[mythtv-users] Can MythTV support the new raspberry pi dvbt hat - cheap network tuner?

[Stephen Worthington]

On Thu, 18 Oct 2018 11:50:22 +0200, you wrote:

>Raspberry Pi have announced a DVBT2 Hat for Pi devices.  It is selling for approximately 22€.   Does anyone know if MythTV can support this somehow?    Would really like to move to a network tuner so this could be a cheap method of giving it a try.   https://www.raspberrypi.org/products/raspberry-pi-tv-hat   Thanks

I do not know specifically about Pis or that tuner.  But the general
rule is that MythTV on Linux supports any tuner that has Linux drivers
that conform to the Linux DVBAPI specification.  So if the tuner has
drivers that create a /dev/dvb device that looks like this:

root at mypvr:/tmp# ll /dev/dvb/adapter0
total 0
drwxr-xr-x   2 root root      120 Oct  8 04:31 ./
drwxr-xr-x  18 root root      360 Oct  8 04:31 ../
crw-rw----+  1 root video 212, 32 Oct  8 04:31 demux0
crw-rw----+  1 root video 212, 33 Oct  8 04:31 dvr0
crw-rw----+  1 root video 212, 35 Oct  8 04:31 frontend0
crw-rw----+  1 root video 212, 34 Oct  8 04:31 net0

then it is likely to work.  And so will almost any other Linux
software that supports DVBAPI tuners.

To create a network tuner out of a DVBAPI tuner, there are several
programs you can use that do it in different ways:

minisatip
  SAT>IP protocol
mumudvb
  multicast, HTTP unicast
TVHeadend
  SAT>IP protocol, HTTP unicast, probably others I have not tried

TVHeadend is the most capable but also by far the most complicated.

MythTV will generally not be able to scan for channels on a network
tuner created by one of the above programs - that is a limitation of
MythTV as those programs do support scanning a tuner.  MythTV is only
capable of scanning for channels on network tuners it has special code
for, such as HDHRs.

I am using minisatip for my DVB-S2 tuners, and manually configuring
the channels in MythTV.  I keep hoping that one of the devs will get a
SAT>IP tuner and will then implement scanning code for it.  Most of
what is required to do it is already in the MythTV code, but it needs
to be linked together.

There used to be software that created a virtual tuner over a network,
so that a /dev/dvb/adapter<x> device appeared on the MythTV box and
could be used for scanning and all normal use.  But it has not been
maintained for quite some time and does not compile against recent
kernels.  Last time I looked, there were lots of variants of this code
on github and other sites, but I never found one that worked.  I think
some of the TV boxes that you can buy use older kernels and can do
this still, but only between the same type of box.

And with the virtual tuner setup, the tuner is only able to be used by
one PC at once.  With the other programs, many different devices on
your network can be using the networked tuner at the same time, as
long as they all want channels that are on the same broadcast
frequency.  I often have my MythTV box recording from my DVB-S2 tuners
via minisatip and also am watching a programme on my Windows box at
the same time using DVBViewer.  The SAT>IP protocol specification
requires that if the same tuner can be reused for multiple
connections, it will be done that way, rather than using a separate
tuner for each network connection.

There is no need to have a separate box like a Pi just to run network
tuners.  My networked DVB-S2 tuners are in my MythTV box, but they
could be on any of the Linux boxes on my network.  It just happens
that the MythTV box is the one closest to where my satellite dish's
aerial cable arrives inside the house.