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868/504/HDMI chroma bug?

Discussion in 'Blu-ray & DVD Players & Recorders' started by Brogan, Jan 20, 2004.

  1. Brogan

    Brogan
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    I'm not entirely sure what the "chroma bug" is but I think it's related to some kind of jagged edge effect.
    If so then I have just seen it on my 868/504/HDMI set up.
    It's the scene on Star Wars II at the start of the film, when they're all in the conference room.
    The effect can clearly be seen on Samuel L Jackson's head outline against the red background.

    The 868 is set to output 1920x1080i so I wonder if that's got anything to do with it...

    If this isn't the chroma bug then please disregard this thread.
     
  2. KraGorn

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  3. Brogan

    Brogan
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    Thanks for that.
    Perhaps it's not the chroma bug then as the effect is only a jagged edge rather than the interlaced kind of banding problem seen on that site.
     
  4. fred123go

    fred123go
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    i get this with my denon 2800 mk11 now and again, seems really strange, like in some scenes faces in the background seem smeered and well jaggedy.
    Also try the opening scene of TLOTR:TTT when the title comes on, if you look at frodos face when he is in the background it is seriously smudged by jagged lines.
    i think it is a progressive scan problem, something to do with flag signals or something
    cheers
    fred
     
  5. Tim Ashdown

    Tim Ashdown
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    Hi Brogan.

    I'm not an expert, far from it. But it could posibly be because you're sending the 504 an interlaced signal. I'm not familiar with the operations of the 868, and hopefully someone will chime in and correct me if I'm wrong. But I assume that if you can select 1080I on the 868 then you probably have other options like 480P or 720P. The P being progressive which should reduce the jaggies. Might be wrong but I hope this helps.
     
  6. Brogan

    Brogan
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    Yes - I've already considered that.
    I only recently changed the output res to 1920x1080i based on comments from some of the other members who claim that is the best setting.
    I'll do some testing with the other progressive resolutions and see what the difference is.
     
  7. joys_R_us

    joys_R_us
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    Yes PLEASE and don't forget the 576p :D
     
  8. buns

    buns
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    im in no way an expert...... but jagged lines is what has been described to me when someone is refering to aliasing. However i cant really say what causes it or how to sort it

    ad
     
  9. Brogan

    Brogan
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    Did some very quick testing with the various resolutions last night (720x576p, 1280x720p and 1920x1080i) and the jagged edge effect appears on all of them so I guess it's just that particular scene.
    Either that or Samuel L Jackson's got a zig-zaggy head...:D
     
  10. ailean

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    I've heard a number of referances to Samuel LJ's forehead in various scaler threads, seems to be a challenging thing. ;)

    Noise correction has been mentioned a couple of times so you might want to play with those settings too.
     
  11. Brogan

    Brogan
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    LOL - that was probably me too when I posted about the "wobbling" issue.
    Perhaps it's just that SLJ has a head which is not progressive scan capable? :D
     
  12. Adam M

    Adam M
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    brogan,

    I have tested the same scene on my 868 hs20 via hdmi, and I don't seem to get any jaggedness.

    I have mine set up at 1280x720p at all times.
     
  13. Brogan

    Brogan
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    Thanks for the feedback Adam.
    Could you try pausing the scene when SLJ's head is framed against the red background? That's when it is more noticeable?
    Out of interest, what are your 868 (and 504 if you have one) settings?
     
  14. Brogan

    Brogan
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  15. ReTrO

    ReTrO
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    Is the problem you are referring to one that makes all edges on the picture look like they're being viewed through a heat haze?

    Good example being on Gladiator when mr Maximus is standing in the area and his legs look like jelly (when he is about 10% height of the screen).

    If it is then I may have seen this somewhere else also...
    (With true 1920x1080i material)
     
  16. Brogan

    Brogan
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    Not sure if it's the same effect you're referring to but it's basically a zig-zag/jagged edge instead of a smooth outline.
    A bit like the graphics you used to get on old video games running at 640x480 resolution.
     
  17. ReTrO

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    This more like a wobble, than a interlaced effect kind thing.
     
  18. Brogan

    Brogan
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    Ah, OK - I've seen that too.
    I posted a thread about that a few days ago.
    One of the deleted scenes from the 2nd disc shows this very clearly.
    Co-incidentally, it's Samuel L Jackson's head again....
     
  19. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    Tried it on my Panny6 from Lumagen Scaler fed SDI out of DVD player. Don't see this effect. Hope to get over to Joe's in next few days and will take disc to see if I can make it happen on his hdmi 504.

    Gordon
     
  20. Brogan

    Brogan
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    Thanks Gordon - would appreciate any feedback on the results.
    It may just be settings or it could be a "normal" effect but it certainly looks a bit odd.
    I'll try and find the exact time stamps of each scene so were looking at the same point.
     
  21. Brogan

    Brogan
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    OK, the best time to spot this jagged edge problem is at time stamp 4:38.
    As SLJ says "We're keepers of the peace, not soldiers", he inclines his head slightly on the word "peace" and the jagged edge effect can be clearly seen on the right hand side (his left) outline of his shaven head.
    It's more noticeable if the disk is paused and can also be seen on the outline of his robe (left shoulder).

    Maybe it's just something to do with the pixel/size shape on the 504?

    Edit: I've noticed that the jagged effect occurs on almost all paused images along clearly defined edges.
     
  22. Brogan

    Brogan
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    The wobbling can be seen on disc 2, deleted scene 3, timestamp 4.01.
    SLJ says "Obi-Wan you must have faith that he will choose the right path".
    As he says "choose the right path" he is nodding his head slightly and his whole forehead kind of wobbles as if it is lagging slightly behind the rest of the head movement.
     
  23. ReTrO

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    My wobble is quite clear on all scenes with hard edges on.
    I have only noticed it on a JVC SX-21 when being fed by a 1080i D-Theater source.

    Any ideas on this Gordon?
    Unless it's just the tape, but I don't think it is.
     
  24. cwick

    cwick
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    Don't know if this helps, but I've noticed wobbling pictures a couple of times recently. I find it particularly noticeable on titles, especially the rolling white-on-black jobbies at the end of films. To date I've seen this on some film on Channel 5 (freeview) into a Panny plasma - the initals titles were really bad, but the wobbling persisted into the film proper. Changing channels confirmed it was the source.

    Also noticed it at the cinema, again during titles (think it was the last Matrix film). It wasn't noticeable once the action started.

    Up until now I'd always assumed it was just by wobbly eyes ... I'd guess it's a de-interlacing problem, but I don't thiink that would explain seeing it in a cinema :confused:

    Cheers, Carl.
     
  25. Brogan

    Brogan
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    I wonder if this "wobble" is the same effect I am seeing?
    The wobble I refer to is hard to explain but imagine a face moving slightly and it's as if the features are floating on the surface and lagging slightly behind the rest of the face movement.
    It's very strange but if you've seen it you'll know exactly what I mean.
     
  26. ReTrO

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    My wobble's like a heat haze effect on the vertical sides of images.

    cwick's sounds like that caused by film bo being perfectly aligned when tele-cined onto a digital format.
     
  27. Brogan

    Brogan
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    Sounds like a different effect then.
    To avoid confusion, perhaps we should refer to your wobble as the Retro-wobble...:D
     
  28. ReTrO

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    Sounds good to me.

    I guess mine must be alcohol induced then. :D
     

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