DVD to AVI quality loss?

Discussion in 'Professional Video Production' started by P.C. Ford, Jun 26, 2008.

  1. P.C. Ford

    P.C. Ford Guest

    I am doing a corporate video; tomorrow I am going to pick up some
    footage from the client. Though I have requestion only original source
    materials, I qould wager that I am going to get at least some DVDs.

    How bad a quality hit am I going to take converting a DVD to AVI (or
    to whatever) ?
     
    P.C. Ford, Jun 26, 2008
    #1
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  2. That's rather a subjective question. Are you exhibiting these on a
    big, high-res screen? Or are these for a little web page window,
    or what?
     
    Richard Crowley, Jun 26, 2008
    #2
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  3. P.C. Ford

    Toby Guest

    Depends entirely on the encoding parameters. You can also play out analogue
    and capture.

    Toby
     
    Toby, Jun 26, 2008
    #3
  4. P.C. Ford

    Arny Krueger Guest

    That all depends.

    BTW, the question is arguably not well-formed since not all DVDs are the
    same and not all AVIs are the same. AVI is a family of formats. DVDs are
    MPEG format, and that's another family of formats.

    Your question is really something like "Are girls named Smith prettier or
    smarter than girls named Jones?" Which Smith? Which Jones?

    I routinely convert DVDs to DV-AVIs for production purposes and often
    convert them back to DVDs. The degradation ranges from imperceptible to
    slight.
     
    Arny Krueger, Jun 26, 2008
    #4
  5. P.C. Ford

    P.C. Ford Guest

    I knew I was going to get the old "You don't understand that AVI is a
    wrapper..." sermon that is trotted out whenever the term is used.
    My fault...I should have precluded this. A rather more useful answer
    may have been to how to ensure highest quality.

    Richard....yes, in your post you ask what the delivery format is going
    to be. Good point, I should have mentioned that. They are to be .in
    the form of DVDs which will be sent out to prospective clients. Most
    likely they would be played on a computer. Though a LCD projector is
    possible as well. Thanks.
     
    P.C. Ford, Jun 26, 2008
    #5
  6. P.C. Ford

    Arny Krueger Guest

    IME a computer is about the toughest format, it puts the most demands on
    video quality.

    Large scale video projectors are pretty easy - there isn't that much
    visible difference on them between DVD quality (720 x 480) and XGA (1024 x
    768).
     
    Arny Krueger, Jun 27, 2008
    #6
  7. P.C. Ford

    Larry in AZ Guest

    If the projector is XGA, then it scales all inputs to 1024x768.
     
    Larry in AZ, Jun 27, 2008
    #7
  8. P.C. Ford

    Arny Krueger Guest

    In this case, the scaling happens well before the video hits the projector.
    IOW, the video projector is always driven at 1024 x 768.

    The point is that the projector looks sharp enough when we drive it with a
    VGA card dishing out 1024 x 768 from a say PowerPoint presenation, but when
    we upsample DVD format MPEG-2 videos of the same presentation, the
    degradation is only just slightly noticable.
     
    Arny Krueger, Jun 27, 2008
    #8
  9. P.C. Ford

    P.C. Ford Guest

    Ok, what I am inferring is that there is a modest degradation when
    converting DVDs.

    Thanks all.
     
    P.C. Ford, Jun 27, 2008
    #9
  10. What a waste. Just get a good multi-format editor like Canopus Edius, and
    there is no need to convert your material. Just whack all on the timeline,
    cut-cut-cut-render, and Bob is your uncle.

    cheers

    -martin-
     
    Martin Heffels, Jun 27, 2008
    #10
  11. P.C. Ford

    Arny Krueger Guest

    Hmm Canopus Edius, from $1,025 to $3,739 depending on version.

    Currently using Premiere Elements 4 @ $79.95.

    It just ain't takin' that long to convert those files that need it to
    DV-AVI. ;-)
     
    Arny Krueger, Jun 28, 2008
    #11
  12. P.C. Ford

    Mike Kujbida Guest


    If all you want to do is straight cuts with no recompression, look up
    the offerings from Womble (MPEG Video Wizard DVD - $99.00) and Video
    ReDo ($75.00).
    Demos are available.

    Mike
     
    Mike Kujbida, Jun 28, 2008
    #12
  13. P.C. Ford

    P.C. Ford Guest

    Turns out Premiere Pro 3 does that also. .

    Rename VOB and plop it on the timeline.
     
    P.C. Ford, Jun 28, 2008
    #13
  14. P.C. Ford

    Arny Krueger Guest

    That procedure also (often) works in Premiere Elements, but it does not
    prove that there is no conversion.
     
    Arny Krueger, Jun 29, 2008
    #14
  15. P.C. Ford

    P.C. Ford Guest

    I am using Premiere Pro CS3. It appears to be able to import VOBs by
    renaming them to MPEG and dropping on the timeline. On rendering all
    seems well.

    Here is a question that I should understand....I commonly do a rough
    edit and then take the footage over to a post house to do the final
    edit. I originally wanted to move the stuff via external hard drive.
    However, to do that the drive had to be on their network. (I am on PC;
    the posthouse is Mac.) The transfer rate was glacially slow so I just
    exported to tape and took it over.

    I assumed at the time that since everything was digital no data would
    be lost in this process. Now I realize that there may be data lost in
    my process of exporting to tape and importing. Like the DVD>AVI
    processthere are changes in compression.

    I have not noticed problems but.....is there potentially a problem?
    Thanks.
     
    P.C. Ford, Jun 29, 2008
    #15
  16. Digital does NOT imply "lossless". Nearly every form of
    digital video storage uses some amount of lossy compression.
    Some is rather slight (such as the 5:1 compression used by
    DV). And it ranges to much greater compression in the
    MPEG protocol used for DVDs, etc. And even greater
    compression for internet presentation of videos on web
    pages, movies on cell phones, and iPods, et.al.
    Not explicitly in the process of exprting to tape. Perhaps
    concurrently in the choice of formats/codecs, etc.
    DVD is, by design, significantly compressed. And that
    is *lossy compression* that is unrecoverable. With good
    hand-tuned encoding as the *final step* (distribution NOT
    editing) of the production proces, the MPEG compression
    used by DVD can be quite acceptable. But as an intermetiate
    step in a production process, it is not an optimal choice
    of format.
    The fewer lossy compression steps in your production
    process, the better you will preserve whatever quality
    is present in your camera original video.
     
    Richard Crowley, Jun 29, 2008
    #16
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