DVD's (Ones you burn yourself vs. Hollywood)

Discussion in 'Archived Threads 2001-2004' started by MarkHastings, Feb 28, 2003.

  1. MarkHastings

    MarkHastings Executive Producer

    Joined:
    Jan 27, 2003
    Messages:
    12,013
    Likes Received:
    1
    Trophy Points:
    0
    I have a question concerning DVD-R's. Why is it that a DVD-R is only compatible with certain players? I understand the difference in layers, etc. My question is merely on play-a-bility (made up word [​IMG]). What makes the DVD's you buy in the store different? Does it have to do with the fact that DVD-R's are burned instead of pressed (stamped)?

    The reason for this is the fact that my boss owns "Rabbit Ears Entertainment" and he's looking to make DVD's of all the titles. Besides not being dual layered, I would think that DVD-R's would be the wrong way to sell DVD's (i.e. People, without DVD-R capable players, won't be able to play them).

    Please inform me on the differences...
     
  2. Jeff Kleist

    Jeff Kleist Executive Producer

    Joined:
    Dec 4, 1999
    Messages:
    11,267
    Likes Received:
    0
    Trophy Points:
    0
    DVD-Rs, like CD-Rs use a dye layer rather than a stamped alumninum sheet. Therefore they are less readable, and many DVD players don't have the software in them to compensate for that,so they can't read DVD-Rs

    It's a bad idea to release your titles on DVD-R, from a consumer perspective standpoint
     
  3. MarkHastings

    MarkHastings Executive Producer

    Joined:
    Jan 27, 2003
    Messages:
    12,013
    Likes Received:
    1
    Trophy Points:
    0
     
  4. Steven K

    Steven K Supporting Actor

    Joined:
    Jan 10, 2000
    Messages:
    830
    Likes Received:
    0
    Trophy Points:
    0
    Another big difference is that DVDs that you buy in stores are "Authoring DVDs," so to speak. These DVDs have a special section of the disc that contains a list of DVD decryption keys. The player reads this section of the disc, and matches up a key to the key that the player also has, and is able to decrypt the scrambled contents of the disc.

    DVD-Rs (and RWs and +Rs and +RWs) dont have this special authoring section
     
  5. MarkHastings

    MarkHastings Executive Producer

    Joined:
    Jan 27, 2003
    Messages:
    12,013
    Likes Received:
    1
    Trophy Points:
    0
    Stephen,

    Is that like a country code? Is that also contained in the DVD-Rom section of the disc?
     
  6. Steven K

    Steven K Supporting Actor

    Joined:
    Jan 10, 2000
    Messages:
    830
    Likes Received:
    0
    Trophy Points:
    0
    Mark,

    At the risk of violating forum rules, I'd be glad to explain a bit although i'll try not to delve too technical.

    Commercial DVDs contain a file, called an IFO file, that contains a summary of the contents of the disc. Included in an IFO file:
    -number of "chains" of video (1 chain might be the main movie, another chain might be a trailer, etc...)
    -region code
    -audio streams
    -chapter info

    The entire package is wrapped up into one, or several, VOB files (video object). If you explore the contents of a DVD, you will see a folder, most likely called "video_ts" and inside of that you will find the VOB files (each VOB file has a maximum file size of ~1 GB, so most times VOB files are unmerged). The VOB file contains both the video and audio stream(s).

    The VOB files are encrypted... the only way to access the unencrypted data is to decrpyt it. The special section at the beginning of the DVD (the authoring section) contains a list of decrpytion keys. Your DVD player also has a unique decryption key of its own (some 400 of these keys exist). Because each player only has 1 decryption key (companies have to pay big $$$ to license one of these keys), the DVD itself has to contain all of the keys in order to avoid a situation where a movie has one key, and the player has a different key. The player then uses this key to decrypt the contents of the VOB file, and process the correct data.

    You may have heard of the infamous "DeCSS" algorithm, created by a group of hackers who call themselves "Masters of Reverse Engineering," which is used in DVD Ripping software (I wont mention any such program by name as this is in direct violation of forum rules). Basically, the ripping software uses the DeCSS (De-Content Scrambling System) algorithm to decrpyt the contents of the VOB file. The rippers also generate a seperate IFO file which the user can alter (to make a movie region free, for instance).

    I'm not in any way condoning or condemning this behavior, and the HTF has strict rules against posting any information about defeating copy protection. But, in this case, I think it pertains more to your original question than going into the specifics of defeating copy protection.

    A very good resource site for information is www.vcdhelp.com. If you have specific questions feel free to email me.
     
  7. Thomas Newton

    Thomas Newton Screenwriter

    Joined:
    Jun 16, 1999
    Messages:
    1,544
    Likes Received:
    35
    Trophy Points:
    1,610
     
  8. Steve Berger

    Steve Berger Supporting Actor

    Joined:
    Sep 8, 2001
    Messages:
    973
    Likes Received:
    3
    Trophy Points:
    110
    On the other hand ,if he is thinking of low volume needs or burn to order then DVD-Rs might work for him. He could approach it two ways ; buy high quality name brand blanks which have the best chance of working in most machines or go cheap but with a "no hassles" policy of replacing an unplayable disk with one of a different brand. A local company has been doing regional stock car races on DVD-R with no problems for about a year.
     
