Compression experiment

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  • The Maynard
    Super Member
    Super Member
    • Jan 2003
    • 260

    Compression experiment

    I am currently doing a little experiment in DVD copying. This all stemmed from my re-edit of Jay and Silent Bob. I could've swore that the original size of the original cut of the movie was around or over 6GB.

    Then after I ripped it I had to convert it to a high definition Divx format. After this compression it went down to around 5GB.

    Then I cut in all the deleted scenes and redid all the audio. Then after I merged in the finished audio with the finished video it was a little over 5GB still.

    Then I used the program DivxToDVD which takes any video files and converts them to the VOB structure of a DVD. Then I used Shrink to make the ISO and burn it. But when I opened the VOB files in shrink it said that the total size of the disc would only be 3.5GB. After I burned it and watched it I noticed that, even though it was only in stereo, it sounded very good and the video was EXACTLY DVD quality. There was no instance of blockiness or compression noise.

    My whole point to this is that using Shrink to compress a movie on to one DVD+R usually adds in compression noise. As long as the compression stays anywhere over 75% it's not really noticable...but it IS noticable to me.

    So I am thinking that, for those really special movies (like Star Wars and LORT) that you could rip the movie, convert to High-Def Divx, merge the 5.1 audio track into the Divx and re-encode the Divx back to the normal DVD VOB structure and maintain perfect DVD quality while cutting the file size down by almost half.

    So right now I am testing this with the movie National Treasure. I set it up to convert to Divx over night. This morning I am merging in the 5.1 audio file which it's almost done now. Then I will convert it back to DVD format and we'll see.

    I will post my data when it's all said and done.
  • setarip
    Retired
    • Dec 2001
    • 25141

    #2
    "I could've swore that the original size of the original cut of the movie was around or over 6GB."

    "But when I opened the VOB files in shrink it said that the total size of the disc would only be 3.5GB"

    Have you taken into consideration how much of this reduction may be due to elimination of audiostreams?

    Comment

    • The Maynard
      Super Member
      Super Member
      • Jan 2003
      • 260

      #3
      Yes, I have. The J&SB size, with the one audio stream that I had wanted, I think, was the size that I mentioned above. Again, I didn't write any of this down and I no longer have the original DVD so I can't check it myself. That's why I'm doing this little experiment.

      Comment

      • setarip
        Retired
        • Dec 2001
        • 25141

        #4
        "I no longer have the original DVD"

        Comment

        • The Maynard
          Super Member
          Super Member
          • Jan 2003
          • 260

          #5
          Very good.

          Comment

          • The Maynard
            Super Member
            Super Member
            • Jan 2003
            • 260

            #6
            Now that we're done (for now) with the customary positive, happy remarks from Setarip, I'll post the numbers. Pics will follow shortly, as soon as Shrink is done doing its compression thing. The pics will be taken using PowerDVD.

            Movie: National Treasure
            Original full disc size: 7.38GB
            Original Main Movie file size with only one audio track and no subtitles: 5012MB
            Compression percentage needed in order to make it 4464MB: 96.2%
            Ripped file size: 5.17GB
            File size after converting to Divx (no audio): 4.84GB
            File size after converting to Divx (with 5.1 audio): 5.26GB
            File size after converting back to VOB format: 3.22GB

            So the final size of the Divx disc would be 3.22GB and the Shrink disc would be 4.46GB.
            Last edited by The Maynard; 18 Jul 2005, 04:58 AM.

            Comment

            • The Maynard
              Super Member
              Super Member
              • Jan 2003
              • 260

              #7
              Here are the pics. THey are uncompressed BMP so you can see how they really look without further JPEG compression. They are also not incredibly dialup friendly.

              Personally I think that the Divx pics look better than the Shrink pics and the DVD is alot smaller than the Shrink version is. Granted, this process takes ALOT longer but I will use this on those certain movies, like LOTR and Star Wars, to get a much better looking compressed DVD. Take a look and come up with your own conclussions.
              Attached Files
              Last edited by The Maynard; 18 Jul 2005, 04:58 AM.

