86 replies to this topic

[Huevos]

When you have two DVB-T tuners, connected to two different antenna's, pointing to two different transmitters?

 

For example, you live on the border, and you are in the coverage of both the transmitter in your own country, and in a neighboring country. The case for example with a lot of Dutch people (who grew up watching German and Belgian TV).

As an aerial installer by profession I can tell you that is not how it is done. For a start a typical multi tuner receiver only has one socket. A cheap install would have the 2 aerials fed into a mixer. A dearer install would have an individual amplifier per multiplex and lift the signal level on each multiplex individually. Then everything is fed down one cable.

[Huevos]

BTW, using the network id isn't foolproof either, since you can easily have two DVB-T tuners pointing to two diffferent local transmitters, for example for regional channels. Both transmitters will use the same network id.

Yes but they won't be on the same frequency. So namespace subnet will work to divide them. And BTW, in UK regional channels are on different TSIDs. Only in Holland that I know of that regional channels have same TSID on different transmitters.

Edited by Huevos, 17 December 2017 - 16:24.

[WanWizard]

As an aerial installer by profession I can tell you that is not how it is done. For a start a typical multi tuner receiver only has one socket. A cheap install would have the 2 aerials fed into a mixer. A dearer install would have an individual amplifier per multiplex and lift the signal level on each multiplex individually. Then everything is fed down one cable.

 

And how would you de-multiplex the two aerials at the other end? I haven't seen any switches that allow multiple aerials to be connected, so I'm curious who that will work, given the fact that both would receive the same frequency band.

 

Anyway, I have no control over the building infra here. I have an outlet in the wall connected to the GSO which has an aerial on the other side of the building, pointing west-ish. And I have my own aerial on the balcony with a separate cable, that I can point to two different transmitters in range.

[WanWizard]

p.s. TSID's won't help. Those will make the service ref unique, but doesn't help selecting the correct tuner.

[dhwz]

 

It can easily be done using the last 4 positions of the namespace, the challenge is what value to use

I´ve read in another board that some DVB-T italian channels use it already, i.e. RAI 1 HD

1:0:1:218C:4:13E:EEEE0204:0:0:0

 

Thats just a DVB-T namespace caluculated by DreamOS, so nothing special at all.

[Huevos]

p.s. TSID's won't help. Those will make the service ref unique, but doesn't help selecting the correct tuner.

Like I said almost all multi tuner receivers only have one socket. Only a handful of enigma receivers are an exception for this.

 

 

 

As an aerial installer by profession I can tell you that is not how it is done. For a start a typical multi tuner receiver only has one socket. A cheap install would have the 2 aerials fed into a mixer. A dearer install would have an individual amplifier per multiplex and lift the signal level on each multiplex individually. Then everything is fed down one cable.

 

And how would you de-multiplex the two aerials at the other end? I haven't seen any switches that allow multiple aerials to be connected, so I'm curious who that will work, given the fact that both would receive the same frequency band.

 

e.

 

Band or frequency. Obviously if 2 multiplexes were on the same frequency you can't mix them onto the same cable or feed both in through a single socket. And TBH even if DVB-T transmitters are in different countries there is usually some common sense used so they don't end up on the same frequency.

 

Much more of a problem for real users is the hybrid T2/C tuners. They only have one socket so even though they can be set up as cable and terrestrial at the same time in the software, the hardware makes this an impossibility.

[Abu Baniaz]

Some people in Rep of Ireland and Northern Ireland combine two aerials and connect to the one tuner.

 

If we can add the extra namespace details just for dvb-t, that would be great.

[WanWizard]

Like I said almost all multi tuner receivers only have one socket. Only a handful of enigma receivers are an exception for this.

 

What do you mean by "one socket"? All my boxes have a connector per tuner (an FBC tuner is 1 tuner in this respect) to connect a cable to, whether they are S, C or T, not a single exception?

 

edit: obviously simultaneous combi tuners are an issue, but that is indeed a design problem. Ideally a combi tuner does either one or the other, but not both, as that would mean they're actually two tuners, and need two inputs.

