High Definition-A brief Discussion

[raj1402]

Can some one Define what do you mean by High Definition

any video which got resolution of 1280x720 -for 720p
1920x1080- for 1080p is called as High Definition irrespective of the bitrates it got

Scenario-1:

Resolution - 1280 x720p
Bitrate - 1500kbps - 2500kbps
File Size 1/2DVDr- 2.25GB

Scenario -2

Resolution 720x304
Bitrate -3500kbps - 4500kbps
File Size 1DVDr -4.5GB

in scenario1 just because it got HD resolution of 1280x720p its called as HD video?

and in scenario 2 its not HD even though it got higher bitrate for given area!!!

for me second Scenario is considered as better Quality than first

expecting your opinion on this!!!


Regards
Raj1402

[nurbs]

in scenario1 just because it got HD resolution of 1280x720p its called as HD video?
Yes.
for me second Scenario is considered as netter Quality than first even
That's debatable, it depends on the content. 2.5 Mbps isn't too low for many HD sources, it's about in the middle of the bitrate range my own 720p CRF 21 encodes come out, and the first video has 4 times the number of pixels than the second. The downsizing also destroys some details and higher resolutions generally don't need proportionally higher bitrate to look good (e.g video 1 has 4 times more pixels than video 2, but you need less than 4 times the bitrate of video 2 to get the same subjective quality). Downscaling makes sense when you don't have much bitrate available, but unless the encode is really starved it can be better to keep the higher resolution.

[Ghitulescu]

Can some one Define what do you mean by High Definition
A sinple google could have answered you -> http://en.wikipedia.org/wiki/High-definition_video
Scenario-1:

Resolution - 1280 x720p
Bitrate - 1500kbps - 2500kbps
File Size 1/2DVDr- 2.25GB

Scenario -2

Resolution 720x304
Bitrate -1500kbps - 2500kbps
File Size 1/2DVDr -2.25GB

for me second Scenario is considered as better Quality than first

Quality is personal. And is to be judged on real samples, not on figures.

Besides bitrate is not a definition for quality. A static image (like the HDTV demos, with flowers and stuff) may be way better at 2Mbps that a sport event or an action movie at 6Mbps.

[mariush]

It also highly depends on the content of the video.

If you're recording a video tutorial recording your desktop screen, 2.5 mbps for 720p can be almost (if not) lossless.

But generally, I would consider 720p 2.5 mbps barely High Definition, 4-6 mbps would be HD in my opinion.

720x304 is not HD.

[yetanotherid]

HD and SD really just define resolutions. I'm not sure how you can say a lower bitrate 720p video isn't HD any more than you could claim a higher bitrate 480p video is high definition. Low quality maybe....

Obviously there's a point where the latter can actually look better than the former, but I've got plenty of 720p TV encodes at around 3000kbps that certainly look way better than the SD versions, so I'm not sure I'd be trying to draw some imaginary bitrate line.

[Ghitulescu]

HD and SD really just define resolutions. I'm not sure how you can say a lower bitrate 720p video isn't HD ...

720p is a HD format, a HD video is generally characterised by an enhanced optical resolution in comparison to SD.

Any 320x240 pixels youtube video can magically become HD just because it was scaled to 1280x720? Or even matted up to 1920x1080 with black borders?

Any HD format allows (or provides the prerequisites) for a HD video to be stored. It does not transform any video into a HD one. In mathematical language it is necessary but not sufficient. That's the trick they use in selling crappy camcorders - they pack SD optical resolution or even less into a nice FullHD package.

Low bitrate "decorates" the HD video with blocks, so the optical resolution will decrease.

[yetanotherid]

Any 320x240 pixels youtube video can magically become HD just because it was scaled to 1280x720? Or even matted up to 1920x1080 with black borders?

And painting a pig grey doesn't make it an elephant, but thanks for stating the obvious.


Obviously there's a point where the latter can actually look better than the former, but I've got plenty of 720p TV encodes at around 3000kbps that certainly look way better than the SD versions, so I'm not sure I'd be trying to draw some imaginary bitrate line.

Forgetting the possibility of painting the pig grey, my point was that there's a subjective perception of quality which can't be determined by the bitrate.

[2Bdecided]

Anything shot native 720p or above and preserved at 720p or above through to the viewer is HD.

BTW, in Australia, 576p is classed as HD by the government when regulating broadcasters and minimum amounts of HD required.

Some people think anything less than 1080-lines isn't HD. But there's no official basis for this.

Cheers,
David.

[yetanotherid]

720p is a HD format, a HD video is generally characterised by an enhanced optical resolution in comparison to SD.
Any 320x240 pixels youtube video can magically become HD just because it was scaled to 1280x720? Or even matted up to 1920x1080 with black borders?

By scaling a 320x240 pixel YouTube video to 720p are you increasing it's resolution?? No.

What was it I said?

HD and SD really just define resolutions.

[GodofaGap]

By scaling a 320x240 pixel YouTube video to 720p are you increasing it's resolution?? No.
By some (and common) definitions of resolution, yes you would.

The problem here is if you want to define HD as a practical standard or as some sort of philosophical concept about quality. For the first 2Bdecided answer is clear enough. For the second I predict another 10 page episode of you and Ghitulescu having a go at eachother.

[yetanotherid]

By some (and common) definitions of resolution, yes you would.

I'll confess I'd completely disagree, but to be honest for the purpose of this discussion I'd have assumed it's generally understood, through the application of common sense, that upscaling a SD video doesn't make it HD and therefore it's not part of this discussion, but maybe that's just me.

The problem here is if you want to define HD as a practical standard or as some sort of philosophical concept about quality.

Well for me quality does come into it, but that's the area where it becomes subjective, I guess.

For the second I predict another 10 page episode of you and Ghitulescu having a go at eachother.

Nah.... not unless we're told we shouldn't be discussing the subject because we shouldn't be converting our discs, or learn how the definition of HD relates to the history of the analogue pixel. ;-)

[Sharktooth]

High Definition or HD is a sort of trade mark that defines a precise standard for video resolution. Bitrate is not included... so quality is subjective.
However, those words indicates not only the RESOLUTION (otherwise it would have been High Resolution) but the image "definition" too, that is by itself some sort of quality representation.
So, by HD you can assume a video has a higher resolution and quality than standard definition video.

