Confused about the pixels

[patrick]

Hello, i am confused about why people use this as their pixels and call it HD. Every tv or movie video has this size and labeled as hd but hd is 1280x720 so is this possible? if not then why do they call it hd? i searched the net but to no avail. being a long time lurker here and thought this is the best place to ak. thank you

all claim of HD
-----
Width 720 pixels
Height 406 pixels
------
1280x540
-------
640x352
ratio 16:9

----
640x272
ratio: 2.35:1

bluray
1280x536 pixels
-----

edit:
Width 720 pixels
Height 406 pixels or 400 pixels

this is the one most call hd and just clarifying if its real hd or not, thanks

[jagabo]

Anybody can write anything they want. Or name any file anything they want. Their source may have been true HD but the resulting video may not be. Most people consider a width of 1280 or more, or a height of 720 or more, to be HD. And picture quality is a part of being HD. Upscaling a VHS capture to 1920x1080 doesn't make it real HD.

[hech54]

The term HD has been rode hard and put away wet since forever.

[_Al_]

It might be labeled as HD rip, which is sort of a statement that video was actually made out of HD, isn't it like that?

Anything below 720 x something is not obviously HD (but might be ripped from BD). Quality of that video suppose to be better comparing it to same resolution rip made out of DVD. Mostly, it might be true but anyway it is just people who rip/encode it.

[patrick]

ohh, so the source is from HD or higher and thats why they label them like this in the titles but if the pixels is not 1280x720 persay then its not hd. I think when they do this it throws people off thinking its hd when its not. Thank you for the help

[teodz1984]

lots of stuff are mislabeled on the Internet... so just beware..
lots of fake hd, fake sources.. eg bdrip..

usually you can visually inspect t whether the files are true to their name.

[johnmeyer]

HD does have fairly specific meaning when used for broadcast television. Those definitions are codified by standards committees. The first section of this document describes the three resolutions:

High-definition television
From Wikipedia, the free encyclopedia

[patrick]

very interesting, thank you. learned quiet a bit here about this.
This was driving me nuts trying to know why and what. thanks

[pandy]

HD is 1280x720p50/60 or 1920x1080p/i 24/25/30 50/60 .

[teodz1984]

Yup there are standards, but a lot of people (esp the the amateurs) don't adhere to these...

[jagabo]

So 1440x1080 isn't HD? What about 1278x718? 1904x1072? 1922x1088? Only Blu-ray and broadcast standard resolutions can be considered HD?

[teodz1984]

Loosely, anything that is greater than SD i.e 640 x 480 (originnal DVD resolution in 4-3 or its equivalent widescreen variants) is HD

[johnmeyer]

So 1440x1080 isn't HD? What about 1278x718? 1904x1072? 1922x1088? Only Blu-ray and broadcast standard resolutions can be considered HD?

I didn't say anything like that. I said:

HD does have fairly specific meaning when used for broadcast television.

In that context, my statement is true because, as my link showed, there are only a few resolutions and frame rates which are permitted for broadcast.

Adding Blu-Ray's spec is a good idea because it too is a standard.

And, since there is no other definition that has been approved or widely accepted, unless someone can point to some other standards body definition, then I think the only answer that has any meaning is the one I gave. I'm not trying to be arrogant; I'm simply stating that the term has never been defined by any other group.

Of course one could make the argument that anything beyond "standard definition" is "high definition," but trying to do that is a sure way to start a major flame thread because it will just be dueling opinions, with absolutely nothing of substance to back up any particular point of view. Using that as a starting point, 721x481 could be "HD."

[Cornucopia]

It is pretty accepted among engineers that <= 768x576 (square pixelled, 4x3) is SD. > that is HD, up to ~1920x1200. Above that is UHD.
These don't include film rez listings (2k, 4k, etc) cuz of different nomenclature and measuring criteria.
Nor do they include resolutions that are a nonstandard, very widescreen format.

But note that your previous listings of 1280x540, etc are likely really just simple BD rips of HD material where the source was non-anamorphic extra widescreen (e.g. 2.4:1 AR) wherein the ripper cropped out the letterbox padding prior to re-encoding.

So, just use your good judgement. Because this also assumes pristine, non-heavily-compressed material (which blocking would effectively lower perceived resolution) or that the who process was faithful & truthful to the resolution of the original source material.

Scott

[pandy]

So 1440x1080 isn't HD? What about 1278x718? 1904x1072? 1922x1088? Only Blu-ray and broadcast standard resolutions can be considered HD?

Use bandwidth as equivalence for HD, based on other standards, recommendations and good practices there are some limits on supported resolutions and frame rates - in many cases 1440x1080 is not considered as valid HD format (unless 4:3 but in such case it will violate requirement for 16:9 as native aspect ratio in HD world).

[Cornucopia]

Hdv, dvcprohd and many other formats use 1440x1080, it's an optional part of some broadcast tv specs and is included in the bd spec. OF COURSE it's HD. Maybe not "preferred", but definitely not NOT hd.
Not Hd, that's the silliest non-political thing I've heard all week.

