I've had a quick look at the Freesat EPG patch for VDR to try to understand how it works. I think I've read that the Freesat EPG is broadcast on Eurobird (and only on one transponder?) whereas most of the programs are actually broadcast on Astra 28.2E, but the patch doesn't seem to add anything to VDR for selecting transponders.
So does VDR periodically scan all the transponders it knows for EPG etc, or when you ask it to scan, or is the Freesat EPG actually available on all the transponders in its network?
I'd also like to find some more information about the Huffman encoding tables it uses. Apparently these need updating periodically. Are the tables broadcast alongside the EPG, but means to receive them hasn't made it into the VDR patch (yet)?
I'd also like to know if and how Freesat's logical channel numbers are broadcast and if there are alternative SDTs, PATs and PMTs especially for Freesat instead of the BSkyB ones.
If I try to search for this sort of info on Google all I seem to get are non-technical articles written before Freesat's launch, speculating on what the EPG might look like.
On Fri, 27 Feb 2009, Tony Houghton wrote:
I've had a quick look at the Freesat EPG patch for VDR to try to understand how it works. I think I've read that the Freesat EPG is broadcast on Eurobird (and only on one transponder?) whereas most of the programs are actually broadcast on Astra 28.2E, but the patch doesn't seem to add anything to VDR for selecting transponders.
I believe that it's broadcast on all Freesat transponders, certainly for me, tuning to a BBC channel starts pulling in all the EPG info.
I'd also like to find some more information about the Huffman encoding tables it uses. Apparently these need updating periodically. Are the tables broadcast alongside the EPG, but means to receive them hasn't made it into the VDR patch (yet)?
They're hardcoded into STB so the complete tables zip file won't need updating - the only reason why the tables might need updating is if you're using the "derived by observation" set, which I've not had a chance to do recently - stick to the complete set and you can't go wrong.
I'd also like to know if and how Freesat's logical channel numbers are broadcast and if there are alternative SDTs, PATs and PMTs especially for Freesat instead of the BSkyB ones.
As far as I've seen everything is fairly standard, though the tables are off set by 3800 pids, so the BAT is at pid 3841. In terms of features I suspect that if you look at how Freeview handles thing, add 3800 to the pid then things will be the same - certainly TVAnytime is implemented the same.
Regards,
d.
On Fri, 27 Feb 2009 21:30:35 +0000 (GMT) Dominic Morris dom@suborbital.org.uk wrote:
On Fri, 27 Feb 2009, Tony Houghton wrote:
I've had a quick look at the Freesat EPG patch for VDR to try to understand how it works. I think I've read that the Freesat EPG is broadcast on Eurobird (and only on one transponder?) whereas most of the programs are actually broadcast on Astra 28.2E, but the patch doesn't seem to add anything to VDR for selecting transponders.
I believe that it's broadcast on all Freesat transponders, certainly for me, tuning to a BBC channel starts pulling in all the EPG info.
I found some more useful information by Googling "Freesat Huffman". One page said the official transponder for the EPG repeats it every 30 seconds whereas it can take as many minutes to get the whole EPG on the others. http://forums.gbpvr.com/showpost.php?p=297759&postcount=6. But AFAICT the pids for SDT and NIT given there are either wrong or the table_ids must be non-standard too.
I'd also like to find some more information about the Huffman encoding tables it uses. Apparently these need updating periodically. Are the tables broadcast alongside the EPG, but means to receive them hasn't made it into the VDR patch (yet)?
They're hardcoded into STB so the complete tables zip file won't need updating - the only reason why the tables might need updating is if you're using the "derived by observation" set, which I've not had a chance to do recently - stick to the complete set and you can't go wrong.
I'd also like to know if and how Freesat's logical channel numbers are broadcast and if there are alternative SDTs, PATs and PMTs especially for Freesat instead of the BSkyB ones.
As far as I've seen everything is fairly standard, though the tables are off set by 3800 pids, so the BAT is at pid 3841. In terms of features I suspect that if you look at how Freeview handles thing, add 3800 to the pid then things will be the same - certainly TVAnytime is implemented the same.
I haven't checked BATs or EITs yet, but Freeview seems to use standard pids (from ETSI EN 300 468) for PATs, PMTs, SDTs and NITs. The standard BAT pid is 0x11 so I don't see how simply adding 3800 works :-/.