Understanding video file properties and relation to DVD/CD ROM/VCD etc.

Discussion in 'Amateur Video Production' started by HiC, Oct 2, 2003.

  1. HiC

    HiC Guest

    It's my understanding that DVD holds a max of 4 gigs, correct?

    After doing a mere 45 minute capture, at what I thought isn't a
    paricularly high bit rate, I end up with a whopping 6 gig plus file,
    and even before compression the resolution doesn't blow me away,
    presumably compression reduces the image quality even farther. So, how
    do they cram what looks like a very high resolution 1 1/2 - 2 hr movie
    on a single DVD? Surely they must have to compress the stew out of it
    to get it to fit.

    What are the specs for a typical commercial DVD file? Bitrate, frame,
    dimensions, etc.

    Also, what's the difference between capturing something as a VCD as
    opposed to just burning an mpeg video file onto a CD rom?
     
    HiC, Oct 2, 2003
    #1
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  2. HiC

    Lawrence Lin Guest

    A "DVD-5" (single-side, single layer) holds about 4.7 GB.[1] There are other
    formats, most commercial DVD movies arrive on a "DVD-9" which is single-sided
    and dual-layered.
    Better (clean) source, better (expensive) compression program.
    Most parameters are standardized, read the DVD FAQ[2] for more info.
    Some extra folder/files with metadata for standalone VCD players.

    [1]: http://www.timefordvd.com/glossary/GlossaryD.shtml
    [2]: http://www.dvddemystified.com/dvdfaq.html
     
    Lawrence Lin, Oct 3, 2003
    #2
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  3. HiC

    Dan Maas Guest

    After doing a mere 45 minute capture, at what I thought isn't a
    Some lossy codecs are quite good at 4-5:1 compression. IMHO MPEG-2
    looks great at 20:1. (you can take >200Mbit/sec uncompressed SDI down
    to <10Mbit/sec MPEG-2 with little visual loss of quality)
    Bitrate is typically VBR, with the average around 3-6 Mbit/sec, though
    higher in some parts. Hollywood DVD releases make very careful use of
    bitrate allocation to keep the average low without destroying image
    quality.

    Also consider that most film releases are encoded at 24fps, not 30fps,
    which gives you a 20% savings right off the bat.

    NTSC DVDs are always 720x480 pixels with 4:2:0 Y'CbCr color, at either
    30/1.001 fps or 24/1.001 fps (in which case the DVD player performs
    3:2 pulldown on playback). Wide-screen movies are usually encoded
    anamorphically (the DVD player stretches the image appropriately for
    4:3 or 16:9 displays). Audio is usually 5.1 channel Dolby Digital,
    although other audio streams can be added (stereo Dolby Digital, DTS,
    PCM, etc).

    A DVD is more like a small website than a single file, in that most
    DVDs include menus and a bit of software code for handling the menu
    and remote control buttons.

    Regards,
    Dan
     
    Dan Maas, Oct 3, 2003
    #3
  4. HiC

    Samuel Paik Guest

    Roughly 4,700,000,000 bytes.
    DVD-Video sets the maximum bitrate for audio and video to about 10
    megabits/sec. DVD-Video supports a bunch of frame dimensions,
    720x480 is the largest and probably the most common.
    It's exactly the difference between burning an audio CD as opposed
    to burning a bunch of WAV files onto a CD-ROM. Basically, VideoCD
    formats MPEG audio and video data, as well as some navigational
    data and optionally some ISO9660 formatted data onto a CD in a
    specific way. The MPEG audio and video has to be encoded with
    specific parameters.

    Sam
     
    Samuel Paik, Oct 3, 2003
    #4
  5. HiC

    HiC Guest

    Thanks for the info. Btw, are you any relation to Dusty Paik, the chic
    in the Mitsubishi commercial?
     
    HiC, Oct 3, 2003
    #5
  6. HiC

    Samuel Paik Guest

    I don't think so.
     
    Samuel Paik, Oct 3, 2003
    #6
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