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Copying A DVD To A CD?

Posted by Hemos on from the major-compression-goin'-on-in-here dept.

Kreed wrote to us about an article on Tom's Hardware that details the process of compressing the content of DVDs down to CD length. Pretty cool compression.

8 of 311 comments (clear)

  1. Other great techniques by Voltage_Gate · · Score: 5

    My idea is to scan a DVD into Photoshop, then resize it way the hell down and burn it onto a cd. Or even better, just photocopy the disc, cut out the circles, and glue or tape them onto some of your old AOL promo discs. Try it, it works!

  2. FlaskMPEG legality? DeCSS? by barracg8 · · Score: 5
    • Warning:
      The author declines any responsability from the use of this program. This software can not be used with copyrighted material because doing so, would infringe many laws all around the world.
      The author doesn't intend to promote piracy by any means, and the scope of the application is limited to video processing tasks with home made digital video material.
    This is kinda like selling guns unrestricted and saying "please don't shoot anyone, cuz that would be against the law". Oh wait, you guys already do that. ;-)

    Joke, okay. Calm down and don't flame.

    But seriously, I want the ability to back up my DVDs, and play them back on machines without DVD drives, in exactly the same way that I can backup audio CDs to tape, and play them in my car.

    I don't see anything in the least bit illegal about FlaskMPEG, but I'm sure that the MPAA lawyers will be doing their best to take a different view on that.

    I wonder whether this could have any impact on the DeCSS situation? Surely, it would be better to let people view DVDs unrestricted under Linux, rather than be a pain in our ass and encourage us to start backing our DVDs up on CD.

    cheers,
    G

    1. Re:FlaskMPEG legality? DeCSS? by Ho-Lee-Cow! · · Score: 5
      This is kinda like selling guns unrestricted and saying "please don't shoot anyone, cuz that would be against the law". Oh wait, you guys already do that. ;-)

      I think that the general problem here is that there is a perception that you cannot own and use tools in a responsible manner. You cannot outlaw a screwdriver because someone in Timbuktu used one to commit murder, rape, or burglary, because screwdrivers have legitimate legal uses. Guns, screwdrivers, and DeCSS/technology of the moment are tools. Do we outlaw them because our world has decide that because there is an illegal use, that these things must be outlawed?

      Personal responsibility is the issue. Does someone become a dangerous criminal solely because they have a legally purchased and safely stored firearm, screwdriver, or copy of DeCSS(used for watching their legally purchased DVD on the Linux machine that is their only computer)? At what point does the government overstep its bound in quelling the fears of the 'people' when they remove legal ownership and access rights on the basis of spurious claims of lost revenue streams by corporations who are not being held accountable for their claims of loss?

      What truly justifies things like Carnivore, if not the 'compelling interest' of a would be police state? Yes, Carnivore -could- be used in ways consistent with the Constitution, but who trusts an organization whose headquarters is the J. Edgar Hoover Building? I can assure you that Freeh is even less ethical than his infamous predecessor.Or whatever? Wanna bet we have a long legal fight before we get this tool outlawed?

      At the core of the American system is the struggle of the common man to use the things he owns versus the 'compelling interest' to protect the revenue streams of Tine Warner and Disney. Corporations are not citizens and should not have the ability to vote, but they do--it's called money. Citizens have the ability to vote and often don't, because they are being brainwashed by corporations NOT to. Think for a moment on the current protests in the UK and Europe about fuel prices.

      Think about how mad those people are. Realize that the Prime Ministers of most of the EU are defying the people to rise up in rebellion. Think about the parallels in the MPAA and RIAA. What is going to happen when they finally get what they are begging for?

      --
      In space, no one can hear you moo.
  3. I've Tried It: by Dlugar · · Score: 5

    Back when DivX;-) first appeared, I took a DVD, a handful of programs, and a lot of spare time to see what I could come up with. Here are my results:

    • It's not really that very difficult.
      But it's not that easy, either. If you're a CS major, you should be able to do it in three or four hours. If you're an average Joe, good luck. You'll need it. MPAA, your day is coming, but it's not here yet. (See below.)
    • Fast Computer Needed
      No kidding here, guys. On a PIII 350mghz, playback was choppy. Tom here used an 800mghz Thunderbird. You probably need around that to get decent playback.
    • Time
      It took, on my aforementioned PIII, about seven hours to encode half an hour of Wallace and Gromit. Even with a smokin' computer, you'll probably need to let it run for a while.
    • Quality
      It's not perfect, guys. Especially in scenes with lots of movement of colours (like an explosion), you get some fuzzies. It's about the quality difference from mp3 from cd, though, I'd say. I certainly wouldn't mind watching a movie in DivX;-) format, but it's no home theatre.
    • DeCSS
      DeCSS makes it easy to rip a movie quickly, but other programs exist that are just as simple. I've heard rumours of one that brute-forces the key to the DVD--anybody know about this one? At any rate, I don't think it can be argued that DeCSS's even main purpose is for this sort of thing. It's obvious that DeCSS is used more often for some easy-listening music and t-shirt wear than for piracy.

    • Conclusion:
      MPAA, your day is coming. But take note that it's because of DivX;-), just like the RIAA's problems are mp3 (not RealJukebox). As for DeCSS? You're barking up the wrong tree with that one. Of course, if you're worried about people disabling region codes and/or watching their DVDs on their Linux machines, DeCSS is your man.


      Dlugar, bearer of the spork

    --
    Computer Go: Writing Software to Play the Ancient Game of Go
  4. Fractals and Wavelets and FFTs, oh my! by Crutcher · · Score: 5

    Really, we know how to do GOOD video compression, we just don't have the space/time to do it with modern computers.

