1080p source material ???

Sami · April 2005

http://www.ultimateavmag.com/thomasjnorton/305tjn/

"But here's the rub: current HDTV sources are all either 720p or 1080i. There is no 1080p source material available to the consumer."

Does it matter? There is no source material for 480p either, it is done by either the DVD player or the display device. Wouldn't 1920x1080 source then be both 1080i and 1080p capable?

Toxis · April 2005

depends on the processor used in the unit it's coming from.

Sami · April 2005

I think I figured it out. 1080i source would be 60 frames per second of 1920x540 images. 1080p source 60 frames per second of 1920x1080 images.

How much difference human eye could tell between the two I am not sure. I think 1080i material displayed in 1080p unit would still look pretty darn good, (much?) better than 720p.

Toxis · April 2005

there's a very small difference between 720p and 1080i but I prefer 1080i. I've heard from some people that 1080p is leaps and bounds better than 1080i but we have yet to see that.

PhantomOG · April 2005

Originally posted by Sami
I think I figured it out. 1080i source would be 60 frames per second of 1920x540 images. 1080p source 60 frames per second of 1920x1080 images.

are you saying the actual resolutions are different? (1920x540 vs 1920x1080)

i don't think that's right. the resolutions should be the same, just that in the progessive material, in every frame the lines or resolution are all updated, where as in the interlaced material, each line is only updated in every other frame, with adjacent lines updating in sequential frames.

Sami · April 2005

Originally posted by PhantomOG
are you saying the actual resolutions are different? (1920x540 vs 1920x1080)

i don't think that's right. the resolutions should be the same, just that in the progessive material, in every frame the lines or resolution are all updated, where as in the interlaced material, each line is only updated in every other frame, with adjacent lines updating in sequential frames.

If the material is recorded in different formats, 1080i or 1080p, then the resolutions would be different while the framerate would be the same. That's how I have started to understand it.

1080i:

60 f/s * 1920 * 540 pixels / f = 62208000 pixels / s.

1080p:

60 f/s * 1920 * 1080 pixels /f = 124416000 pixels /s.

1080i could also be:

30 * 1920 * 1080 pixels / s which is the same total number of pixels per second as in the first. But I got the understanding that 1080i source material is the first equation.

NOTE: The resolution would still be the same, 1920 * 1080. But in 1080i it would be formed from two different 1920 * 540 images interlaced after one another where in 1080p material it would be whole 1920 * 1080 images displayed every 60Hz.

PhantomOG · April 2005

from hometheaterhifi.com:

The 1080i format (i is for Interlaced) has a resolution of 1920x1080, or about 2,073,600 pixels per image, and the 720p format (p is for Progressive, where all the scan lines are shown sequentially) has 1280x720, or about 921,600 pixels per image. The top HDTV resolution, 1080i, paints a full screen 30 times a second, which gives a rate of about 62.2 million pixels a second. HDTV at 1080i has a pixel rate about 6.7 times greater than NTSC TV.

As mentioned above, the 1080i resolution for HDTV has a rate of 60 interlaced fields per second (when the image is interlaced, there are no real frames, since each interlaced image - called a "field" - is different from the next, and one could combine a field just as easily with the one before it as with the one after it - therefore, the proper terminology is 60 interlaced fields per second, rather than 30 frames per second), and the 720p resolution has a frame rate of 60 progressive frames per second.

While both 1080i and 720p/60 (the 60 is for 60 frames per second) have a temporal resolution of 60 Hz, 1080i is still an interlaced format. Interlaced display does not work well for a subject in motion, as the alternating fields are not complementary, dramatically reducing the effective vertical resolution. 720p is progressive. A high temporal resolution combined with a high progressive line count, both of which are satisfied by the 720p/60 format, makes for better representation of a subject in motion. Progressive scan lends itself very well to sports, making the action smoother and more detailed than interlaced scan. This is why sports oriented channels like ESPN are using the 720p format.

AsSiMiLaTeD · April 2005

Sami · April 2005

Originally posted by PhantomOG
from hometheaterhifi.com:

Yep, that would confirm what I said: "60 interlaced fields per second"

60 * (1920 * 540) pixels / second.

BTW, I corrected the numbers in my previous post, I forgot to multiply by the frequency, 60Hz.

bknauss · April 2005

Not true about there being no 1080p source material... for the adults in the room, there's a movie called "Island Fever 3" which is on regular DVD and then there's also an HD-DVD included. I downloaded a clip, and the PQ is simply amazing, even on my crappy laptop monitor.

Sami · April 2005

Originally posted by bknauss
Not true about there being no 1080p source material... for the adults in the room, there's a movie called "Island Fever 3" which is on regular DVD and then there's also an HD-DVD included. I downloaded a clip, and the PQ is simply amazing, even on my crappy laptop monitor.

But is it 1080i, 720p or 1080p material?

Seems to be 720p according to this (NWS page) http://www.hdtvtotal.com/module-pagesetter-viewpub-tid-1-pid-669.html

"The 720p progressive video (1280x720 pixels) at 24 frames per second just needs 6.5 out of 6.9Mbit, which is lower in camparison to other WMV-HD movies like High-Def.de's with average rates of 8 - 9 MBit, but it seems to be enough to display a fine, detailed and nearly sharp and colourful images. Nevertheless, a DVD-9 with a storage capacity twice as high as the DVD-5 which was used here, and with that an increased bitrate would have been worth considering."

1080p source material ???

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