Scanning for new/updated channels results in a mess (1 Viewer)

riksmith

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I don't know which of those is the channel ID I mentioned either :) It's what I see in TVServer config when I click on a channel and it shows under ID, a number from 1-xx.

I appreciate you can't just use this, as other sources might also use these numbers, but why not just (for DVB-T/Freeview) T-1, T-2, etc?

I don't get the question. On one side you seem to understand we can't do that since we have other sources. But on the other side your are asking if we can make an exception for one of those sources?
 

doveman

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I probably just don't understand the problem fully, but I'm not suggesting you make an exception just for one source (although if that's all that's required for Freeview/DVB-T, perhaps the other fields can be left blank for that as it seems pointless filling them with details that aren't required).

What I meant was, I understand why Freeview channels can't just be ID'd as 1, 2 etc but can't DVB-T channels be ID'd as T-1, T-2 and DVB-S channels ID'd as S-1, S2 or is there some good reason why all the three IDs + Channel Type have to be used?
 

riksmith

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Aah that is the question. There is no guarantee that the channel id you mention is unique. Only those three are guaranteed to be unique.
 

jameson_uk

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    Aah that is the question. There is no guarantee that the channel id you mention is unique. Only those three are guaranteed to be unique.

    and logical channel numbers (ie BBC One is 1, Channel 4 + 1 is 13 etc) change (and indeed did a few days ago
    Freeview - Home Resolutions About Channels Channel changes ITV1+1 to launch on 11 January 2011)

    And just having had a play with this Freeview seem to have not done what the DVB standards say they should.

    Previously ITV2 + 1 had
    ONID = 9018
    TSID = 8198
    SID = 8362

    According to the specs when they move the channel the ONID/SID should have stayed the same (in which case we could have updated the tuning details) but the details are now
    ONID = 9018
    TSID = 12290
    SID = 15952

    so as far as MP is concerned a brand new channel.

    More annoyingly is that ITV1 + 1 has the details that ITV2 + 1 had previously. I had this merged with ITV2 + 1 on Freesat so now I have two different channels merged together.

    Not a lot we can do about this is they are not following the rules. They have effectively renamed ITV2 + 1 as ITV1 +1 so even using the channel number as you said this would not work

    With the new logic (and assuming channel was not combined with Freesat etc) what would have happened is that ITV2+1 would have become ITV1+1 (and hopefully we will put in a little extra fix that would have renamed the channel). ITV2+1 would then have become a new channel. So in theory this would of worked for you
     

    riksmith

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    According to the specs when they move the channel the ONID/SID should have stayed the same (in which case we could have updated the tuning details)

    Well it is just an advise, no requirement.

    it is strongly recommended that service_ids, once assigned to a specific service within a
    network, remain unchanged in order to enable IRDs to implement features like favourite
    channel lists, etc.
     

    doveman

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    Aah that is the question. There is no guarantee that the channel id you mention is unique. Only those three are guaranteed to be unique.

    Well it's unique in the sense that there's only one T-1, T-2, etc. :)

    I must admit I didn't really comprehend how the channels on DVB-T were identified and I think I understand now that these three identifiers are what is needed at the base level to tune to the correct channel. But according to the issue you linked to, previously just the channel name was being used as the unique identifer, which must have been linked to a separate table containing these three identifiers, so I don't understand why we can't just use T-1, T2, etc as the unique identifier, which as before will then look up the three identifiers elsewhere, although it seems then we would need another table of the channel names.

    As far as I can tell, the channel names are picked up when (re)tuning, so perhaps we could use T-BBC1, T-ITV-2 as the unique identifier and then if the ONID, TSID or SID change for any channels, these are changed in the separate table. If the unique identifier is no longer going to be the channel name, there must be a separate table of these which is linked to the new three ID unique identifier. I think I'm just confusing myself now, so I'll think I'll stop there and hope you can explain it to me :confused:

    If the channel names are picked up when tuning, is it not possible for MP to quite easily recognise that ITV2+1 is now on 9018+12290+15952 and link the channel name to the correct tuning details when re-tuning?
     

    riksmith

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    Two things:
    I can not really give a different answer from what i said earlier.
    And what is your problem with how we solved it currently? What is the reason that you do not want to follow the DVB specs?
     

    doveman

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    I'm sure you could answer my questions if you wanted to, I think they're clear enough. If you can't be bothered, fair enough.

    I never said I didn't want to follow the DVB specs, but from what you've told me, changing the unique ID from channel name to the 3 identifiers doesn't seem to make much sense, unless lots of other things have been changed or there are plans to do so.
     

    tourettes

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    changing the unique ID from channel name to the 3 identifiers doesn't seem to make much sense, unless lots of other things have been changed or there are plans to do so.

    Channel name is not ever unique. Same channel name can be received from multiple sources (-S, -T, -C, -IP) or broadcaster can even use the same channel name multiple times in the same broadcast type. Also broadcaster can change the channel name (rename it) and the channel content would be still the same.

    I have seen all those to happen and name is not able to make unique channel identifier in those cases. DVB spec has already that issue sorted out, it just needs that both applications and broadcasters behave correctly. Now MP is complying the specs and if broadcaster isn't then we cannot unfortunately do anything about it.
     

    riksmith

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    I'm sure you could answer my questions if you wanted to, I think they're clear enough. If you can't be bothered, fair enough.

    I never said I didn't want to follow the DVB specs, but from what you've told me, changing the unique ID from channel name to the 3 identifiers doesn't seem to make much sense, unless lots of other things have been changed or there are plans to do so.

    If you read my reply i never said i did not want to give answers. I already gave them to you: We follow the specs. That's it. The only reason you give is that it doesn't make sense to you. It works, and it makes sense to the dev team and the people who invented the DVB specs, so why should we bother arguing about it?

    If you find something is WRONG with how we implemented it or if you run into a bug i am happy to discuss that with you or anybody else.
     

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