[mythtv-users] IPTV in .23

[Robert Johnston]

On 14/08/2010 5:35 PM, Greg Mitchell wrote:
>
>> And a followup question to my last email: do you also need as many
>> NICs in your backend as IPTV streams you wish to record, or do you
>> either create "virtual" network cards or just use the same network
>> card that connects your backed to your network?
>
> I guess it depends on your provider. I think you could probably get away
> with one NIC if your provider has multi-tuner IPTV boxes.
>
>> I seemed to recall reading a document where someone had configured
>> MythTV to record IPTV stream and they had to give a NIC the same MAC
>> address as the STBfrom the provider.
>
> That's what I've done.
>
> I'm on Sasktel, which has a howto on the wiki (created by Robert
> Johnston, who has chimed in on this thread) which is likely what you
> remember reading.
>
> I am able to record 2 SD or one HD stream with a single NIC set up with
> the MAC address from one of the HD boxes I got from Sasktel. I have a
> second backend set up with a second NIC spoofing the second box - as
> Robert said, unfortunately you can't tell Myth what NIC to use for
> tuning/recording, so the only way to expand is to have multiple backends
>
> That said - with two backends, I'm able to record two HD streams, or 1
> HD and 2 SD, or 4 SD streams at once. Beyond that, my provider won't
> give me another HD box anyway - at least the last time I checked, they
> were limited to two HD boxes per household.
>
> I have on occasion been able to coax it into recording 3 SD streams, or
> 1 HD and 1 SD on the same NIC, but it's far too unstable, so it seems
> like there's some configuration on the provider end that's limiting me
> like this.

As it stands, I've not yet worked out the configuration jiggery-pokery 
necessary to get "Virtual" NICs working properly, so you have to have 
one physical NIC for each STB you wish to emulate. There is a limitation 
in MythTV that causes it to join and listen on all interfaces for 
multicast streams, which means if you have eth1 and eth2 emulating 
separate STBs, Myth will request the stream from both interfaces (and 
eth0, not that that makes a difference), and you run out of stream 
slots. It is a simple change to make (in theory, a call to SetSockOpts 
with the required interface will lock a socket to just the interface 
specified), but I don't have the coding know-how to implement it (and 
the necessary preferences changes) in the Myth codebase, and it seems 
that nobody is willing or able to add this "feature". So, for now, as 
Greg has said, you have to use a second backend to host the second STB 
NIC to tune the extra streams.

Each NIC emulates one STB. Most STBs can handle up to two SD streams 
(For PiP or DVR functionality, though that is decided by the provider) 
or one HD stream (As determined by available bandwidth and (more likely) 
processing power in the box).

So, as Greg has, he uses 2 NICs to emulate 2 STBs, which gives him 4 SD 
"Tuners" *or* 2 HD "Tuners" *or* 2 SD + 1 HD "Tuners". With only one 
backend, I have 1 NIC that emulates 1 STB that has 2 "Tuners" on it (No 
HD here, I'm not paying for it).

Hope this helps.