Btw 1440x1080 uses 4:3 par so is still 16:9 dar.

Scott

[pandy]

1440 for 16:9 is classical anamorphic case - Y bandwidth will be reduced (to approx 27MHz instead over 37MHz for full 1920) and yes, some older equipment use this as compromise between bitrate (MPEG-2 compression) and quality.
HD or not HD - well is same as 1368x768 considered not as HD but HD like - overall bandwidth for 1440x1080i30 is lower than for 1280x720p60 so IMHO this is not HD - sorry.

[jagabo]

So 320x240 at 800 fps is HD in your book because the bandwidth is roughly the same as 1080i? And broadcasts at 1920x1080i25 isn't HD because it's bandwidth is 10 percent less than 1920x1080i30?

[pandy]

So 320x240 at 800 fps is HD in your book because the bandwidth is roughly the same as 1080i? And broadcasts at 1920x1080i25 isn't HD because it's bandwidth is 10 percent less than 1920x1080i30?

At first for first example Reductio ad absurdum https://en.wikipedia.org/wiki/Reductio_ad_absurdum, ad second - still more pixels per second in 1920x1080i25 than in 1440x1080i30 (for 25 frame rate we use as a reference 1280x720p50).

btw in first case statistical processing can be used to improve resolution especially if signal is captured in particular way (for example stochastic sampling)...

[jagabo]

Use bandwidth as equivalence for HD

Reductio ad absurdum?

[Cornucopia]

pandy, you can argue and believe what you want on this, but as I mentioned before, the engineering community is already in great agreement. Your saying otherwise doesn't make it so.

Scott

[pandy]

Use bandwidth as equivalence for HD

Reductio ad absurdum?

Oh... propose better criteria than just mirroring argument from interlocutor...

pandy, you can argue and believe what you want on this, but as I mentioned before, the engineering community is already in great agreement. Your saying otherwise doesn't make it so.

Scott

Well... suddenly Scott you begin to be representation for whole engineering community... and opposite to this community large group of consumers don't consider as HD anything bellow 1920x1080p60(50)...

So where is border - clear line to split two worlds - HD and not HD?

[jagabo]

So where is border - clear line to split two worlds - HD and not HD?

There is none.

[pandy]

So where is border - clear line to split two worlds - HD and not HD?

There is none.

So 320x240p800 is indeed HD... fine for me.

[jagabo]

So where is border - clear line to split two worlds - HD and not HD?

There is none.

So 320x240p800 is indeed HD... fine for me.

Not for me. It's not just bandwidth. The frame size, frame rate, real resolution (sharpness) of the video, bit depth, etc. all play a part. As was said ealier, you have to use some judgement.

[awgie]

ohh, so the source is from HD or higher and thats why they label them like this in the titles but if the pixels is not 1280x720 persay then its not hd. I think when they do this it throws people off thinking its hd when its not. Thank you for the help

More often than not, the term "HD" is included in the title simply as click bait. It may not have come from an HD source, and it may not be HD resolution, but saying it's HD gets them more views.

[pandy]

Not for me. It's not just bandwidth. The frame size, frame rate, real resolution (sharpness) of the video, bit depth, etc. all play a part. As was said ealier, you have to use some judgement.

IMHO subjectively resolution and framerate are least important factors than overall perceived quality (still plenty of services at least in Europe are SD) however market created such line (1280x720p60(50) is considered from marketing perspective as lowest full HD format).

[jagabo]

market created such line (1280x720p60(50) is considered from marketing perspective as lowest full HD format).

But a 2.35:1 movie will only occupy about 1280x540 of that frame. If someone crops away the black borders and encodes at 1280x540 isn't it still HD? And often there are small black borders at the left and right edges too. Cropping those away might leave 1276x540. All the original picture information is still there (aside from additional compression losses) so isn't it still HD?

Or a 1.37:1 movie will only occupy about 988x720 of the frame. So isn't cropping to that size still HD?

The OP wasn't asking about broadcast standards which are restricted to particular frame sizes.

[pandy]

market created such line (1280x720p60(50) is considered from marketing perspective as lowest full HD format).

But a 2.35:1 movie will only occupy about 1280x540 of that frame. If someone crops away the black borders and encodes at 1280x540 isn't it still HD? And often there are small black borders at the left and right edges too. Cropping those away might leave 1276x540. All the original picture information is still there (aside from additional compression losses) so isn't it still HD?

Or a 1.37:1 movie will only occupy about 988x720 of the frame. So isn't cropping to that size still HD?

The OP wasn't asking about broadcast standards which are restricted to particular frame sizes.

Fair arguments but you skipped framerate - cinema use 24p (with few exceptions) as such 1280x720p24 perfectly valid from video perspective is not HD format as main goal for 1280x720p60 was to provide experience of smooth, fluid motion without interlace and at the same time increased spatial resolution - for cinema broadcast 1920x1080 video format can be used without interlace penalty.

So no - 1280x540p24 is for me EDTV (Extended Definition when compared to SDTV) same as 480p60... it offer better parameters than SD but not matching what is expected from real HD.

[awgie]

pandy, I must respectfully disagree with you.