I migrated from MythTV 30 to 31 using the latest git pull. Unfortunately, MythTV 31 does not recognise my DMB card and the log shows:
2020-09-20 12:37:35.236898 E CardUtil: TODO Add to switch case delivery system:13 DMBTH
2020-09-20 12:37:35.267303 I CardUtil(/dev/dvb/adapter1/frontend0): dvb api version 5.11
2020-09-20 12:37:35.267312 I CardUtil(/dev/dvb/adapter1/frontend0): Delivery systems: DMBTH
2020-09-20 12:37:35.297679 I CardUtil: Current delivery system: DMBTH
2020-09-20 12:37:35.297689 I CardUtil: Supported delivery systems: DMBTH
When running mythtv-setup, the DVB device is recognised as /dev/dvb/adapter0/frontend0 but the Frontend ID states
"Could not get card info for card /dev/dvb/adapt..."
If I revert back to MythTV 30 it all works again. I'm guessing that the TODO in the CardUtil log implies that this coding is not yet complete and may have been forgotten?
Best regards to all
Brendan
Last edited by bonhug on Tue Sep 22, 2020 1:14 am, edited 1 time in total.
The interesting bit is why it works with Mythtv v30 as I cannot find support for DMBTH / DTMB in the code. My guess is that it is treated as a DVB-C device and I could do that in v31 as well. To confirm this, can you please make a channel scan (Full Scan or Full Scan (Tuned) whichever you use) with the v30 mythtv-setup, with debug output like this:
dvb-fe-tool
Device AltoBeam ATBM8830/8831 DMB-TH (/dev/dvb/adapter0/frontend0) capabilities:
CAN_FEC_AUTO
CAN_GUARD_INTERVAL_AUTO
CAN_INVERSION_AUTO
CAN_QAM_AUTO
CAN_TRANSMISSION_MODE_AUTO
DVB API Version 5.11, Current v5 delivery system: DTMB
Supported delivery system:
[DTMB]
Frequency range for the current standard:
From: 474 MHz
To: 858 MHz
Step: 50.0 kHz
The complete log file is about 330k in size. Unsurprisingly, I can't just paste that here. I'll read up on that later (it's 4:30am here) and work out how to give you the log
Thanks for the log. MythTV v30 sees your DTMB card as a DVB-T device and because your tuner accepts "auto" for all modulation parameters this does work. This suggests that if I add DTMB as a synonym for DVB- T that it might just work. A more complete implementation would have e.g. modulation parameter selection that is correct for DTMB as there are some differences with DVB-T.
There is the problem that I cannot test the changes that I make. It would be great if you can compile v31 from source, then I can send you patches and if it is all OK I can put it in the repo.
Would that work for you?
I've committed a fix to mythtv v31 that selects now tuner type DVB-T when modulation system DMBTH (DTMB) is found on the card. This should solve your problem so please test it once the repo you use is updated.