[mythtv] DVB EPG tables, (was Beginning radio pvr support)
jmp at tarantella.com
Tue Jan 13 09:29:41 EST 2004
On Tue, 2004-01-13 at 13:49, Edward Wildgoose wrote:
> > I haven't really looked into this yet, but is the now/next data synced
> > with the show, ie, if a show starts late, the now/next data will only be
> > updated when the show actually starts or when it is scheduled to start?
> In the UK on freeview, you are lucky if the data is there and for the correct day... Actually it's not quite that bad, but sometimes it seems to get messed up quite badly.
> Rumour has it that from "Jan 2004" we will get full 7 days epg.... Anyone still got a normal box plugged in to see if it's broadcasting yet?
> I think it handles schedule changes, but I doubt it handles very short term delays or over-running programs (perhaps though...?)
I think that should be handle by a different table (can't remember which
one, but I'm sure I've seen it in the spec). So we have the following
tables, Now/Next,EPG, and Program Schedule updates, that myth would be
> Kenneth has already kindly built a parser into the DVB code. The epg info is continuously broadcast with the tv data as I understand it. You would simply write extra code to continuously update the epg data in the database based on the DVB data.
> Your problem comes if the user never changes channel (well, changes mux really). VDR has a process which early in the morning flicks across all multiplexes and makes sure that it has all the new data at least once that day.
> Basically have a look at the DVBChannel.cpp code (I think) and see if you can use it to dig out your DVB epg data (also look at the tools from Metzler bros, etc which can dump all the data out of a live stream so you can check if you are doing the right thing in myth code)
As I understand it, the EPG,now/next, is broadcast in several tables
(0x4e - 0x60 on pid 0x12). It's meant to have the current channel
information (obviously) and also in adjacent tables information for
other channels, (think this information is less detailed)
Now I can see this working in theory for Freeview due to the limited
number of channels but I'm not sure how it pans out with other types of
I might have a look at the DVBChannel stuff and see if I can get it to
parse something out (the format is quite simple if I remember correctly)
P.S I haven't seen any live EPG data only the now/next stuff, so I
could be completely wrong about it.
John Pullan <jmp at tarantella.com>
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