4K/UHD Blu-ray Discs and BDXL

[Roycal]

You should hold out for the solid state experience. And don't dump all the DVD's
I got a massive collection of DVD's I would never dump, they all play just fine on my HTPC .

 

[gereral1]

Just as a point of interest, we all keep calling it 4K but its UHD i.e. HD X 4 (pixels)

You mean x2 for UHD x4 for native. I know as looking into camcoders for my channel that downsampling uhd to 1080p you can go 50 percent and not loose detail. Anything over 50 percent you start to loose quality. The 4k native the gh4 camera can record can be taken down 4 times to display in 1080p allowing panning and more options in post for movies.

 

[rotty dog]

Hi Gereral

Not quite sure what you mean.

4K UHD TV is 4 times the pixels of HD TV, i.e. (2 x Horizontal HD) x (2 x Vertical HD) = (2 x 1920) x (2 x 1080)

in other words:

HD TV total Pixels 1920 x 1080 = 2073600 Pixels
4K UHD TV (not 4K Native) total Pixels 3840 x 2160 = 8294400 Pixels (i.e. 4 times the Pixels @ HD)

i.e. down-scaling and up-scaling are exact multiples (no aliasing effects)

4K Native total Pixels 4096 x 2160 = 8847360 Pixels

 

[gereral1]

I thought uhd was half the resolution as 4k native is always downsampled to 2x 1080p to be displayed on those new 4k tvs. But uhd is double that if 1080p. Im thinking as a guy who edits videos. Example ax100 camcorder produces what a uhd tv can display (2x1080=2160 2×1920=3840) As an editor of video I would consider this 1/2 when editing videos or downsampling to 1080p production

 

[rotty dog]

Its the number of Pixels that make up the 2 display resolutions here, there are 4 times the pixels for 4K UHD TV than HD TV
4K UHD TV 8294400 Pixels
HD TV 2073600 Pixels.

If you multiply HD 2073600 by 4 you get 8294400

It is confusing because the 4 fold increase in the number of Pixels gives the eye a 2 fold (2x) increase in definition of course, 2H 2V.

 

[dellsam34]

4096x2160 professional screen resolution AFAIK called 4K because the horizontal resolution is 4000, the same goes to professional HD 2048 it is called 2K, they just neglect the 96 and 48 pixels they are usually used for overscaning the screens, 1000 in French is called one Kilo and commonly called K so 4000 is 4K, 1000 grams is 1Kg, Also used in money $800,000 house price is referred to as $800K, If it is referred to 4 times the resolution it would have been 4x

 

[Ch3vr0n]

The 48/96 is not over scanning. The computer world works with multiples of 2 to indicate real numbers. 4096 is such a value. The manufacturing world uses 'fake' values in thousands. It's that same reason why eg blank single layer DVD's packaging day 4.5GB but only 4.35GB is actually usable, or why a 1TB hard drive point has 921GB available.

For manufacturers 1TB : 1,000,000,000 bytes
IT world 1TB: 1,073,741,824 bytes

1,000,000,000/1024/1024/1024= approx 921GB.

The same math is true for screen resolutions.

Verstuurd vanaf mijn Nexus 7 met Tapatalk

 

[dellsam34]

The 48/96 is not over scanning. The computer world works with multiples of 2 to indicate real numbers. 4096 is such a value. The manufacturing world uses 'fake' values in thousands. It's that same reason why eg blank single layer DVD's packaging day 4.5GB but only 4.35GB is actually usable, or why a 1TB hard drive point has 921GB available.

For manufacturers 1TB : 1,000,000,000 bytes
IT world 1TB: 1,073,741,824 bytes

1,000,000,000/1024/1024/1024= approx 921GB.

The same math is true for screen resolutions.

Verstuurd vanaf mijn Nexus 7 met Tapatalk

Yes I'm aware of that, I was just explaining the 4K part, Movie theatre projectors are overscanned of few pixels it may not be exactly 96 or 48 pixels but I meant those pixels are not really important, and they are ignored.
In the international system of unit measurement 1000 pixels is one Kilo pixel
In the IT world 1024 bytes is one Kilo byte
And because the images are processed by computer the resolution is chosen to be of the form of multiple of 1024, So 2048, 4096 and the coming resolution is going to be 8192 for computing purposes.

