:: #mythtv

Daily chat history

Current users (59):

aloril_, amessina, Anssi, benklop, betheynyx_, blahdodo, brfransen, ChanServ, Chutt, clever-afk, Cougar, CyberJacob, davic, dblain, dekarl, dmfrey, dym, eharris, ElmerFudd, gary_buhrmaster, ghoti, gigem, gregbert, GreyFoxx, Hydr0p0nX, ikevin, jab416171, jams, jheizer_, jpabq_, jpharvey_, jst, justinh, jya, knowledgejunkie, KooeeeeennN, kukks, libsci, logan-, mad_enz, markspieth, membiblio, MitchCapper, MythBuild, MythLogBot, nephyrin`, peper03, poptix, pppingme, sphery, stuarta, tgm4883, Tobbe5178, tris, vincent43, wagnerrp, XDS2010, xris-, _charly_
Saturday, March 25th, 2017, 00:20 UTC
[00:20:31] membiblio (membiblio! has quit (Remote host closed the connection)
[00:22:35] membiblio (membiblio! has joined #mythtv
[00:39:48] justinh (justinh! has joined #mythtv
[00:40:40] justinh: hi all. I have a question about the channelscanner code – trying to understand why scanning for channels is failing to produce valid channums from UK freeview LCNs
[00:42:55] justinh: QMap<qlonglong, uint>::const_iterator it = ukChanNums.find 1364 (((qlonglong)info.orig_netid<<32) | info.service_id);  — what will this do? I've looked in channelscan_channel & it seems all the orig_netid fields are 0 – which I guess means myth thinks it hasn't seen this network before – but I know it has. networkid 9018 has been with me since I moved house over 2 years ago
[00:43:39] justinh: it has because that;s the networkid of all the transports in dtv_multiplex – and it's the one currently being broadcast too
[00:47:45] justinh: ah wait I'm mixed up. it's netid which is 0 in the channelscan_channel table. orig_netid are all 9018 which is correct
[00:48:30] justinh: anyway 9018 is definitely the networkid & the usual scan utils are picking that up corrctly too – so is myth's scanner by the look of things in my log here
[00:52:20] arescorpio (arescorpio! has joined #mythtv
[02:00:17] amessina (amessina!~amessina@unaffiliated/amessina) has quit (Remote host closed the connection)
[02:00:51] amessina (amessina!~amessina@unaffiliated/amessina) has joined #mythtv
[03:28:33] amessina (amessina!~amessina@unaffiliated/amessina) has quit (Remote host closed the connection)
[03:30:56] amessina (amessina!~amessina@unaffiliated/amessina) has joined #mythtv
[03:43:34] peper03 (peper03!~peper03@mythtv/developer/peper03) has quit (Ping timeout: 256 seconds)
[03:50:26] peper03 (peper03!~peper03@mythtv/developer/peper03) has joined #mythtv
[04:15:16] amessina (amessina!~amessina@unaffiliated/amessina) has quit (Quit: Konversation terminated!)
[05:24:30] arescorpio (arescorpio! has quit (Quit: Leaving.)
[05:37:07] ShapeShifter499 (ShapeShifter499!~ShapeShif@unaffiliated/shapeshifter499) has quit (Quit: Leaving)
[06:29:09] Warped (Warped!~Warped@unaffiliated/warped) has quit (Quit: ChatZilla 0.9.93 [Firefox 52.0.1/20170316213829])
[06:30:50] Warped (Warped!~Warped@unaffiliated/warped) has joined #mythtv
[07:41:32] SteveGoodey (SteveGoodey! has joined #mythtv
[08:07:14] dekarl: 9018 ist "DVB-T UK" at
[08:07:57] dekarl: network_id is mostly unused for DVB-T around here, 9018 is the original_network_id. But we have them mixed up all over the place (like many code bases do)
[08:09:31] dekarl: orig_netid << 32 | service_id is creating a key from the theoretical primary key of the channel. If you have the same tv service on two multiplexes you may see a collision that should be "mythically resolved" with prefering the stronger signal
[08:26:51] dekarl1 (dekarl1!~dekarl@mythtv/developer/dekarl) has joined #mythtv
[08:27:05] dekarl (dekarl!~dekarl@mythtv/developer/dekarl) has quit (Ping timeout: 240 seconds)
[08:55:41] dekarl1 is now known as dekarl
[10:03:00] justinh: dekarl: ahhh. Well as far as I can tell I can't receive multiple signals – and besides I was scanning existing transports
[10:37:21] dekarl: justinh, sometimes, when you are between transmitters, you receive the same multiplex multiples times. e.g. over here we have 5 regional and 1 national mux. so in the center of 4 transmitters you get 4 instances of the national mux with identical tv services
[10:37:56] dekarl: there is a collision in original_network_id | transport_id in this case
[10:38:11] justinh: eew
[10:38:37] dekarl: its all nicely documented in the spec, but not implemented in our channel scanner :)
[10:39:22] justinh: I'm not sure it's that which is the problem. a blind scan only ever finds the transports I have defined already
[10:39:24] dekarl: a good improvement would be to ensure that the orignal_network_id is properly scanned / added (in cases where it was not scanned earlier)
[10:39:43] dekarl: then all the UK specific voodoo can be activated based on ONID
[10:40:21] justinh: looking in the channelscan_channel table for the scan I tried last night none of the channels have in_nit set
[10:40:37] justinh: and the LCN is broadcast in the NIT in descriptor 0x83