[GodofaGap]

I'll confess I'd completely disagree
I don't see how you can disagree on the fact that people have been using the term resolution to describe horizontal and vertical pixel count of a video for years? You can just check the Avisynth documentation on their resize filters if you want.

but to be honest for the purpose of this discussion I'd have assumed it's generally understood, through the application of common sense, that upscaling a SD video doesn't make it HD and therefore it's not part of this discussion, but maybe that's just me.
Yeah sure, and that's why I don't understand why you fall for Ghitulescu's "trap". If he wants to state the over-obvious, let him.

[yetanotherid]

I don't see how you can disagree on the fact that people have been using the term resolution to describe horizontal and vertical pixel count of a video for years? You can just check the Avisynth documentation on their resize filters if you want.

I don't, in principle, but it's an argument of semantics. You can take a SD image and double it's size using some sort of pixel interpolation, but at best you're going to end up with an image of the same quality as the original, you're not going to increase the resolution of the image. But you know all that....

Yeah sure, and that's why I don't understand why you fall for Ghitulescu's "trap". If he wants to state the over-obvious, let him.

Like you're doing now??? :confused:

It's not fair.... now I'm really confused..... :):D

[GodofaGap]

I don't, in principle, but it's an argument of semantics. You can take a SD image and double it's size using some sort of pixel interpolation, but at best you're going to end up with an image of the same quality as the original, you're not going to increase the resolution of the image. But you know all that....
So what you mean is "definition", not resolution.

Like you're doing now??? :confused:
I'm not responding to him, I'm responding to you saying that resolution is not resolution.

[yetanotherid]

So what you mean is "definition", not resolution.

No, I mean "real" resolution.

I'm not responding to him, I'm responding to you saying that resolution is not resolution.

I meant me falling for your trap. Obviously my humour meter is a little off... ;)

But no, I'm not saying resolution isn't resolution, I'm saying interpolated resolution isn't resolution. :)

[GodofaGap]

I meant me falling for your trap. Obviously my humour meter is a little off... ;)

Or mine. ;)

[Groucho2004]

I'm saying interpolated resolution isn't resolution. :)

Huh? Resolution represents the number of pixels. The content is irrelevant.

[Midzuki]

High Definition or HD is a sort of trade mark that defines a precise standard for video resolution. Bitrate is not included... so quality is subjective.
However, those words indicates not only the RESOLUTION (otherwise it would have been High Resolution) but the image "definition" too, that is by itself some sort of quality representation.

So, by HD you can assume a video has a higher resolution AND quality than standard definition video.

:goodpost: && :thanks:

[yetanotherid]

Huh? Resolution represents the number of pixels. The content is irrelevant.

It can't be, otherwise a 320x240 pixel YouTube video to upscaled to 720p would be high definition. :)

Did we just come full circle?

Maybe the content isn't irrelevant?

[Groucho2004]

It can't be, otherwise a 320x240 pixel YouTube video to upscaled to 720p would be high definition. :)

Did we just come full circle?

Maybe the content isn't irrelevant?

You're obviously not reading the posts you're replying to. "High Definition" has nothing to do with what I stated.

[AnonCrow]

There is really only one way to take an existing 320x240 video and upscale it to 720p and have it actually increase the quality:
if the QVGA video is shot at a high framerate (120+ fps), and it's upscaled to 720p30 using some fancy spatiotemporal upscaling trickery.

Otoh, by some definitions, even a 16:9 video with a resolution of 64*720 can be called HD (that's sixtyfour, not 640)

Personally (since that is what the OP was asking), I tend to consider almost anything better than DVD resolution HD, but usually draw the line at 960 horizontal OR 600 vertical (actual content, no black borders)

[Ghitulescu]

For the second I predict another 10 page episode of you and Ghitulescu having a go at eachother.No, no, it's your turn I see :p to discuss this matter with yetanotherid.

[yetanotherid]

You're obviously not reading the posts you're replying to. "High Definition" has nothing to do with what I stated.

No, I'm reading them, it's just that arguing semantics is really fairly pointless.

[yetanotherid]

No, no, it's your turn I see :p to discuss this matter with yetanotherid.

Well, eventually the task had to be undertaken by someone who's up to the job. :p
In fact I've kind of given up, so I guess it means he won.

Did you notice I'm arguing the point you made, or did that get by you as well? :stupid:

[Groucho2004]

No, I'm reading them, it's just that arguing semantics is really fairly pointless.

Sigh. How is it semantics? You wouldn't argue about a square of 10 inches x 10 inches having 100 square inches, would you?

You wrote "I'm saying interpolated resolution isn't resolution". This does not make sense.

"High Definition" is a marketing statement whereas Resolution is something one can quantify.


Edit: As for the OP's question - I think Sharktooth answered this quite eloquently and I don't think there's much to be added.

[yetanotherid]

Sigh. How is it semantics? You wouldn't argue about a square of 10 inches x 10 inches having 100 square inches, would you?

Of course not. But if for every square inch there's 10 dots, just because I stretch it out to 100 inches it doesn't mean I've got more than 10 real dots per inch.
Edit:.... Well that's not quite right, I maybe should have said it doesn't mean I've still got any more than a line of 100 real dots.

You wrote "I'm saying interpolated resolution isn't resolution". This does not make sense.

See above.

"High Definition" is a marketing statement whereas Resolution is something one can quantify.

The number of pixels is something you can quantify. Maybe instead of thinking I should be using the term definition in preference to resolution, you should consider using the term pixels instead?

10 inches of resolution isn't the same as 100 inches of resolution no matter how much you stretch the 10 inches of resolution and try to fill in the gaps.

[Groucho2004]

Of course not. But if for every square inch there's 10 dots, just because I stretch it out to 100 inches it doesn't mean I've got more than 10 real dots per inch.
Edit:.... Well that's not quite right, I maybe should have said it doesn't mean you've got any more than a line of 100 real dots.



