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32PF9986: green look

Discussion in 'LCD & LED LCD TVs' started by Diving Bear, Feb 1, 2005.

  1. Diving Bear

    Diving Bear
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    How do I stop my 32PF9986 giving a green tinge to some DVDs played through DVI? I am only getting this on DVI connections and not on all DVDs either. Is it the 32PF9986 or the DVD (A denon 2910)?
     
  2. ianh64

    ianh64
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    Are you sending an upscaled HD source to the display in YUV? In that case, the 9986 will be doing a HD colourspace YUV->RGB conversion as it thinks that it is getting a true HD input rather than an upscaled SD input. This will show itself as a slight green push. I think that you should beable to set the format of the 2910 to RGB in which case, it should use the colourspace information from the disc and get the YUV->RGB conversion right - unfortunately not all discs are correct in this respect which could explain why some discs have the problem whilst others do not.

    Im not saying that this is the cause, but it should beable to disproove it by sending a non upscaled image to the 9986 to see if the problem persists.

    -Ian
     
  3. jimsan

    jimsan
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    Diving Bear,

    IanH64 is the Man for this HiTek stuff, but I'm learning all the time. You say only some disks show the Green? If this is the case then Ians solution sounds good. If everything had a green cast then some twiddling in the sevice menu might have been required...

    Jimmy
     
  4. Diving Bear

    Diving Bear
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    Thanks for that I'm trying to see if I understand it...
     
  5. Diving Bear

    Diving Bear
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    What is YUV???
     
  6. Diving Bear

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    OK, I've set the 2910 output to RGB and it doesn't make any difference :mad:
     
  7. ianh64

    ianh64
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    You sure that setting you just touched effects the digital output not the SCART? Oh well. Is it the same over HDMI and DVI? Otherwise, no more ideas other than below.

    To clear up my post, basically colour and luminence information stored on a DVD is encoded in YUV. The display ultimately needs RGB. To convert YUV to RGB, you need to use a formula. A different formula is used for SD and HD. Which formula to be used is also encoded on the disc, but it can sometimes be wrong! This may be why some discs look green and other don't.

    If you let the DVD player do the decoding from YUV to RGB, the DVD player can use the information on the disc to select what formula to use. If you let the display do the decode, it can't use the information (I think with HDMI this information is passed so with HDMI it may not be strictly true) so the display has to make its own decision of what formula to use. Quite often this is based upon what type of input is being seen. For an HD signal, the HD formula is used, for SD, the SD is used. The problem is, with an upscaling DVD player, the source is treated as an HD source when infact it is really SD colour and luminence information. Hence, the picture will have a colour tint of some form.

    -Ian
     
  8. jimsan

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    Hi DB,

    The YUV system delivers pictures with a combination of Luminance (Y) and Chrominance (UV) The human eye is more sensitive to colour intensity than actual colours. This system delivers the intensity (Liminance) of the image over a separate full bandwidth and the colour (chrominance) over a reduced bandwidth - giving a more natural image.

    There, you asked!

    Anyway, I have heard that some Denons have a tendancy to make some disks look green. This, of course, is of little help to you. Am I right in saying that only some disks are effected? Take note of which ones are OK and which aren't. You may have to watch some via analogue and some via DVI. Hardly ideal. If you can't get it sorted it may be worth while having a go in the DVD player Forum. They'll be able to help...

    Jimmy
     
  9. Alan D

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    Diving Bear - what about the DVI lead you are using - how long is it? what make is it? Long (and/or cheaper) DVI leads can cause problems with some images. For ref: I paid £40 for my 2 metre Supra DVI-DVI lead and have had no problems. As this problem only affects DVI and not Scart - the lead could be the problem.
     
  10. Diving Bear

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    Ianh64
    I realise that I am in the wrong forum for this now, but you seem to know what you are talking about... how do I know if I have changed the digital output and not the scart. What I adjusted was in the 'video' menu.

    Jimsan
    I think you are right and that the solution is going to be playing different DVDs in diferent ways: component, scart and dvi and at different settings. It is intersting that there is no wya all of this is accessible to 'normal' people who would just want to plug and play. This needs a degree in AV to understand what is going on and how to set things up!!!
    Thanks for help.. I am aware I am asking a lot more questions on the forums than I am answering. It's all take take take with me.
     
  11. jimsan

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    You're right DB, I hate to think of the mess that some people must get into. Terrifying! Even worse, some folks will be sitting at home watching dreadful quality pictures on perfectly good displays thinking that these LCD screens are cr*p!

    They'll probably have their Digibox connected to a 37" LCD with one of those plastic fantastic free scarts and it'll most likely be set on PAL composite and they'll probably be sitting 6 feet from the screen and ..oh my God wake me up! This is a nightmare! argghhh...

    It really is far too difficult to get this technology working properly. I was inolved in a very amusing thread on Monday night which covered this, you should check it out - good laff! http://www.avforums.com/forums/showthread.php?t=184064

    Jimmy
     
  12. Diving Bear

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    Have you ever thought that you need to get out more... :blush:
    I too have a Philips, bit concerend about the DVD thing at the moment. It seems that the better the kit you get the more it shows up the faults in other stuff like the discs or whatever. When you use use cheap stuff the quality isn't so good but you expect less and are less dissapointed??
     
  13. ianh64

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    DB

    I have seen your post in the DVD forum. Based upon its response, you could also try borrowing a HDMI->DVI-D lead and see if that makes any difference.

    Good luck.

    -Ian
     

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