ATSC 3.0 channel lineups?

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mm650
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ATSC 3.0 channel lineups?

Post by mm650 »

Wondering if SD will be providing channel/lineup information for ATSC 3.0 channels, and if so how they will appear.

For my application having the modulation included in the station ID / channel map would suffice, though I can also see this potentially causing problems for clients that don't expect to have to pay attention to the modulation.
tzr95206
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Re: ATSC 3.0 channel lineups?

Post by tzr95206 »

ATSC 3.0 channels are starting to pop up in my area now
rmeden
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Re: ATSC 3.0 channel lineups?

Post by rmeden »

can you provide a sample channel /zip so I can look at the data?
tzr95206
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Re: ATSC 3.0 channel lineups?

Post by tzr95206 »

Sacramento California zip code 94203
SiliconDust ATSC 3.0 channels show up with HEVC tag
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kyl416
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Re: ATSC 3.0 channel lineups?

Post by kyl416 »

The HDHomerun adds 100 to the virtual number of ATSC 3.0 stations so people watching on devices that don't support AC-4 audio or interlaced HEVC can still tune to the ATSC 1.0 version. The actual ATSC 3.0 signal uses the same virtual numbers as the ATSC 1.0 channels so most NextGen TVs will display the ATSC 3.0 versions instead of their ATSC 1.0 counterparts.

i.e. On a real NextGen certified TV directly connected to your antenna those HEVC channels will appear as 3.1, 10.1, 13.1, 19.1, 40.1 and 58.1.
rmeden
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Re: ATSC 3.0 channel lineups?

Post by rmeden »

I don't see anything different on the datadirect service (not really surprising) but if ATSC 3.0 will use the same virtual channel as ATSC 1.0, what would you expect to be different in our guide data?

I do find it interesting the HDHR isn't reporting a valid callsign for the ATSC 3.0 stations.. that could be a problem.
tzr95206
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Re: ATSC 3.0 channel lineups?

Post by tzr95206 »

These are "lighthouse" stations, just temporary test stations until some day in the far away future when ATSC 1.0 is cut off. I think for now, Schedules Direct just needs to "mirror" the guide info of the primary station onto these lighthouse stations and give them what ever call signs they want. If something isn't done soon about this, I'll end up changing my subscription service.
kyl416
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Re: ATSC 3.0 channel lineups?

Post by kyl416 »

SiliconDust already said these fake 3 digit numbers are only a temporary workaround until they implement a fix to deal with platforms that can't handle AC-4 audio or interlaced HEVC. If they're going to screw up the lineups for every OTA user because HDHomeRun is temporarily using fake channel numbers, they might as well also add the fake channel numbers for 3rd party applications who use things like 1561 to represent 56.1 because they can't handle subchannel numbering. Not to mention it will break some importers because the ATSC spec only allows for major numbers up to 99 and could cause the guide data import to fail or the viewing application to crash after it force adds a new channel with a fake 3 digit major number to a database for an application that's designed to only handle 2 digit major numbers.

The HDHomerun supplies their own guide data so it has nothing to do with Schedules direct, and already maps the existing guide data to these fake channel numbers. If you're missing guide data for any of these channels on your HDHomeRun app, file a support ticket with SiliconDust.

If you're using a 3rd party platform to view these channels, you can use that platform's channel/guide management tool to manually map the guide data for KCRADT, KXTVDT, KOVRDT, KUVSDT, KTXLDT and KQCADT to the fake numbers. (Something nearly all platforms should support since providing channel numbers with the xmltv data was kind of a schedules direct/data direct only thing)


ATSC 3.0 is much more complicated than ATSC 1.0 for future applications that want to handle the physical aspects of tuning to stations, it isn't as simple as tuning by RF/Major-Minor like ATSC 1.0, and the actual OTA signals use DASH manifests instead of MPEG-TS streams. There's also multiple PLP layers and program configurations that can change without notice, and it can provide alternate low bitrate streams on different PLP layers for mobile reception and/or weak reception conditions, so developers of applications planning to implement physical ATSC 3.0 tuning shouldn't get into the habit of relying on 3rd party data to set the tuning parameters for their end users.
Last edited by kyl416 on Sun Jun 20, 2021 5:59 pm, edited 2 times in total.
rmeden
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Re: ATSC 3.0 channel lineups?

Post by rmeden »

tzr95206 wrote:
Sat Jun 19, 2021 6:58 am
These are "lighthouse" stations, just temporary test stations until some day in the far away future when ATSC 1.0 is cut off. I think for now, Schedules Direct just needs to "mirror" the guide info of the primary station onto these lighthouse stations and give them what ever call signs they want. If something isn't done soon about this, I'll end up changing my subscription service.
I doubt that would happen (we probably wouldn't do it, and I doubt our upstream/Gracenote will either). We'll continue to provide callsign and logical channels. It's up to the application to map it to any special channel numbers.
gtb
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Re: ATSC 3.0 channel lineups?

Post by gtb »

kyl416 wrote:
Sat Jun 19, 2021 10:24 am
SiliconDust already said these fake 3 digit numbers are only a temporary workaround until they implement a fix to deal with platforms that can't handle AC-4 audio or interlaced HEVC.
SiliconDust can likely get their apps updated, but it is going to be difficult for some other software to be updated due to IP licensing.
If they're going to screw up the lineups for every OTA user because HDHomeRun is temporarily using fake channel numbers
SiliconDust tuners do offer an option to disable (and essentially make invisible) all the +100 channels, but that, too, has issues.
... or the viewing application to crash after it force adds a new channel with a fake 3 digit major number to a database for an application that's designed to only handle 2 digit major numbers.
Of course, applications that crash when fed bad data should have tickets opened on them, since bad data happens.
The HDHomerun supplies their own guide data so it has nothing to do with Schedules direct, and already maps the existing guide data to these fake channel numbers. If you're missing guide data for any of these channels on your HDHomeRun app, file a support ticket with SiliconDust.
Although SiliconDust does happen to use the same upstream (Gracenote) for the guide data, and then internally adjusts it for their own use. FWIW, SiliconDust also provides their own XMLTV feed if you have one of their tuners (I think it is 4 hrs without their DVR service (intended for "playing now and next"), and around 14 days if you pay for their DVR service). For some users that might be an alternative approach, although that too would not be a Schedules Direct issue.
If you're using a 3rd party platform to view these channels, you can use that platform's channel/guide management tool to manually map the guide data for KCRADT, KXTVDT, KOVRDT, KUVSDT, KTXLDT and KQCADT to the fake numbers.
Depending on the 3rd party app, some people have already written tools (sometimes a 3rd party tool for the 3rd party) to make those adjustments easier. The OP should consider making a request to the 3rd parties user community to explore if someone has already done the work during this phase of testing and experimentation as to what works best (even the lighthouse stations are sometimes doing the most interesting things from time to time).
(Something nearly all platforms should support since providing channel numbers with the xmltv data was kind of a schedules direct/data direct only thing)
XMLTV does (somewhat) support providing channel numbers to apps, but few applications can utilize some of the more recent options such as --get-lineup rather than just the default output (or the abbreviated --list-channels output), and AFAIK for Schedules Direct source, only one of the Schedules Direct grabbers supports --get-lineup with it's more specific data format (--list-channels just provides a set of names, one of which is usually the channel number; --get-lineup provides the numbers explicitly under a formal definition).
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