See above.



The number of pixels is something you can quantify. Maybe instead of thinking I should be using the term definition in preference to resolution, you should consider using the term pixels instead?

10 inches of resolution isn't the same as 100 inches of resolution no matter how much you stretch the 10 inches of resolution and try to fill in the gaps.

I was trying to make a point, the example wasn't necessarily apt.

Now I hope Ghitulescu will take over and I can have dinner.

[yetanotherid]

I was trying to make a point, the example wasn't necessarily apt.

It worked for me.

Now I hope Ghitulescu will take over and I can have dinner.

Nah.... I'm off too. Maybe tomorrow once he's worked out which side he's on.

[ramicio]

I would rather watch something that's 720p72 versus 1080p24. The way the eyes see it the 720p72 would be higher resolution than 1080p24.

[Mug Funky]

resolution is a much older term than would be implied by the world of pixels. it's a term that comes from analog land, where sample rates were irrelevant and not considered, and actual, measurable detail determined the resolution of a system. this is usually done with test charts of converging lines, densitometry measurements (for film), etc.

really, people should be saying "sample rate" when they define an array of pixels like "1920x1080". it says nothing of the resolution of the pictures depicted - it just defines an upper limit to the resolution that can be achieved when all other parts of the chain are perfect.

[Ghitulescu]

Any HD format allows (or provides the prerequisites) for a HD video to be stored. It does not transform any video into a HD one.

resolution is ... a term that comes from analog land, where sample rates were irrelevant and not considered, and actual, measurable detail determined the resolution of a system. this is usually done with test charts of converging lines, densitometry measurements (for film), etc.

really, people should be saying "sample rate" when they define an array of pixels like "1920x1080". it says nothing of the resolution of the pictures depicted - it just defines an upper limit to the resolution that can be achieved when all other parts of the chain are perfect.

HD per se became, like someone said, a marketing issue. A HD format is however something quantised, something that can be assessed and compared, and more important, assures compatibility. What's inside the HD format, that's another story and this provides the manufacturers with a huge playground for marketing halffacts and halflies. Why would a professional spend 15000€ for a pro model of a HDV camcorder when an entry level consumer HDV has the same format and thus the same resolution :p, at only 2-5% of the price? Because the optical details of the first simply kills the last one...

Planet Earth was taped on 720p which is less than 1Mpixels, yet it's far superior to any home-made FullHD video (more than 2Mpixels) in terms of details (or optical resolution).

[smok3]

the wikipedia starts so well:
High-definition video or HD video refers to any video system of higher resolution than standard-definition (SD) video

so based on the continent, High Definition is either:

721*577 or 721 x 481

:devil:

(ignoring the analog era)

[2Bdecided]

High Definition is either:

721*577 or 721 x 481

:devil:

(ignoring the analog era)Oh you youngsters, don't you know that anything with more than a few tens of lines lines is HD...

http://en.wikipedia.org/wiki/High-definition_television#History_of_high-definition_television

Cheers,
David.

[raj1402]

High Definition or HD is a sort of trade mark that defines a precise standard for video resolution. Bitrate is not included... so quality is subjective.
However, those words indicates not only the RESOLUTION (otherwise it would have been High Resolution) but the image "definition" too, that is by itself some sort of quality representation.
So, by HD you can assume a video has a higher resolution and quality than standard definition video.

well in my opinion HD should include bps too with resolution

here is something i got it from another forum

HD can be considered video which got pixels/bps as 100 - 400

do you ppl accept this?

[ramicio]

No, I don't accept that. If you want to base the bitrate off the dimensions you are better of using the square root of the area. HD is defined by the vertical resolution, not bitrate. 8,300 kbps for 1080p is also a joke. Why is there an upper cap? Would something 401 pixels/kbps not be HD anymore? HD for video is very very muddled, as there have been mentions of and standards of it since the 1930s. "HD audio" is something very recent, and it's clearly anything over 16/44.1, plain and simple. 24/44.1 is HD, 16/48 is HD.

[manono]

do you ppl accept this?

Of course not. It's utter nonsense. HD isn't defined by quality (and pixels/bps is only distantly related to quality), but by resolution. Did you learn nothing from the 2-page discussion?

[jmac698]

Fun discussion.
I think High Definition is a marketing perception; the very word Definition implies some aspect of quality, not strictly resolution.
One can refer to HD standards and official declarations, but I don't think this is really answering the question. HD standards are only partially related to the perception of HD meaning higher definition.
I think what we have here is a layperson trying to come to terms with their perception of what HD is compared to the technical people referring to it in precise terms. I think the technical answer is, they are not the same, I mean that what is technically HD (say, one of the ATSC standards for resolution above 720P), is not necessarily the quality you are expecting.
Sharktooth was perceptive enough to note this ;)
Now try to answer this the other way around - find technical specs which nearly guarantee a perception of quality. I would propose a simple answer to this, any codec with it's -quality preset. For example x264 has been examined in great depth for quality, and it seems to be quite successful. As for bitrate, we'll have to arbitrarily pick a bitrate which can handle the most difficult content and call that a minimum for quality. This would be similar to the famous "transparent" audio quality tests (see Hydrogen audio forums).
Finally, perception and specs can meet in the middle.

As for upscaling, let me point out that some rescale methods create true detail, it's just not accurate detail. I would propose this technical definition:
-It's upscaled with a linear filter, and the new version cannot have frequency components near nyquist - in other words there is no extra detail, it's just blown up. This is definitely not HD in perception.
-It's upscaled with new details, which are artificial and not accurate. This is HD, and I think is probably perceived as HD and high quality even though the details are artificial, unless they are obviously artificial.
-It's upscaled with accurate details recreated somehow (such as super resolution), in a way that's measureably accurate (perceptionally measured like SSIM), then it's also HD, though people will feel it's theoretically better and demand it.
-It's created in high quality, high resolution which is kept through the production process until viewing, or reduced to a suitable high quality format (such as Blu Ray). This is intuitively, without a doubt HD perception-wise, both philosophically and in blind quality measurements.

