Newbie with a technical question re: NTSC. - Blu-ray Forum

jproberts · 03-02-2009, 02:53 PM

Hello, I'm new to the Blu-ray Forum, but I have been reading this site for information before. Great info. on Blu-ray discs, BTW. I have a question from a colleague who thinks that "Blu-ray; NTSC," which, according to his understanding, is not possible, since Blu-ray is a digital standard and NTSC is analog and no dual-layer discs carrying both data standards exist (again, to his knowledge)."
I vaguely know that Blu-ray discs will accommodate earlier technologies, but I need your help to provide a more solid argument to why having NTSC communication format on Blu-ray discs is possible.
I'd appreciate any help I can get from this forum.
Thanks!
JP

WriteSimply · 03-02-2009, 03:46 PM

NTSC is 480i. Most newer DVDs are encoded at 480p. For BDs, the main feature are in 1080p/i. Some of the supplemental features may be in 480p or 576p (PAL).

So for BD, NTSC comes into play only when you have the ol' TV sets, where all of the video signals from 1080p to 480p are converted to 480i to match NTSC. Some older plasma/LCD panels are 480p too.

fuad

zicmubleu · 03-02-2009, 03:50 PM

Quote:

Originally Posted by jproberts

Hello, I'm new to the Blu-ray Forum, but I have been reading this site for information before. Great info. on Blu-ray discs, BTW. I have a question from a colleague who thinks that "Blu-ray; NTSC," which, according to his understanding, is not possible, since Blu-ray is a digital standard and NTSC is analog and no dual-layer discs carrying both data standards exist (again, to his knowledge)."
I vaguely know that Blu-ray discs will accommodate earlier technologies, but I need your help to provide a more solid argument to why having NTSC communication format on Blu-ray discs is possible.
I'd appreciate any help I can get from this forum.
Thanks!
JP

I may not be reading your post correctly, but a Blu-ray player will normally have composite video and S-video outputs which I think is what you are referring to with NTSC. Then as far as your reference to dual layer, do you really mean dual-disc, where one side is Blu-ray and the other side is DVD? I doubt that is allowed within the Blu-ray specifications in a similar manner as SACD uses hybrid instead of dual-disc. But the concept of dual layers on a single Blu-ray with different formats is pointless I believe. The media itself is going to require a Blu-ray laser to read it, it isn't like a SACD Hybrid disc where the lower layer is read by a more focussed laser, etc. because the outside layer would still have to be read with a Blu-ray laser anyway. Once you require a Blu-ray player/drive to read the disc there is no point in using a different technology to record it. However you can record Blu-ray format to a DVD and who knows maybe somehow you could write a short Blu-ray version of a movie on one side of a dual sided disc (not dual-disc) and the other side with DVD format. That would be an interesting twist but for a very small market.

Did I confuse you? I confused me.

Sorry 'bout that.

zicmubleu · 03-02-2009, 03:57 PM

Quote:

Originally Posted by WriteSimply

NTSC is 480i. Most newer DVDs are encoded at 480p. For BDs, the main feature are in 1080p/i. Some of the supplemental features may be in 480p or 576p (PAL).

So for BD, NTSC comes into play only when you have the ol' TV sets, where all of the video signals from 1080p to 480p are converted to 480i to match NTSC. Some older plasma/LCD panels are 480p too.

fuad

jproberts - go with his explanation, he knows his stuff, I just didn't see it before I started blathering on and on.

jproberts · 03-02-2009, 05:09 PM

Hello All,
Thanks so much for your answers. I will go with "WriteSimply' answer. But thanks to 'zicmubleu' for trying too.
Best,
JP

Anthony P · 03-03-2009, 12:11 AM

NTSC was a transmission standard (i.e. read TV) created in the US, In Europe they used something called PAL.
VHS was based on this and that is why if you brought a VHS tape from the US to Europe it would not work. With DVD that stopped and (except for possibly regioncoding) a DVD bought in the US would play in a player in Europe. So from the time of DVD it did not make sense to talk of NTSC on the disk but of SD. Now once the SD image on the DVD is created it needs to be transmitted to the TV, and if you use the composite out it would need to take the SD data on the disk and assuming it is a US DVD player and TV change it to NTSC so that the TV could understand. Now over the years (for manufacturing reasons) players and TVs had become less particular (well they give you the choice).

Now we come to BD, the guy making the disk has more choices for example many will have the movie in 1080p (HD) but some extras in 480i/p (SD), then most players will have HDMI, component, s-video, composite (quality goes down ->) HDMI is the best choice for a newer HD TV but if someone has a real old TV and all that it jhas is composite then the player will downscale it so that it can play on older TVs

in essence if he has a DVD player today he should be able to watch BDs on a BD player.

