TV Station Launches Multiple 4K Broadcasts OTA on ATSC 1.0

[elvisimprsntr]

If that isn’t a poke in the eye of ATSC and A3SA

https://youtu.be/e_94q9TCCDY

[kyl416]

That LPTV station in Eugene Oregon has been doing it since at least 2021. The only way they can do it is with 24 fps and/or slow moving content that can be compressed to less than 5 Mbps, which they can't do for actual network 4K sports broadcasts with a lot of rapid motion and camera panning. i.e. the FOX Sports 4K telecasts which are around 18 Mbps at 59.94 fps

While software players like HDHomerun and VLC can support these HEVC ATSC 1.0 broadcasts, very few TVs can as HEVC chipsets didn't become available until 2015 and post-2015, even if your smart TV supports HEVC for streaming, the TV's tuner still has to be coded to recognize StreamType 0x24 as HEVC.

K03IM-D can do this because LPTV stations are exempt from many of the rules that full power and Class A stations have to follow. Even if full power stations didn't have to follow the ATSC specs, no major network is going to allow their affiliates to switch their ATSC 1.0 feed to a codec that most tuners don't support. That's also why H264, which has been an optional part of the spec since 2009, is still only used in limited cases for lesser networks.


Also, it isn't a poke in the eye to anyone. The ATSC committee has final say on what codecs and resolutions are part of the spec that full power and Class A stations have to follow, which for ATSC 1.0 is MPEG-2 and optionally H264/AVC, while the A3SA is made up by the owners of the networks and the Pearl Consortium that contains most of their affiliates.

[TomZ]

I wish more channels would do this. We have three sub-channels that broadcast in AVC in Chicago, and you can see the quality difference. At the same time, it saves bandwidth.

[emveepee]

I wish more channels would do this. We have three sub-channels that broadcast in AVC in Chicago, and you can see the quality difference. At the same time, it saves bandwidth.

Quality is based on the bit rate and resolution, not the encoding format (although there are good and bad encoders too). All our local ATSC broadcasts are full mux without sub channels and the quality is good, much better than lower bitrate h264 or mp2v on cable.

Martin

[NedS]

Quality is based on the bit rate and resolution, not the encoding format (although there are good and bad encoders too). All our local ATSC broadcasts are full mux without sub channels and the quality is good, much better than lower bitrate h264 or mp2v on cable.

Martin

It's both. Video codec will have a major impact on image quality. Better video compression codecs allow the same or better quality while using less bandwidth. It's possible to still lowball the bitrate too much, but AVC is roughly twice as efficient as MPEG2, and HEVC is roughly twice as efficient as AVC.

[emveepee]

It's both. Video codec will have a major impact on image quality. Better video compression codecs allow the same or better quality while using less bandwidth. It's possible to still lowball the bitrate too much, but AVC is roughly twice as efficient as MPEG2, and HEVC is roughly twice as efficient as AVC.

OK while, I doubt you aren't going to see h264 on a full ATSC 1 mux at 15-20Mbs, but I understand what you are saying. It goes they opposite way, since quality is not as important as efficiency. I remember in the early days of my big ugly dish how fantastic the football network feeds were compared to normal OTA.

Martin

[Cabal]

That LPTV station in Eugene Oregon has been doing it since at least 2021. The only way they can do it is with 24 fps and/or slow moving content that can be compressed to less than 5 Mbps, which they can't do for actual network 4K sports broadcasts with a lot of rapid motion and camera panning. i.e. the FOX Sports 4K telecasts which are around 18 Mbps at 59.94 fps

While software players like HDHomerun and VLC can support these HEVC ATSC 1.0 broadcasts, very few TVs can as HEVC chipsets didn't become available until 2015 and post-2015, even if your smart TV supports HEVC for streaming, the TV's tuner still has to be coded to recognize StreamType 0x24 as HEVC.

K03IM-D can do this because LPTV stations are exempt from many of the rules that full power and Class A stations have to follow. Even if full power stations didn't have to follow the ATSC specs, no major network is going to allow their affiliates to switch their ATSC 1.0 feed to a codec that most tuners don't support. That's also why H264, which has been an optional part of the spec since 2009, is still only used in limited cases for lesser networks.

You would benefit from watching the entire video, or even the full 20-minute interview (https://youtu.be/oQdonemI5Ls?feature=shared). Many of your points are incorrect on the finer details (framerates used, TV compatibility in 2024, etc), but I'm not going to pick them apart.

It's a fascinating watch, and I'm happy to see *someone* pushing the limits of ATSC 1.0, even if it's just for science and/or fun.

[kyl416]

You would benefit from watching the entire video, or even the full 20-minute interview (https://youtu.be/oQdonemI5Ls?feature=shared). Many of your points are incorrect on the finer details (framerates used, TV compatibility in 2024, etc), but I'm not going to pick them apart.

This wouldn't be the first time one of his videos had some inaccuracies.

Look at the TSReader report I linked to from this week. 23.98 or 24 fps on most of the channels and the bitrates of all the 4K HEVC channels are well below 5 Mbps. (Yes some of the channels have varying framerates, which is why I said 24 fps and/or low bitrates) They simply cannot do that with the 4K sports feeds from FOX, NBCU, ESPN/ABC and CBS that originate as 59.94 fps and average 18 Mbps+ bitrates. Things with slow moving content like the NASA 4K feed which 90% of the time is a fixed camera view of the ISS you can compress to bitrates that low, but you can't drop the frame and bitrate that much on fast moving 4K sports content where the camera is constantly panning across the action without it becoming a jumpy and pixelated mess.
(EDIT: I checked out NESN's 4K feed during the Bruins game last night, it averaged ~22 Mbps with ~33 Mbps spikes)

And the fact of the matter is chipsets capable of decoding HEVC didn't become available until 2015, so no TV made prior to 2015 can handle it without a converter box. And even post-2015, it would need to be a 4K TV with an ATSC 1.0 tuner that was coded to recognize StreamType 0x24 as HEVC. It's the same reason why there's compatibility issues with ATSC 1.0 stations that use H264, including on some models that support H264 for streaming and a popular hardware DVR that Scripps recently purchased. So even if the ATSC committee added HEVC as one of the approved codecs for ATSC 1.0, no major network is going to allow their affiliates to switch to HEVC on their ATSC 1.0 signals.


Shared lighthouse bandwidth is also not the only reason why we don't have 4K network OTA today, so being able to transmit HEVC over ATSC 1.0 wouldn't change anything. In order to ingest and retransmit major network 4K programming, the entire pipeline from the networks' broadcast centers to the affiliates' master controls and local control rooms have to be replaced so they can support all the required things for local ads, EAS/Severe weather alerts, closed captioning/descriptive audio, Nielsen coding, etc. In ESPN/ABC's case they would also need to upgrade their 4K production capabilities to be more than raw stadium feeds and seperate skycam telecasts. This is why the few broadcasters that have a lighthouse to themselves still don't carry any of their network's 4K telecasts.


Using HEVC over ATSC 1.0 isn't new either, the LPTV station in question has been doing this since 2021. As long as you fit everything within the 6 MHz bandwidth constraints (and ignore the standards and TV compatibility issues), you can use almost any combo of audio and video codecs with ATSC 1.0 as it's just a MPEG transport stream. i.e. H.266/VVC could handle the 59.94 fps 4K sports broadcasts at lower bitrates, but that codec was only finalized in 2020 so there are currently very few broadcast encoders and consumer grade electronics with chipsets that can handle it.