Even in the last case, the technical picture quality may not be good enough. If you look at BluRay reviews, some get higher video marks, how can that be when the technical quality is excellent? Things like color palette, grain, focus, perhaps some other things add to the perception.

Some of my own perceptions:
-I had an old tube-style SD TV which made the most beautiful picture, I even preferred it (for SD pictures) over my newer LCD HDTV. I think the colors were a lot more accurate (more gamut, better saturation) and the picture was also brighter (more contrast).

-Even though I know it's a "dirty trick", I still like sharpening my videos, they just look better even though I haven' increased resolution.

-Upscaling does work, this whole board is proof of that, and some people are quite happy with the result after a lot of work. The perceived quality has increased quite a bit, probably you could say it's nearly HD.

I should add another thought, I will probably to define HD as "transparent" rather than "high PQ (Production Qualtiy)" as it's often called. This would mean that a high PQ could be displayed without distortion, so that would be HD.

[ramicio]

Upscaling only adds noise, it doesn't add any useful information, just like your precious Hydrogen Audio Nyquist foolery and their mathematical wizardry thinking that what works on paper applies in the real world. Sharpening is another thing that is preferential, not actually adding quality (to everyone.) Audio and video are two completely different animals, so let's stop comparing them and using the word transparent. HD in the modern time is defined as anything over SD.

[jmac698]

HD in the modern time is defined as anything over SD
But I agree - you are missing the point, the original question was about the layperson's perception of what HD means, not a question about a technical standard.
Upscaling only adds noise
Upscaling is used in video forensics to read previously unreadable license plate numbers. There's no doubt that we can make a visible, and practical difference in quality. What I think you're saying, is that you would only accept my last definition of HD as your philosophy.
so let's stop comparing them and using the word transparent
I don't see why I can't apply transparent to video, but do you have another term? I think they say perceptionally lossless in video research. Probably transparent would be confusing because it has alternate meanings.
your precious Hydrogen Audio Nyquist foolery
It's not precious to me, I just referred to it offhand. There's no doubt, dozens of people did ABX testing and proved some audio codecs transparent. I participated in one myself, I certainly know that lossy audio can be transparent.

I have some friends that insist that any lossy audio is just not the same even if they can't tell the difference. My sense is that they have a gut feeling that something is less real and organic when processed. I take it as more of a philosophical opinion.

My post contained some technical points that not necessarily everyone will understand; you'd have to see different types of upscaling or you may not realize how good (and bad) it can be.

[ramicio]

No, they "proved" that their ears & brain couldn't tell a difference. In reality it is far from transparent. It's not hard to tell and ABX test that you can't hear a difference, so I don't even buy their "proof." Where did you get this license plate stuff? CSI on TV? We're talking about deciphering letters. If they can't be resolved then they can't be read. No amount of forensics can change that. Take an image of a letter, shrink it to 1 pixel, and then upscale that back up and try to tell me you can decipher that letter. We're not talking about quality with that forensic stuff, it's just to be able to read a plate, not comfortably watch a video.

[smok3]

In reality it is far from transparent.
which reality would that be? (maybe from a bat?)

[ramicio]

You really think bats can make conscious sense of ultrasonic sounds? They don't hear an echo and then think about where it comes from, it's an involuntary mechanism in their brain. Just because an animal can detect a tone doesn't mean they can extract any meaningful information in those tones. This is about lossy vs. lossless. You CANNOT prove that you CANNOT hear a difference. Lossy is for idiots. Idiots also cling to mathematical theorems and think they apply in the real world.

[AnonCrow]

HD can be considered video which got pixels/bps as 100 - 400
That itself would limit HD video to something that is digital as opposed to analog, encoded in a lossy format
(, and with a format that has any concept of a pixel to begin with).
Even if you increase the range to 32-1024 ,to have any hope of something that your Average Joe consumer
might call 'High Definition' for most sources, without needlessly high bitrate, the lossy codec used would
have to fall somewhere between MPEG1/2/4 and H.264/265 with regard to how well it compresses video.


Take an image of a letter, shrink it to 1 pixel, and then upscale that
If you take only a single image, then yes, there's almost[1] zero chance. When you have multiple images where the car ,the camera or both are moving , resolving a letter slowly starts becoming possible.


[1] surrounding pixels - color of the car , image meta-data, DMV meta-data, etc.

[ramicio]

You're talking about combining multiple images plus using other known data...what forensics doing stuff like that has to do with upscaling for video playback I have no idea.

[jmac698]

r,
I think that you are not familiar with image processing and how it works, therefore you don't believe these claims. I'll make a simple explanation for you.
How can a scanner build an image of a picture when it only "sees" one row of pixels at a time? Obviously it scans the many rows and puts them together. So if you want to read a license plate, you merge several frames of video together. The result is a provably, real high resolution image. Here's an example

The original letter A
o
e e
eoe
e e
e e

an unreadable, half-resolution version (the even pixels in this case)

ee
ee
ee
ee

an unreadable, half-resolution version, diferent frame, odd pixels:
o

o


And now we upscale them and put them together:
and o gives o
e e e e
e e o eoe
e e e e
e e e e

Some questions you may have, how do we know that frame 1 has even pixels and frame 2 has odd pixels? We know from measuring how the surrounding images have moved in general. I can show an example of this, but it starts getting more complicated to explain.
And no this isn't from CSI, you can do it yourself, for free, right now, I can give you a list of links to this software. I've used them myself, I wanted to see the same thing.


It's not hard to tell and ABX test that you can't hear a difference, so I don't even buy their "proof."

I'm sorry, I don't understand your sentence. Can you say it a different way? I realize that not all of us have English as a native language.

[jmac698]

Here's another example, fractal compression. Imagine a field of flowers. Each flower looks about the same, but in different places and positions. If you store just one image of a flower, and then record all their positions, you can recreate the picture artificially from one flower, with an amazing 1000:1 compression. The picture looks real, but it isn't. How do you know that the real flowers were in a slightly different position, or that one flower looked slightly different? You can't tell.
Upscaling based on that would look HD, it's just not the real one.