U4K61 · 03-09-2009, 03:31 AM

NTSC: Encoding/Decoding

When they added color to the B&W signal in 1953, the American system became known as NTSC - National Televison Standard Committee. PQ could be spotty and the color was not always on the mark, so it was also called Never Twice the Same Color.
Analogue Video Signals

NTSC:
525 lines, 59.94Hz 262.5 line interlaced fields.
line frequency of 15,734 Hz (59.94 x 262.5).
Color subcarrier frequency: 3.579545(3.85).
Color of Grey 6500K.

Encoding NTSC:
To fit in a 6MHz bandwith that was for B&W(Y= luminance), the RGB color output of a camera, where each video signal can be up to 100 IRE. This is reduced by the Matrix Coder to the luminance signal: Y = 0.3R + 0.59G + 0.11B, that when added together, has a max amplitude of 100 IRE. Lots of green, some red, a little blue with Y containing most of the picture information. G is removed to save space. We end up with Matrix Coder outputting Y and 1.3Mz for R-Y, 0.5MHz for B-Y, to be transformed by the Color Encoder to I(in-phase) = 0.877(R-Y)[orange-blue] and Q(quadrature) = 0.493(B-Y)[purple-green]. This is modulated together with Y by the Adder as NTSC composite, Y+I&Q.

Decoding NTSC:
This signal goes though the comb (Y/C ) filter in the TV to be seperated out as Y,C. PQ is reduced by constructive/destructive interference and dot crawl or cross-luma - where chroma is incorrectly interpreted as high frequency luma information. The degree of degration depends on filter type being used: Two-line, Three-line, or 3D Y/C comb filter. The outputted Y/C signal, Y is delayed and the Color Decoder takes C and outputs R-Y, B-Y. The Matrix Decoder converts Y, R-Y, B-Y to RGB.

1080p Blu-ray/480p DVD passed though the composite limits it to NTSC.
See - Informative page on NTSC listed below.

What NTSC made for:

Back to Getting Started HD POST

Anthony P · 03-09-2009, 10:50 PM

component is limited to 1080i

U4K61 · 03-10-2009, 12:06 AM

Quote:

Originally Posted by Anthony P

component is limited to 1080i

Cabel Options - From good to bad:
HDMI > Component video > S-video > Composite video > Analogue RF

Component is capable of 1080p(Games), 1080i, 720p, 480p, 480i.(Games & Video)

Many older HD 16:9 sets only provided 1080i through component - there was no digital HDMI or DVI. Most standard 4:3 CRT analogue sets that had component video for DVD, it was 480i, but there was also progressive IDTV. There were some 16:9 EDTV 480 'progressive scan' sets that took 480p, but did not go higher. I never owned a 16:9 480p set, though it was on my wish list at the time of DVD's introduction. A native 480p scan rate was ideal for DVD as it mapped 1:1 to the sets resolution. But they wer hard to come buy. You usually got 520p or 1080i at the time, which ment you had to upscale 480i/p. This can degrade PQ.

Home Theater Connections (Explained)
Advanced Access Content System (AACS)
AACS protected movies

Next Post: Informative page on NTSC
Back to Getting Started HD POST

scweb13 · 03-10-2009, 03:19 PM

Quote:

Originally Posted by jproberts

Hello, I'm new to the Blu-ray Forum, but I have been reading this site for information before. Great info. on Blu-ray discs, BTW. I have a question from a colleague who thinks that "Blu-ray; NTSC," which, according to his understanding, is not possible, since Blu-ray is a digital standard and NTSC is analog and no dual-layer discs carrying both data standards exist (again, to his knowledge)."
I vaguely know that Blu-ray discs will accommodate earlier technologies, but I need your help to provide a more solid argument to why having NTSC communication format on Blu-ray discs is possible.
I'd appreciate any help I can get from this forum.
Thanks!
JP

It might have to do with 50hz and 60hz displays and players. 50hz being PAL and 60hz being NTSC.
Also, there are some European release BD's that are 1080i50 and they will only play on a few BD players in the US (and only if the display accepts a 50hz signal).

Anthony P · 03-10-2009, 10:49 PM

Quote:

That is False.

did you read what I wrote?

Quote:

component is limited to 1080i

did I say component can't pass 1080p? no, I picked "limited to" because that was the right term and in the end it is all that matters when deciding how to connect a player and what you will get. AACS does not allow 1080p over component and so no player is allowed to send out a real 1080p over component.