              Comment

              • LT. Columbo
                Demigod of Digital Video
                • Nov 2004
                • 14427

                #8
                what happened to the original dvd?
                "One day men will look back and say I gave birth to the 20th Century". Jack The Ripper - 1888
                Columbo moments...
                "Double Shock" "The Greenhouse Jungle" "Swan Song" FORUM RULES
                "You try to contrive a perfect alibi, and it's your perfect alibi that's gonna hang ya."
                (An Exercise In Fatality, 1974)


                Comment

                • The Maynard
                  Super Member
                  Super Member
                  • Jan 2003
                  • 260

                  #9
                  Why do you ask? It's funny how, out of everything that was posted here, data, ideas and pictures that this is the only thing that has peaked anyone's interests. What was posted has, in no way, violated the rules of this board, especially rule #6. Saying that I no longer have the original DVD is no different than saying "I downloaded a movie and want to know how to burn it to VCD."

                  So, to answer your question as to what happened to the original I just have to say that it's none of your concern.

                  Comment

                  • setarip
                    Retired
                    • Dec 2001
                    • 25141

                    #10
                    To The Maynard

                    "the only thing that has peaked anyone's interests."

                    That's simply untrue.

                    Re-read my first post in response to yours...

                    (By the way, the word is "PIQUED")

                    Comment

                    • setarip
                      Retired
                      • Dec 2001
                      • 25141

                      #11
                      (At the risk of eliciting more "deflective" remarks)

                      "Saying that I no longer have the original DVD is no different than saying 'I downloaded a movie and want to know how to burn it to VCD.'"


                      Naah. You might want to read the "signature" of moderator "cynthia", regarding DVD media:

                      "All programs is to be used for backing up personally owned copies of DVD media, any other use violates international copyright laws and also the rules for this forum, any questions regarding copying rentals or anything that intones the media is not owned by that person will not be answered and the thread will be locked due to the forum rules. Please be nice to each other when you post."
                      Last edited by setarip; 18 Jul 2005, 10:17 AM.

                      Comment

                      • The Maynard
                        Super Member
                        Super Member
                        • Jan 2003
                        • 260

                        #12
                        I understand that. But nothing in what I wrote implies that I got this via illegal means. If it's OK to say that you downloaded a movie then it's OK to state that you no longer have the original. Afterall...isn't this the purpose of creating backups? In case something happens to the original. It could've been broken, stolen, misplaced, scratched, eaten by a pack of rapid dogs, lost in a breakup or divorce etc.

                        I didn't state it in such a way as to imply that I rented it and copied it or that I owned it, copied it and then sold the original or anything along these lines. Simply that I no longer had it. I will not entertain everyone's paranoia regarding the current location of the original so you all can take it to mean whatever you want it to mean.

                        Comment

                        • The Maynard
                          Super Member
                          Super Member
                          • Jan 2003
                          • 260

                          #13
                          Now, back to the prior topic. Personally, I think that this movie may not have been the best one to do this test on because the Shrink version only had 96% compression ratio. I think a better test would be one that would require 75% or lower. But even though the pics are very similar in quality (actually they both look kinda crappy when using the capture option of PowerDVD) I think the Divx one looks a little bit better. I'll set a movie up to convert over night and see what results that one yields.

                          I started this thread as a possible option to create superior looking compressed DVDs, not bickering amongst elitests who have nothing better to do than nitpick over mundane details and misspellings. If this is all that anyone wants to contribute than please save it. There was no violation of the rules here. So let's keep this on topic.

                          Comment

                          • setarip
                            Retired
                            • Dec 2001
                            • 25141

                            #14
                            "nothing better to do"

                            There you go again. Your initial post WAS responded to...

                            Bye

                            Comment

                            • The Maynard
                              Super Member
                              Super Member
                              • Jan 2003
                              • 260

                              #15
                              I'm not refering to your original response. I'm refering to every other response since then. Since your initial response, every other response fits in with the "nothing else better to do" catagory.

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