Here's another example: the nneedi3 plugin, has a type of smart "brain" that recognizes images, and fills in the missing information based on what it should look like. Let's say you have a picture of bricks. It learned in the past what bricks look like (from real HD pictures), and so it upscales and fills in the missing pixels.
It's not easy to explain, but at some level, things look the same - so all bricks look the same, even different ones - when you think about them as lines and textures. So the brain understands what it's looking at. It turns out that is is provably accurate, that is it's filling in the real pixels. It's adding information based on an example, from learning from a lot of videos to teach it.

[manono]

But I agree - you are missing the point, the original question was about the layperson's perception of what HD means, not a question about a technical standard.

I disagree, although I don't quite catch the distinction you're trying to make. The OP was asking for exactly that - the technical standard. And, once again, Hi-Def has nothing to do with quality, or 'perception', or anything else other than resolution. You can upscale 640x360 to 1920x1080. It may look like crap but it's still Hi-Def (from a Standard-Def source).
Can some one Define what do you mean by High Definition
.
.
.
in scenario1 just because it got HD resolution of 1280x720p its called as HD video?

[GodofaGap]

You really think bats can make conscious sense of ultrasonic sounds? They don't hear an echo and then think about where it comes from, it's an involuntary mechanism in their brain. Just because an animal can detect a tone doesn't mean they can extract any meaningful information in those tones. This is about lossy vs. lossless. You CANNOT prove that you CANNOT hear a difference.
So you mean to say that you don't understand the purpose of an ABX test?

Lossy is for idiots. Idiots also cling to mathematical theorems and think they apply in the real world.
Lets just say if they wouldn't apply in the real world, you wouldn't be typing any of this unless it were on an old-fashioned mechanical typewriter.
:readfaq::search:

[Ghitulescu]

So you mean to say that you don't understand the purpose of an ABX test?

Many ABX tests are flawed and many people simply lost the confidence. It's so easy to trick an ABX test, I said it too many times. The only real ABX tests are done internally in a company and they never get public.

[GodofaGap]

Many ABX tests are flawed and many people simply lost the confidence. It's so easy to trick an ABX test, I said it too many times.
Oh so that must make it true then. :)

The only time an ABX test needs to be performed is when someone claims to hear the difference and then it needs to be performed by that person. So unless he wants to trick himself, there are no flawed results from this. Absence of proof is not proof, but you'd hope the critics of digital audio in general and lossy audio in particular would bring more to the table then they are doing now (which is mostly nothing). There is a test that can show they hear the differences they say they hear, but yet those people are often the ones not willing to use it.

Of course, the inevitable conclusion is that mathematics doesn't work and therefor this whole conversation never existed.

Poof. There goes the internet. Poof. There goes my computer, there goes my TV, there goes my radio and the rest of the electronics devices.

Yes, I'm sure I'm the idiot here coz it is starting to look like 1864.

Poof.

[Ghitulescu]

The only time an ABX test needs to be performed is when someone claims to hear the difference and then it needs to be performed by that person. So unless he wants to trick himself, there are no flawed results from this.That's why I said this.
The only real ABX tests are done internally in a company and they never get public.
Which is equally true for any person. S/He will not trick her-/himself because s/he has a legitimate interest. One can even compare incomparable things if s/he has an interest in comparing them.

Like it was once said: The music is in the ear of the listener.

[jmac698]

Monao,
Actually you're right! But they did mention the idea of perception vs technical standards, which is how I took it as an alternative thread to his question

for me second Scenario is considered as better Quality than first

And yes I agree, HD is defined in the standard as a resolution, has nothing to do with quality. How could I disagree? It's a published standard.
I'm still making a point however about the marketing use of HD as being perceived by the layperson as equating higher quality. Then I'm looking at, is there a way to translate higher quality back into a technical standard?
That is, is it technically possible to define quality somehow?

I think as technology progresses, there will be nothing but 'retinal' displays and ultra high frame rates and full color gamut. No doubt we will reach perfection in the mainstream in even 10 years (the UltraHD standard is progressing, we now have 10 layer Bluray Discs on sale and drives to use them).

[ramicio]

Your forensic image processing still uses two pictures and other known data, so it has nothing to do with this case of video upscaling. If the camera was black and white they can still possibly get the color of the car if there are eye witnesses. We already have retinal displays...it's called proper viewing distance.

[jmac698]

Just to clarify, my post where I reconstructed the letter "A", did not need any additional information. Yes, it does apply to upscaling.
Please visit http://www.compression.ru/video/super_resolution/super_resolution_en.html
I think this technology is used in some Samsung products.

[Ghitulescu]

And yes I agree, HD is defined in the standard as a resolution, has nothing to do with quality.

It allows a higher optical resolution to be stored within. It doesn't require, just provides the technical means.

[ramicio]

Your example used 2 frames to construct one. If that's not additional information then I don't know what is...

[jmac698]

We're talking about video here - why is it not fair to extract extra resolution from different frames? If done in realtime, there will be a slight lag in playback,but it will be upscaled.
Many upscaling algorithms use one frame, but there's no reason why they can't use more.

I also gave you two examples of how it's possible to create accurate detail from just one frame; the fractal example and the "smart" brain example (which uses neural nets, training previously on HD videos).

[ramicio]

It's not accurate detail, it's just enough detail to be able to extract a plate number. It's still interpolated data. So I guess in your world the frame interpolation tech. in TVs is also just as good as filming in those rates in the first place.

[jmac698]

No, not at all. In a previous message I listed 3 scenarios of upscaling; superresolution upscaling comes closest to the real thing and has a significant measured accuracy (not perfect of course). If you looked at the link, you will see that the quality is quite a bit improved. So we do agree after all!
I'm glad you've learned more about upscaling techniques.

[ramicio]

No, I don't agree. I'm not one who add an avisynth script into my player for upscaling. I make sure the source is up to snuff, not compensate for space/quality and then use post-processing to give me a fake.

[Ghitulescu]

Without said upscaler the playback would be even more grotesque.

[ramicio]

Which means it's gross in the first place because of upscaling...

