[mythtv-users] DVB-S2 and DVBT2 via SAT>IP

[Klaas de Waal]

On Mon, 10 Feb 2025 at 13:12, Ken Smith via mythtv-users <
mythtv-users at mythtv.org> wrote:

> Hi Everyone,
>
> I've been experimenting with minisatip on a system that has a TBS Dual
> S2 card, a TBS Dual T2 card and a Hauppauge DVB-T card. I've been
> collecting logs and wireshark captures, with various combinations of
> enabled interfaces, to find out why DVB-S and DVB-T don't work
> together.  I'm finding that I can get DVB-T to work or DVB-S, but not
> both together. My aim is to have the host system be a SAT>IP server and
> run MythTV backend on a VM. It should simplify backend upgrades.
>
> In one of my tests I had two DVB-S2 interfaces enabled and one DVB-T2. I
> used MythTV to run a DVB-S2 channel scan.
>
> minisatip logs the DVB-S2 request from MythTV like this:-
>
> minisatip[733468]: [02/02 18:32:38.786 main]: detect_dvb_parameters
> (S)->
>
> fe=1&src=1&freq=11428.00&pol=h&ro=0.35&msys=dvbs&mtype=qpsk&sr=27500&fec=23&plts=auto
>
> A subsequent channel scan of the T2 interface is logged by minisatip
> like this
>
> [02/02 18:48:09.572 main]: copy_dvb_parameters -> src=1, fe=1,
> freq=474000, fec=0 sr=0, pol=0, ro=3, msys=3, mtype=0, plts=2,
> bw=8000000, inv=2, pids=, apids=NULL, dpids=NULL x_pmt=NULL
>
> wireshark captured this request as
>
>
> rtsp://...:554/?fe=1&freq=474.00&bw=8&msys=dvbt&tmode=auto&mtype=auto&gi=132&fec=auto
>
> This second scan of the T2 source fails with "no channels found".
>
> Notice that in both the S2 scan and the T2 scan, MythTV requests fe=1.
>
> I initially asked about this on the minisatip github and the suggestion
> from there is that MythTV should omit specifying fe= parameter in its
> SAT>IP requests. Instead the msys= parameter be used to identify the
> type of tuner being addressed. I'm aware that there is also a session
> id. I'm not fully familiar with the SAT>IP Specification, however, I do
> see the fe= parameter used in many examples in that Specification.
>
> I've kept all the logs and wireshark captures in case they are useful. I
> could re-run some of my tests, possibly also using dev-fe-tool to track
> which tuner is actually getting addressed.
>
> Although to me it seems suspicious that, although fe=1 appears in both
> the S2 and T2 scans, that does not explain why a system with just two
> S2, or just two T2 tuners is working.
>
> Thoughts???
>
>
> Hi Ken,

It could just be that you found a bug...
Can you please create an issue in Github
https://github.com/MythTV/mythtv/issues for this problem?

Thanks,
Klaas.
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