[mythtv-users] duplicate callsigns? (was: Re: utterley confused)

[Stephen Worthington]

On Mon, 23 Jun 2014 23:15:13 +1000, you wrote:

>On 6/23/14, James Linder <jam at tigger.ws> wrote:
>>
>> Here is a sequence that shows this bizare behaviour:
>>
>> 16:59
>> 1 program scheduled to record
>> http://tigger.ws/myth1.png
>>
>> 17:01
>> It has started to record
>> http://tigger.ws/myth2.png
>>
>> 17:03
>> The second instance has started. It reports start time as 16:58 but really
>> it is 17:02 ish
>> http://tigger.ws/myth3.png
>>
>> I can’t make sense of this. It is a new DB. Anybody help please 

>>
>
>This may be sending you down the wrong track here so I've tweaked the
>subject line...
>I have noticed that some Australian broadcasters send out more than
>one program stream in their multiplex that has the exact same
>callsign. I am not sure how mythtv copes with this.
>
>If you want to check whether this is happening in your case, here is
>what I would try.
>Stop the mythtv-backend, and do a scan with 'w_scan -f t -c AU -X -a 0'.
>it will spit out a bunch of detailed channel information. The reason
>for using w_scan
>is that I find it simpler to see the raw detail of what is being
>transmitted than the myth channel editor.
>
>Here is what I get for the channel 10 multiplex in Sydney (on 219500000 Hz)
>(I took out a few spaces in the first field to keep the long lines together).
>
>ONE(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:672:1569
>TENDigital(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1573
>TVSN(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:518:690:1574
>ONE(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:672:1575
>ELEVEN(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:516:681:1576
>SpreeTV(TENSydney):219500000:INVERSION_AUTO:BANDWIDTH_7_MHZ:FEC_3_4:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:520:700:1577
>
>It's not obvious to me (without additional information from other
>sources) whether the duplicate callsign indicates exactly the same
>content in the program stream - the programid field (the last one I
>think, w_scan's output needs better documentation) is different.
>
>Hope this helps a bit
>Vince

The last field will be the mplexid, which identifies the stream for
that channel on the multiplex, so it is not significant in that all it
says is that it is a different channel.

Here in New Zealand, we have similar things on the DVB-S broadcasts.
They are for different areas of New Zealand so that different local
advertisements can be transmitted.  Might Sydney be large enough for
them to want to do that within one city on DVB-T?