Opened 3 years ago

Closed 18 months ago

#13222 closed Bug Report - General (Fixed)

Channel scan with DVB-T2-capable tuner giving bad channel numbers

Reported by: J.Pilk@… Owned by: Klaas de Waal
Priority: minor Milestone: 31.0
Component: MythTV - Channel Scanner Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no


PCTV-290e, current master, fedora 26

qam_64:698000000:BBC ONE E Mid::0:9018:*4166*:4166=4166:dvb       0:cnt(pnum:1,channum:172)                                                                                                                                                                                           
qam_64:698000000:BBC TWO::0:9018:*4287*:4166=4166:dvb     0:cnt(pnum:1,channum:172)                                                                                                                                                                                                   
qam_64:698000000:BBC NEWS::0:9018:*4352*:4166=4166:dvb    0:cnt(pnum:1,channum:172)                                                                                                                                                                                                   
qam_64:698000000:BBC Red Button::0:9018:*4416*:4166=4166:dvb      0:cnt(pnum:1,channum:172)                                                                                                                                                                                           
qam_64:698000000:BBC FOUR::0:9018:*4544*:4166=4166:dvb    0:cnt(pnum:1,channum:172)

The numbers marked above are being displayed instead of the correct ones marked below.

DVB-T-only tuner 

qam_64:698000000:BBC ONE E Mid:*1*:12323:9018:4166:4166=4166:dvb  0:cnt(pnum:1,channum:1)
qam_64:698000000:BBC TWO:*2*:12323:9018:4287:4166=4166:dvb        0:cnt(pnum:1,channum:1)
qam_64:698000000:BBC NEWS:*231*:12323:9018:4352:4166=4166:dvb     0:cnt(pnum:1,channum:1)
qam_64:698000000:BBC Red Button:*250*:12323:9018:4416:4166=4166:dvb       0:cnt(pnum:1,channum:1)              

Attachments (2)

DVB_TuningTest2.txt (15.1 KB) - added by J.Pilk@… 3 years ago.
Part output of "mythtvsetup --verbose channel,chanscan,siparser,record"
DVBTuningTests3.txt (181.5 KB) - added by J.Pilk@… 3 years ago.
Full log of "mythtvsetup --verbose channel,chanscan,siparser,record | tee ~/Documents/DVBTuningTests3.txt"

Download all attachments as: .zip

Change History (13)

comment:1 Changed 3 years ago by Stuart Auchterlonie

Milestone: needs_triage30.0
Status: newinfoneeded_new
Version: UnspecifiedMaster Head

It looks like it's missing the LCN (Logical Channel Number) which is usually signalled in the UK.

Can you grab the output of running

# mythtv-setup --verbose channel,chanscan,siparser,record

it should be sufficient to rescan just the multiplex that broadcasts these channels.

Regards Stuart

Changed 3 years ago by J.Pilk@…

Attachment: DVB_TuningTest2.txt added

Part output of "mythtvsetup --verbose channel,chanscan,siparser,record"

comment:2 Changed 3 years ago by J.Pilk@…

It shot off the top of the screen but here's what looks like the most relevant part. I should be able to capture more if you need it.

The scan was of the main HD mux at 770 MHz. Data for the BBC HD mux for which 9018:4166 apply.

comment:3 Changed 3 years ago by J.Pilk@…

Correction. The data in the attachment refer to the SD mux but were obtained from a scan of the HD mux.

Changed 3 years ago by J.Pilk@…

Attachment: DVBTuningTests3.txt added

Full log of "mythtvsetup --verbose channel,chanscan,siparser,record | tee ~/Documents/DVBTuningTests3.txt"

comment:4 Changed 3 years ago by J.Pilk@…

I don't know if this is significant, but I just scanned with the same device on a 'buntu xenial laptop. Channel numbers were good with 30-pre-438 and 30-pre-484. It's the only tuner on the laptop. I haven't often used it on the Fedora box, where it was 'competing with' an SD tuner. Something might not have been quite right. I think that was 30-pre-484 too. Possibly apologies are appropriate.

comment:5 Changed 3 years ago by J.Pilk@…

Another single-mux scan on the Fedora system, where the two-device setup now seems OK, still gave the bad channel numbers. 30-pre-512, Qt 5.9.4

comment:6 Changed 3 years ago by J.Pilk@…

The laptop from comment 4 is now on 30-pre-556. Yesterday I found that BBC FOUR HD was not working. It seems that the '700 MHz clearance programme' had swapped the muxes on 754 MHz (now QAM-256) and 602 MHz (now QAM-64), and several attempted retunes all gave failed recordings. What eventually worked was deleting both those transports, rescanning with seek-new-linked-transports enabled and scanning yet again on 754 MHz only.

The ubuntu/Fedora channel numbers puzzle persists, but my TV and the Fedora box could both see all the revised muxes without my knowingly having taken special measures during tuning.

comment:7 Changed 2 years ago by Stuart Auchterlonie

Milestone: 30.030.1

comment:8 Changed 18 months ago by Klaas de Waal

Milestone: 30.131.0
Owner: set to Klaas de Waal

Can you please check if this problem is still present when doing a scan with the current pre-v31 master mythtv-setup?

comment:9 Changed 18 months ago by Klaas de Waal

Component: MythTV - GeneralMythTV - Channel Scanner

comment:10 Changed 18 months ago by jpilk

I have just rescanned 'all known transports' for DVB-T and DVB-T2. The EPG shows 4 channels with LCNs outside the normal range (1 to 800) but the tuning log and my TV have them between 790 and 795, numbers which seem to be used for recent or upcoming changes. I think the ticket can be closed. Thank you.

v31-Pre-9eba7cc9449, Branch: devel/2019-render, Mygica T230 DVB-T/T2/C, Philips TDA10046H DVB-T

comment:11 Changed 18 months ago by Klaas de Waal

Resolution: Fixed
Status: infoneeded_newclosed
Note: See TracTickets for help on using tickets.