1080i or 720p?

[Ace H]

Which resolution is considered better of the two 1080i or 720p?

[GMichael]

Which resolution is considered better of the two 1080i or 720p?

The answer is not as simple as the question seems. 1080i has more lines of resolution so should look better. But because of how interlacing works, 1080i only looks better when there is little or no movement. For sports, the 720p looks better for the most part.
Now it gets even stickier if you have a 1080p TV. A 1080i source can be converted to 1080p easier than a 720p source can. So then the 1080i signal would look better than the 720p source would.
So now comes a question. Are you talking source or display?

[Woochifer]

GM got it right. You will notice more image detail with a good 1080i signal, but 720p definitely holds up better with motion. FWIW, 1080i requires more bandwidth to display.

[Ace H]

I ask because I have my HDTV hooked up to both Antenna and HD Cable Box. The QAM tuner from the antenna source indicates it's 1080i but the source from the HD Cable Box displays at 720p. The 1080i does appear to be a bit more crisp, sharp and clear. I knew that 1080p is supposed to be the best pictue (for now) so I was just trying to figure out if the progressive signal of the 720 would "trump" the interlace signal of the 1080?

[Woochifer]

I ask because I have my HDTV hooked up to both Antenna and HD Cable Box. The QAM tuner from the antenna source indicates it's 1080i but the source from the HD Cable Box displays at 720p. The 1080i does appear to be a bit more crisp, sharp and clear. I knew that 1080p is supposed to be the best pictue (for now) so I was just trying to figure out if the progressive signal of the 720 would "trump" the interlace signal of the 1080?

On that particular channel, the 1080i source SHOULD look better simply because the antenna gives you the original signal at the original resolution. Your cable box signal is a retransmission that might have gotten compressed or otherwise modified in the process.

Are all sources using the HD cable box getting sent out in 720p? If so, you'll need to check you box setup and make sure that it is setup to output 1080i signals in their native format. If it's not a setup issue, then your cable company is downconverting the signal to 720p to conserve on bandwidth -- not a good idea. All satellite and cable services will compress the video signals on their systems, but I thought thatmost of the time they will transmit the signal in the original resolution.

[GMichael]

Hmmm... Interesting. So maybe they are broadcasting 1080i via the air but 720p by cable to save bandwidth?

[GMichael]

On that particular channel, the 1080i source SHOULD look better simply because the antenna gives you the original signal at the original resolution. Your cable box signal is a retransmission that might have gotten compressed or otherwise modified in the process.

Are all sources using the HD cable box getting sent out in 720p? If so, you'll need to check you box setup and make sure that it is setup to output 1080i signals in their native format. If it's not a setup issue, then your cable company is downconverting the signal to 720p to conserve on bandwidth -- not a good idea. All satellite and cable services will compress the video signals on their systems, but most of the time they will maintain the signal in the original resolution.

Ahhh...
I didn't think of that.

[pixelthis]

Is a moot point really, because most sets sold these days are either 1080p or 720p.
1080I AS A DISPLAY is just about out the door, even tho its still an exelent
broadcast medium, since its so easy to deinterlace to 1080p.
Get a 1080p, stay ahead of the curve.

[Ace H]

So far I see that all the HD channels coming from the HD box are in 720p. My HD box is a Motorola DCH3200. I downloaded the manual for this box from Motorola's website and discovered something interesting. The manual has a section called "OPTIMIZING YOUR DCH RECEIVER FOR HIGH-DEFINITION TV". This allows you to get into the box's settings example:
User Setting Status - TV Type: 16:9, YPbPr OUTPUT 1080i, 4:3 Override 480i
This setting seems to be geared to the Component Video but I'm using HDMI. Later I well hook up some Component Video and see if I get the 1080i as indicated. I'll keep this thread posted as to the outcome when I do.

[Jack in Wilmington]

I don't see 720p on my set anywhere. How do you get 720p? I get 480i on my SD signals and 1080i when I go to the HD channels. I have verizon, maybe they don't broadcast in 720p anymore.

[Ace H]

I have Cox Communications as my provider.

[Ace H]

Just did the component video hookup and all signals via HD Box are still 720p.

[hermanv]

GM got it right. You will notice more image detail with a good 1080i signal, but 720p definitely holds up better with motion. FWIW, 1080i requires more bandwidth to display.

