PQ Observation

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Andrew Sullivan

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I am switching back and forth between the ND game on NBC and the Wisconsin game on ABC. The PQ is noticeably better on the 720P ABC broadcast than it is on the 1080i NBC broadcast. The ND game is also on the 4K channel 106 and that is not great. All of my resolution boxes are checked.
 

rad

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How many sub channels does your ABC affiliate have vs the NBC? If they're broadcasting sub channels the ABC station doesn't have to compress the signals as much as NBC since the 720p stream is 'smaller' then the 1080i stream.

The 4K version on channel 106 looks great. ;-)
 

raoul5788

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How many sub channels does your ABC affiliate have vs the NBC? If they're broadcasting sub channels the ABC station doesn't have to compress the signals as much as NBC since the 720p stream is 'smaller' then the 1080i stream.

The 4K version on channel 106 looks great. ;-)
Many of the channels send a full bandwidth signal to Directv via fiber even if their ota signal has subchannels.
 

raoul5788

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And then again many locals are pulled buy using the OTA signal and not fiber.
Correct, and since we don't know which it is in this case, there is no point in assuming the reason one looks better than the other is because of subchannels.
 

slice1900

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You can't read anything into that, as you are watching over your locals. Every market has different locals, and some have better PQ and some have worse PQ (due to having a lot of subchannels etc) Also the way Directv collects the signal from them matters a lot too.

You'd might well have different experiences if you watched those NBC & ABC channels on Directv versus watching them on your local cable TV provider and picking them up OTA with an antenna. My local CBS and Fox outlets (one 1080i and one 720p) used to be VASTLY superior via OTA than what I'd get via Directv. Why? Because for the first few years after the HD transition, neither had any subchannels, so the whole 19.2 Mbps ATSC bandwidth was devoted a single HD channel. Now that they have three subchannels each, they are not nearly as good, and there's no real difference from what I get via Directv.

After stations begin to transition to ATSC 3.0 that'll shake things up again, and you might get better quality picking some up via OTA while others will look better on Directv. Just depends on how that transition happens in one's local market, and how Directv is acquiring the local broadcast signals. Only thing you can say for sure if that even if ATSC 3.0 results in locals broadcasting in 4K (personally I'm skeptical) you will NEVER get 4K locals via Directv satellite.
 

goaliebob99

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Many of the channels send a full bandwidth signal to Directv via fiber even if their ota signal has subchannels.
Not quite... Usually, it's a direct copy of what goes to their transmitter and is the same as pulling the OTA signal.

And then again many locals are pulled buy using the OTA signal and not fiber.
I would say that the majority of the signals DirecTV gets is from the OTA feed as it's cheaper to get it that way versus paying for a ASI/Fiber feed.
 

slice1900

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From what I understand Directv generally locates their LRF (local receive facility) for a DMA at a broadcast facility if possible. For example, in my DMA it is located at the broadcast facility for the local CBS & Fox stations (the studio, not the antenna site) So they are able to get a direct feed for the CBS & Fox stations, and use an antenna at that site to pick up everything else. They must be getting the same thing that is being broadcast (i.e. including all the subchannels) because the quality is basically the same as OTA. If they were getting a full bandwidth version of the main station, Directv should have superior PQ compared to OTA.

Supposedly some stations do give Directv that full bandwidth version, but if so I have no idea why some do and some don't - probably it is just up to the station and what they do depends on what's easier for the station engineer. Getting the full bandwidth version could be more expensive for Directv, since they'd need an encoder located at the LRF, so maybe they don't even want that unless the station leaves them no choice.
 

rad

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Here's where you can find out where your LRF is located, Local Receive Facilities for Local Television Stations. For our DMA the LRF is not located at any of our local TV stations and in the past when a local station has been off the air via OTA the DIRECTV signal is also gone while or local cable companies do have fiber connections to the stations and continue to provide the channels.
 

Jimbo

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From what I understand Directv generally locates their LRF (local receive facility) for a DMA at a broadcast facility if possible. For example, in my DMA it is located at the broadcast facility for the local CBS & Fox stations (the studio, not the antenna site) So they are able to get a direct feed for the CBS & Fox stations, and use an antenna at that site to pick up everything else. They must be getting the same thing that is being broadcast (i.e. including all the subchannels) because the quality is basically the same as OTA. If they were getting a full bandwidth version of the main station, Directv should have superior PQ compared to OTA.

Supposedly some stations do give Directv that full bandwidth version, but if so I have no idea why some do and some don't - probably it is just up to the station and what they do depends on what's easier for the station engineer. Getting the full bandwidth version could be more expensive for Directv, since they'd need an encoder located at the LRF, so maybe they don't even want that unless the station leaves them no choice.
My local Facility is at the CBS station downtown ...
Had a nice chat with the Chief Engineer after I fixed thier internet at the station.
It was quite interesting.
 
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