It's the same garbage they spew when they upscale SD content to HD and argue that it's HD. A good example would be the Family Guy version of Blue Harvest on Blu-ray. It wasn't made in HD so they upscaled it to HD, and with line art it's disgusting. Why they can't just go re-render it is beyond me.

[jmac698]

I don't either, I encode from HD to anamorphic xvid, that I have to use for compatibility reasons. My bluray player does upscaling anyhow, I don't have a choice! And I believe ppl use upscaling scripts under ffdshow to view their SD clips for better looks (on the computer).

If the only source of a movie is SD (not all are released in bluray), then why not?

[ramicio]

There is no reason to have to compromise in compatibility other than cheapness. I don't know of any movie before the HD era that wasn't shot with film, so they ARE in HD. If they didn't use a film camera then it probably was some low-budget piece of crap that I wouldn't be watching anyway.

[jmac698]

So did we pay for the introductory argument or the full course? :)

[jmac698]

Yes, most earlier material is in film, but some TV shows moved to video tape later.
My point was that this film based material is not released in any HD version yet. In some cases the film is lost, like with Dr Who (and yes it's low budget, but fans still love it :)
My encodes must be viewed on devices which only support Divx/Xvid (my dvd player, mediabox, and portable device, and low-power netbook which can't play HD), which I started before bluray existed.

[ramicio]

Exactly...cheaping out on playback devices. Even on tape it wasn't some 480-line crap, it was closer to common HD than you think. How is it so hard to understand that upscaled crap is not HD?

[jmac698]

On tape it was 486 lines in NTSC, and even betacam SP is not the same quality as a modern DVD.
And I've said a few times now, I agree with you, upscaling is not the same as the original produced in HD.
I'm not cheaping out on display devices - I have to start a new collection in HD now that Blurays are available, and that will take some time.

[ramicio]

Rent blu-ray from netflix and rip them...

[jmac698]

netlfix ? What's that? Is that some US thing?

[ramicio]

It's in the US and Canada. It's mainly a streaming service, and they do mail rental too.

[jmac698]

Interesting use of superresolution, just as I described with the letter "A":

Hasselblad has announced a camera capable of producing 200MP images based on shifting its 50MP sensor. The H4D-200MS uses an extension of the company's sensor-shift, multi-shot (MS) technology to create a 200 megapixel file from six images taken at slight offsets. It can also use the four-shot mode used by the H4D-50MS that shifts the sensor by one pixel in each direction to capture all colors at each position. The latest approach adds 1/2pixel offsets to increase the captured resolution to 200MP. The H4D-200MS is available for €32,000 or as a €7,000 factory-return upgrade for H4D-50MS owners

[ramicio]

Still not real. For it to be real it has to be one image. They are capturing different moments in time. Good luck with motion with that.

[jmac698]

Ah, but there is no real - there is a problem called rolling shutter. The camera "eye" is read a row at a time, and there was motion meanwhile.
http://en.wikipedia.org/wiki/Rolling_shutter
This problem exists in most cameras and camcorders today.

Another problem is motion blur, where the "eye" is accumulating light while an object is moving. It's nearly impossible to capture an exact moment in time, because there is so little time to accumulate light. For example, in the clips with high speed photography (slow motion), these need a huge amount of light.

For this Hasselbad camera, there is no information in the press release about how quickly the process occurs, but you will have the same problems as all cameras, if you are taking a picture of sports or other action.

For studio shots, landscapes, this could be a useful feature.

Actually, it is impossible to capture a moment in time, due the Heisenburg Uncertainty Principle. This says you can't measure position at the same time as something else (which can be converted into various statements). I would guess if you applied the formula to a camera, you couldn't record the brightness of the pixels at one moment of tiime?

Are you planning to photograph the bullet train? In practical movements with humans, it's not a big problem.

[ramicio]

Which only applies to CMOS, which is crap. It does not apply to CCD or film. That camera is CCD. Why anyone would use a CMOS image sensor in anything better a camera phone is beyond me.

[smok3]

actually CCD sensors are usually used in phone cameras.

[jmac698]

There are a few advantages of CMOS; they are smaller, can integrate image processing circuitry in the same chip, and faster at aquiring images. But yes, generally a high end camera would use 3 CCD's; for each color.

Since this Hasselbad uses CCD, you would agree then that this superresolution is not as much as a problem.

I think you only need a B/W camera though, as that's how you tend to see things :)

[ramicio]

What the hell cell phone uses CCD? I'd say 99% of phones use CMOS. And that extra 1% would be phones that are otherwise crap. Small sensor size is only a good thing for small devices, such as phones. CMOS are not used in anything serious. If so, then shame on any professional for buying that product. One sensor for each color is still reading the data at the same point in time... But those cameras are extremely high end and pointless, for video, that is. What the hell is the point of anything beyond 4k? For that Hasselbad crap, I don't agree that it's not a problem. You still must take multiple images, which means two different points in time.

[jmac698]

Well, gigapixel images are used in art exhibits:
http://upcoming.yahoo.com/event/8047921/PA/Pittsburgh/Gigapixel-Imaging-for-Science/Carnegie-Museum-of-Natural-History

You can enjoy them online:
http://gigapixelphotography.com/image-gallery/
Tell me those are not beautiful pictures!

And the quality of IMAX is beyond 4k.

Baraka was filmed in 70mm and scanned in 8k:
http://en.wikipedia.org/wiki/Baraka_%28film%29#2008_remastered_release_and_sequel
I've rented it, it looks beautiful!

Having 3 CCD's is not pointless for video, have you heard of the Bayer Filter?
http://en.wikipedia.org/wiki/Bayer_filter

Even witha high end CCD camera, the quality has issues due to the demosaicing process - that's why you hear this talk about RAW processing. One of the processes in raw processing is to find the optimal demosaicing settings.
All cameras, CMOS and CCD, (except Foveon, 3 CCD and greyscale) use upscaling as part of the process, in the form of demosaicing.