Now I'm confused, since 1080i requires two passes to complete a picture, the update data rate is equivalent to 540p. No? So I think 720p requires a greater bandwidth than 1080i because the entire screen is updated twice as often. By the end of two screens 1080 pixels have been sent for 1080i, but during the same time interval I think 1440 pixels have been sent for 720p.

I have insomnia, it's early in the AM and I could easily have forgotten to turn off the stupid gene.

'Course all this is moot since mostly it's sent as Mpeg 4 and the actual data rate varies enormously with picture content.

[pixelthis]

Now I'm confused, since 1080i requires two passes to complete a picture, the update data rate is equivalent to 540p. No? So I think 720p requires a greater bandwidth than 1080i because the entire screen is updated twice as often. By the end of two screens 1080 pixels have been sent for 1080i, but during the same time interval I think 1440 pixels have been sent for 720p.

I have insomnia, it's early in the AM and I could easily have forgotten to turn off the stupid gene.

'Course all this is moot since mostly it's sent as Mpeg 4 and the actual data rate varies enormously with picture content.

This is what I HAVE BEEN trying to explain for the longest time on this board, and its why 720p is inherently better than 1080i.
When theres movement the resolution breaks down and sometimes you dont get 600 lines of res.
However with 1080p 1080i is deinterlaced and you get a spectacular picture, 1920 x 1080.

[pixelthis]

So far I see that all the HD channels coming from the HD box are in 720p. My HD box is a Motorola DCH3200. I downloaded the manual for this box from Motorola's website and discovered something interesting. The manual has a section called "OPTIMIZING YOUR DCH RECEIVER FOR HIGH-DEFINITION TV". This allows you to get into the box's settings example:
User Setting Status - TV Type: 16:9, YPbPr OUTPUT 1080i, 4:3 Override 480i
This setting seems to be geared to the Component Video but I'm using HDMI. Later I well hook up some Component Video and see if I get the 1080i as indicated. I'll keep this thread posted as to the outcome when I do.

On Motorola boxes you turn the power off, then hit the menu button.
The configuration screen comes up and you have choice of several different options.
720P if you have a 720p set, if the deinterlacer in your TV is better choose the 480i
on the 480 override option, if not choose 480p.
CHOOSE SOMETHING THAT TAKES THE PIC OFF, AND YOU CAN USE THE FRONT DISPLAY TO GET IT BACK.
Good luck.

[Ace H]

"CHOOSE SOMETHING THAT TAKES THE PIC OFF, AND YOU CAN USE THE FRONT DISPLAY TO GET IT BACK."

pixelthis,
I don't quite follow what you mean with the above.

[Woochifer]

Now I'm confused, since 1080i requires two passes to complete a picture, the update data rate is equivalent to 540p. No? So I think 720p requires a greater bandwidth than 1080i because the entire screen is updated twice as often. By the end of two screens 1080 pixels have been sent for 1080i, but during the same time interval I think 1440 pixels have been sent for 720p.

You forgot to account for the smaller number of pixels per frame on a 720p image. 1080i is rendering a 1,920 x 1,080 pixel map at a frame rate of 30 frames/sec, while 720p renders a 1,280 x 720 pixel map at a frame rate of 60 frames/sec. Do the math, 1080i gives you a pixel rate of approximately 62.2 million pixels/sec, while 720p gives you 55.3 million pixels/sec.

In addition, all things being equal, both the MPEG-2 and MPEG-4 codecs compress progressive video more efficiently than interlaced. More data + less efficiency = greater bandwidth

Because of this, 1080i requires a higher bandwidth, but whether or not that equates to a "better" picture is debatable. On my TV, I can see that 720p sources have less image detail (could also be a byproduct of the rescaling needed on a 1080p TV), but I can also see that it has smoother motion on the backgrounds than 1080i.

[Woochifer]

Just did the component video hookup and all signals via HD Box are still 720p.

Yep, sounds like your cable provider is downconverting all its HD/DTV content to 720p. If you want to maximize your picture quality, you'll need to stick with the OTA signal, since that has not gone through any rescaling or other format conversion.

Unfortunately, cable and satellite companies alike do stuff like this to save on bandwidth. I use Directv, and while the HDTV signals on that service are maintained in their original resolution, they are also all converted to MPEG-4. For any channels that don't originate in MPEG-4 (I read that HBO and Showtime transmit in MPEG-4, but not too many other channels have followed suit), Directv has to do a real-time format conversion. Then again, Directv's older MPEG-2 HD service increased the signal compression in order to save on bandwidth.

