# 60HZ VS 59.940



## Sonic Angel Knight (May 30, 2018)

I was curious if someone can help me. I noticed that my android tv shows me various display options, normally I uses 60HZ but it recommends I use 59.940 which I never heard of. It also says I should use RBG 8 bit instead of YUV 422 12 bit. Just wonder what the heck this all means.


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## Pleng (May 31, 2018)

Sonic Angel Knight said:


> I was curious if someone can help me. I noticed that my android tv shows me various display options, normally I uses 60HZ but it recommends I use 59.940 which I never heard of. It also says I should use RBG 8 bit instead of YUV 422 12 bit. Just wonder what the heck this all means.



Hopefully somebody better versed in this stuff will come in and confirm or contradict this, but I'm guessing that the app in question has measured the refresh rate of your screen to be 59.940 and therefore suggests that speed accordingly.


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## FAST6191 (May 31, 2018)

Historically black and white NTSC had an update rate of 60Hz, when colour came along the need for a bit of delay was felt and thus the frame rate dropped to various flavours of high 59.9 Hz. We all then went digital but various cameras, workflows and whatnot were adapted for it (see also why interlacing still exists...) and thus that number stuck. A lot of video is made to it and if your screen supports it then it makes sense. 

RGB and YUV then.
Basic childhood science says you can make any colour by mixing red, green and blue light. Initially colour on screens was treated much the same way, however owing to a quirk of maths you can still represent those colours by doing some calculations instead (which technically results in less storage needed and other niceties) and then you have the YUV family of colour spaces. Depending upon what is used it can be slightly lossy.
http://blogs.adobe.com/VideoRoad/2010/06/what_is_yuv.html if you want more technical.

Frankly you would probably struggle to notice either way as far as quality goes, probably also decode speed as well (and if it is just a video player then definitely) so use whatever combo you like.


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## SomeGamer (May 31, 2018)

Yeah, my laptop also has this setting, IDK which one is better though.


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## SG854 (May 31, 2018)

Sonic Angel Knight said:


> I was curious if someone can help me. I noticed that my android tv shows me various display options, normally I uses 60HZ but it recommends I use 59.940 which I never heard of. It also says I should use RBG 8 bit instead of YUV 422 12 bit. Just wonder what the heck this all means.


Y'UV is not used in the digital realm. It's an analogue scaling for NTSC and PAL displays.
The fact that your digital device has Y'UV as an option, could mean that the video engineer is incompetent, has no knowledge of color science when designing the Android TV, and used the *wrong* mathematical formula which then gives you worse color accuracy. 

Y'UV - Scaling for Composite Analogue NTSC and PAL
Y'PbPr - Scaling for Component Analogue Displays
Y'CbCr - Scaling for Component Digital Displays

Sometimes people use Y'UV and Y'CbCr interchangeably. To the lay person it doesn't matter, but for video engineers it does. You can't use the terms interchangeably because they all use different formulas. If you use the wrong equation then you'll get a worse picture. Which is probably what the incompetent Android tech designer did. 

The 3 numbers (422) on the right of Y'UV is subsampling. And it only should be used for component digital video. 
If you see "*Y'UV 422*" then you have a problem.


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## Sakitoshi (May 31, 2018)

SG854 said:


> Y'UV is not used in the digital realm. It's an analogue scaling for NTSC and PAL displays.
> The fact that your digital device has Y'UV as an option, could mean that the video engineer is incompetent, has no knowledge of color science when designing the Android TV, and used the *wrong* mathematical formula which then gives you worse color accuracy.
> 
> Y'UV - Scaling for Composite Analogue NTSC and PAL
> ...


seems like incompetency can be found in the less expected places, right? like in yourself

YUV is just another way to represent color, just like RGB and that's about it.
compressed video formats (such as h/x264 and vp8/9) use YUV to store color because is more efficient, RGB is redundant and waste precious space.

as for the topic in question. choose whatever you like more, it's the same.
electronics are not perfect and 60hz is usually 59.something in reality and 59hz is that 59.something rounded down, so either will do and is not like you could actually tell if there is a difference anyway.


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## Sonic Angel Knight (May 31, 2018)

Sakitoshi said:


> as for the topic in question. choose whatever you like more, it's the same.
> electronics are not perfect and 60hz is usually 59.something in reality and 59hz is that 59.something rounded down, so either will do and is not like you could actually tell if there is a difference anyway.


That's what i was concerned with. The numbers seem too close to actually mean any difference the way I thought, but if that is true, then why would it exist a option? The other part of thinking that is curious about this.


