[mythtv-users] Selecting from multiple cards (2xSAA7134, 1xNova-T) - using profiles?

Christian Hack christianh at pdd.edmi.com.au
Thu Oct 2 13:54:51 EDT 2003


> -----Original Message-----
> From: Bruce Markey [mailto:bjm at lvcm.com] 
> 
> Christian Hack wrote:
> > I have a master mythbackend with 3 cards in it. Currently 
> the first two
> > (cardid 1 and 2) are normal analogue SAA7134 based cards. 
> Cardid 3 is a
> > Haupauge DVB Nova-T card. Essentially all cards can capture the same
> > channels - just the DVB captures them digitally of course.
> 
> In other words, are you are using the same video source for
> all three card inputs?

Yes that is correct currently. The way DVB seems to be is that it takes
it's channels from the channel table and finds matching ones in the DVB
table. I have one channel that doesn't have a DVB broadcast. Because of
that I can't change up/down through this channel on the DVB card. This
might just be a minor limitation of the  DVB code as it stands.

> > I have been experimenting with the profiles stuff that's 
> been recently added
> > by Geoff Hausheer (sp?). From Isaac's description at the 
> current top story
> > on www.mythtv.org it was to support multiple types of 
> cards. Is it meant to
> > allow me to select to record on a particular card? i.e. Can 
> I say record a
> > particular show on the DVB card?
> 
> Actually, no. what determines which card will be used is the
> scheduler. The first recording is assigned to the first card
> etc. The card order is determined by the order you entered the
> card inputs with setup. See the tricks and tips in:
> http://www.mythtv.org/docs/mythtv-HOWTO-21.html#ss21.12
> 

I understand the order bit which is why my DVB card is cardid 3.

> By default, the scheduler decides which overlapping show is
> preferred by checking the type, length and channel. However,
> now with rankings, the higher ranked show is preferred. The
> highest ranked show will go to the first card input but the
> second, third, fourth, etc. may still be assigned out of order.
> 
> So, if your DVB card was first, you could be sure that the
> highest ranked show would be recorded on that card.
> 
> > Looking at tv_rec.cpp ->
> > TVRec::HandleStateChange(void) it doesn't appear that it 
> works like that. It
> > appears that the profile is looked up _after_ the card had 
> been selected.
> 
> It needs to use the codec params for the card that will do
> the recording regardless what happened leading up to the
> recording being assigned to that card ;-).
> 
> > So I'm trying to record unimportant shows to me, to test 
> the DVB stuff. Is
> > there anyway I can do this? Currently it only ever gets 
> used if I'm already
> > recording 2 things at once.
> 
> Exactly, pick three random things and one will be recorded on
> the DVB card. Or use two different video sources but that
> anticipates the next question...
> 
> > Also can anyone think of any tricks to record on both a DVB 
> and one of my
> > SAA7134 cards at the same time? I can imagine some simple 
> database tricks
> > could fool MythTV as long as I can select which card to record on.
> 
> I assume you meant to record the same show to compare the two
> files. You can run "setup" again and create a record video
> sources. Use a different name but configure it to grab the same
> listings. Next, go into input connections and change the DVB
> card to use the second video source.
> 
> Channel 3 for the analogue cards will be chanid 1003. Channel 3
> for the DVB card will be chanid 2003 and can only be recorded
> by the DVB card. Now if you choose to record the show a 8:00 on
> 1003 and 2003 you will get two distinct recordings of what we
> know is the same show.
> 
> The down side of this is that when you go to the EPG you will
> see two lines for every channel and you can't tell which row
> goes with witch card. You could change the fields in the channel
> table so that you can see which is which (channum?, callsign?
> name?).
> 

I was doing it more so I don't miss any "important" shows that I want to
watch if the DVB stuff falls over for some reason. Having the extra
video source will do what I want - thanks for the idea _ I hadn't
thought of that. I will just name them so I will have a channel 9 and a
channel 9Digital or something like that.

> Of course, using this approach will make testing the DVB card
> much easier because you can just choose a show on the DVB channel
> rather than choosing three and not knowing which will be assigned
> to the DVB card. 
> 

Thanks for the response.

CH



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