|Found in version:||9d775da||Affected Versions:|
When perfoming the first mux scan, duplicate muxid's are created. It seems TVheadend will only scan one of the two muxid's for services, and which one is being scanned appears random.
I see duplicate mux id's and incorrect transponders for the following multiplexers
12344.000 1097 (incorrect frequency)
12344.500 1097 (correct frequency)
12515.000 1105 (incorrect frequency)
12515.250 1105 (correct frequency)
12722.000 1119 (incorrect frequency)
12721.750 1119 (correct frequency)
I also saw duplicate mux id for TVPolonia, but did not investigate that any deeper.
Result is that services are not found, and result differs from one scan to the other.
#2 Updated by Johan van der kolk almost 2 years ago
Added DVB network, ASTRA 19.2E, and it added the initial mux. Then autodetect muxes. This creates both the good and bad muxes. I receive 99 muxes that way.
I now removed the initial mux, added the 3 correct muxes manually. All services are detected. Autodetect was switched off.
After switching the autodetect back on, the invalid muxes are added:
Aug 14 13:24:35 dvb: New mux "12,344,000 kHz Horizontal (Default (Port 0, Universal LNB))" created by automatic mux discovery
Aug 14 13:24:35 dvb: New mux "12,515,000 kHz Horizontal (Default (Port 0, Universal LNB))" created by automatic mux discovery
Aug 14 13:24:35 dvb: New mux "12,574,000 kHz Horizontal (Default (Port 0, Universal LNB))" created by automatic mux discovery
Aug 14 13:24:35 dvb: New mux "12,722,000 kHz Horizontal (Default (Port 0, Universal LNB))" created by automatic mux discovery
I have not re-added the initial mux, and therefore I assume it does not detect any further muxes. After the autodetect process above no new service were created, and I deleted the bad muxes again.
In the original scenario
full autodetect with initial mux, deleting the bad muxes did not make TVheadend create the services from the good muxes.
#3 Updated by Hein Rigolo almost 2 years ago
if they are added by automatic mux discovery then these muxes are present in the DVB NIT information tables that are transmitted on this network.
It would be good to find out where they are coming from, but this is not something that can be fixed within tvheadend. If these muxes are really incorrect, then the NIT information is incorrect and that is not something tvheadend can correct automagically.
#4 Updated by Johan van der kolk almost 2 years ago
I assume that TVHeadend actively uses the muxid for storing information, and once it has a certain muxid in its database identical muxids will not be scanned anymore on a different transponder. Even though this may be theoretically correct, in practise it seems that Astra (or Canaldigital) does not adhere to the standards.Neither my personal sat receiver nor mythtv seems to mind about the duplicate id's though.
Not being familiar with the standards, I do not know if the muxid should be unique per transponder, per satellite or per satellite constellation. TVHeadend seems to tend to use the first approach.
Workaround: add the correct muxid first, then perform an automatic scan using the initial transponder. Due to the implementation in TVHeadend, the incorrect muxids will not be used.
#5 Updated by Hein Rigolo almost 2 years ago
As far as i can tell this problem can only be found if it can be determined which NIT table is adding the incorrect muxes.
The dvb-s astra 19.2 initial tuning file is only adding the 12551.500 frequency. All the other muxes are determined from there on. Because you also see this happening when you manually add only the 3 good transponders, the NIT table that is causing this problem must be transmitted on one of these 3 transponders.
So it would be a matter of taking the NIT table that is transmitted on those frequencies and checking what information is in those tables. Then we can determine if the actual transponders are sending incorrect data, or that tvheadend reads it incorrectly.
You could create a mux dump for these tables and then analyze them using dvbsnoop or an other dvb analysis tool. (have a look at this one: http://www.digitalekabeltelevisie.nl/dvb_inspector/ )
You can create the mux dumps directly from tvheadend by enabling the mux dump option, and then tune to a service on these transponders. This will create a dump of the mux in the recording directly in a separate directory.
#6 Updated by Johan van der kolk almost 2 years ago
dvbsnoop 0x10 |grep Frequency
Frequency: 19088384 (= 12.34400 GHz)
Frequency: 19207424 (= 12.51500 GHz)
Frequency: 19231744 (= 12.57400 GHz)
Frequency: 19341824 (= 12.72200 GHz)
Same on two out of the 4 transponders. I can attach a full dvbsnoop 0x10 output if required or run it with different options. Let me know.