[mythtv-users] DVB-T Hell in Sydney

HP-mini blm-ubunet at slingshot.co.nz
Fri Jun 3 20:18:07 UTC 2016


On Fri, 2016-06-03 at 13:33 +0000, Doug Scoular (dscoular) wrote:
> 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
> 
> 

I've found w-scan to be very good & fast.
https://linuxtv.org/wiki/index.php/W_scan
http://wirbel.htpc-forum.de/w_scan/index_en.html

Mythtv-setup scan with verbose logging (of scanning/tuning) is very
impressive & informative.

"Femon" is handy for checking cables/connections etc..



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