If a user does a a daytime scan, is TVHeadend aware not to change the configuration for the working nighttime values, ie no video PID in the scan? In NextPVR a users would specifically have to remember not to update BBC THREE/FOUR HD.
TVHeadEnd - BBC 4 has vanished
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LybsterKodi -
October 9, 2024 at 10:28 AM -
Thread is Unresolved
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If a user does a a daytime scan, is TVHeadend aware not to change the configuration for the working nighttime values, ie no video PID in the scan? In NextPVR a users would specifically have to remember not to update BBC THREE/FOUR HD.
From memory you need to scan time-exclusive services during both transmission times to ensure both get added correctly (I think the video and audio PIDs need to be actively associated with the SID in the SDT for it to be stored correctly?) (In the UK Time-ex services use the same audio and video PIDs for both services and just remap during active hours - I think)
They don't replace each other though, so there's no issue with just doing a straight re-scan.
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Thanks. I was wondering if TVHeadend knows not to overwrite the non broadcasting channels during the update, since they still are in the scan they just don't have video and audio PIDs.
NextPVR users a separate libdvb style conf file for tuning, that is were the replacement needs to take place
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Thanks. I was wondering if TVHeadend knows not to overwrite the non broadcasting channels during the update, since they still are in the scan they just don't have video and audio PIDs.
NextPVR users a separate libdvb style conf file for tuning, that is were the replacement needs to take place
Yes - it seems to have no problem and doesn't overwrite them (they have different LCNs too) - it just doesn't know what to do with the off-air channels as they have no associated audio and video PIDs when they are off-air.
TVH may do something odd in Sweden during regional news - as on their DVB-T platform two SVT1 regional variations are usually broadcast on the same DVB-T mux, with both mapped to the 'network' audio and video PIDs outside of regional news times (so they don't have to send out a pair of identical audio and video streams wasting bandwidth, but then during the regional news there's a crash-bang switch to remap the two SVT1 regional services to two different sets of audio and video PIDs carrying the regional audio and video streams. (Or at least that's roughly what used to happen. They could use the regional audio and video PIDs to associate with either SVT2 or SVT1 regional variations - though I think because of changes on satellite only SVT1 now has regional variations?)
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Sorry to perhaps hijack this thread but it could explain the users problem. When I compare the two results from libdvb I only see the video and audio pids change of note. The tsid changes but that is for all frequencies so that probably can be ignored.
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Display More[BBC FOUR HD] SERVICE_ID = 18048 NETWORK_ID = 9018 TRANSPORT_ID = 16522 VIDEO_PID = 6701 AUDIO_PID = 6702 6706 PID_0b = 7302 PID_06 = 6705 PID_05 = 7108 FREQUENCY = 634000000 MODULATION = QAM/256 BANDWIDTH_HZ = 8000000 INVERSION = OFF CODE_RATE_HP = 2/3 CODE_RATE_LP = AUTO GUARD_INTERVAL = 1/128 TRANSMISSION_MODE = 32K HIERARCHY = NONE DELIVERY_SYSTEM = DVBT2 STREAM_ID = 0and
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Display More[BBC FOUR HD] SERVICE_ID = 18048 NETWORK_ID = 9018 TRANSPORT_ID = 4170 PID_0b = 7303 7302 PID_05 = 7109 FREQUENCY = 634000000 MODULATION = QAM/256 BANDWIDTH_HZ = 8000000 INVERSION = OFF CODE_RATE_HP = 2/3 CODE_RATE_LP = AUTO GUARD_INTERVAL = 1/128 TRANSMISSION_MODE = 32K HIERARCHY = NONE DELIVERY_SYSTEM = DVBT2 STREAM_ID = 0 -
Sorry to perhaps hijack this thread but it could explain the users problem. When I compare the two results from libdvb I only see the video and audio pids change of note. The tsid changes but that is for all frequencies so that probably can be ignored.