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## Sakitoshi (May 31, 2018)

Sonic Angel Knight said:


> That's what i was concerned with. The numbers seem too close to actually mean any difference the way I thought, but if that is true, then why would it exist a option? The other part of thinking that is curious about this.


my guess is that android tv is asking your tv "what video format are you most comfortable with?" and your tv is answering with those recommended options you said in the op. so I say use them.


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## Fishaman P (May 31, 2018)

Absolutely use RGB instead of YUV, better color.

60 Hz vs 59.94 Hz shouldn't make a noticeable difference, but depending on what your display was optimized for it might be *technically* better as one or the other. Monitors are definitely optimized for 60.00 Hz, TVs usually for 59.94 Hz historically but I'm not sure how true that is nowadays.


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## tbb043 (May 31, 2018)

My TV offers better options for color space in RGB than YUV, so I use it. Slightly washed out in YUV, or the other choice for colorspace (high vs low). You equipment and options may vary.

59.numbers is the real rate of ntsc, 60 is just rounding.


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## SG854 (May 31, 2018)

Sakitoshi said:


> seems like incompetency can be found in the less expected places, right? like in yourself
> 
> YUV is just another way to represent color, just like RGB and that's about it.
> compressed video formats (such as h/x264 and vp8/9) use YUV to store color because is more efficient, RGB is redundant and waste precious space.
> ...


You are completely wrong. Here is a paper on why.
http://poynton.ca/PDFs/YUV_and_luminance_harmful.pdf

Jesus I get tired of stuff like this. People criticizing me when i'm not wrong. 
I calibrate displays so I know a bit about this.


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## Sakitoshi (May 31, 2018)

SG854 said:


> You are completely wrong. Here is a paper on why.
> http://poynton.ca/PDFs/YUV_and_luminance_harmful.pdf
> 
> Jesus I get tired of stuff like this. People criticizing me when i'm not wrong.
> I calibrate displays so I know a bit about this.


and here in the info that says that is a pixel format used to represent color inside a video file.
https://wiki.videolan.org/YUV/

this seems a case of same name different meaning.


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## SG854 (May 31, 2018)

Sakitoshi said:


> and here in the info that says that is a pixel format used to represent color inside a video file.
> https://wiki.videolan.org/YUV/
> 
> this seems a case of same name different meaning.


Right away I found errors in that site you linked. Y component should be called "Luma" not "Luminance". 
Luma and Luminace are two different things. They can't be used interchangeably. The paper I linked clearly explains that.

And the pixel format you are talking about, that's what *Y'CbCr 4:2:2* is. It should not be called Y'UV because that is not used in the digital realm. 
They are using the terms interchangeably when they shouldn't. The paper clearly explains all of this. If they are using Y'UV then they are probably using the wrong equations. And you get a worse picture because of it.


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## Sakitoshi (May 31, 2018)

SG854 said:


> Right away I found errors in that site you linked. Y component should be called "Luma" not "Luminance".
> Luma and Luminace are two different things. They can't be used interchangeably. The paper I linked clearly explains that.
> 
> And the pixel format you are talking about, that's what *Y'CbCr 4:2:2* is. It should not be called Y'UV because that is not used in the digital realm.
> They are using the terms interchangeably when they shouldn't. The paper clearly explains all of this. If they are using Y'UV then they are probably using the wrong equations. And you get a worse picture because of it.


if you are so experienced about this you should know then that the yuv color space has been in use as a pixel format pretty much since the invention of compressed video formats.
so as I said, this must be a case of same term different meaning.


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## ThoD (May 31, 2018)

FAST6191 said:


> Historically black and white NTSC had an update rate of 60Hz, when colour came along the need for a bit of delay was felt and thus the frame rate dropped to various flavours of high 59.9 Hz. We all then went digital but various cameras, workflows and whatnot were adapted for it (see also why interlacing still exists...) and thus that number stuck. A lot of video is made to it and if your screen supports it then it makes sense.
> 
> RGB and YUV then.
> Basic childhood science says you can make any colour by mixing red, green and blue light. Initially colour on screens was treated much the same way, however owing to a quirk of maths you can still represent those colours by doing some calculations instead (which technically results in less storage needed and other niceties) and then you have the YUV family of colour spaces. Depending upon what is used it can be slightly lossy.
> ...


