Question regarding pixilation - "Blade" owners especially

Discussion in 'Archived Threads 2001-2004' started by Martin Rendall, Nov 26, 2001.

  1. Martin Rendall

    Martin Rendall Screenwriter

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    I'm a little worried that there may be something wrong with my new JVC-S60BK DVD player. But the question applies to all players.



    Is pixilation common with DVDs? I've noticed on a few discs a high amount of pixilation at times. By no means is the effect always occurring, and it looks like the data bandwidth is lower when it occurs. I know that DVD production companies have to pick and choose the resolution, based on the amount of detail or movement required in a scene, but sometimes it looks really bad.



    For example, during the movie "Blade", at around the 35 minute mark, there's a scene where the heroine is packing a suitcase. The gray wall behind her is alive with large pixilation - big square blotches which vary in hue from frame to frame. Does this occur with all players, or just mine? Anybody with the movie want to check it out for me?



    I've messed with various picture settings, such as sharpness, gamma, contrast, brightness, both on the player and the TV (where applicable), and all I can do is change where the giant pixels are noticeable. There's no setting which "cures" the problem.

    I've also tried viewing with interlaced and progressive settings - no difference at all.

    I've seen the effect quite regularly on many dvds. It manifests itself as "shimmering" on walls and such. It's like the pixilation described above, but the squares are much smaller. It's usually move evident when there is a uniformity of colour over most of the image, and only subtle differences from area to area. Are these types of scenes more likely to have a lower bandwidth assigned, given that many TV's won't distinguish the subtle differences all that well?



    I need help in setting my expectations on what I should be seeing.



    Thanks,



    Martin.
     
  2. Eujin

    Eujin Supporting Actor

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    Martin,

    It sounds like your player might have a problem. I don't want to be a doom-and-gloomer, and I'm not familiar with the JVC, but it sounds to me like you're experiencing severe posterization. Could your Blade disc be bad? I'll check my copy tonight, but I've never noticed anything wrong with that disc and it was one of my reference discs for a while (gotta love those bright red credits against the black backgrounds!) I'll let you know what I find out at the 35 minute mark--it'll probably be pretty late tonight by the time I get around to it. What other discs have you seen this with?
     
  3. Tom S

    Tom S Agent

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    This is not "normal" for any player.

    Do you, consistantly, clean the DVD's in question. That usually explains 95% of the problem, the other 5% involved purchasing or repairing the player.

    Topm
     
  4. Mark Dubbelboer

    Mark Dubbelboer Screenwriter

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    If a good cleaning doesn't do the trick i'm afraid it might be your player.

    I've never had problems with my blade disc and it's one of the older ones in my collection
     
  5. Martin Rendall

    Martin Rendall Screenwriter

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    I've also noticed the problem with Sphere during some of the underwater scenes. Unfortunately, Sphere is hardly a reference DVD to be checking picture quality against. One other DVD, but I can't remember what it was.

    Thing that makes me suspicious is that I haven't seen the issue with the "better" discs, like Fifth Element Superbit or Star Wars...

    Eujin, I'd be very grateful if you could check the scene out for me. You may want to temporarily up your brightness when viewing the material, to see if it could be there and just not noticeable under your normal viewing conditions. Thanks!

    Martin.
     
  6. Martin Rendall

    Martin Rendall Screenwriter

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    Mark,

    You're comment suggests that if there's something wrong with the read head, then this type of thing could happen?

    Martin.
     
  7. Martin Rendall

    Martin Rendall Screenwriter

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    A gentleman on another forum tried it out on his JVC, and saw the same thing. He also tried it on two PC's, and saw it there. So perhaps this is a problem with the encoding of the disc after all?

    Martin.
     
  8. Henry Colonna

    Henry Colonna Stunt Coordinator

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    Martin, I have a JVC75GD player (something like that, single DVD Audio Gold) and have noticed this problem inside the Enterprise on Star Trek First Contact fairly regularly. I even commented on it but no one wrote back.

    Please look up that thread. In it I comment on a web site that someone has put up showing his home theater. I see the problem next to the Borg Queen's head on his web site (see the thread for specifics.) I'm curious if this is what you are seeing.

    I do not see this very much on Dark City or Gladiator, maybe 10 percent as much as I see it on First Contact.
     
  9. Martin Rendall

    Martin Rendall Screenwriter

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    Henry,

    I tracked down your thread, and checked out the picture. Yes, I can see what you're asking about. I have this disc, so I can try it out. Do you have some time indexes for me?

    A question for you: when you step frame by frame, do you notice the "pixels" changing colour and position between frames? Or are the "flaws" basically static?

    Martin.
     
  10. Carl Philip

    Carl Philip Agent

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    i just played that disc in my dvdplayer (Pioneer 626) and watched that scene..i couldn´t see that pixelation, but if you looked closely, the grey wall dídn´t look too good..a little bit more bitrate might have helped in that scene [​IMG]
     
  11. Henry Colonna

    Henry Colonna Stunt Coordinator

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    Martin,

    Give me a few days, lots going on and big presentation at work tomorrow :-] As I remember, the pixelative colorized effective movitization (how's that for a new name for an effect) seems to fluctuate between frames. If you ZOOM with the remote the problem is really bad. It happens pretty much *inside* the Enterprise more than anywhere else.

    I'm darned tempted to buy a Toshiba 3750 and Panasonic RP56 to test. This is one of my very favorite movies and I found the pixelative colorized efective movitization to be distracting and disappointing. No one responded to me over there.

    Considering that it happens far less in other DVDs...who knows. Maybe it IS this DVD player is sensitive to certain color conditions..hmmm...
     
  12. Kevin C Brown

    Kevin C Brown Producer

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    I have seen this too. On a Pioneer DV-333 (I think) as well as a DV-05.