U4K61 · 03-18-2009, 03:48 PM

Informative page on NTSC:

140 IRE = 1 volt: 100 IRE above 0 volts, 40 IRE below 0 volts.
Black = 7.5 IRE, NTSC system limited to an amplitude of 100 IRE.

http://nemesis.lonestar.org/referenc...sc_primer.html
Sine/Cosine Waves:
http://en.wikipedia.org/wiki/Sign_Wave
IQ Modulation:
YIQ
http://education.tm.agilent.com/index.cgi?content_ID=4

ICos - in phase with 3.58MHz carrier signal.
QSin - 90 deg. out of phase with carrier signal (Quadrature).
33 = degrees I & Q are rotated relative to YUV color space.
wt = 3.579545(3.58)MHz, Angular/Radians(Circular Measure) per second.
Y = 0.3R + 0.59G + 0.11B
I = 0.877(R-Y)[orange-blue], Q = 0.493(B-Y)[purple-green]
NTSC = Y + [QSin(wt+33) + ICos(wt+33)]
I and Q are combined to Produce C(color) whose magnitude is saturation and phase is hue.
NTSC Color Signal

C code for converting a colour image to grescale - BobPowel

Code:

public Bitmap ConvertToGrayscale(Bitmap source){
  Bitmap bm = new Bitmap(source.Width,source.Height);
  for(int y=0; y<bm.Height; y++){
    for(int x=0; x<bm.Width; x++){
      Color c=source.GetPixel(x,y);
      int luma = (int)(c.R*0.3 + c.G*0.59+ c.B*0.11);
      bm.SetPixel(x,y,Color.FromArgb(luma,luma,luma));
    }
  }
  return bm;
}

Color Theory

Glossery

Additive primaries - Red, Green, Blue
Subtractive primaries - Red, Yellow, Blue
CMYK - Cyan, Magenta, Yellow, Black, the primary colors of pigment

HSV Color Space
Hue - X axis
Saturation - Y axis
Brightness - Z axis

Color Space - the area inside the triangle created by the RGB color points.
Deep Color - extra bits added to the color chain to create more shades.
xvYCC - expands the color triangle.

YPbPr - converted from RGB.
Y - luma
Pb - difference between blue and luma (B - Y)
Pr - difference between red and luma (R - Y)
Green is derived using the blue, red and luma information.

03-02-2009, 02:53 PM	#1
jproberts New Member Member since:Mar 2009	Newbie with a technical question re: NTSC. Hello, I'm new to the Blu-ray Forum, but I have been reading this site for information before. Great info. on Blu-ray discs, BTW. I have a question from a colleague who thinks that "Blu-ray; NTSC," which, according to his understanding, is not possible, since Blu-ray is a digital standard and NTSC is analog and no dual-layer discs carrying both data standards exist (again, to his knowledge)." I vaguely know that Blu-ray discs will accommodate earlier technologies, but I need your help to provide a more solid argument to why having NTSC communication format on Blu-ray discs is possible. I'd appreciate any help I can get from this forum. Thanks! JP

03-09-2009, 03:31 AM	#7
U4K61 Special Member Member since:Mar 2007 Location:Connecticut Blu-ray collection:40 Blu-ray reviews:4	NTSC: Encoding/Decoding When they added color to the B&W signal in 1953, the American system became known as NTSC - National Televison Standard Committee. PQ could be spotty and the color was not always on the mark, so it was also called Never Twice the Same Color. Analogue Video Signals NTSC: 525 lines, 59.94Hz 262.5 line interlaced fields. line frequency of 15,734 Hz (59.94 x 262.5). Color subcarrier frequency: 3.579545(3.85). Color of Grey 6500K. Encoding NTSC: To fit in a 6MHz bandwith that was for B&W(Y= luminance), the RGB color output of a camera, where each video signal can be up to 100 IRE. This is reduced by the Matrix Coder to the luminance signal: Y = 0.3R + 0.59G + 0.11B, that when added together, has a max amplitude of 100 IRE. Lots of green, some red, a little blue with Y containing most of the picture information. G is removed to save space. We end up with Matrix Coder outputting Y and 1.3Mz for R-Y, 0.5MHz for B-Y, to be transformed by the Color Encoder to I(in-phase) = 0.877(R-Y)[orange-blue] and Q(quadrature) = 0.493(B-Y)[purple-green]. This is modulated together with Y by the Adder as NTSC composite, Y+I&Q. Decoding NTSC: This signal goes though the comb (Y/C ) filter in the TV to be seperated out as Y,C. PQ is reduced by constructive/destructive interference and dot crawl or cross-luma - where chroma is incorrectly interpreted as high frequency luma information. The degree of degration depends on filter type being used: Two-line, Three-line, or 3D Y/C comb filter. The outputted Y/C signal, Y is delayed and the Color Decoder takes C and outputs R-Y, B-Y. The Matrix Decoder converts Y, R-Y, B-Y to RGB. 1080p Blu-ray/480p DVD passed though the composite limits it to NTSC. See - Informative page on NTSC listed below. What NTSC made for: The Sharpness Controle Best HD Setup My First Game System The Cable Guy Back to Getting Started HD POST Last edited by U4K61; 03-08-2010 at 09:39 PM.