[Smokey]

This is what I HAVE BEEN trying to explain for the longest time on this board, and its why 720p is inherently better than 1080i.

Pix

720p is not inherently better than 1080i. It just show smother picture on high motion scenes albiet lower resolution than 1080i. Also as Wooch mentioned, 720p uses less bandwidth than 1080i.

[pixelthis]

"CHOOSE SOMETHING THAT TAKES THE PIC OFF, AND YOU CAN USE THE FRONT DISPLAY TO GET IT BACK."

pixelthis,
I don't quite follow what you mean with the above.

When you are trying to set this up there is a config screen, which you manuver through with the up-down left-right buttons.
Hit a wrong choice and your pic might go off, but the info is still on the front display, which will help you get back to a config your set will display.
THERE ARE SEVERAL CHOICES on this display , 16:9 or 4:3, 480i override choice, etc.
Stay away from HDMI submenu, that could mess you up.
You will understand what I am talking about when you get to the menu.

[Ace H]

Thanks for the additional info.

[Sir Terrence the Terrible]

This is freakin rediculous. Pix you need to shout the hell up. It does not matter if it takes two fields to paint 1080i, you cannot SEE the painting in action, so to the eyes(you must take visual perception into consideration, not just the numbers or the process) its all one process. Our eyes perceive one pass, or the two fields combined second by second, and even half second by half second, so the interlacing process is transparent to the eyes. No matter how you slice it, there is more information in a 1080i signal than in a 720p signal progressive. 1080i is better for movies, and 720p is better for sports. That is why channels that mainly show movies have picked 1080i, and the sports channels choose 720p, There is another reality here, any advantage 720p has with motion is also negated be the panels performance dealing with motion blur and panel lag.

Pix, please spare us your 480i experience trying to paste over a 1080i reality.

[pixelthis]

This is freakin rediculous. Pix you need to shout the hell up. It does not matter if it takes two fields to paint 1080i, you cannot SEE the painting in action, so to the eyes(you must take visual perception into consideration, not just the numbers or the process) its all one process. Our eyes perceive one pass, or the two fields combined second by second, and even half second by half second, so the interlacing process is transparent to the eyes. No matter how you slice it, there is more information in a 1080i signal than in a 720p signal progressive. 1080i is better for movies, and 720p is better for sports. That is why channels that mainly show movies have picked 1080i, and the sports channels choose 720p, There is another reality here, any advantage 720p has with motion is also negated be the panels performance dealing with motion blur and panel lag.

Pix, please spare us your 480i experience trying to paste over a 1080i reality.

There is more info in a 1080i pic, but its not on the screen at the same time.
AND when theres movement it all falls apart.
With a 1080P pic you get a full 1,080 lines AT ONE TIME.
The advantage in "sports" you talk about is the fact that theres a lot of movement in sports, so you dont lose half the res everytime the pitcher spits.
Funny how the field changes with you, a LCD with a 5ms response time has "motion
blur" even though it refreshes much faster than the eye can discern, but the eye cant
discern two fields being interleved to create one frame.
Make up your mind, which is it nimrod?

[Sir Terrence the Terrible]

There is more info in a 1080i pic, but its not on the screen at the same time.
AND when theres movement it all falls apart.
With a 1080P pic you get a full 1,080 lines AT ONE TIME.
The advantage in "sports" you talk about is the fact that theres a lot of movement in sports, so you dont lose half the res everytime the pitcher spits.
Funny how the field changes with you, a LCD with a 5ms response time has "motion
blur" even though it refreshes much faster than the eye can discern, but the eye cant
discern two fields being interleved to create one frame.
Make up your mind, which is it nimrod?

You are lying again pixel. You cannot see the effect of the double field painting, it looks like a single field to the eyes because it refreshes faster than we can see. On CRT's during motion there is less loss during movement than there is on your average progressive panel. Your cheap ass 42" vizio resolution drops down to 330p during motion, which is far more loss than a CRT has.

5ms is not faster than the eye can see, or you would not experience any motion blur. Two fields painted at 30 times a second is invisible to the eye as it is much faster than 5ms. Get your fact straight stupid ass.

[bobsticks]

It's been too long since we've had one of these punch-in-the-face contests.

Really.