[mythtv-commits] Ticket #13121: Sat>IP client support

MythTV noreply at mythtv.org
Sun Nov 29 18:46:56 UTC 2020

#13121: Sat>IP client support
 Reporter:  cg@…                |          Owner:  Klaas de Waal
     Type:  Patch - Feature     |         Status:  assigned
 Priority:  minor               |      Milestone:  32.0
Component:  MythTV - Recording  |        Version:  Master Head
 Severity:  low                 |     Resolution:
 Keywords:                      |  Ticket locked:  0

Comment (by Klaas de Waal):

 Thanks for reporting back.

 About the UDP buffer size. I've looked in the HDHomeRun library and there
 the UDP buffer size is set to 1024x1024 bytes, the actual value depending
 on the net.core.rmem_max value of the system. Note that it overall saves
 memory if you only set the net.core.rmem_max value and not the
 net.core.rmem_default because MythTV only extends the buffer size for the
 socket that is actually used for the video data stream. There is also a
 socket for the control data and the buffer size of that socket does not
 need to be changed.

 I've looked into the "bad patch" problem and this is caused by the
 multirec feature not yet being implemented completely. What happens is
 that when your second recording starts the box is tuned again, on the same
 channel. This causes the disruption in your first recording. The correct
 behavior is to recognize that the channel is already in use and that it is
 already correctly tuned so the tuning can be skipped.
 This is how it is implemented for the /dev/dvb/adapter*/* devices
 (PCI/PCIe, USB) and this is also how it should be done for SatIP.

 About the bitrate of the incoming stream. The code is now such that when
 more than 32 PIDs are requested the full transport stream is received.
 When there are less PIDs requested then the Sat>IP box is doing the PID
 filtering so then you only receive the PIDs that are needed.
 This is done because the Digibit R1 box effectively dies when your request
 more than 36 or 37 PIDs. The minisatip software, running on a PC, does not
 have this limitation but we write software for the worst case situation.
 Still to investigate why recording a channel on the BBC One/Two HD mux
 requires so many PIDS that it needs to receive the full transport stream.

Ticket URL: <https://code.mythtv.org/trac/ticket/13121#comment:45>
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