MPEG decoding and de-interlacing? What is the order?

Discussion in 'Archived Threads 2001-2004' started by Chris PC, Oct 13, 2002.

  1. Chris PC

    Chris PC Producer

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    Which process takes place first? MPEG decoding or de-interlacing? I have an idea but I'm asking here anyways. I'm just wondering about how to come up with a way to ZOOM in on 4:3 widescreen material from LD, VHS (and to a lesser extent, non-anamoprhic DVD's). Do you take a 480p signal from a line doubler and use an HTPC to ZOOM in and squeeze the 4:3 widescreen? My DVD player right now is interlaced but I'll be getting an iScan for use with an AE100 or 200 projector.
     
  2. Lewis Besze

    Lewis Besze Producer

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    The MPEG decoding comes first.
    DVD is a 480p[though not all disc authored that way] format but most player interlace the signal, then de-interlace it again.I think JVCs are among the few players that bypass the interlacing on DVD's that's originally 480p.
     
  3. Chris PC

    Chris PC Producer

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    OK, so the frames/fields are MPEG decoded first. Actually, DVD is recorded on the disc in interlaced fields, thats why the DVD player has to de-interlace the video. Proof of this is the fact that DVD's have flags for progressive scan players. So if I wanted to do some squeezing/zooming, it'd have to be after the whole thing is converted to 480p.
     
  4. Vince Maskeeper

    Vince Maskeeper Producer

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    Chris,

    See my posts in your related thread in HTPC.



    Yes and no- I'm still unclear on this, but it seems from the technical authoring people I have spoken with that video can be encoded progressive with flags for interlacing as easily as it can be interlaced with flags for progressive.

    -Vince
     
  5. Chris PC

    Chris PC Producer

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    Right. Thing is, I still don't know about squeezing horizontal and zooming 4:3 letterbox, basically non-anamorphic DVD. I know HTPC's put out 480p but I am talking about non-anamorphic, be dvd, ld or vhs widescreen. Thanks for the info. I'll check out your reply in HTPC. I almost forgot I posted the question there.
    [​IMG]
     

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