[Bug] Scan for open Qam finds no channels (1 Viewer)

[mm1352000]

Hi Ryan1

Yes, I think the command line switch has changed (to match the MP style - TV Server and MediaPortal used to be different). I'm at work right now so I'm not able to figure out what the correct switch is, but it is some combination of --, - or / plus DebugOptions, debugoptions or debug. Hopefully you're able to work it out...

 

[ryan1]

Hi Ryan1

Yes, I think the command line switch has changed (to match the MP style - TV Server and MediaPortal used to be different). I'm at work right now so I'm not able to figure out what the correct switch is, but it is some combination of --, - or / plus DebugOptions, debugoptions or debug. Hopefully you're able to work it out...

Figured it out. It was /DebugOptions

Uploading a 1 minute QAM TS dump right now of an unencrypted open channel (TBS-HD) to the FTP server.

If I didn't do it right, or you need me to dump something else/another channel, just let me know.

 

[x4mer]

Any luck mm?

Any chance of an updated dll or such, so I can get my channels back before RC1?

 

[ferrocene]

What happened to this thread? I have the exact same problem.

2011-07-23 01:23:19.883219 [(21)]: Found Unknown: type:0 onid:0 tsid:2BDD sid:13E9 pmt:32 hasVideo:1 hasAudio:1
2011-07-23 01:23:19.883719 [(21)]: Found Unknown: type:0 onid:0 tsid:2BDD sid:13EA pmt:30 hasVideo:1 hasAudio:1
2011-07-23 01:23:19.883719 [(21)]: Found Unknown: type:0 onid:0 tsid:2BDD sid:13EB pmt:31 hasVideo:1 hasAudio:1

This is with a HD HomeRun that worked fine under 1.1.3.

 

[x4mer]

It got marked as Bug a long time ago, but I haven't seen anything about it since.

It may be in the roadmap here 0003636: Scan Changes in 1.2 Beta need reworking - MediaPortal Bugtracker but I'm not sure if it's the same issue, as it lists the originating thread as some private one, and not this one. It also says reproducibility hasn't even been tried. Since this thread has already been marked Bug, it must have been reproduced by someone in the inner circle.

 

[mm1352000]

Hi everyone

This issue can definitely be reproduced with the sample provided by ryan1. His sample doesn't have either SDT or NIT information, so I have no idea how we're meant to get service names and types for streams like that. Perhaps one of the other muxes has information for all the muxes or the private descriptors have the information encoded in some provider-specific fashion. The plan is currently to either:

1. Reinstate the 1.1.x scanning behaviour in 1.2.0rc so that services will be detected as either TV or radio based on whether they have audio and/or video streams.
2. Add a data or miscellaneous channel section and put any channels that 1.2.0b isn't picking up in there. Any channels in that section could be moved into either the TV or radio channel lists.

If anyone knows whether service information is provided on other transponders, or how the info could be decoded from the private descriptors then please let us know. Getting that information would be a better long term solution in my opinion - I mean who wants a list full of "Unknown..." channels!

mm

PS: When there is no SDT then scanning will take the entire length of the SDT timeout time. There is no point in wasting 20 seconds scanning each mux if there is no SDT available though. You could probably reduce the SDT timeout to around 10 seconds without any problem.

PPS: x4mer, this also impacts on your request to have the ability to change channel by keying in logical channel numbers. In DVB those come from the NIT, and in ATSC I think they come from the VCT. If there is no NIT or VCT available then it would be pointless adding that ability as the logical channel numbers won't be available.

 

[x4mer]

MP has always listed all the QAM channels as unknown. It's been a PITA to dig through them all trying to find the OpenQAM ones, as they all used to list their encrypted status as open. Once I saw the detection for open had been corrected for my ATSC (which always showed as encrypted even though ATSC is never encrypted in N.A.) channels it lead me to erase and rescan QAM on cable. I was expecting to be able to easily recognize the open ones under the new scan, based on the coloured ball next to them.

The request for 5-1, 5-2 etc channel entry in the other thread, was for ATSC, not QAM. ATSC is over the air free entenna service, and includes PSIP for providing the channel map info, as stated in the other thread. Canadian cable operators using QAM, are not forced to embed any standard info, as it is a closed system used solely by their proprietary cable boxes. As far as they're concerned, only their rental boxes need to be able to parse the data, as they don't support digital cable without one of their boxes. For this reason, almost nothing is open QAM in Canada, it's almost all encrypted.

