[mythtv-users] DVB-T Hell in Sydney

Doug Scoular (dscoular) dscoular at cisco.com
Thu Jun 2 07:00:52 UTC 2016


Hi All,
	From my home in Church Point I've always had a very marginal signal from
our local DVB-T transmitter (Bouddi, NSW) but I replaced the antenna, got
a Sony Play-TV tuner and put in quad shielded cable and everything was
peachy for the last 3 or 4 years. All networks were working brilliantly:
ABC, Seven, Nine, Southern Cross Ten and SBS with a full compliment of
each network's channels.

	However, at the end of May I noticed I couldn't reliably tune in to
channel 10 or SBS... now I can't get MythTV to get lock on any channel.

	I'm running mythbuntu 16.04 with mythbackend version v0.28-2-g15cf421:

root at spug:~# mythbackend --version
Please attach all output as a file in bug reports.
MythTV Version : v0.28-2-g15cf421
MythTV Branch : fixes/0.28
Network Protocol : 88
Library API : 0.28.20160309-1
QT Version : 5.5.1

	Nothing, I'm aware of has changed other than the recent auto-update of
the mythtv 0.28 to g15cf421 but I looked at that commit and it seemed
quite unrelated to my DVB-T woes.

	When I shutdown the mythtv backend daemon, I can scan my local
transponder with either old skool scan(1) and the dvb-legacy initial
tuning files or the new fangled dvbv5-scan(1) with the new format initial
tuning files. 

	Here I go old skool:

root at spug:~# scan -t 1 -5 /usr/share/dvb/dvb-legacy/dvb-t/au-Newcastle  >
~/.tzap/channels.conf
scanning /usr/share/dvb/dvb-legacy/dvb-t/au-Newcastle
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
initial transponder 599500000 1 2 9 3 1 2 0
initial transponder 585500000 1 3 9 3 1 1 0
initial transponder 704500000 1 3 9 3 1 1 0
initial transponder 592500000 1 3 9 3 1 1 0
initial transponder 690500000 1 3 9 3 1 1 0
>>> tune to: 
>>>599500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>599500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_2_3:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE (tuning failed)
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE
0x0000 0x0065: pmt_pid 0x0100 NBN Television -- NBN Newcastle (running)
0x0000 0x006f: pmt_pid 0x0101 NBN Television -- 9HD Newcastle (running)
0x0000 0x00bf: pmt_pid 0x0105 NBN Television -- NBN Newcastle (running)
0x0000 0x0079: pmt_pid 0x0106 NBN Television -- 9GEM Newcastle (running)
0x0000 0x0083: pmt_pid 0x0107 NBN Television -- 9GO! Newcastle (running)
0x0000 0x0097: pmt_pid 0x0104 NBN Television -- 9Life Newcastle (running)
0x0000 0x008d: pmt_pid 0x0102 NBN Television -- eXtra (running)
0x0000 0x00b5: pmt_pid 0x0103 NBN Television -- 9GO! Newcastle (running)
Network Name 'NBN Newcastle'
>>> tune to: 
>>>704500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>704500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE (tuning failed)
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE
0x0000 0x02a0: pmt_pid 0x0102 ABC -- ABC News 24 (running)
0x0000 0x02a1: pmt_pid 0x0100 ABC -- ABC (running)
0x0000 0x02a2: pmt_pid 0x0101 ABC -- ABC2/KIDS (running)
0x0000 0x02a3: pmt_pid 0x0103 ABC -- ABC (running)
0x0000 0x02a4: pmt_pid 0x0104 ABC -- ABC3 (running)
0x0000 0x02a6: pmt_pid 0x0105 ABC -- Double J (running)
0x0000 0x02a7: pmt_pid 0x0106 ABC -- ABC Jazz (running)
Network Name 'ABC NSW'
>>> tune to: 
>>>690500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>690500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
>>>SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE (tuning failed)
WARNING: >>> tuning failed!!!

>>> tune to: 
>>>226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMIS
>>>SION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE
WARNING: >>> tuning failed!!!
>>> tune to: 
>>>226500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMIS
>>>SION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE (tuning failed)
WARNING: >>> tuning failed!!!
dumping lists (15 services)
Done.

	For some reason the above old skool scan no longer shows network Seven,
Southern Cross Ten or SBS and the new-fangled dvbv5-scan fairs worse only
finding the SBS and Nine network channels. It doesn't see the ABC network
(even with extra delays):

root at spug:~# dvbv5-scan -T 5 /usr/share/dvb/dvb-t/au-Newcastle
Cannot calc frequency shift. Either bandwidth/symbol-rate is unavailable
(yet).
Scanning frequency #1 599500000
       (0x00) Signal= -63.29dBm
... output omitted for brevity ...

root at spug:~# cat dvb_channel.conf |grep \\[
[SBS ONE]
[SBS HD]
[SBS TWO]
[Food Network]
[NITV]
[SBS Radio 1]
[SBS Radio 2]
[SBS Radio 3]
[NBN Newcastle]
[9HD Newcastle]
[NBN Newcastle]
[9GEM Newcastle]
[9GO! Newcastle]
[9Life Newcastle]
[eXtra]
[9GO! Newcastle]


	Well, maybe something happened to the antenna or the cable run and I lost
a few channels... the important thing to note is that scanning and tuning
outwith MythTV work.