From an idealistic point of view, perhaps you might like the Foveon sensor?
http://en.wikipedia.org/wiki/Foveon_X3_sensor#Comparison_to_Bayer_filter_sensors_.E2.80.93_operational_differences

Of course they built in on CMOS, so you will probably hate it. Just face it, there is no perfect anything - there is always a tradeoff. Trust me, engineers dream of perfection as well and try as hard as they can, and thus technology keeps advancing.

Having higher than needed resolution gives you some flexibility in editing - for example you could crop out a mistake such as a boom mike in the frame, while still retaining sufficient quality for your delivery format.
The producers on Baraka said in the making of documentary that the 8k process made a noticeable difference to the Blurray delivery version.

[ramicio]

I see film as perfection. The only thing is the framerate is pathetic. There's no excuse to have any video below 60 Hz. 8k won't show you any quality over 2k or 4k if you are watching in a consumer format. CMOS is crap, period. You can rant all you want about filters and masks, but it's only interpolated detail, not real. If you have 3 sensors, R, G, and B, and each are 1920x1080, then you will get a 1920x1080 image. Anything above that is only some approximation, NOT real useful data.

[jmac698]

Btw, BBC requires 3CCD cameras to be used in programs submitted for transmission on TV:
http://www.bbc.co.uk/commissioning/tv/production/delivery/hd-production-delivery.shtml

Yes, I agree, and all high-end CCD (still) cameras have interpolation, which is as you say crap. There are film cameras that record up to a million fps, but remember film and it's processing is very expensive, which is why it uses the lowest framerate possible. The manufacturers and processors are also shutting down. I think technicolor was one of the best processes, but I'm not a film expert.
Anyhow some films have faded, even recent ones, and had to be restored, like Apocolypse Now.

Film is not perfection, as it requires a lot of light, and quite grainy. CCD can achieve up to 90% light efficiency, film is around 2%. See, there is always a trade-off! The new RED digital camera far exceeds the quality of film. Several new movies are in production using the latest generatation of UltraHD cameras, but you won't get to see them for another year at least. They will be virtually noiseless and crystal clear.

As for, why does Baraka look better on bluray from the 8k scan? Because a down-sampled scan from 8k to 2k is better quality than a 2k scan. This implies that a 2k scan is not an ideal 2k scan. In engineering, in general, "oversampling" creates a better signal. The reason is that it's hard to engineer ideal processing "close to the edge", so downsampling a higher resolution will always give a slightly better picture/audio.

[ramicio]

Good for the BBC, it's not my fault those people are snobs. It makes no point. Interpolation IS crap. It's fake data. This is very dangerous ground saying oversampling creates something better. Better not say anything subjective like that to anyone from hydrogenaudio.org. You don't think it possibly looks better because it came from 70mm film and that's why it needed a 8k scan? Even so I doubt a 4k scan and a 8k scan will look any different in 1920 width.

[jmac698]

Why do you pick 60Hz as the cutoff? There seems to be an internet myth that your eye can only see 60Hz. That's not true. If you have an old film camera, set the shutter to 1/1000s and watch it flick under bright light. I can see it move.
In experiments, for example we can distinguish between a circle and a donut in 1/1000s. Our eyes process different kinds of information at a different speeds.
I think the 60hz myth comes from the (I'll have to look this up later..) but the eye retains an image for some amount of time, I mean that as images come in, they merge with previous images, until the oldest images fade away. We can still see faster motion, just that it's super-imposed on top of older images. I hope that made some sense.

Anyhow, maybe we want to refer to the smooth perception of motion - or maybe we want to be able to do smooth slow motion at home as a special effect on playback? It depends for what purpose you are thinking.

[ramicio]

I used it as a minimum. Your eyes cannot see 1000 Hz. Just because you can see a single flash of light that lasts 1/1000 of a second does not mean you can see 1000 images per second. You would be able to see a bullet fly. 60 Hz just makes sense. 72 FPS was studied to be the greatest point to which beyond that there are no benefits. 72 FPS makes no sense except it's a multiple of 24. Why film makers feel the need to stick with 24's is beyond me. It's just retarded. 48 FPS or 72 FPS would never play on any known TV smoothly (maybe CRT, but they don't count for anything anymore, they're dead.)

[jmac698]

This is my last message, I actually have to work :)
In sampling anything, video or audio, you have to obey the sampling theorem. This says that you get distortions (called aliasing) if you try to record frequecies too high for your sampling rate. If your sampling rate is 44100hz (or 1920 pixels), you can only record frequencies up to 22050Hz (or 960 line pairs? I don't know the unit of measurement here). To avoid this distortion, we first filter the signal. In audio that can be done with a circuit with capacitors and resistors. There's an equivalent in optics, the antialiasing filter.
We can't engineer these filters perfectly, to let in all frequencies just below the cutoff, while perfectly blocking all the frequencies above (that would be called the theoretical "brick-wall filter"). That's because of the physical precision of making analog components.
However if you boost the sample rate, now your filter can be much less precise. So we over-engineer the sample rate and make an average analog filter.
For example, 192khz sample rate and a gradual filter which cuts off at 96khz. Then we downsample to 48Khz (say) and have a nearly ideal 0-22Khz signal.
Hope that made some sense.

http://en.wikipedia.org/wiki/Oversampling#Motivation
You won't understand some of the technical parts of the article, but you will see quite clearly that it follows what I'm saying.

[ramicio]

Talking about that Nyquist crap has nothing to do with video. It's about analog and digital conversions. And its hugely presumptuous. The example of audio and the sample rate being 2x the highest possible frequency has nothing to do with scanning video. It's just a theorem, which means it's only proven on paper and doesn't apply in reality. I understand plenty, I just realize that not everything in the world has to be as technical as it is. Over-engineering to get a better result from false data never works. It only pleases the masses, not people who actually care about quality.

[jmac698]

http://en.wikipedia.org/wiki/Persistence_of_vision

There it is.

So tell me, how can you catch a baseball at 90mph if you can only see in 60hz?
It's going to take me too long to find the reference to the experiment showing we can recognize some images at 1/1000s. But yes, seeing a flash of lighting could be explained by the persistence of vision of the flash on the eye.

