longhornsk57's profile

Mentor

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33 Messages

Friday, July 13th, 2012 1:39 AM

what's up with 1080i setting but no 1080p?

So I ordered HD upgrade. On the DVR settings I figured I'd see what settings there are, so I go the screen settings and the highest one is 1080i...

What's up with that? Am I really getting interlaced frames? Can this DVR not output 1080p?

What am I missing here?

I have to believe you guys are getting 1080p...

ACE - Expert

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27.6K Messages

12 years ago

I have no idea what SomeJoe is talking about but, darn, he's smart!  Smiley Happy

New Member

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25.7K Messages

12 years ago

If technology keeps going the way it is, SJ is going to need more RAM and a bigger hard drive.  I read that twice and still can't remember everything he just said.Smiley Very Happy

Expert

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9.4K Messages

12 years ago

More RAM and a bigger hard drive makes everything better.  Kinda like bacon. Smiley Wink Smiley Very Happy

 

Wanna make your computer better?  More RAM and a bigger hard drive.

 

Wanna make your turkey sandwich better?  Bacon.

 

 

Mentor

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33 Messages

12 years ago

Bacon on literally EVERYTHING. 🙂

Tutor

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5 Messages

12 years ago

Seriously, what method is  used to encode/compress each stream? I am actually under the impression that the 1080i hd setting is nothing more than "upconverted" 720p happening at the stb. That is if the method of encode/compress actually even results in true 720p exiting your stb.

Expert

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9.4K Messages

12 years ago

Each stream's resolution is encoded and compressed at the native resolution that the broadcaster provides. Many broadcasters natively provide 1080i signals (NBC, CBS, Discovery, HBO, several others). Some broadcasters provide native 720p signals (ABC, FOX, Disney, ESPN, a few others).

AT&T uses H.264 (AVC) to compress/encode their video streams. This is the same encoding used on most Blu-Ray discs, but AT&T uses far lower bitrates. The native bitrate that AT&T is using for HD streams is approximately 5.7 Mbps.

The STB will output whatever resolution is selected in the Menu -> Options -> System Options -> Aspect Ratio screen, regardless of the native resolution of the stream. For example, if you have selected 1080i output, the STB will output 1080i for all channels: incoming streams that are 1080i will be sent natively to the TV, and incoming streams that are 720p will be converted to 1080i, then sent to the TV.

The opposite happens if you've selected 720p output. 720p streams will be sent natively to the TV, 1080i streams will be converted to 720p and then sent to the TV.

Some providers, notably DirecTV, have a selector in their STBs called "Native Mode", where the STB will send the stream to the TV in the native resolution, no matter what it is, and your TV can then handle it. This selection is unfortunately not available on U-Verse.

Master

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4.2K Messages

12 years ago

I wish Uverse had Native Mode maybe a hope for future STB's.

Tutor

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7 Messages

11 years ago

The reason for 1080p output is not to receive 1080p channels, it's so that BOTH 1080i and 720p content get scaled properly. If you have 1080i output, then you're losing resolution on 720p channels, and if you use 720p output, then you lose resolution on 1080i channels. With 1080p output, you don't ever lose resolution. 

ACE - Professor

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7.6K Messages

11 years ago

But since satellite offers 1080p movies, couldn't U-Verse offer them as well?

ACE - Expert

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34.7K Messages

11 years ago


@morphinapg wrote:

The reason for 1080p output is not to receive 1080p channels, it's so that BOTH 1080i and 720p content get scaled properly. If you have 1080i output, then you're losing resolution on 720p channels, and if you use 720p output, then you lose resolution on 1080i channels. With 1080p output, you don't ever lose resolution. 


Perhaps you should re-read the thread above?

 

The TV has exactly ONE native resolution.  It is either 720 or 1080 vertical pixels.  If it gets the other resolution, the TV will scale it to the TV's native resolution.

 

So... if the TV is 1080i and the channel comes in as 1080i, then no scaling occurs.  If the TV is 1080 and the channel is 720p, even if this is the "native" format for the content, it will STILL get scaled by the TV.

 

1080p and 1080i have the same vertical resolution, it's just that on 1080i only frames are "sort of" broken up into fields containing half the lines in each field.

 

The only thing having the STB lock the resolution at a certain number of pixels does is move the scaling from the TV to the STB.  The STB, especially a newer one, has fairly good scaling ability.

 

 

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