  9. MarkHastings

    MarkHastings Executive Producer

    Joined:
    Jan 27, 2003
    Messages:
    12,013
    Likes Received:
    1
    Trophy Points:
    0
    To address the DVD-R problem: My boss is probably looking for mass-distribution. I'm almost positive he wants to have me just make the master and then send it out to be pressed. We are working with a DVD consultant to get the proper equipment/training. I've already suggested that we probably use Sonic's Solutions and go for the Professional software, but my boss looks to me (initially) to figure out any issues that could arise in the future. I told him that buying a DVD burner probably wouldn't cut it because (even if we weren't doing mass-production), we'd still run into the problems with the discs not being compatible with some players. Right now, we send all of our DVD's to a vendor that gives us DVD-R's and I've had clients who couldn't play them on their laptops without first updating software...and this is (obviously) unacceptable for my boss.

    So, of course, my boss asked me why I couldn't make a DVD that would play in every player and all I could say was "DVD-R's don't play in most players because they are different than the ones you buy in the store"...I mentioned that the Hollywood DVD's are stamped and not burned (at least to make him understand for right now), but I just wish I had a better explanation for him.

    Steven K,
    I understand that we're not allowed to divulge "hacking" secrets, so I appreciate anything you can say (even if you have to generalize without getting too technical). What you've explained makes some sense, but remember, I also have to explain this to my boss who is even more illiterate to DVD authoring.

    My question is, don't DVD-R apps create the IFO files? If I understood you correctly, this is the big difference why DVD-R's are different than Hollywood DVD's? And if so, is it just that the "Home User" software doesn't create IFO files in the manner which they are sufficient for all DVD players?



    Buzz Vinard,
    I think we're leaning toward your example #1. I'd author the DVD and burn a DVD-R, then send it to a duplication house where they will take it from there. I just want to be sure that if I burn a DVD-R, that it is possible (for the dupe house) to turn that into an authoring disc? I assume (from your explanation) that it is.
     
  10. Jeff Kleist

    Jeff Kleist Executive Producer

    Joined:
    Dec 4, 1999
    Messages:
    11,267
    Likes Received:
    0
    Trophy Points:
    0
    All royalties would be included in your pressing cost. No worries on that
     
  11. Thomas Newton

    Thomas Newton Screenwriter

    Joined:
    Jun 16, 1999
    Messages:
    1,544
    Likes Received:
    35
    Trophy Points:
    1,610
    Mark,

    If

    (1) You are not interested in using CSS scrambling, or region codes, or Macrovision flags, on the final product, and

    (2) The material is short enough to fit on a single-layered DVD

    I would guess that any correctly-written DVD authoring application could produce a "General" DVD-R that is "bit-for-bit" what you would ship. The stages of (optionally?) making an "Authoring" master and of pressing discs would just be so you could ship the more-compatible, more-professional factory-made DVDs.

    If either (1) or (2) is not the case, you will need to look for a more high-end DVD authoring application -- and will probably need to invest in a Digital Linear Tape (DLT) drive. (Even the "Authoring" blanks are single-layer, so you need something like a DLT drive, or a virtual DVD image spanned over multiple DVD-Rs, to hold a dual-layered DVD image.) I am going here by the requirements I saw for Apple's DVD Studio Pro, which said that creating dual-layered discs required a DLT drive and sending the DLT tapes away to a pressing plant.

    I do not know if there are per-disc MPEG-2 or Dolby Digital royalties associated with commercial production of DVDs. That is something you would want to check out (a production plant should know that sort of information, or at least have pointers). There are per-disc fees if you turn on the flag(s) that direct DVD players to add Macrovision signal pollution to analog output.
     
  12. Thomas Newton

    Thomas Newton Screenwriter

    Joined:
    Jun 16, 1999
    Messages:
    1,544
    Likes Received:
    35
    Trophy Points:
    1,610
     
  13. Wayne Bundrick

    Wayne Bundrick Cinematographer

    Joined:
    May 17, 1999
    Messages:
    2,358
    Likes Received:
    0
    Trophy Points:
    0
    I don't think there are per-disc royalties on MPEG2 or Dolby Digital. If that was the case then you would owe a royalty on DVDs you burn yourself, and you certainly do not. MPEG2 and Dolby royalties are collected on the sale of encoders and decoders.

    There is a per-disc royalty on Macrovision, and I think on CSS as well. The production plant will certainly include it in your bill.

    But the MPEG Licensing Authority (MPEG-LA) wants to collect per-use royalties on the MPEG4 codec, both per-disc and on every Internet stream. As a result, much of the industry has given MPEG4 the cold shoulder, and if MPEG-LA isn't careful the next big thing is going to be another codec that doesn't include a tollgate.
     
  14. MarkHastings

    MarkHastings Executive Producer

    Joined:
    Jan 27, 2003
    Messages:
    12,013
    Likes Received:
    1
    Trophy Points:
    0
    I realize that a DVD-R is only going to give me 4.7GB, but the DVD's we're going to produce are only going to be about an hours worth of material, no 5.1 or DTS (probably just the bare minimum 2.0 surround) and no extras, so I believe I am safe with a single layer.
     
  15. John_Berger

    John_Berger Cinematographer

    Joined:
    Nov 1, 2001
    Messages:
    2,489
    Likes Received:
    0
    Trophy Points:
    0
    No belief. You are safe with single layer. If I remember correctly, when DVD-R was first announced being able to store one hour in DVD quality was a main marketing phrase. One hour of video on a DVD-R is very nice bit rate (around 8000 Kbps), especially if you use Dolby Digital instead of PCM and put the saved audio space towards the video bit rate.

    I've actually created DVD-Rs with three hours of video on them and they look pretty damned good except for scenes with a lot of movement in the frame.
     

Share This Page