 

[dellsam34]

I think software developers such as nero, Roxio ... will have to purchase the 4k/UHD license to make the BDXL authoring software for home movies, if that happened that means BDXL players will have a firmware update for 4K/UHD write/read/playback and that's where the fun begins.

 

[Roycal]

Until UHD becomes available in real 4K content, it all seems to be mostly smoke and mirrors. Nice to have a higher resolution TV but what matter does it make if you don't have any real 4K content?

On the confusion of the 4K UHD standard, it's 4 times the pixels of 1080p HD. Twice the pixels in the vertical and horizontal direction. 1080p viewed on a true 4K UHD monitor (without upconversion) would only cover 1/4 of the screen. Thus the 4X difference in resolution.

 

[dellsam34]

Until UHD becomes available in real 4K content, it all seems to be mostly smoke and mirrors. Nice to have a higher resolution TV but what matter does it make if you don't have any real 4K content?

On the confusion of the 4K UHD standard, it's 4 times the pixels of 1080p HD. Twice the pixels in the vertical and horizontal direction. 1080p viewed on a true 4K UHD monitor (without upconversion) would only cover 1/4 of the screen. Thus the 4X difference in resolution.

There is no big difference between UHD and 4K, 4K is for movie theatres and UHD for TV's, there is some consumer projectors that have native 4k resolution and maybe some TV's too, viewing native UHD contents on them will lead to very tiny black strips on left and right, 128 vertical lines on each side to be more specific.

 

[rotty dog]

Until UHD becomes available in real 4K content, it all seems to be mostly smoke and mirrors. Nice to have a higher resolution TV but what matter does it make if you don't have any real 4K content?

On the confusion of the 4K UHD standard, it's 4 times the pixels of 1080p HD. Twice the pixels in the vertical and horizontal direction. 1080p viewed on a true 4K UHD monitor (without upconversion) would only cover 1/4 of the screen. Thus the 4X difference in resolution.

Hi Roycal

Sorry fella but your wrong, 4K UHD TV is 2x resolution not 4.

The easiest way to think of it is if you say have a 50" TV and you make it 2x i.e. you DOUBLE the size of the TV BUT keep the original Pixel density (i.e.) same Pixels per centimetre then you will have 4 times the Pixels, yes, but the TV screen is only Double (2x).

8K UHD TV is 4x resoulution (16 times the Pixels ' HD).


There is a thought experiment for this and it goes like this:
As we are talking about TV lets use that in the experiment.

Imagine a 4K UHD Camera looking at a small square, for arguments sake lets say the square is 1mm by 1mm, and at the distance from the 4K Camera, it is fitting into 1 Pixel.
(This all assumes the optics are perfect etc, its just a thought experiment)

How much bigger would the square have to be to show on an HD Camera...
Answer double (2x) i.e. 2mm by 2mm

Or forget the HD Camera and stay with the 4K Camera, if you double the size of the square, how many Pixels will it illuminate on the 4K Camera...
Answer 4.

The 4K UHD Camera can see objects half the size of the HD Camera. (An 8K Camera can see objects quarter size of HD Camera)

In other words, 4 times the info, gives us a doubling (2x) increase in Resolution.

 

[dellsam34]

What matters is the pixel count and that is 4 times, 4k doesn't mean 4 times thou and it is not a consumer format.

 

[rotty dog]

No I know that 4K does not mean 4x, 4K UHD has 4 times the pixels of HD, that's all.

The trouble is that people are fixated on the Pixel count and it gives a completely false impression of the increase in Resolution.

We don't perceive the Pixel count, we only perceive the Resolution.

If we talk about (UUHD), i.e. 8K UHD TV , that's 16 times the Pixel count of HD, BUT its only 4x the Resolution of HD.

For me, Resolution is the important point not the Pixel count.

But there are more important things in life eh, LOL.

