[mythtvnz] Some channels missing while recording

[Nick Rout]

On Thu, May 14, 2009 at 8:36 PM, Vance McIndoe <vance at juniper.net> wrote:
> I have a Hauppauge Nova-S PCI card on Mythbuntu 9.04. I've noticed that when recording on Tuner 1 (Tuner 2 available) that a few channels go missing.
>
> For example, TV3 and a few others are okay, but TV1 is missing. I can still see it in the programme guide, but can't find it when in Live TV mode - therefore can't switch to it.
>
> However, if Tuner 2 is recording (and Tuner 1 is available), then all channels are available as you'd expect.
>
> How do I confirm if I have both tuners set up correctly? Can I run some db queries to provide some more info?
>

I think what you are seeing is that the nova-s plus has only one real
tuner. It looks like 2 because you have multi-rec working.

What happens is that dvb is transmitted as multiple streams per
multiplex (or mux). ie several video streams and their accompanying
audio streams. one physical tuner can access all streams on a mux at
once. One physical tuner can be multiple virtual tuners, each virtual
tuner takes one channel (ie a video plus 1 or more audio) and presents
it for recording/watching.

The corollary is that if you are tuned to a channel on mux A on
virtual tuner 1, you can only get other channels on the same mux,
because the tuner can only access one mux at a time.

The good thing is satellite freeview only has two muxes, and two cards
will record all the TV you can get on satellite freeview. (I have each
card set up as 4 virtual tuners.)

You can see from http://www.lyngsat.com/optusd1.html what is on each
mux - basically all TVNZ plus MaoriTV on one mux and the rest on the
other.