24p DVD encoding in DVD SP2?

Discussion in 'Mac Apps and Mac App Store' started by D*I*S_Frontman, Apr 26, 2003.

  1. D*I*S_Frontman macrumors 6502

    Joined:
    May 20, 2002
    Location:
    Lombard, IL
    #1
    Seeing that a lot of talk about the DVX100 and 24p DV technology abounds on the Apple site, do you think DVD SP will include an encoding process for 24fps DVD playback? Isn't that how Hollywood DVD releases are actually done?

    It uses fewer fps, meaning less data space on your DVD for the exact same video output.

    Anyway, here's hoping...
     
  2. patrick0brien macrumors 68040

    patrick0brien

    Joined:
    Oct 24, 2002
    Location:
    The West Loop
    #2
    Re: 24p DVD encoding in DVD SP2?

    -D*I*S_Frontman

    Umm <shifting in chair> Well no. The filming is done in 24p, but NTSC television operates at 30i, there is a drop-up conversion. Even though the filming and editing are at 24 progressive, you still need to make it work with your TV, and that means 30 interlace. They used to call that color-transfer.

    Now, when talking HD, that's different, and will probably end up being 1080 lines Progressive - but that's a different story :D
     
  3. D*I*S_Frontman thread starter macrumors 6502

    Joined:
    May 20, 2002
    Location:
    Lombard, IL
    #3
    yes, but...

    Do all DVDs encode all 30fps, or do the good "Hollywood" ones encode only 24 and flag a few for repeating during playback to give you 30fps?

    The appearance would be the same as 24 to 30 pulldown schemes without the unnecessary extra frames encoded. 25% data savings, right?

    I am obviously a bit sketchy on the DVD encoding/decoding process, aand I have no idea if standard DVD players could work this way. Please straighten me out.

    Thanks.
     
  4. nuckinfutz macrumors 603

    nuckinfutz

    Joined:
    Jul 3, 2002
    Location:
    Middle Earth
    #4
    The DVD Spec is based on MPEG2. Which in this case is strictly 30frames Interlaced.

    Modern televisons support Progressive DVD players but the 30i signal is converted to Progressive by the DVD player. The DVD itself is still recorded in 30i.

    It's definitely confusing. That's why Apple has included Cinema Tools in Final Cut Pro 4. This allows Film and other 24p capture to be efficiently moved to other output formats.
     
  5. ctcushing macrumors newbie

    Joined:
    Sep 3, 2003
    #5
    24p authoring

    This is not true. MPEG-2 can be encoded at 24fps, in fact, it is the preferable way to do it, but not all encoding systems will do it. All commerically released films are on the disk at 24p. The player adds 3:2 (adds interlaced in-between frames changing every 4 progressive frames into 3 progressive and 2 interlaced) on output to bring it up to 29.97. A flag is set in the authoring process to tell the player to do this.

    Now, you can store interlaced video on the DVD and it will simply pass through to the monitor on output, but it is the less efficient was to do it (25% more picture info).

    If you couldn't store progressive films, you also couldn't release anamorphic widescreen. In this case, when the DVD player is set to letterbox the player is vertically squeezing the anamorphic signal, then adding 3:2 for output. Otherwise, you would end up with a jumbled mess of fields.

    Chris Cushing
     
  6. patrick0brien macrumors 68040

    patrick0brien

    Joined:
    Oct 24, 2002
    Location:
    The West Loop
    #7
    Re: 24p authoring

    -ctcushing

    That's quite interesting! Thanks!
     

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