[mythtv] DVB EIT Implementation

[John Pullan]

On 12/10/05, Stuart Auchterlonie <stuarta at squashedfrog.net> wrote:
> On Wed, Oct 12, 2005 at 09:57:52AM +0100, John Pullan wrote:
> > On 11/10/05, Daniel Kristjansson <danielk at cuymedia.net> wrote:
> > > On Tue, 2005-10-11 at 23:26 +0100, Stuart Auchterlonie wrote:
> > > >
> > > > Can anybody explain why the EIT processing in siparser
> > > > contains all those section trackers & the rest?
> > >

> > >
> > > John Pullan and I know a bit about it, but it is Jacob's baby.
> > >
> >
> > I'm just trying to decipher the code myself. see
> > http://svn.mythtv.org/trac/ticket/344
>
> That's what got me back looking at this.
>
> Something I noticed while looking at the memory leaks is the
> Events map contains events for EVERY channel available, but
> GetEmitID only ever picks events from the channels on the
> current mplex.
>
> Put another way, there can be event information in the Events
> map, but they won't be inserted because of the way GetEmitID
> works.
>

I don't believe this is true. Empirically at least, it adds all the
EIT data seen on the mplex  (at least it did). I.e it should read the
60-6F tables for other mplex's and use them as well. Note the  use of
"should" and "did".

> It would also be nice to clear each set of events after we
> have inserted them in the database. At the moment we only
> do that when siparser is deleted.
>
> IMHO, ideally if GetEmitID is going to say there is nothing
> to do then there should be 0 events in the Events map.
>

Seems reasonable.

WRT #344 I plan on writing a debug patch in EmitRequired to try and
work out why it's not emitting. It's hard to see from logs what's
happening just at the moment.

> >
> > > > Why don't we just
> > > > 1) Decode event(s) (ParseDVBEIT, ParseATSCEIT etc)
> > > > 2) Queue event(s) directly into eithelper.
> > > You need to assemble the TS packets into PES packets before
> > > you can call the parse functions, which is what the section
> > > trackers do.
>
> I have to say, this was not obvious at all from the code.
>
> It looked like it was just trying to keep track of which
> tables it has seen.
>
> > >
> > > > After looking for those memory leaks and analysing that
> > > > code it made me want to get out the hatchet and perform
> > > > some surgery in that area.
> > > > Unless there is a good reason I'll start sharpening
> > > > the hatched :-)
> >
> > > There is one reason, this is scheduled for 0.20...
>
> Cool.
>
> > >
> > > I for one would like to get 0.19 out before the Linux
> > > Journal article on MythTV comes out next month...
> > >
> >
>
> That's a good plan.
>



--
John