    I mean, if you do the following, you'll get great encoding, but it is EXPENSIVE.

    step 1: drop the color space resolution in half, the eye can't see it. (this is the first step in JPEGs)
    step 2: Resample the image in time to 30fps (this is ideal)
    step 3: resample the image in space to a hexagonal, instead of a rectangular grid, this spreads the corner distance problem.
    step 4: resample at half the luminance resolution, compress, but cycle the resampling offset in time. Persistance of vision reconstructs the proper luminance map.
    step 5: search the (much reduced by this point) 3d matrix for domain/range mapings (this is the fractal step, it takes much processor power) You probably need to select smallish block sizes for this in time, or it gets much harder. Of course, the bigger the chunk you encode at a time, the better the encoding ratio.

    and to view it, just reverse steps 5 and 3.

    Its kind of like strong AI, its easy to say 'search for domain/range mappings', and it's easy to write code to do it. It just takes more memory and processor time than we have available to give useful results.

    -- Crutcher --
    #include <disclaimer.h>

    --

    -- Crutcher --
    #include <disclaimer.h>
  5. Re:Inevitable DeCSS parallel by RedWizzard · · Score: 5
    You're argument is based on the assumption that you need DeCSS in this process - you don't. Up till now everyone has assumed that people will want to keep the video in MPEG2 format. After all why re-encode in something else when it'll only lower the quality? MPEG4 is the answer - because the result is 10-15 times smaller. If you're going to re-encode it then you don't need an MPEG2 stream so you don't need DeCSS - any decoder software will do. You just need a means of capturing the decoder's output.

    The result is that the MPAA's assertion that the DeCSS case is about piracy is gone. It was never true anyway but now any fool can see it for what it is - a smokescreen. So this actually helps the DeCSS defendants.

  6. Re:He calls that "hardly noticeable" !?! by Flounder · · Score: 5
    Don't get me wrong, this is very cool tech, and I'm glad it leaked into our hands... this tech has it's place, but it is NOT a drop-in replacement for DVD discs...

    The quality is just not there.

    You're right, it isn't a replacement for DVD. It wasn't meant to be. Just like MP3 isn't meant to be a replacement for CDs. It's a great way to compress the file down to be easily transferrable across the internet.

    Compressing an 8GB file to 700MB will be lossy, and there's not much you can do about it. However, I'm willing to trade some picture quality for portability. I can burn several CDs with movies and watch them on the road on my DVD-less PC.

    Besides, I'm spending $40 a month for this cable modem. At least I'll never have to rent another video.

    --

    No boom today. Boom tomorrow. There's always a boom tomorrow. - Cmdr. Susan Ivanova

  7. More DiVX info than you probably wanted... by Anonymous Coward · · Score: 5

    I've been downloading nAvi and DiVX for quite some time now and even lately have been hitting up the local Blockbuster for DVD's to rent and rip to DiVX ;-). I will say that I am suprised at how many people havent heard of the mpeg4 (divx) codec as of yet around here since the readers here at slashdot are supposed to be on top of this sort of thing, but anyway, i guess some of you guys have jobs lol. anyway, a few points...

    - Tom's hardware exaggerates when they say the quality is almost unnoticable. In order to fit an entire movie onto one 700 MB CD you have to set the video bit rate at about 700kbits/sec. Even then, the DiVX codec will compensate for high motion scenes by raising the bitrate and will lower the bit rate for still scenes with only talking. However, the difference between a movie encoded at this bitrate and the DVD is still quite noticeable in scenes where there is a high amount of movement, and even in low motion scenes the background begins to look blocky since the compression algorithm somehow determines that the background data isnt as important as the foreground.

    - another good thing about the DiVX codec is that you can use the new WMA 2.0 audio codecs for extremely high quality audio compression which crunches down 2 hours of audio in to approx 60 MB. the difference in the audio quality is negligible to me, but then again, i dont have a 5.1 surround system (you can only encode to WMA at stereo or mono).

    - you STILL have to decrypt the movies using either DeCSS or a program similar to this. I've started to use CladDVD 1.6 over the past couple of weeks or so since it parses the VOB files as it decrypts them to check for multi-angle scenes and the sort (which can REALLY screw you up when ripping a DVD by desynching the audio and video). my method has been to decrypt using cladDVD, encode to DiVX using FlaskMPEG with PCM audio, opening the audio in sound forge and normalizing it (flaskmpeg has a bug in the latest version which causes the volume to be quite low), and then multiplexing the divx audio with the new normalized sound file with Virtual Dub (which will also compress the audio at the same time to your format of choice).

    - this process takes TIME!!! an hour to decrypt the VOB's...10 hours or so for a 2 hour movie to encode in flask (my p3-550 averages about 4.71 frames per second)...an hour to normalize the audio, and another 20 minutes to create the final avi with the normalized audio track.

    - everyone saying that you need an 800Mhz machine to playback DiVX is misinformed. My p3-550 plays them back just fine. i also have a friend with a k6-2 500 that is able to play them back without dropping frames.

    - TV out on your video card is a MUST, unless you want to watch movies on your monitor. there's been rumors of a DiVX player for the Playstation 2 (oh, goh, i will have died and gone to heaven if that ever comes to light). until then, there are NO standalone divx players : (

    here's some links for more info...

    DiVX: http://divx.ctw.cc http://www.gdivx.com
    FlaskMPEG: http://go.to/FlaskMPEG
    VirtualDub: http://www.geocities.com/virtualdub
    Divx-digest: http://www.divx-digest.net/

    RACK ME!!!!