HDHomeRun new 4K ATSC 3.0 tuner

I have yet to receive Close Captions using my SD 4K atsc 3.0 tuner. Contacted Silicon Dust and they say Govt. mandate requires them to support CC, and the problem is with Channels, I seem to recall reading somewhere here in the forums of some folks getting CC on ATSC 3.0 channels using Channels. I use the ATSC 3 feeds of the major networks exclusively as the quality is great but I need the CC option to work. Where does the problem lie?

I'm not sure where SD is referencing, but I haven't heard that. In fact, I've read the opposite. The way closed captions are defined for ATSC 3.0 is with Timed Text Markup Language (TTML, a W3C standard); using CEA-702 digital closed captions embedded in the video stream is optional. (CEA-702 is how ATSC 1.0 streams embed closed captions.)

Channels' video player cannot read TTML closed captions, but it can read CEA-702 closed captions.

Quote:

"Hi,

Closed Captioning is a feature of the player/client device. If you are using Channels DVR you will need to ask them to support ATSC 3.0 closed captioning.

Nick"

This is the response I got from SD.

Further he responded:

"The currently released HDHomeRun firmware delivers ATSC 3.0 closed captions to the client app.
The currently released HDHomeRun app does not include support for ATSC 3.0 closed captions.

With ATSC 3.0 subtitles are delivered in XML files along with the audio and video segments. When the HDHomeRun converts to TS format the audio, video, and subtitles are delivered as elementary streams."

That is all the info I have. I'd like to resolve this issue.

Let me reiterate my reply, slightly differently and in response to Nick's comments:

Classically, in the US/NA closed captions were delivered in a rather "hack"-like manner. For NTSC (analog) broadcasts, the closed captions were encoded in the 21st scanline of the broadcast (line 21). When ATSC and digital broadcasts came about, the digital standard of CEA-702 was introduced, which encoded the closed captions as part of the video stream itself.

With ATSC 3.0, they completely changed how closed captions are to be delivered. Instead of being embedded as part of the actual video stream itself, it is now a completely separate stream in the broadcast. This separate stream is a subset of XML called TTML (Timed Text Markup Language), which is an international standard. What Nick from SiliconDust is saying is that when their tuners receive ATSC 3.0 broadcasts, they take the audio, video, and TTML/subtitle streams, and remux those into standard MPEG transport streams that most programs understand.

However, because XML is so prone to bad formatting, many programs don't handle it properly. While most programs (including Channels) understand transport streams, they don't always know how to understand the component parts. (Compare it to being able to read a card catalog and a book's table of contents, but not necessarily knowing how to read the language of the text itself.) So, while Channels is receiving the closed captions, it doesn't know how to display them yet. At least, this is the case for TTML closed captions; these are the new standard/required closed captions for ATSC 3.0 broadcasts.

But, there is a slight silver lining. The new standard also says that while closed captions have to be delivered in this new way, they can also be delivered in the old way, too. So, while Channels cannot (yet) do closed captions for TTML captions in ATSC 3.0 broadcasts, as long as the broadcaster has chosen to additionally transmit CEA-702 closed captions embedded in the video stream, then Channels can display those.

I hope this clarifies some of the discrepancies.

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I am still only getting 1080p using my new HDHomeRun ATSC 3.0 tuner. How can I change the resolution to 4k quality?

It is based on what they are broadcasting.

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almost no 4k being broadcast over atsc3. Not really a setting in play here

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Call the station(s) sending lower resolutions?

The 4 in my area are 1080 and 720P. ATSC 3.0 is in its early stages, people are expecting the full technology now when it's likely several years away still, at least.

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PSA: Do not hold your breath waiting for (free) 4K content over ATSC 3.0.

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Almost?

I don't want to say anything definitive without fully knowing what I'm talking about. I'm not aware of any, but lord knows if one of these pay-for-use crazy ATSC3 schemes has stuff.

I don't think there are any now or even on the horizon which is disappointing.

Turns out I was right - thought i had heard about this.

So, if you live in Boise or Arizona, AND can get this channel, AND subscribe to their service, you get a placeholder eye candy channel. Yeehaw.

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Interesting.
At first glance it looks like some sort of hybrid OTA / Streaming thing. There is even a sports package for the Colorado teams.

Yeah, it's a combo streaming/OTA setup. EG in Phoenix you get a bunch of "cable only" channels OTA, but encrypted:

https://rabbitears.info/market.php?request=station_search&callsign=187703#station

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Nice find.

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These 'extra' channels are for a lighthouse ATSC 3.0 project that's based out of the Phoenix area. These are not intended for any longterm evaluation or general public access (hence the encryption). Phoenix was chosen as the host area since these trials for NextGen TV services needed to happen somewhere and TPTB were able to get approval relatively early to conduct their tests in this market.

With most of the major networks lighting up ATSC3 broadcasts here in Houston in December, I thought it time to jump in and buy a SD 4k tuner.

Frankly, I was amazed how easy it was to swap out my old SD Duo and get everything working in Channels. I am sure there will be questions at some point but for now, its working spiffy!

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Can you provide an update on the broadcast in the SLC area? Are any of the 4 stations broadcasting 4k content? Is it worth upgrading to HDHR Flex 4K?

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Don't expect 4K broadcasts OTA any time soon. Anywhere.

The Flex4K is an excellent device, so if you need the product, it's worth future-proofing.

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