In the US, the FCC mandates that all local available OTA station be available OpenQAM over cable. I've read on a number of forums though, that channels jump around from time to time as the cable company moves them to a diffferent frequency. The change is transparent to users of cable company receivers, but anyone getting it "free" with the TVs built in tuner, has to dig around to find the channel again, and it doesn't remap to a standard channel reference like OTA does.

 

[mm1352000]

Hi again x4mer

MP has always listed all the QAM channels as unknown.

Do you know if there is any way that we can correct this. In other words, do you know where the equivalent of the DVB SDT information (service type and name) is stored?

I was expecting to be able to easily recognize the open ones under the new scan, based on the coloured ball next to them.

... but you haven't been able to confirm this because of the problem?

The request for 5-1, 5-2 etc channel entry in the other thread, was for ATSC, not QAM.

In MP there is no difference. Apart from the checkbox that you set when you scan, ATSC is treated the same as QAM... and even worse, in most cases there is no clear separation between DVB and ATSC handling.

ATSC is over the air free entenna service, and includes PSIP for providing the channel map info, as stated in the other thread.

Canadian cable operators using QAM, are not forced to embed any standard info, as it is a closed system used solely by their proprietary cable boxes. As far as they're concerned, only their rental boxes need to be able to parse the data, as they don't support digital cable without one of their boxes. For this reason, almost nothing is open QAM in Canada, it's almost all encrypted.

In the US, the FCC mandates that all local available OTA station be available OpenQAM over cable. I've read on a number of forums though, that channels jump around from time to time as the cable company moves them to a diffferent frequency. The change is transparent to users of cable company receivers, but anyone getting it "free" with the TVs built in tuner, has to dig around to find the channel again, and it doesn't remap to a standard channel reference like OTA does.

That is helpful info, thank you. Even if QAM services are mostly encrypted, there *must* be some way that the providers' boxes get the service names and some sort of protocol for the service movements. If it is not via ATSC PSIP then do you have any idea how it is done - proprietary protocols?

mm

 

[x4mer]

I was expecting to be able to easily recognize the open ones under the new scan, based on the coloured ball next to them.

... but you haven't been able to confirm this because of the problem?

Correct.

The request for 5-1, 5-2 etc channel entry in the other thread, was for ATSC, not QAM.

In MP there is no difference. Apart from the checkbox that you set when you scan, ATSC is treated the same as QAM... and even worse, in most cases there is no clear separation between DVB and ATSC handling.

Oh....I see.

That is helpful info, thank you. Even if QAM services are mostly encrypted, there *must* be some way that the providers' boxes get the service names and some sort of protocol for the service movements. If it is not via ATSC PSIP then do you have any idea how it is done - proprietary protocols?

I'll ask around on another forum, and see if I can find anything out.

Thanks mm

 

[x4mer]

early response about ATSC/QAM channel data

Apparently ATSC uses TVCT (terrestrial virtual channel table), to store the name and virtual channel number like 5-1. MP must already be parsing this, as I see the names and virtual channel info in the edit interface of the channel.

For QAM, CVCT (cable virtual channel table) is used. Like I mentioned before, in Canada open QAM is not officially supported, so none of the channels have this table filled in. A guy from the board I asked on, is from the U.S.. According to him, the in the clear local channels have the table filled in for those QAM channels on his cable provider. All other channels on his system, have the table blank like here in Canada. He said he was going to post some tsreader outputs for me, showing the CVCT for a properly labelled/remapped channel on his cable system, as well as one with the table not filled in.

He said that in the case of either TVCT or CVCT, if the table is not filled in, the channel name is parsed as blank, and the channel number will be referenced as (RF CH#)-(SID #).

So it would seem the request I made for 5-1, 7-1 etc channel handling support, would be useful for people using ATSC via OTA, and users of Open QAM stations via cable in the U.S.(provided MP supports parsing the CVCT). Any other ATSC/QAM stations, while not having any useful naming or remapping, wouldn't need it anyways, as those channels are more than likely encrypted or one of a handful of open cable stations in Canada (which could be accessed as (RF CH#)-(SID #) with name added in by the MP user).

I'll post the CVCT grabs, once he does.

I've also further pushed the question of how the boxes "know" about the channels with no CVCT. If there's any further on that, I'll update also.