    I also checked it out on a friend's Sony (don't know/didn't check the model number), and it had it too.

    Both are attached to direct view TVs. I attributed it to the DVD and mastering itself.

    Don't assume you don't have it until you specifically check for it. I found it very apparant on Blade too.

    Haven't really noticed as much on other DVDs, but it is there.

    I use S-video connection.
     
  13. Martin Rendall

    Martin Rendall Screenwriter

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    I visited a friend with a Toshiba SD-2200 connected to a 27" Wega. I saw the exact same effects on the same discs in the same places. I checked out First Contact, too. The internal wall shots are riddled with the compression artifacts.

    In my mind - case closed. DVD just isn't quite the visual perfection I thought it was.

    Martin.
     
  14. John Garcia

    John Garcia Executive Producer

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    What type of cable are you using to connect the DVD to the TV?

    Does the TV have the ability to do 16X9 Enhanced display (squeze a la WEGA)?

    Has the TV been calibrated using any reference material? (Video Essentials or Avia)? This can be a big factor.

    What settings are you using for this? The artifacts could be more noticable because of the fact that these movies are 16X9 enhanced and are not being played back in enhanced mode.

    I only notice a SLIGHT pixellation on the wall in that particular scene and a few other walls in that scene. If I pause, it is more noticable, but even in forward or reverse slow-mo, it is almost not visible.

    Had it not been pointed out, I never would have noticed.

    Gear:Sony DVP-S560, KV32FV26 via component video, calibrated with VE.
     
  15. Martin Rendall

    Martin Rendall Screenwriter

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    John,

    I've seen it with two different setups.

    First, mine: Toshiba 40H80, high quality component cables, JVC S60 in progressive mode, 3:2 pulldown on. Also tried interlaced though the component cables.

    Friend: Sony Wega 27", composite cable, Toshiba SD-2200 interlaced.

    Exact same effect.

    A nice person on another board tried the scene out on their HT, and also on two PC's. They saw it in all three cases.

    Now, neither set has been calibrated, beyond a THX video calibration. Do you think that could make the difference? I suspect it may hide the effect from casual inspection, but there's no way it would make the effect go away. Assuming it would make a great big difference, is AVIA sufficient? I don't want to go down the ISF route.

    Martin.
     
  16. John Garcia

    John Garcia Executive Producer

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    As I said, I can also see it, but it is not really "shimmering" on my particular setup, just a little "fuzzy".
    I can't say that calibration would fix the problem, but it is worth trying out to see if there is at least an improvement. I prefer to use Video Essentials. That is what I have been using for a few years to calibrate my, and other's, sets with great success.
    I'd have to agree with others though, that this sounds like a problem with the disc itself, not the gear. [​IMG]
     
  17. Kevin C Brown

    Kevin C Brown Producer

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    Calibration, in my opinion, isn't going to fix it.

    Calibration affects sharpness, color, contrast, brightness, etc. (Although perhaps decreasing sharpness could make it less apparent. But it would still be there.) What we are seeing is visual artifacts on the screen. The reason that I mentioned that I had seen on 2 different direct view TV set ups, is that it might not be as apparent with projectors, big screen (rear projection) TVs because their resolution might not be as high.

    Non-anamorphic vs anamorphic may affect it. But with an analog direct view TV, don't have a choice anyway.

    By the way, I also see the same thing sometimes with my digital TV cable connection to the Sci Fi channel. I think the person who said those particular scenes need a higher bit rate got it right. The changes in color across that wall aren't being represented with enough bits to hide the transitions. (Or something!)

    Would be curious if Blade ever gets the SuperBits (or similar) treatment.
     
  18. Bryan Acevedo

    Bryan Acevedo Second Unit

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    I posted something in this thread
    http://www.hometheaterforum.com/htfo...threadid=28547
    that may explain what you guys are seeing.
    In spite of all the hype, DVD's use a lossy compression scheme for both the audio and video, which when used poorly, can result in subpar performance. The audio is harder to tell, but video is generally easy to see when using bad settings on encoding.
    And yes, Digital cable is the worst on this. I couldn't stand watching pay per views on Digital cable. You could see the MPEG compression artificts on scenes where it was dark and there was something like smoke, or steam. The gradients were way off. DirecTV is much better (but not perfect either). On local channels, you can sometimes see the actual blocks of pixels I describe in the other post. Watching some sports on local TV, the players almost looked like blocky computer game characters!
    Bryan
     
  19. Kevin C Brown

    Kevin C Brown Producer

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    Bryan- Yes very excellent description on the other thread (both threads started by Martin!).
    It's refreshing to see a scientific description of a problem instead of the ubiquitous, "well I don't see it on *my* system." [​IMG]
     
  20. Jeff

    Jeff Supporting Actor

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    (Sorry if I'm repeating those above, I just posted without reading replies)

    Compression artifacts is what you're seeing. Check out Star Trek Insurrection or to a lesser degree, First Contact. In the beginning of Chapter 4 in ST:FC, look at the wall behind Picard and Riker. What you see is a dithering effect where the shading isn't perfect and it forms little blocks. I've seen this using a Pioneer DV-09 and Panasonic RV80. It's tough to see on a smaller non 16x9 TV. It's not even very noticable on my Sony Wega with 16x9 mode but if I go up to the screen I can see these things in many DVD's. Of course, many of the newest ones are much better or don't have it at all.

    Insurrection and FC have artifacts all throughout the movie but can only been seen in certain scenes. If you FF the movie on the first speed, you can really see the blocks almost anywhere when you're near the screen. Do this in the bridge scenes!

    Finding Forrester is bad too because there is an intentional haze throughout the movie and this effect takes up more space on the DVD. The compressionist did not take that into account and the hazy scenes are all blocky.

    Jeff
     

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