Next PVR and UK Logical Channel Numbers (LCNs) - why can't it get them right?

[martinu]

I've had to retune NextPVR to pick up changes to the Logical Channel Numbers (LCNs) in the UK.

And yet again NextPVR sorts the channels in a stupid order, assigning channel numbers that bear no relation to the LCN.

Is there a way of forcing NextPVR to assign the correct LCN in its channel list (Settings | Channels) or is it necessary, as I've had to do every time in the past, to do a Bulk Map to sort out the mess that has been made of the channel numbers?

I've done the delete all channels / scan process several times and it gives different results each time, so it's not even consistently wrong :-(

This is for DVB-T/T2 from the Tyne Tees / Bilsdale transmitter, using version 4.0.4

[sub]

It should be using the LCNs from the stream. Do a scan, then post the npvr.log and I'll take a look.

[paul67]

I am on the same transmitter as you

Not done the retune yet, recordings are in progress

Will do mine shortly, let you know if i have the ame issues

[nottmsteve]

I had something similar yesterday. Just deleted everything and rescanned and everything is in order now lke it should be

[jcjefferies]

Many people complain about being forced to use the Freeview LCNs on a Freeview box and not being able to change the order to something logical to them. I have my own system with all associated channels grouped together so the Freeview LCN changes yesterday are not of interest to me!

Chris

[martinu]

OK. This is the sequence of operations I've done:

- Settings | Devices | (select DVB-T device) | Device Setup | (select all channels) | Delete
- with Country=UK and Region=Tyne Tees - Bilsdale, 8 MHz bandwidth... Scan
- OK

And it's worked this time. But I'm sure it's what I did two days ago, when it put some channels (especially those from the PSB1 multiplex on 514 MHz) in various bizarre places which I had to correct.

One thing I noticed as it was scanning is that it included several frequencies that are additional to those for Bilsdale (eg 578, 474, 498, 522, 642 MHz). I'd have thought that if I chose a specific transmitter it would only look at the known frequencies. Ah, looks like these are the old frequencies (https://en.wikipedia.org/wiki/Bilsdale_t...ng_station "Before Switchover") before switchover in 2012. You might want to remove these entries for each transmitter's record, in case they happen to coincide with the new frequencies used by a neighbouring transmitter.

I've attached both today's logfile (npvr.log.1) and the one from 2 Aug (npvr.log.2), when I first retuned to pick up the changes made by broadcasters, to see if you can see a difference. My experience has been that on several previous occasions when I've deleted and re-scanned, the channels have been allocated random LCNs which I've had to correct.

I'm curious why the same set of operations has worked today when it didn't two days ago. And when I tried it two days ago, the changes definitely had taken place: I could see the old and new LCNs for the affected channels, using TSReader.

Weird!

[Graham]

. Ah, looks like these are the old frequencies (https://en.wikipedia.org/wiki/Bilsdale_t...ng_station "Before Switchover") before switchover in 2012. You might want to remove these entries for each transmitter's record, in case they happen to coincide with the new frequencies used by a neighbouring transmitter.

There are 1,345,722 TV transmitters in the world and only one Sub so he needs us to help him a bit. NextPVR scans frequencies as specified in an .ini file at Users\Public\NPVR\Tuning. You may wish to update your local transmitter .ini file and attach it to a post.

In my experience, a reliable source of tuning info is ukfree.tv.

[martinu]

Done! Good idea. Glad to be able to help. I've removed the obsolete frequencies and added one that had been omitted (COM8) - I wondered why the number of channels was a bit less than I was expecting! Until there's another release of NextPVR, people who use the Bilsdale transmitter might like to download the file from https://forums.nextpvr.com/showthread.ph...post516319 and patch it into c:\users\public\NPVR\Tuning\DVB-T over the top of the existing one.

[sub]

I'm curious why the same set of operations has worked today when it didn't two days ago. And when I tried it two days ago, the changes definitely had taken place: I could see the old and new LCNs for the affected channels, using TSReader.

It's a timing issue, related to when it receives two separate bits of info from the stream (SDT and BAT). I thought I'd tweaked the settings so that it should be waiting long enough to get both bits of info when scanning, but we still occasional get reports of it not getting the correct LCNs. I'm not entirely sure why - I suspect it's something quirky about the timing of these bits of info in the UK streams.

[martinu]

It's a timing issue, related to when it receives two separate bits of info from the stream (SDT and BAT). I thought I'd tweaked the settings so that it should be waiting long enough to get both bits of info when scanning, but we still occasional get reports of it not getting the correct LCNs. I'm not entirely sure why - I suspect it's something quirky about the timing of these bits of info in the UK streams.

Ah. Timing issues and race conditions are a pain. Maybe you need to tweak the wait time even more :-)

It's interesting that since I retuned yesterday and it worked, I've deleted and re-scanned several times as I was altering the ini file for my transmitter, and it has always worked flawlessly.

By the way, I meant to say earlier. When I saw that lots of unknown frequencies were being scanned (due to obsolete entries in the transmitter's ini file, and not due to duplicate channels from neighbouring transmitters as I first thought) I tried a manual scan of each known-good frequency in turn. And doing 8 separate scans, one per mux, seemed to number the channels in order of multiplex, so it had no relation at all to what was in the streams. Maybe that situation has a more extreme bug.

As for compliance to standards, a standard only exists so you know how extreme you can get and still, technically, remain compliant. Or am I being too cynical?