Little correction, it was actually to match the radio signals for distributing the video feed on TVs back when color was first introduced and it was actually 30Hz for PAL/SECAM and 29.97Hz for NTSC (ONLY in US though, Japan had 30 like the others). The 59.94 and 60 are just doubles of those from the old days. The rest you said is all valid, just wanted to clarify it a bit.


On topic, I suggest you just go with 60, since if you are using it for more than just watching regular channels, you will encounter very slight distortions (depends on how good your eyes are at reaction so average person should barely be able to notice any every few minutes) and the performance difference is negligible. On top, if you use the TV for stuff like video playback, games, etc., it's preferable to have a rounded Hz value to prevent aforementioned distortions. If you only use the TV for watching normal channels, then you won't ever have an issue with 59.94Hz.


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## SG854 (Jun 1, 2018)

Sakitoshi said:


> if you are so experienced about this you should know then that the yuv color space has been in use as a pixel format pretty much since the invention of compressed video formats.
> so as I said, this must be a case of same term different meaning.


What you said is wrong "YUV Color Space."

Y'UV is not a Color Space. 
Color Spaces are Rec.709 and Rec.2020. This is what Y'UV is not.
Y'UV is an analogue encoding. With a specific mathematical formula. 
Y'UV, Y'IQ, Y'PbPr and Y'CbCr all have specific math properties that are not interchangeable. 

Y'UV was invented to make color broadcast signals backwards compatible with Black and White (Y') displays.
They separated the Luma (Y') and Chroma (UV,) so that people with black and white displays (the majority at the time), could still enjoy the shows. 
Y'UV is not used in Digital Component. Thats what Y'CbCr is for. Why use Y'UV when you have Y'CbCR? With a specific equation that was made for Digital Displays? Anyone that is using Y'UV for Digital Displays is using it wrong.


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## Sakitoshi (Jun 1, 2018)

SG854 said:


> What you said is wrong "YUV Color Space."
> 
> Y'UV is not a Color Space.
> Color Spaces are Rec.709 and Rec.2020. This is what Y'UV is not.
> ...





> Colorspaces are graphs of components that make up the way we represent colors. There are several different ways to do this, each having its own benefits and drawbacks. Common colorspaces used today include RGB, YUV, HSL (also incorrectly called HSV), CMYK, LAB, and XYZ.


but whatever. if you cannot understand that a single term can mean 2 or more different things (like HDR that, if I remember correctly, it refers to 3 different things), that is your problem.


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## SG854 (Jun 3, 2018)

Sakitoshi said:


> but whatever. if you cannot understand that a single term can mean 2 or more different things (like HDR that, if I remember correctly, it refers to 3 different things), that is your problem.


No, its not. This article clearly explains that Y'UV is not a Color Space. Its an encoding system that uses Color Difference formula.
https://wolfcrow.com/blog/whats-the-difference-between-yuv-yiq-ypbpr-and-ycbcr/



Sakitoshi said:


> if you are so experienced about this you should know then that the yuv color space has been in use as a pixel format pretty much since the invention of compressed video formats.
> so as I said, this must be a case of same term different meaning.


Pixels is a digital concept. Analogue CRT's don't display pixels. They display lines. Phosphor dots are not pixels. Pixels are dots that can be individually manipulated. Crt's can't individually manipulate its phosphor dots. So Crt's don't have pixels.

Y'UV is an analogue encoding system. CRTs are analogue. Y'UV is for CRT's not LCD's. The 4:x:x is a digital concept that manipulates individual pixels. Since Crt's don't have pixels saying Y'UV 4:2:2 or Y'UV 4:1:1 is incorrect terms. The "compression" in Y'UV comes from the need to lower bandwidth use because back in the day they had limited bandwidth they can work with. The "compression" comes from the color carrier signal occupying a narrow frequency spectrum then Luma signal. And can you get the color component from the Luma component using some math which is what Y'UV does. This saves a lot of bandwidth then using RGB. RGB is not efficient and will triple bandwidth. 

Its a different compression than the digital compression like reducing megabytes and gigabytes. Analogue doesn't use megabyte or gigabytes. How do you compress analogue VHS tapes? Do you cut the tape in half with scissors so you can fit more movies on the VHS tape? Is that how that works? 4:x:x is used to reduce digital file sizes (megabytes) by reducing color information at the individual pixel level. You can't digitally manipulate individually pixels on VHS tapes, since VHS is not digital. And since Y'UV is analogue, saying Y'UV 4:2:2 is wrong. The reason why people are using it to mean 2 different things is because most people are using the terms wrong.


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