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Copying A DVD To A CD?
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.
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Reviewing something for the pure geek nature of it all, regardless of the wrath the RIAA will bring down ;)
:)
Yeah.. let's see them try to silence Tom
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!
Compression ratios like that make me very happy. Any guesses to what ogg video will look like? I'm anxiously awaiting ogg vorbis (audio format) myself. I hope this project catches on, because I would like to see a suite of fully-opena and free multimedia formats. Vorbis promises to be very flexible, and it would be nice if we could get the same kind of compression in MPEG-4 into a free package, and this looks like it could be the outlet for it, with the right modifications.
WARNING: there is a trojan on your
In a year's time, most if not all new PCs will be shipping with DVD drives. And most of those who have not upgraded will not be target customers for the pirate CDs this will presumably produce. Likewise, anyone who uses this technology for their own copying obviously already has a DVD drive.
So who would really use this?
Seriously...speaking of DivX encoding (or MPEG-4 or whatever you want to call it) will all you people out there stop leaving these files with the .AVI extension? Is it that hard to put use a new extension like .divx or .dvx? Are Windows users that lazy that they can't be bothered to register a new extension to Media Player? Maybe we need to get some of those DivX warez groups on IRC to change the name of the file before they release them. Just imagine the chaos that would ensue if people started releasing .WAV files encoded with using the MPEG-1, Audio Layer 3 codec instead of .MP3 versions.
= -=-=-=-=-=-=-
PS - I'm looking at you Microsoft. Quit naming a billion files ".DOC" when not single version is intercompatible.
Bleah! The one thing I miss from the Macintosh is the fact that every file had a four byte header that identified the type of file so that this whole extension mess was unnecessary.
- JoeShmoe
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-- I wonder which will go down in history as the bigger failure: the War on Drugs or the War on Filesharing
- Warning:
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.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.
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
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:
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.)
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.
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.
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 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
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>
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.
It was explicitly mentioned in Judge Kaplan's decision that one of the concerns the MPAA raised over DeCSS was that it would enable people access to the content of the DVDs and thus it would be possible to compress the entire movie to a size which would fit onto a CD. He then went on to say that since blank CDs were about $1 a pop that the risk of piracy was very much increased.
However one of the MPAA's arguments to distinguish copying of DVDs from copying of video cassettes was that there would be no degradation of quality since everything was "digital". This degradation was important in allowing fair use copies and the like.
So is a CD copy of a DVD fair use? It's certainly a degraded quality and is conceptually almost identical to taping a music CD to use in the car.
My 2 cents is all I have.
:wq
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
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!!!!
I think tkhe perfect culmination of all of this would be a MPEG4 copy of Valenti shooting an eggroll out of his arse when he finds out about this program. I'd pay quite a pretty penny to witness that, firsthand... Ten bucks says he keels over on the spot. Preferably after the eggroll, tho.
.02
My
Quux26
My
Quux26
www.crashspace.net
recompress dvds, that is... :-)
:-) files is considerably (and very noticeably) below DVDs if you're squeezing the movie into a CDROM-sized disk. Many folks who do this scale the frame size down, which greatly improves image quality. If you don't, almost anyone would notice the extremely-obvious compression artifacts. I've found that using the "low motion" codec with bitrates of 1900-2100 kb/s works very well, and is very acceptable. You'll notice artifacts in scenes where the codec is having to make tough choices about where to spend its bits (like scrolling credits with live action behind them), but the result is otherwise *very* good. This gets you movies around 1.5GB (depends on length, etc...) that are too big for a CD, but fine for a HD.
.IFO files to rip just the files needed for the main video stream, Macrovision removal, etc...).
:-) distribution is also "illegal", in that I think it includes pirated codecs (ie, the Fraunhofer "professional" quality MP3 encoder).
I travel for work a lot, but my laptop doesn't support an internal DVD drive. So rather than lug DVD's and a clunky external drive around with me, I recompress and put them on the HD. Decompress speed is just fine on the laptop's 500MHz PIII once it gets going, but it is jerky for about 20 seconds until everything gets buffered and cached correctly. I know the MPAA disagrees with me, but I see this as fair use...
Anyway, a couple of points to add:
1. Video quality of DiVX
2. As you mention, DeCSS is not the best way to rip DVDs anymore. I much prefer "cladDVD". Other than the short delay to brute-force the encryption key (which is often almost instant) it's just as fast as DeCSS, is considerably easier to use, and has more features (like interpreting the
3. Besides DeCSS, the DiVX
4. How hard or easy doing this is depends on the movie. Fancy releases like the Matrix and T2 are hard because of all of the extra crap thrown in, especially multi-angle stuff. Subtitles are a real pain in the neck too. A few movies have poor telecining (the process of taking a 24fps movie and converting it to NTSC) that can't be removed. I won't go into the details, but the result is a crappy-looking conversion because every few frames is the interleaved result of the two two frames immediately before and after it. This is really annoying on a non-interleaved display like a computer monitor.