03-18-2009, 03:48 PM	#12
U4K61 Special Member Member since:Mar 2007 Location:Connecticut Blu-ray collection:40 Blu-ray reviews:4	Informative page on NTSC: 140 IRE = 1 volt: 100 IRE above 0 volts, 40 IRE below 0 volts. Black = 7.5 IRE, NTSC system limited to an amplitude of 100 IRE. http://nemesis.lonestar.org/referenc...sc_primer.html Sine/Cosine Waves: http://en.wikipedia.org/wiki/Sign_Wave IQ Modulation: YIQ http://education.tm.agilent.com/index.cgi?content_ID=4 ICos - in phase with 3.58MHz carrier signal. QSin - 90 deg. out of phase with carrier signal (Quadrature). 33 = degrees I & Q are rotated relative to YUV color space. wt = 3.579545(3.58)MHz, Angular/Radians(Circular Measure) per second. Y = 0.3R + 0.59G + 0.11B I = 0.877(R-Y)[orange-blue], Q = 0.493(B-Y)[purple-green] NTSC = Y + [QSin(wt+33) + ICos(wt+33)] I and Q are combined to Produce C(color) whose magnitude is saturation and phase is hue. NTSC Color Signal C code for converting a colour image to grescale - BobPowel Code: public Bitmap ConvertToGrayscale(Bitmap source){ Bitmap bm = new Bitmap(source.Width,source.Height); for(int y=0; y<bm.Height; y++){ for(int x=0; x<bm.Width; x++){ Color c=source.GetPixel(x,y); int luma = (int)(c.R0.3 + c.G0.59+ c.B0.11); bm.SetPixel(x,y,Color.FromArgb(luma,luma,luma)); } } return bm; } Color Theory* 1931 CIE Chromaticity Diagram 1931 CIE Color Space SMPTE color bars Color Theory Web Colors Color Calculator Glossery Additive primaries - Red, Green, Blue Subtractive primaries - Red, Yellow, Blue CMYK - Cyan, Magenta, Yellow, Black, the primary colors of pigment HSV Color Space Hue - X axis Saturation - Y axis Brightness - Z axis Color Space - the area inside the triangle created by the RGB color points. Deep Color - extra bits added to the color chain to create more shades. xvYCC - expands the color triangle. YPbPr - converted from RGB. Y - luma Pb - difference between blue and luma (B - Y) Pr - difference between red and luma (R - Y) Green is derived using the blue, red and luma information. Last edited by U4K61; 12-04-2010 at 08:52 PM.

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03-02-2009, 03:46 PM	#2
WriteSimply Blu-ray Ninja Member since:Sep 2006 Location:Kuala Lumpur, Malaysia	NTSC is 480i. Most newer DVDs are encoded at 480p. For BDs, the main feature are in 1080p/i. Some of the supplemental features may be in 480p or 576p (PAL). So for BD, NTSC comes into play only when you have the ol' TV sets, where all of the video signals from 1080p to 480p are converted to 480i to match NTSC. Some older plasma/LCD panels are 480p too. fuad

03-02-2009, 05:09 PM	#5
jproberts New Member Member since:Mar 2009	Hello All, Thanks so much for your answers. I will go with "WriteSimply' answer. But thanks to 'zicmubleu' for trying too. Best, JP

03-03-2009, 12:11 AM	#6
Anthony P Blu-ray Count Member since:Jul 2007 Location:Montreal, Canada	NTSC was a transmission standard (i.e. read TV) created in the US, In Europe they used something called PAL. VHS was based on this and that is why if you brought a VHS tape from the US to Europe it would not work. With DVD that stopped and (except for possibly regioncoding) a DVD bought in the US would play in a player in Europe. So from the time of DVD it did not make sense to talk of NTSC on the disk but of SD. Now once the SD image on the DVD is created it needs to be transmitted to the TV, and if you use the composite out it would need to take the SD data on the disk and assuming it is a US DVD player and TV change it to NTSC so that the TV could understand. Now over the years (for manufacturing reasons) players and TVs had become less particular (well they give you the choice). Now we come to BD, the guy making the disk has more choices for example many will have the movie in 1080p (HD) but some extras in 480i/p (SD), then most players will have HDMI, component, s-video, composite (quality goes down ->) HDMI is the best choice for a newer HD TV but if someone has a real old TV and all that it jhas is composite then the player will downscale it so that it can play on older TVs in essence if he has a DVD player today he should be able to watch BDs on a BD player.

03-09-2009, 10:50 PM	#8
Anthony P Blu-ray Count Member since:Jul 2007 Location:Montreal, Canada	component is limited to 1080i

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