
> I think the +1 is for the pointer field, but this is from
> memory so I'll need to look it up before writing the comment.

You're probably right. That sounds familiar.
>
> Am I correct in assuming that this fixes the problem with the
> DVB EIT sections getting tossed with an incorrect CRC?

Yes and no. The failing CRC was on other tables and EIT data was just 
not assembled correctly and got ditched. But with the patch I don't see 
them anymore.

Janne


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