[10:40:50] dekarl: I'm not sure what "in_nit" means
[10:45:31] dekarl: the LCN is in the NIT? huh?
[10:45:49] dekarl: I think the NIT only has a transport stream loop
[10:46:00] justinh: lcns are defined in descriptor 0x83 which is only in the NIT AFAICT
[10:46:18] dekarl: let me look. I'd have expected it in the SDT
[10:46:53] justinh: channelscan.cpp around line 1804 I think
[10:47:26] dekarl: I'm looking at the spec :)
[10:47:53] justinh: I took captures of dvpsnoop parsing the SDT & couldn't find 0x83 descriptors in there but they're in the NIT snoop grab I took (0x11)
[10:48:04] justinh: *dvbsnoop even
[10:52:26] dekarl: "The Logical Channel Descriptor is inserted in the second descriptor loop of the Network Information Table." source . . . rch_2010.pdf
[10:52:36] dekarl: guessing that AU follows UK more or less closely
[10:52:43] justinh: :)
[10:53:12] justinh: could still be my local tx doing something funky but my tv & other linux scan apps get the LCNs ok
[10:53:31] dekarl: ahh, the logical_channel_descriptor has its own embedded service loop
[10:53:50] justinh: and other UK users aren't reporting problems
[10:53:56] dekarl: I was asuming it is a descriptor that goes into the service loop of the SDT
[10:54:39] justinh: UK TV is a bit of a pain. they shuffle LCNs around quite often & even move services between transports
[10:55:32] dekarl: that makes one wonder if passice channel scan could be a thing (similar to passive EIT scan)
[10:55:39] justinh: my rescan was brought about by tinypop, a Sony kids' channel moving to a 'local' low powered transmitter (on the same site as the main one)
[10:56:13] dekarl: but that only works if the tables are properly managed with all services present and only running status being fiddled with while they are off air
[10:56:13] justinh: dekarl: that doc says it recommends STBs do LCN updates in their sleep lol
[10:57:16] justinh: oh wait or was it another doc I read? anyway...
[10:58:07] justinh: it might be I'm the only mythtv user using this transmitter. I'm gonna try a fresh database & rule out the possibility it's my ancient – fiddled with database not causing this
[10:59:06] dekarl: maybe you can collect a specimen with hexdump that we can turn into a unit test to see if something is fishy
[11:39:44] justinh: oh a dump of a transport you mean?
[11:40:25] justinh: can easily arrange that :)
[12:01:44] tgm4883 (tgm4883!uid23806@ubuntu/member/tgm4883) has quit (Quit: Connection closed for inactivity)
[12:15:54] sraue (sraue!~stephan@kodi/staff/sraue) has quit (Ping timeout: 268 seconds)
[12:28:07] SteveGoodey (SteveGoodey! has quit (Quit: Konversation terminated!)
[12:28:49] dekarl: just the dvbsnoop of the NIT (and other interesting tables) decoded + hexdump (for turning it into a test case like . . . specimen.cpp if there is anything fishy in it)
[13:08:20] justinh: ahhh right
[13:35:27] membiblio (membiblio! has quit (Remote host closed the connection)
[14:05:42] amessina (amessina!~amessina@unaffiliated/amessina) has joined #mythtv
[14:39:05] rubbergsx (rubbergsx! has joined #mythtv
[14:49:32] rubbergsx (rubbergsx! has quit (Remote host closed the connection)
[14:52:20] tgm4883 (tgm4883!uid23806@ubuntu/member/tgm4883) has joined #mythtv
[15:13:25] rubbergsx (rubbergsx! has joined #mythtv
[15:24:42] rubbergsx (rubbergsx! has quit (Quit: Bye boys..)
[15:29:17] rubbergsx (rubbergsx! has joined #mythtv
[15:34:48] rubbergsx (rubbergsx! has quit (Remote host closed the connection)
[16:16:11] gbee (gbee!~stuartm@mythtv/developer/stuartm) has quit (Quit: Gone)
[16:18:23] gbee (gbee! has joined #mythtv
[16:18:23] gbee (gbee! has quit (Changing host)
[16:18:23] gbee (gbee!~stuartm@mythtv/developer/stuartm) has joined #mythtv
[16:55:32] kukks (kukks! has joined #mythtv
[17:45:48] membiblio (membiblio! has joined #mythtv
[17:56:59] SteveGoodey (SteveGoodey! has joined #mythtv
[18:09:26] amessina (amessina!~amessina@unaffiliated/amessina) has quit (Remote host closed the connection)
[18:10:38] amessina (amessina!~amessina@unaffiliated/amessina) has joined #mythtv
[21:18:36] SteveJGoodey (SteveJGoodey! has joined #mythtv
[21:33:41] Warped (Warped!~Warped@unaffiliated/warped) has quit (Quit: ChatZilla 0.9.93 [Firefox 52.0.1/20170316213829])
[22:20:21] amessina (amessina!~amessina@unaffiliated/amessina) has quit (Remote host closed the connection)
[22:20:42] SteveGoodey (SteveGoodey! has quit (Quit: Konversation terminated!)
[22:20:53] amessina (amessina!~amessina@unaffiliated/amessina) has joined #mythtv
[22:22:36] AndChat|176409 (AndChat|176409! has joined #mythtv
[22:22:36] SteveJGoodey (SteveJGoodey! has quit (Read error: Connection reset by peer)
[22:32:06] Roklobster (Roklobster! has quit (Remote host closed the connection)
[22:49:57] AndChat|176409 (AndChat|176409! has quit (Ping timeout: 260 seconds)
[23:55:52] rmeden (rmeden!~Robert@ has quit (Quit: Leaving.)

IRC Logs collected by BeirdoBot.
Please use the above link to report any bugs.