Broadcasting In 1080P

ag9670

Does anyone broadcast in 1080P? I've heard that it's just not feasible at this point. You probably can't tell the difference (maybe you hardcore folks can ), but I was just curious.

Thanks

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AG

cb2367

The best broadcast currently available right now is 1080i. From what I understand, the TV technology is way ahead of broadcast technology. It will probably be several years before 1080p broadcasting comes around. I would say that 1080i broadcast format isn't used that often and instead the 720p is what's used for HD content.

joekewl1971

I thought there was more 1080i than 720p. Fox, ABC, ESPN, and PBS are examples of 720p. Heard that National Geographic uses 720p but I have not been able to confirm this. Seems that leaves a lot of channels. My favorite premium movie channels brag about 1080i on thier web sites. Universal HD brags 1080i on the channel. Anyone know about others that I have left out?

PS I watched both extensively, and mostly could not tell the difference. But during the action scenes in movies, when the motion is fastest, 720p helps.

fmw

There isn't really any reason to broadcast 1080p. The 1080p TV sets de-interlace the signal just fine resulting in the same thing. No loss of content at all. There is no point in using the bandwidth to broadcast 1080p.

rbinck

The ATSC spec allow broadcasting 1080p/30 and 1080p/24, but not 1080p/60. When the question is asked it usually means the questioner want to know about 1080p/60. That is not necessary as fmw explained. Point here is the question is actually incomplete without adding the frame rate.

As far as 1080p/24 or 30 they won't adopt these either because the 24 fps would only be good for film based content and would make any live video difficult since most existing cameras do not support that format. 1080p/30 will actually give worse motion response than 1080i/30 depending on the HDTV being used and its ability to switch between video and film processing modes.

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joekewl1971

Can anyone please fill me in on what channels are 1080i/720p? I would still like to know more about the origins of these channels. I know some already, but not all. Thanks

Doom878

MOJOHD is in 1080i.

zeroyon04

The technology is definitely there to broadcast in 1080p/30 or 1080p/24, but the available bandwidth is not. I remember back when HD came out, that many of the 1080i broadcasts were in full 1920x1080 resolution, but almost all (if not all) stations have moved to broadcasting in the HDV format of 1440x1080 with 1.33:1 pixel aspect ratio.

I believe that most HD is broadcast in 1080i in the USA. The only exceptions I can think of are FOX, ESPN, and ABC, which broadcast in 720p.

I think that 1080p/24 broadcasting MIGHT become a reality in 5 years or so, but only for countries that have extensive fiber optic networks, or high bandwidth capacity satellites.

rbinck

Just for the record, the bandwidth required for 1080p/24 is less that what is required for 1080i/30. The bandwidth for 1080p/30 is roughly the same as it is for 1080i/30. I use roughly the same because there can be a slight reduction in bandwidth required for 1080p/30 due to progressive frames compressing slightly better than interlaced frames.

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gobogie

When I was talking to a CSR from Direct TV just his week, he told me that they have been broadcasting in 1080p for a while now... wanna say he said for a couple of months!

Don't know if this is true?

rbinck

It was a Directv CSR. Anything beyond signing you up for service begins to tax their knowledge. It is not true.

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BrianO

You might add that the bandwidth required for 1080p/24 is about 10% less that that required for 720p/60.

rbinck

You just did!

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danksterzone

I agree with zeroyon04. Bandwidth is the reason. Any interlace format will use less bandwidth than a progressive format. Reason being interlace only displays half the lines at a time which in turn uses less bandwidth. It is also why NTSC used 480i instead of 480p originally.

1080PsF

True... interlaced is half of the lines but it is double of the fields. If you do the math you will see that they are the same. In this example I will not include the horizontal and vertical blanking information.

interlaced 1080i/59.94

each field consists of 1920 pixels per line and each field has 540 lines and there are 59.94 fields per second.
1920 * 540 * 59.94 = 62,145,792 pixels per second

progressive 1080p/29.97

each frame consists of 1920 pixels per line and each frame has 1080 lines and there are 29.97 frames per second.
1920 * 1080 * 29.97 = 62,145,792 pixels per second