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Display More[BBC FOUR HD] SERVICE_ID = 18048 NETWORK_ID = 9018 TRANSPORT_ID = 16522 VIDEO_PID = 6701 AUDIO_PID = 6702 6706 PID_0b = 7302 PID_06 = 6705 PID_05 = 7108 FREQUENCY = 634000000 MODULATION = QAM/256 BANDWIDTH_HZ = 8000000 INVERSION = OFF CODE_RATE_HP = 2/3 CODE_RATE_LP = AUTO GUARD_INTERVAL = 1/128 TRANSMISSION_MODE = 32K HIERARCHY = NONE DELIVERY_SYSTEM = DVBT2 STREAM_ID = 0and
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Display More[BBC FOUR HD] SERVICE_ID = 18048 NETWORK_ID = 9018 TRANSPORT_ID = 4170 PID_0b = 7303 7302 PID_05 = 7109 FREQUENCY = 634000000 MODULATION = QAM/256 BANDWIDTH_HZ = 8000000 INVERSION = OFF CODE_RATE_HP = 2/3 CODE_RATE_LP = AUTO GUARD_INTERVAL = 1/128 TRANSMISSION_MODE = 32K HIERARCHY = NONE DELIVERY_SYSTEM = DVBT2 STREAM_ID = 0Yes - I think we're saying the same thing.
The first BBC Four HD details are for when the channel is on-air - and thus Video and Audio PIDs are associated with the Service, and CBeebies HD (which it's time-exclusive with) is off-air.
The second details are for when when BBC Four HD is off-air (and thus has no Video and Audio PIDs associated with it) and CBeebies HD is on-air (which will be using the same Video and Audio PIDs mapped to its Service instead)
When TV Headend scans PSB3/BBCB during BBC Four HD transmission hours it sees the Audio and Video PIDs mapped to the BBC Four HD service and stores them with the BBC Four HD service. When TV Headend tunes the same mux during BBC Four HD non-transmission hours it doesn't see the Audio and Video PIDS associated with the channel and thus doesn't store them (as it has no idea they will be used at other times of day). Instead it will see CBeebies HD active instead and store the same Video and Audio PIDs shared between CBeebies HD and BBC Four HD with the CBeebies HD service. Effectively to get both CBBC and CBeebies AND BBC Three and BBC Four (which they are time-ex with) you need to tune during both pairs of services transmission hours.
In reality the playout and transmission chains for CBeebies HD and BBC Four HD are one and the same, the same network playout area transmits both channels, and the same encoder chains encode them. The only thing that changes is some metadata that tells the mux chains to re-map the Video and Audio pids from the encoders between the two services. (And also to trigger an MHEG5/HbbTV data service that tells you the off-air channel is off-air when you tune to it on a regular TV).
I think this is a quirk of TV Headend that's always been there for time-exclusive services - you need to do a scan during transmission hours for non-continuous, time-exclusive, services like CBBC/BBC Three and CBeebies/BBC Four. It may be that the UK is relatively unusual in implementing time-ex stuff on a channel-basis (to allow CBBC/CBeebies to be on Kids EPG channels and BBC Three/Four to be on general channel numbers in the EPG etc.) as I've seen other countries just keep to one channel/service.
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Thanks for that. I guess there could be a related issue if the audio PIDs increase or in the Swedish case you noted more video PIDs. I'd love to get a full mux from Sweden when the regional news is plays to send to my demodulator.
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Thanks for that. I guess there could be a related issue if the audio PIDs increase or in the Swedish case you noted more video PIDs. I'd love to get a full mux from Sweden when the regional news is plays to send to my demodulator.
https://www.digitalbitrate.com/dtv.php?mux=MU…live=38&lang=en shows the main DVB-T SVT HD mux in Stockholm - you can see two regional variations of SVT1 with the same video and audio PIDs most of the time.
If you look at the mux graph at the bottom you can see SVT1 Sörmland with SID 5850 switches between 5771 and 5851 for Video PIDs, whereas SVT1 Stockholm with SDI 5770 stays with 5771 Video PID all the time (as Stockholm = Network)
The switch is done by their muxing provider on a clock start I believe - unlike in the UK where BBC regions switch themselves.
