Denon 2900 video based chroma bug?

Discussion in 'Playback Devices' started by Chris Madalena, Jan 13, 2004.

  1. Chris Madalena

    Chris Madalena Stunt Coordinator

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    I've recently purchased a 2900 and am very happy over all, but as I was watching some video sourced material (Peter Gabriel Growing Up Live) I noticed some streaks running through saturated reds. Also noticed it on some of the Alien Quad supplements. I have not seen any in film based material, and am aware of the alt. flag issue. Is this a function of the Sil 504 chip, or the Mits. deinterlacer perhaps?
     
  2. Roger J

    Roger J Stunt Coordinator

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    The chroma problem with alternating progressive flag material is an artifact of the Mitsubishi MPEG decoder.
     
  3. Dale Adams

    Dale Adams Extra

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    What you're seeing is an inherent limitation of using 4:2:0 encoding for interlaced video. I think the Secrets guys dubbed this one "ICP", or interlaced chroma problem. It's produces very much the same onscreen artifacts as the 'chroma bug', but it's not really a defect of the MPEG decoder. Rather, that's just the way interlaced video looks when encoded as 4:2:0 (i.e., where the chroma is vertically subsampled).

    The only way to get rid of these artifacts are to filter them out. Some video processors include a vertical chroma filter to deal with CUE and ICP problems. There are various levels of sophistication - the Lumagen Vision products have a always-on chroma filter, the iScan Ultra has a user-switchable filter, and the new iScan HD has an automatic CUE and ICP detector and can switch in a chroma filter on the fly when ICP errors occur, even on a player which does not have the normal chroma bug (i.e., CUE).

    - Dale Adams
     
  4. John Garcia

    John Garcia Executive Producer

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    Yep, what Dale said, and the 2200 has the same thing. I found that film based material, CUE is almost not worth mentioning, but ICP shows up quite obviously on certain video based material. So far, I've only seen it very bad on one disc, in one scene, so I won't complain.
     
  5. Chris Madalena

    Chris Madalena Stunt Coordinator

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    Thanks guys for the responses. I figured it had to be a limitation of an encoding process as opposed to the player itself. It's too bad the Gabriel disc is encoded that way because otherwise it has a very film-like appearance and the audio is incredible.
     
  6. Edward J M

    Edward J M Cinematographer

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    I have the 2900 and Dog Soldiers in littered with the ICP. Bad Boys II also has a few scenes with a very noticeable ICP.

    It would have been nice if Denon had included the vertical low pass filter in the interlacer to knock out the ICP.

    Regards,

    Ed
     

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