YCbCr vs YPbPr

Discussion in 'Beginners, General Questions' started by David Nusair, Sep 25, 2006.

  1. David Nusair

    David Nusair Auditioning

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    Hi all,

    Okay, I just bought a 32" ViewSonic 16:9 television and it has two component inputs: YCbCr and YPbPr. My HD terminal only works on YPbPr, but my Panasonic DVD player works on both (as a side note, I'm only able to get 480i on both inputs - though my player supposedly possesses progressive scan).

    My question is: What's the difference between YCbCr and YPbPr? Should I just use YPbPr for HD television and YCbCr for DVDs?

    Many thanks in advance.

    -David
     
  2. homthtr

    homthtr Supporting Actor

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    Definition of: YCbCr

    One of two primary color spaces used to represent digital component video (the other is RGB). The difference between YCbCr and RGB is that YCbCr represents color as brightness and two color difference signals, while RGB represents color as red, green and blue. In YCbCr, the Y is the brightness (luma), Cb is blue minus luma (B-Y) and Cr is red minus luma (R-Y). See component video.

    YCbCr Is Digital
    MPEG compression, which is used in DVDs, digital TV and Video CDs, is coded in YCbCr, and digital camcorders (MiniDV, DV, Digital Betacam, etc.) output YCbCr over a digital link such as FireWire or SDI. The ITU-R BT.601 international standard for digital video defines both YCbCr and RGB color spaces. See YCbCr Sampling.

    YPbPr Is Analog
    YPbPr is the analog counterpart of YCbCr. It uses three cables for connection, whereas YCbCr uses only a single cable (see YPbPr). See YUV, YUV/RGB conversion formulas and ITU-R BT.601.

    See this link for more info..

    http://www.pcmag.com/encyclopedia_te...i=55163,00.asp


    And
    Definition of: Y (B-Y) (R-Y)

    Refers to the formula used to convert RGB into the various signals used for TV/video. This designation is also found on video equipment to represent analog component video inputs and outputs, although they are also designated as Y, Pb and Pr (YPbPr). The Y represents the luma (brightness), and B-Y and R-Y represent color difference signals. For TV/video storage and transmission, RGB signals are converted to either YUV (NTSC/PAL composite video), YPbPr (component analog) or YCbCr (component digital). See YPbPr, YCbCr, YUV and YUV/RGB conversion formulas.

    see link..

    http://www.pcmag.com/encyclopedia_te...i=55119,00.asp


    Your head spinning yet?
     
  3. David Nusair

    David Nusair Auditioning

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    Wow, Steve. That's WAY more info than I ever thought I'd need. [​IMG]

    At any rate, the whole thing turns out to be moot: I finally turned on progressive scan on my DVD player, and now it won't play on the same one that the HD box also refuses. *sigh* Guess I gotta switch between the two now.

    Thanks again,

    David
     
  4. homthtr

    homthtr Supporting Actor

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    You might want to check the settings on you cable box. Most have "more" or "advanced" settings. Make sure that the Cable box (or sat box) is set to output 1080i. I know in Milwaukee here the cable guys hardly ever turn the 1080i on. There are settings in most all of our cable boxes for 480i, 480p, 720p, and 1080i ( I don't even think most of the "cable guys" know what 1080 is...if they do they just don't bother to turn in on!! [​IMG] ) It's simular to turning on the progressive scan in the DVD player. Some come factory defaulted to progressive and some come with progressive turned off. Don't know why... it's like buying a V8 and it only runs on 4 cylinders when you drive it off the lot![​IMG]
     
  5. ChrisWiggles

    ChrisWiggles Producer

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    I'm confused at what outputs you are looking at.

    As already described, YPbPr properly describes analog component video (3-wire analog video), and YCbCr properly describes digital component video (usually HDMI when set to YCbCr transmission).

    However, manufacturers are buffoons and mislabel these things ALL the time. It is not uncommen to see the analog output labeled YCbCr or YPbPb/YCbCr or something like that. If it's analog it should be labeled YPbPr, which is analog component video. If it's digital component video it should be described YCbCr. In either case if the labels or descriptors are wrong of confusing, ignore them because it doesn't mean anything. Component video is component video, it's either analog or digital and it's obvious which is which.

    Some analog input/outputs that handle YPbPr may also handle RGB video, so that may be another label you run into.

    Also, DVI is digital RGB, HDMI is digital RGB or it could be YCbCr depending on the equipment and the settings and what you choose. If using a DVI-HDMI adapter, it should usually revert back to DVI only, which is 8-bit RGB.
     
  6. 300m

    300m Auditioning

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    On this topic I have a question that I need a yes or no answer.
    I have a Toshiba 36' TV with "colorstream" component inputs labeled yCbCr.
    I plan on purchasing a satelite receiver labeled YPbPr.
    Will the Sat. work !00% with the TV?
     
  7. ChrisWiggles

    ChrisWiggles Producer

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    Yes. AS I explained, your television is just mislabeled. Not uncommon.
     
  8. Allan Jayne

    Allan Jayne Cinematographer

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    >>> TV with Colorstream(tm) inputs labeled Y/Cb/Cr

    You will need to double check the TV instructions to find out what scan rates the TV accepts. Colorstream suggests to me 480p but 1080i may also be an option, I don't know on your TV.

    (Simplified) The satellite receiver needs output jacks that look the same as the input jacks of your TV (ignore the C versus the P as in Y/Cb/Cr) , and also needs a manual selection for a scan rate that matches a scan rate of the TV. If 480p is the only common denominator scan rate, the final picture will be standard def., not hi-def. If the TV accepts more than one scan rate through the same set of input jacks (some TV's have different sets of input jacks) the TV will autoselect the scan rate but the DVD player or sat. receiver still needs the scan rate set manually. THe DVD player with progressive on delivers 480p, with progressive off it delivers 480i.
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    This is actually surprisingly accurate, especially coming from a computer-world oriented source which will notoriously screw this stuff up.

    The only thing I would correct is that they mention Rec. 601 as defining digital video which is not accurate. There are numerous kinds of digital video and images out there with their own standard, among which Rec 601 is one, which is used for pretty much all SD content. HD content uses a different standard, Rec 709. This mis-match unfortunately causes problems when manufacturers get this wrong, which happens pretty frequently.
     

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