[mythtv-users] DVB-T Hell in Sydney

[Doug Scoular (dscoular)]

Hi All,
	Well, skeptical though I was, deleting my DVB tuners and channels fixed
all my issues.

	MythTV 0.28 found 7 multiplex and 43 channels... more than I've ever had!
Hooray.

	This knocks my understanding of DVB-T tuning on it's head. I'd always
thought the best way to test tuning was to use /usr/bin/scan to determine
if basic tuning worked without all the complexity of MythTV. Well it seems
things have changed and now MythTV 0.28 tuning is more thorough than
scan(1) or dvbv5-scan(1):

root at spug:/var/log/mythtv# scan
/usr/share/dvb/dvb-legacy/dvb-t/au-Newcastle | tee ~/channels-legacy.conf
dumping lists (15 services)
Done.
NBN 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1000:1010:101
9HD 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1200:0:111
NBN 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1000:1010:191
9GEM 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1100:1110:121
9GO! 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1881:1882:131
9Life 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1400:1410:151
eXtra:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANS
MISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1841:1842:141
9GO! 
Newcastle:585500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:T
RANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:1881:1882:181
ABC News 
24:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMI
SSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:516:0:672
ABC:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSM
ISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:673
ABC2/KIDS:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:
TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:651:674
ABC:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSM
ISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:675
ABC3:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANS
MISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:652:676
Double 
J:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANSMIS
SION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:690:678
ABC 
Jazz:592500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_AUTO:QAM_64:TRANS
MISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:700:679


	The legacy scan(1) only finds two networks and 15 services.

	The new fangled dvbv5-scan(1) only manages 8 services (I think). It seems
a step down from the old skool tzap(1):

root at spug:/var/log/mythtv# dvbv5-scan -v -a 0 -N -p -o ~/new_fangled.conf
/usr/share/dvb/dvb-t/au-Newcastle

using demux '/dev/dvb/adapter0/demux0'
Device DiBcom 7000PC (/dev/dvb/adapter0/frontend0) capabilities:
... lines omitted for brevity ...

root at spug:/var/log/mythtv# grep \# ~/new_fangled.conf
[585.50MHz#101]
[585.50MHz#111]
[585.50MHz#191]
[585.50MHz#121]
[585.50MHz#131]
[585.50MHz#151]
[585.50MHz#141]
[585.50MHz#181]
root at spug:/var/log/mythtv# dvbv5-zap -c ~/new_fangled.conf '585.50MHz#101'
using demux '/dev/dvb/adapter0/demux0'
reading channels from file '/root/new_fangled.conf'
service has pid type 06:  1030
tuning to 585500000 Hz
video pid 1000
  dvb_set_pesfilter 1000
audio pid 1010
  dvb_set_pesfilter 1010
Sync   (0x0f) Signal= -40.95dBm
Lock   (0x1f) Quality= Good Signal= -40.52dBm C/N= 21.76dB UCB= 0 postBER=
65.5x10^-6 PER= 0
Lock   (0x1f) Quality= Good Signal= -40.51dBm C/N= 21.76dB UCB= 0 postBER=
65.5x10^-6 PER= 0



	So it seems like scan(1) and dvbv5-scan(1) have moved backwards in the
DVB-T scanning stakes while MythTV 0.28 has moved forward.

	I've still no idea why mythtv 0.28 worked swimmingly for a month before
carking it or why the retune fixed things.

	I'm just very happy to have MythTV working again and Masterchef recording
so I regain my WAF!

	Cheers,

	Doug