[vdr] [ANNOUNCE] VDR developer version 2.1.3

Klaus Schmidinger Klaus.Schmidinger at tvdr.de
Mon Jan 6 11:49:08 CET 2014


On 06.01.2014 09:59, Reinhard Nissl wrote:
> Hi,
>
> Am 05.01.2014 12:42, schrieb Klaus Schmidinger:
>
>> The changes since version 2.1.2:
>>
>> - Channels that are no longer contained in the current SDT of
>>   a transponder are now marked with the keyword OBSOLETE in
>>   their name and provider fields. That way you can identify
>>   obsolete channels when you switch to them, and you can get the
>>   complete overview of all obsolete channels by sorting the
>>   Channels list by provider (by pressing the 0 key twice).
>>   Automatic deletion of obsolete channels may follow later.
>
> What about channels on transponders which no longer get a lock while tuning, like S13.0E, 10930 H?

The current way of detecting obsolete channels can only work if the transponder
can still be received and a complete SDT is parsed. After that it is absolutely clear
that any channel still in VDRs list, but not in the SDT, is obsolete.

> Shouldn't those channels be declared OBSOLTE too, when a SDT hasn't been received?
>
> Maybe this should only be done if the device doesn't have a lock either, to avoid false positives.

There could be various reasons why a device might not have a lock, like a broken cable,
bad weather, snow on the dish, or maybe the uplink for that particular transponder is
temporarily interrupted.

> But this still seems error prone -- looks like a more complex solution is needed which keeps track of how often a transponder has been seen dead over a certain period of time before declaring these channels OBSOLETE (and later delete them automatically).
>
> I don't know if it is worth to extend the file format of channels.conf for that tracking,

I do know: it is *not* ;-).
The channels.conf file shall contain only information that is broadcast in the SI data.
It's bad enough we have the infamous RID in there...

> but at least in memory VDR could keep track of that, starting from scratch whenever VDR is restarted.

Maybe detecting "dead transponders" could work by checking whether any other
transponder on the same source (and band (high/low, hor/ver) in case of DVB-S) can
actually be received. If one transponder can't be received, but others on the same
source/band can, then chances are the transponder is dead (unless the problem is with the
uplink). However, I'm afraid this requires quite a bit more work than the simple detection
of channels that are no longer in the SDT...

Klaus



More information about the vdr mailing list