 

[dellsam34]

Here is the specifications of the UHD Blu-ray from one of the BDA websites that recently was setup for this purpose, no mention about recording media, kind of sucks:
http://www.uhdbdinnumbers.com/

 

[Roycal]

This point is getting a little trivial and don't want to start a huge discussion but if you take 1080p video and display it on a UHD monitor it only occupies 1/4 of the screen which means it's only 25% of the resolution of UHD. You would have to increase it's area by 4X to cover the entire UHD screen. It's really not that complicated in my mind. Doubling the sides of a rectangle increases it's area by 4X. UHD has 4X as many pixels as 1080p and therefore has 4X the resolution.

On the differences between standards, the standards I'm referring to is the one sold with most 4K HDTV's these days which translates to 2160p (twice 1080p).

On the difference in human perception between 4K and 2K, that doesn't really affect the 4X difference in resolution either. An increase of resolution of video does not necessarily have a proportional increase in human perception, but that does not affect the true resolution. And imaging tools can take full advantage of the true resolution.

 

[Roycal]

Here is the specifications of the UHD Blu-ray from one of the BDA websites that recently was setup for this purpose, no mention about recording media, kind of sucks:
http://www.uhdbdinnumbers.com/

Looks interesting. On the media, they are talking about 60GB D/L and 100GB T/L. 100GB BD-R already exists so if it's a matter of capacity, that's not a problem.
I think this is where the H265 encoder comes in to increase the capacity of the already existing BD media by about 33.3%. Instead of 25GB per layer they are squeezing out 33.3GB per layer.

To get the 3rd layer the BD burners and players would have to be able to focus on that third layer, but it sounds like no significant change in media or laser wavelength. AFAIK so far anyway.

 

[dellsam34]

It is not just about the media capacity but rather the way it is recorded on the disc, PS3 games are blu-ray too but you cannot read them with a computer blu-ray drive, So it is not clear yet if this UHD blu-ray format will be compatible with BDXL drives or not.

 

[Roycal]

Most likely the content will be recordable on existing media anyway. Playback is something else and could be a significant challenge. I agree, recording could be a problem too.

I would just like to see some real 4K content released and then we got something to work with

 

[rotty dog]

This point is getting a little trivial and don't want to start a huge discussion but if you take 1080p video and display it on a UHD monitor it only occupies 1/4 of the screen which means it's only 25% of the resolution of UHD. You would have to increase it's area by 4X to cover the entire UHD screen. It's really not that complicated in my mind. Doubling the sides of a rectangle increases it's area by 4X. UHD has 4X as many pixels as 1080p and therefore has 4X the resolution.

On the differences between standards, the standards I'm referring to is the one sold with most 4K HDTV's these days which translates to 2160p (twice 1080p).

On the difference in human perception between 4K and 2K, that doesn't really affect the 4X difference in resolution either. An increase of resolution of video does not necessarily have a proportional increase in human perception, but that does not affect the true resolution. And imaging tools can take full advantage of the true resolution.

The point IS trivial but you still have to keep saying its 4x Resolution.

Ive just had a look whats about on this. Look up books like "Don't confuse pixel numbers with resolution! "

There are many text books and papers on this, im sure that they can put it across to you much better than I can.

Your thinking it terms of AREA each time, I agree with you that there is 4x the information(pixels) HD to 4K, BUT, this is not the resolution ratio.
A flat object of course always has 2 dimensions.

BOTH these dimensions gobble up information and I think that's where you are going wrong.

Try this, imagine you have a 1.77 test card set up on a wall.
You point your 4K camera at it, you set your zoom to 2x.
You have the camera connected to a 4K TV.
You look at the TV and move the camera tripod to a position where the test card fills the screen.
The test card will now occupy a pixel area of 3840 by 2160 on the TV screen and the zoom is set to 2x.
You now zoom out back to unity 1x.
What area (pixel by pixel) do you think the test card NOW occupies within the 4K TV
Its 1920 by 1080, i.e. a 4x reduction in pixels but a 2x actual reduction.
You have now reduced the info (pixels) for each object seen by 4, i.e. you have reduced the Resolution by 2

Now reverse it and zoom from 1x to 2x, the test card will go from 1920 by 1080 to 3840 by 2160, a 4x increase in Pixels but only a 2x increase.

And most important of all, QED for this is that a 4K camera can resolve an object ONLY half the size of the smallest object the HD Camera can resolve.
ONLY, i.e. no smaller. i.e. has twice the resolution.
If as you think, the resolution is 4x then this would NOT be the case.