[mythtv-users] Satip - cannot change Diseqc position

[Stephen Worthington]

On Thu, 1 Dec 2022 08:05:14 +0100, you wrote:

>Apologies for top posting. See also additional comments at the bottom.
>
>> Op 1 dec. 2022, om 07:00 heeft Johan Van der Kolk <johan.vanderkolk at gmail.com> het volgende geschreven:
>> 
>> Hi Klaas,
>> 
>> Whether or not it works on Disecq 1 or 1.1 switches depends on the implementation of the SatTIP server. 
>> Minisatip supports both versions. 
>> 
>> According to the documentation https://www.satip.info/sites/satip/files/resource/satip_specification_version_1_2_2.pdf <https://www.satip.info/sites/satip/files/resource/satip_specification_version_1_2_2.pdf> on page 43 you’ll find that src is to be used to select a satellite position and its value is a numerical value between 1 and 255. So up to 255 satellite positions are supported by the SatIp protocol. 
>> It’s up to the SatIP server to serve the satellite position based on the sent src value. 
>> 
>> thanks for looking in to this!
>> 
>> Johan
>> 
>> 
>>> Op 30 nov. 2022, om 23:15 heeft Klaas de Waal <klaas.de.waal at gmail.com <mailto:klaas.de.waal at gmail.com>> het volgende geschreven:
>>> 
>>> 
>>> 
>>> On Wed, 30 Nov 2022 at 19:58, Johan Van der Kolk <johan.vanderkolk at gmail.com <mailto:johan.vanderkolk at gmail.com>> wrote:
>>> Been running a long time with standard DVB-S cards but thought to try my luck with satip, now the new “capture card” is available in Myth 0.32.
>>> So running 0.32/fixes on Ubuntu 22.04, compiled Myth the day before yesterday from (git)source.
>>> 
>>> Installed minisatip as a Sat->IP server, also a fresh compile, allocated my 4 DVB-S tuners and ran a channelscan from mythtv-setup. That works fine.
>>> However I have a triple LNB and need to use Diseqc 1.0 to change between the satellites. 
>>> 
>>> The channel search on the SatIP capture card always sends a “src=1” to minisatip, which means it always selects the lowest diseqc position (AA).
>>> 
>>> How do I get mythtv-setup to send the src=2 and src=3 commands so I can use the 2nd and 3rd DiseqC position?
>>> For testing, I created a playlist for VLC for use with DiseqC position “AB” (src=2) and that works fine. 
>>> 
>>> It’s probably hidden somewhere, but after 2 days of searching and trying to assign different video sources I can’t seem to find how to.
>>> Probably simple though once you know it. 
>>> 
>>> 
>>> MythTV SatIP does not support DiSEqC. It is an interesting feature and I am willing to look at it but I just did not know at the time that the "src=1"does select a DiSEqC position. Does that work only for the four channel switches or also for the sixteen channel DiSEqC 1.1 switches? Pointers to documentation would be appreciated.
>>> 
>>> Thanks,
>>> Klaas.
>>> 
>>> 
>
>>> 
>
>
>The MythTv SatIP Wiki states that only one channel (PID) is passed in a full mux stream, and therefore Multirec would not be possible. The protocol however states that multiple PIDs can be selected, and dynamic adding/deletion is supported (without affecting the other PID’s) This would allow Multirec, correct? Described on page 44 and 45 of the document.
>
>Johan 

There is no need for multirec when using SAT>IP with minisatip.
Minisatip will automatically re-use a tuner for multiple different
SAT>IP connections as long as they are for streams from the same
tuner.  My MythTV box and my mother's share the use of my DVB-S2
tuners via minisatip and both boxes frequently use the same tuner at
the same time via minisatip, and they can be recording from multiple
channels on that same tuner.  Some SAT>IP devices seem to lock a tuner
for exclusive use by the first user to request it, but minisatip does
not do that.  I think minisatip actually ignores the fe= parameter
that would be used to specify a particular tuner to be used, but I
have not confirmed that.  Normal SAT>IP connections do not use fe=
anyway, which allows the SAT>IP device to handle the allocation of its
tuners however it likes.

FYI, a PID is the ID number of one stream coming from a tuner.  A
channel normally has several PIDs associated with it, so it will have
a video PID, one or more audio PIDs, one or more subtitle PIDs, and so
on.

Yes, the SAT>IP protocol allows you to specify whatever PIDs you want
from the tuner, and to add and delete PIDs dynamically.  That could be
used to do multirec, but I do not think MythTV does this.  It is much
easier to just use a separate SAT>IP connection for each channel that
you want to record.  If you have only one tuner on minisatip, you can
still tell MythTV that it has two SAT>IP tuners so that it can do
multirec that way.  But MythTV then does not have any way of knowing
when there would be a clash for the use of the tuner.  If it does know
there is a clash, it can try to reschedule one programme to be
recorded at a later time.  Without knowing, MythTV will try to record
both programmes, and one will fail to record.  But MythTV is bad at
handing failed tuner situations - it appears to not actually decide
that there is a problem until the end of the recording time for the
programme, and due to the usual post-roll that is usually too late for
it to then record the missed programme from a +1 channel (a channel
which broadcasts the same content as the main channel but one hour
later).  For channels where programmes are normally transmitted at
least three times in a week (as is often the case on satellite and
cable services), MythTV would likely then be able to later record the
missed programme.  To get MythTV to work properly with SAT>IP devices
and do multirec using multiple MythTV SAT>IP tuners, there would need
to be a way of telling it that despite having say 10 SAT>IP tuners
specified for a source, there are actually only 4 physical tuners on
the SAT>IP device and it can only record from 4 frequencies at once.
Alternatively, it would have to use the fe= option to specify the
tuner number and do the add and delete PIDs trick to do multirec -
effectively treating each SAT>IP tuner as device for its exclusive
use.  But if the fe= option asked for a tuner that was already in use
by another device on the network on a different frequency from what
MythTV wanted to use, the recording would likely fail.  Or maybe not
with minisatip, which I think would just ignore the fe= option and use
a different physical tuner.

You do want to set up MythTV SAT>IP tuners to a multirec setting of 2.
That way mythbackend will reuse the same SAT>IP streams that are
already running when it records back-to-back programmes from the same
channel (as opposed to different channels on the same frequency). Both
recording files will get all the data that is being read from the
SAT>IP connection during the overlap period.