 

Band or frequency. Obviously if 2 multiplexes were on the same frequency you can't mix them onto the same cable or feed both in through a single socket. And TBH even if DVB-T transmitters are in different countries there is usually some common sense used so they don't end up on the same frequency.

 

Ok, so you need a demuxer at the other end, similar to the Johansson Stacker you have for sat multiplexing.

[Huevos]

Boxes with fixed DVB-T tuners only have one socket. Boxes with PnP cards have one socket per card, not per tuner. There are currently no FBC for terrestrial although Vu is threatening to release one. Also same for USB twin tuners... only one socket.

Edited by Huevos, 17 December 2017 - 18:42.

[Huevos]

TBH I think you are missing my point. The chance of you being somewhere where you can access two terrestrial transmitters on the same frequency even if you were using highly directional aerials is extremely remote unless it is an SFN and then it wouldn't matter because both transport streams are identical..

Edited by Huevos, 17 December 2017 - 18:48.

[WanWizard]

All these all arguments (or better, excuses) for "we don't have to address this issue"?  With all due respect, I find that a bit easy...

[Huevos]

All these all arguments (or better, excuses) for "we don't have to address this issue"?  With all due respect, I find that a bit easy...

Sorry, I was just expressing my opinion. It is up to PLi if/how they handle it.

[WanWizard]

If this is being addressed, it would be better to have a generic solution, for compatibility reasons. Don't you think?

 

My point was simply that even if it is your opinion that it is a problem that does not apply to you, it may apply to other users. I think part of our job is to be able to see something from an end-users perspective, and solve their problems even though it doesn't directly affect us. Besides that, it's an interesting challenge.

[Huevos]

I made a patch for handling namespace subnetwork by DVB type for anyone interested.

 

https://github.com/H...44aec102dc25d0c

[Abu Baniaz]

Just for information, this is what I got for my Terrestrial services

 

t:eeee01e2:5040:233a,t:482000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee01ea:1044:233a,t:490000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee01fa:3006:233a,t:506000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee0202:2005:233a,t:514000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee0212:6040:233a,t:530000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee021a:800a:233a,t:538000000:0:5:5:3:2:4:4:2:0:0:0
t:eeee0222:4084:233a,t:546000000:0:5:5:3:2:4:4:2:0:1:0
t:eeee023a:a000:233a,t:570000000:0:5:5:3:2:4:4:2:0:1:0
t:eeee024a:b000:233a,t:586000000:0:5:5:3:2:4:4:2:0:1:0

 

 

eeee01e2:5040:233a
    t 482000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee01ea:1044:233a
    t 490000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee01fa:3006:233a
    t 506000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee0202:2005:233a
    t 514000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee0212:6040:233a
    t 530000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee021a:800a:233a
    t 538000000:0:5:5:3:2:4:4:2:0:0:0
/
eeee0222:4084:233a
    t 546000000:0:5:5:3:2:4:4:2:0:1:0
/
eeee023a:a000:233a
    t 570000000:0:5:5:3:2:4:4:2:0:1:0
/
eeee024a:b000:233a
    t 586000000:0:5:5:3:2:4:4:2:0:1:0

[athoik]

Try to clear terrestrial services now.

Do they clear? Or fix required?

(Is clearing only eeee not eeee+freq)

Edited by athoik, 18 December 2017 - 07:20.

[Huevos]

From a scan of terrestrial transponder the channels clear (EEEE0000). Turn off "DVB-T ignore subnet" and rescan. Channels clear (EEEExxxx).

 

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[Erik Slagter]

p.s. TSID's won't help. Those will make the service ref unique, but doesn't help selecting the correct tuner.

Indeed, we need to have the onid in the "orbital".

[Huevos]

 

[...]

[...]

 

PS: many of the entries on your list are also old or not necessary (e.g. all with ONID = 1 are matched per default in C++), and the entry on 19,2 1:1028 is not existing as duplicate.

 

Why are 0, 1, 0x1111 and  >= 0xFF00 considered invalid ONIDs?

[WanWizard]

See http://www.dvbservic...iers/network_id for 0x000 and >= 0XFF00. These are not invalid, but shouldn't occur in the wild.