	I can use tzap (old skool) or dvbv5-zap to get "lock" on any of the found
channels and then use mplayer to watch the stream:

root at spug:~# tzap  "NBN Newcastle"
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
reading channels from file '/root/.tzap/channels.conf'
Version: 5.10    FE_CAN { DVB-T }
tuning to 585500000 Hz
video pid 0x03e8, audio pid 0x03f2
status 0f | signal be55 | snr 00bb | ber 001fffff | unc 00000000 |
status 1f | signal bf79 | snr 00c9 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK


	Here's dvbv5-zap succeeding on getting "lock" on "SBS HD":

root at spug:~# dvbv5-zap -c ~/dvb_channel.conf "SBS HD"
using demux '/dev/dvb/adapter0/demux0'
reading channels from file '/root/dvb_channel.conf'
service has pid type 05:  7853
tuning to 599500000 Hz
video pid 102
  dvb_set_pesfilter 102
audio pid 103
  dvb_set_pesfilter 103
Lock   (0x1f) Quality= Good Signal= -38.98dBm C/N= 17.67dB UCB= 0 postBER=
13.9x10^-6 PER= 0
Lock   (0x1f) Quality= Good Signal= -39.20dBm C/N= 17.67dB UCB= 0 postBER=
13.9x10^-6 PER= 0


	However, mythtv no longer seems to be able to get lock on *any* of my
channels.

	I see "TL_s Partial Lock" on the screen and the following in the logs:

Jun  2 16:30:56 spug mythbackend: mythbackend[15536]: I TVRecEvent
tv_rec.cpp:1073 (HandleStateChange) TVRec[1]: Changing from None to
WatchingLiveTV
Jun  2 16:30:56 spug mythbackend: mythbackend[15536]: I TVRecEvent
tv_rec.cpp:3685 (TuningFrequency) TVRec[1]: TuningFrequency
Jun  2 16:30:56 spug mythbackend: mythbackend[15536]: N CoreContext
autoexpire.cpp:264 (CalcParams) AutoExpire: CalcParams(): Max required
Free Space: 3.0 GB w/freq: 14 min
Jun  2 16:30:57 spug mythbackend: mythbackend[15536]: N TVRecEvent
recordinginfo.cpp:687 (ApplyRecordRecGroupChange)
ApplyRecordRecGroupChange: LiveTV to LiveTV (2)
Jun  2 16:30:57 spug mythbackend: mythbackend[15536]: E DVBRead
recorders/dtvsignalmonitor.cpp:322 (HandlePAT)
DTVSigMon[1](/dev/dvb/adapter_playtv-0/frontend0): Program #849 not found
in PAT!#012Program Association Section#012 PSIP tableID(0x0) length(45)
extension(0x700)#012      version(0) current(1) section(0)
last_section(0)#012      tsid(1792) programCount(9)#012  program number
 0 has PID 0x0010#012  program number   101 has PID 0x0100#012  program
number   111 has PID 0x0101#012  program number 191 has PID 0x0105#012
program number   121 has PID 0x0106#012  program number   131 has PID
0x0107#012  program number   151 has PID 0x0104#012  program number   141
hasPID 0x0102#012  program number   181 has PID 0x0103
Jun  2 16:30:58 spug mythbackend: mythbackend[15536]: E DVBRead
mpeg/mpegstreamdata.cpp:822 (ProcessPAT) MPEGStream[1](0x7f870402af28):
ProcessPAT: Program not found in PAT. Rescan your transports.
Jun  2 16:30:58 spug mythbackend: mythbackend[15536]: E DVBRead
mpeg/mpegstreamdata.cpp:429 (CreatePATSingleProgram)
MPEGStream[1](0x7f870402af28): Desired program #849 not found in
PAT.#012#011#011#011Cannot create single program PAT.
Jun  2 16:31:02 spug mythbackend: mythbackend[15536]: W TVRecEvent
tv_rec.cpp:4004 (TuningSignalCheck) TVRec[1]: TuningSignalCheck: taking
more than 5000 ms to get a lock.


	I even tried re-tuning but the mythtv scan reportedd that it didn't find
any new transports (or channels, I can't quite remember).

	Do I need to delete my old channels and rescan (after backing up) ?

	I'm puzzled as to why mythtv was working two nights ago and is now
failing to get lock on any of it's channels.

	I've even tried replacing the Sony PlayTV with an old GicaTV (afatech
af9015) dual tuner USB stick just to verify that it wasn't an issue with
the DVB-T hardware.

	Any thoughts or insights hugely appreciated ?

	Oh, and if anyone knows the individual database tables related to DVB-T
channels and scanning, in 0.28, that would save me having to backup the
entire mythtv database.

	Cheers,

	Doug

	"The big print giveth and the small print taketh away..."



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