[mythtv] Problems recording from two channels in a multiplex

Another Sillyname anothersname at googlemail.com
Wed Nov 10 03:03:27 UTC 2010

On 10 November 2010 00:53, William Uther
<willu.mailingLists at cse.unsw.edu.au> wrote:
> Hi all,
>  Thanks for the help so far.  Due to me being a bit stupid with my filesystem, I'm currently doing a full re-install.  Wheeee.  I have an sql backup which I can pull stuff from, but no recordings.  I was planning to do a fresh install just using the sql backup for guidance rather than importing it.  It has been a while (~4 years?) since I list did that and Sydney DVB channels have changed a bit since then :).
>> Date: Sat, 6 Nov 2010 13:04:57 +0000
>> From: Another Sillyname <anothersname at googlemail.com>
>> What card are you using?
> I have two DViCO DVB-T lite cards.  They show up in lspci as two devices each, "Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)" and "Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)".  Each has "Subsystem: DViCO Corporation Device db10".
>> Date: Sat, 6 Nov 2010 13:41:21 +0000
>> From: Mark <irish at irishmark.co.uk>
>> wanna send me a dump of your inputgroup table?
> INSERT INTO `inputgroup` VALUES (1,1,'DVB0'),(2,1,'DVB0'),(3,2,'DVB1'),(4,2,'DVB1');
> My understanding was that the two cardids for a single DVB adaptor should have the same inputgroup.  That is how myth knows that it can only record shows from a single multiplex on those cards.
> This is exactly the opposite of what you suggested offline (I hope you don't mind me replying here):
> On 06/11/2010, at 11:54 PM, Mark wrote:
>> I had this when my input groups were wrong.
>> Counter-intuitively your inputs for multi-rec must be in DIFFERENT groups. if they are in the same group you will see behaviour like you describe
> So I'd then need four input groups, one for each cardid?
> If this is the case, what stops the scheduler from scheduling recordings from from completely different multiplexes on the same card?  Are you sure this isn't just covering up a bug that should be tracked down and squashed?  Otherwise I guess I should understand this and then document it somewhere (or is there already documentation that I've missed?).
> Just before I broke everything I was logging some extra info from TVRec::StartRecording().  If I can't get things going with the re-install I'll go back and do that.
> Thank you all for the help,
> Will       :-}
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
Sorry I don't agree.

I have 2 dual tuner physical DVB-T cards giving me 4 physical tuners
each setup as a 3 channel multirec so 12 virtual tuners and 2 dual
tuner DVB-S(2) tuners so 4 physical tuners each setup as a 2 channel
multirec so 8 virtual tuners on one server. All the DVB-T cards are
all in one input group and all the DVB-S(2) tuners are all in a
separate input group, this works fine and I have no problems with
doing multiple recordings simultaneously (the record was 11
simultaneous recordings spread over all the physical DVB-T tuners and
2 of the DVB-S(2) tuners).

I've never experienced problems with a new recording starting killing
an in progress recording on the same device, I have had occasional
problems if too many recordings start at the same time (9:00pm
occasionally) where one of the recordings may start but give me a zero
content recording, but I've put this down to just a loading problem
and now deliberately schedule shows to have a slightly staggered start

More information about the mythtv-dev mailing list