Frame rates and maximum image size

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  • AgentNoir
    Junior Member
    Junior Member
    • Jul 2004
    • 3

    Frame rates and maximum image size

    Background: I'm researching all elements involved in transferring 16mm film (24 frames per second) to DVD, including audio.

    First, I was curious to see how DVDs handled the 24fps original rate of movies initially recorded on film. So I played a DVD of an older movie and counted the frames that appeared in each second (playing at 1/16th speed, of course). It gave a consistent 24fps. (A VCR playing a tape gives a consistent 30fps.) This impressed me, as it indicated that no changes need to be made to the frame rate I receive from the film (well, except for concerns about audio and the recommended "29.97fps" rate, but that's another topic).

    So I wanted to see if I had any DVDs of modern films that had been shot directly to digital, which I assumed would be 30fps to comply to NTSC television standard. I tried "The Italian Job," and discovered that the frame rate varied from scene to scene. In one instance, it alternated between to camera angles in one scene, and the frame rate changed from 30fps to 10fps (yikes!) depending on which camera was used. I believe that this is a form of video compression, where high (24-30fps) rates are reserved for fast action and low rates (down to 10fps, apparently) are used for largely static shots.

    Now, the movie I want to convert to DVD is only about 31 minutes in length. Since it's coming from film stock, and I'll be scanning each frame directly, I should have some flexibility in choosing the resolution of each image that will make up the video.

    I imagine that DVD has some flexibility with image sizes, just as it does with frame rates, to accomodated different sources (VHS, laserdisc, other DVDs, etc.). So is there a "hard" maximum to the size of the video image, or is it simply an effective maximum, beyond which the machine can't decode or display the video rapidly enough? The idea here is that for a short movie, I would prefer to use the capacity of the DVD for extra video quality. It won't make a difference on a TV, but 1024x768 video would look amazing on a monitor, if it's possible to achieve.

    Any thoughts on this (or corrections on my statements/assumptions) would be appreciated. (If anyone can provide a link to an existing website which deals with this, that would be great.)
  • Phytrax
    Platinum Member
    Platinum Member
    • Jul 2004
    • 169

    #2
    I have no idea what software you might be using to do this, but DVD DOES have a static image resolution. 720x480 i believe. You must meet this and several other criteria for bitrate and sound format, etc or the disk will not play in a DVD player. You can certainly have video clips of much higher resolution but they will only play on a computer or maybe some specialized hardware. HD DVDs are on the way and should offer some additional resolution in the future.

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    • Soulhunter
      Super Member
      Super Member
      • Mar 2004
      • 236

      #3
      Todays DVD standard has a fixed resolution of 720x480 (NTSC) or 720x576 (PAL) !!!

      But this is only valid for current standalones...


      For playback @ PC's you can use HD resolution !!!

      My box (XP 3000+) is able to decode 1920x1080 stuff...

      So, most PC's should be able to play 1024x576 videos !!!


      Btw, the next gen standalones of Kiss will handle HD content as well...


      Bye
      Last edited by Soulhunter; 24 Jul 2004, 04:37 AM.


      Member of E.V.I.L. Corp. 2003 ® - Website in progress...

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      • AgentNoir
        Junior Member
        Junior Member
        • Jul 2004
        • 3

        #4
        Thanks for the replies! It looks like I'll be making two versions (one high-res version for the PC, and one for regular TV-based DVD). I'll do some checking into HDTV and see if its resolution is something I might be able to shoot for.

        By the way, I hope to compile the video using nothing more complicated than LView Pro and Bulent's Screen Recorder. I know it sounds weird, but it seems workable. Audio will be another issue, though. And I will need to find a graphics program that does batch re-sizing and maybe even batch cropping (if that's even possible). And I still have to design the scanning interface that will work with a slowed-down 16mm projector. So I'm still miles away from actually doing this. But I do have the two projectors -- one to modify for slow speed, and one to read the soundtrack in realtime.

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        • Soulhunter
          Super Member
          Super Member
          • Mar 2004
          • 236

          #5
          Originally posted by AgentNoir
          And I will need to find a graphics program that does batch re-sizing and maybe even batch cropping (if that's even possible).
          Batch resizing/cropping pictures ???

          Search for a program called InfranView...


          Bye


          Member of E.V.I.L. Corp. 2003 ® - Website in progress...

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