[mythtv-users] MythTV not using virtual tuners

Nick Rout nick.rout at gmail.com
Wed Dec 3 07:47:31 UTC 2008


On Wed, Dec 3, 2008 at 7:38 PM, MythTV <MythTV at assuredsolutions.com> wrote:
> I have 2 HD-5500 cards in my MythTV system.  I have deleted and
> reconfigured each card to have 3 virtual tuners.  MythTV says I have
> 6 virtual turners available.  However, when I schedule shows, only 2
> tuners are ever used.  Do I have to configure MythFrontend to use all
> tuners or should it just automatically happen?
>
> I'm not sure if I know how/when Multirec is going to work for me.
> Documentation says that I can do simultaneous recordings on the same
> stream.  However, other people say I can do simultaneous recording on
> different channels.  Is a channel the same thing as as stream?

I only know about DVB not ATSC, but in DVB the broadcasts are sent out
on a "multiplex". There are several "channels" per multiplex. A
channel typically consists of a video stream, one or more audio
streams and zero or more caption streams. A multiplex corresponds to a
frequency to tune your card to. Using multirec you can record/watch
all the channels on one multiplex using one card.

So you have to know what channels are on what multiplexes to really
know what you can do. In NZ with DVB-S we have two freeview
multiplexes with approx 6 (lost count) channels on each. So with two
cards I could record everything being broadcast, assuming I can pump
it all over the PCI bus and into the hard drive fast enough. However
on DVB-T the same channels (but in HD) are split over more multiplexes
and to get the lot I would need more cards.

Hope that helps understand the technology.


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