[jmac698]

If you don't believe Nyquist applies to video, we have no common reference to continue that line of thought. Nyquist applies to any sampled signal. It's a technical topic you may not understand - I don't claim to be an expert, but I'm pretty sure I understand it, I'm a programmer in DSP and do electronics so I've used these "theorems" in a practical sense, and done a lot of experiments to understand it better.

nice chat ;) I hope you've become a little more informed, at least.

[ramicio]

Flash 2 different images right after one another at 1ms each and tell me that you see 2 different frames. No, they appear as 1 image. The retinal cells can't react fast enough and the bandwidth to the brain is not sufficient. Your example of the 90 mph baseball makes no sense whatsoever. It makes you look like you just like to throw numbers around, list some criteria, and try to embarrass people. A 90 mph pitch takes about a half a second to reach home plate. That's about 30 frames. Again, I did not say the eye sees only in 60 Hz. It doesn't really have a refresh rate. I merely mentioned it as a good refresh rate for video in today's technology. You're just grasping with some arbitrary numbering to make it seem like it's not possible. So if a baseball moves at say 90 millimeters per second you cannot display that at 60 Hz? The viewing angle makes a difference. If you focus on a 1 inch spot then no, you will most likely only see a baseball in 1 frame of a 60 Hz video. If you focus to 100 feet you will see that motion.

[2Bdecided]

Many ABX tests are flawed and many people simply lost the confidence. It's so easy to trick an ABX test, I said it too many times. The only real ABX tests are done internally in a company and they never get public.
Hardly. BS.1116 (double-blind ABX-like tests) are routinely carried out for each new generation of codecs, and the results published widely. e.g. http://mp3-tech.org/programmer/docs/w2006.zip

Cheers,
David.

[2Bdecided]

I used it as a minimum. Your eyes cannot see 1000 Hz. Just because you can see a single flash of light that lasts 1/1000 of a second does not mean you can see 1000 images per second. You would be able to see a bullet fly. 60 Hz just makes sense. 72 FPS was studied to be the greatest point to which beyond that there are no benefits.Not true...
http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP169.pdf
...but I suppose those people are idiots too? I suppose you're the only one who is not an idiot?

Cheers,
David.
(Hydrogenaudio regular ;) )

[ramicio]

Is an ABX test now magically also a lie detector?

[smok3]

The high frame-rate can be regarded as temporal oversampling in this context, which
leads to the exciting possibility of allowing temporal aspects of the video such as shuttering and
motion blur to be adjusted by the director in post-production, perhaps even selectively within the
frame. This would add additional “looks” to the director’s palette, complementing the well-known
“video” and “film” looks.

interesting, i want a post shutter-speed_fader please.

[GodofaGap]

Is an ABX test now magically also a lie detector?
Lies are not a problem, because I can't lie for you. If you claim to hear a difference, what then would be rationale for you to lie in a subsequent ABX test?

Still I think it's great we can all have a conversation via medium that according to your own words can't exist. :)

[2Bdecided]

If you claim to hear a difference, what then would be rationale for you to lie in a subsequent ABX test?Not much - but you can lie entirely - saying you've taken+passed a test, and posting the results log to prove it - when really you just typed the "log" yourself.

There are things to catch this in the official HA listening tests (checksums in the logs etc), but it's always possible to cheat if you really want to.


Anyway, this isn't the point of ABX. The point is to remove placebo. Placebo isn't lying.

However, placebo is the basis of much of the high end audio industry, which is why some people get so touchy about ABX.

Cheers,
David.

[ramicio]

And it's easy to cheat an ABX test even if you DO hear a difference. It's called just giving random results...

[madhatter300871]

Ramicio.

I have a wonderful garden, full off grass and flowers. I love sitting out there when the sun is shining and a slight breeze is in the air.... maybe be a little cheecky and pour myself a gin and tonic ... don't tell any one but sometimes before 4pm as well !

Anyway, back to this video stuff ... my hobby .... chill out man, life is too short ! You do seem to be rather aggressive in your view of this topic. Shall I send you my gin and tonic secret recipe ?

I'm still amused at the snobs at the BBC ... what where they thinking ! And as for Nyquist Theorem being crap .... well, beat me with a kipper until Woolies re-opens but that has had me chuckling all day.

I love forums.

[ramicio]

Life may seem short for everyone else...for people who choose to pursue non-material and emotional family BS...but I choose materialism and no people, so life is plenty long for me. Where would the world and science be NOW if people in the past hadn't been so passionate about what they believed. Only in today's fluffy foo foo liberal world are people taught to deem celebrities' realities as their own and not have convictions or their own views.

[madhatter300871]

So why be a part of this forum if you choose no people ? Do you need a valium ?

[ramicio]

This isn't people, this is the Internet... I don't pretend that the Internet is some social thing that can replace real human contact. I don't even like having a job where I have to be around other people. I'd be perfectly content in a world where everyone died.

[madhatter300871]

Well your a laugh a minute ! I'll leave you be .... I'm off to play with VirtualDub and amuse myself ... with a gin and tonic at my side :)

Have fun !

[GodofaGap]

And it's easy to cheat an ABX test even if you DO hear a difference. It's called just giving random results...
There is no point in it. Someone else who can hear the same difference can simply provide a positive result.

Where would the world and science be NOW if people in the past hadn't been so passionate about what they believed
Well I'm just glad they didn't all listen to people like you, because science wouldn't be anywhere.

[smok3]

And it's easy to cheat an ABX test even if you DO hear a difference. It's called just giving random results...

Even worse, you may actually hear a difference in certain different context, but you can't prove it with abx due to fatique.

Also as someone else pointed out, you can't prove that you don't hear a difference.

Still, its a usefull test and simple as well to perform.

[Wilbert]

Striked and removed all bullshit. Go somewhere else for such discussions.

[raj1402]

i saw in a encoding group website they have mentioned 1200kbps bit rate is minimum required for 720P

[Blue_MiSfit]

Please don't bring 2 + year old threads back to life :) Start a new topic if you'd like to discuss this.

[Guest]

Also, we don't allow discussions about "encoding groups" and their products, so don't post about that.