blogged bulbs in the web-void
  
Version 00.5, January 2006
Searching for dvds and dvd Information
by Giggle the DVDs Gideon
Heavily edited by fravia+


first published at searchlores in January 2006

Part of the searching essays & of the targets sections.


Introduction
DVD searching
The "zones" (regions) scam
Differences between DVD-R and DVD+R
Bastards: Macrovision clowns and DVD GPL thiefs
Comments and additions


Introduction 
De rerum naturae

"DVDx. I'll repeat it: DVDx.
That's almost all you need to know
"

Caveat: some of the techniques and tricks explained in this essay may only be used if your country's legislation clearly allows it... else move to a country where you are allowed to do it. The world is big and you should always respect those pesky indigenous laws if you don't want to be eaten by the natives.

Dvds (Digital Video Discs) started around 1997, given or taken one year, depending from where you live.
A single-layer DVD can store 4.7 GB, which is around seven times as much as the capacity of a standard CD-ROM. On the other hand a DVD "speed" factor equals nine CD "speeds factors," so an 8x DVD drive has a data transfer rate similar to that of a 72x CD drive. Rule of thumb: a dvd is around 8 time worth a CD :-)

Alas! In their greed, the commercial powers that be have managed to introduce FOUR commercial scam methods inside the dvd format, whose aim is to restrict the user in various ways: Macrovision & CSS (scrambling techniques), region codes, and disabled user operations (UOPs).

We could add to this the Remove Copy Generation Management System (CGMS) annoying flags which cause DVD recorders to display an error message stating that the source "is copy protected and cannot be recorded" (which of course isn't true)

All these scams can be reversed, the user can thus be able to read his own disks, even if he bought them in Singapore or in Brasil.

The (weak!) CSS Content Scrambling System copy protection system used on DVDs, was famously cracked by a then-15 year old Norwegian boy: Jon Johansen - and a couple of years down the line, the lawsuit brought against him by the movie companies was successfully defeated (and DeCSS is now declared legal in Norway).
CSS has hence been once for all nullified by the holy Decss
The DeCSS system of decrypting the encrypted .vob files on all DVDs is the key to grabbing the raw audio and video from the disc to either encode to a "DivX" video file (distributable over the Internet due to its excellent compression) or, as is becoming more popular nowadays, to copy to another (recordable) DVD with a DVD burner (and the appropriate software). There are many companies now offering tools to copy (or 'backup'... heh) DVDs to either another DVD or a CD (DVDs copied to CDs are technically VCDs in MPEG video format, as CDs can't store enough data to preserve anything like the original quality of the DVD). But you can totally ignore the commercial sellers. As usual on the Web, there's also some excellent FREE pieces of software that will let you do this backing up process, such as DVDShrink, available from http://www.dvdshrink.org - an essential piece of free software to add to your seeker's DVD copying toolkit.

DVDx, on the other hand, allows you to convert DVD to VCD2.0 or SCVD1.0 or AVI in one step (Including multiplexing and splitting). Hence it produces good quality movies in MPEG1/2 format

The amount of "time" a DVD can hold depends of course on the quality of the video: we are speaking about billions of pixels flying around.
For the best quality video, a DVD can hold something in between 60-120 minutes worth of video.
If a person encoded at VHS (low) quality, you can get as much as 300 minutes (5 hours) worth of video on a DVD. Note: this is for a single sided DVD-R. See below for different capacities.

DVD searching 
A tour of the house

Ok, "zugegeben", of course you need to find some dvds to play with, if you want to test your approaches and the responsivity of your DVD players. Besides this essays makes sense BECAUSE seekers search for (and find) their DVDs mostly on the web and rarely inside the shops.

We may distinguish software (mostly games) DVDs from film DVDs, but the finding techniques themselves are mutatis mutandis VERY similar.

The usual combing paths: irc, ftp, blogs, P2P channels, torrents, rapidshare-alike services, usenet groups and social engineering and trolling capabilities are required. Going local could also help.
As usual, the "popularity" of a target will be directly proportional to its signal (and to its noise as well) and inversely proportional to the searching time you'll need to invest.

Of course, once you have found your DVD, you'll need the software to copy it. Alcohol, Nero, AnyDVD, Blindwrite, Clone, CDRwin, Isobuster etcetera are all commercial (and yet easy to find everywhere), but there's also a plethora of good free and open source software around as well (like DVDshrink).

The "zones" scam   
How they annoy even zombies and how anyone can defeat annoyances


Each DVD-Video disc contains one or more region codes (sometimes called zones), denoting the area(s) of the world in which distribution and playback are intended. The commercial DVD-Video player specification dictates that a player must only play discs that contain its region code. In theory, this allows the motion picture studios to control the various aspects of a release (including content, date and price) on a region-by-region basis. In practice, many DVD players allow playback of any disc, or can be modified to do so.

DVDs are typically set to play in one of 8 "regions" of the world (actually only 6 real "regions", but they have two more: 7: "Reserved for future use" and 8: "International venues such as aircraft, cruise ships, etc").
You can often switch the region of most DVD players a few times just in case you move, etc, usually five times. But you can also find a "hidden loophole" option that will allow you to switch everytime you like! In fact, since the setting of the region of the player is really done by the player's own software, there are almost always hidden "Loopholes Menus" in the OS software that, if you know how to get into them, will allow you to change the region of the player so it will recognize all discs. The cost of producing separate players for each market would be too high: the switches are somewhere in the software.

A favorite setting, and one you should choose whenever possible, is "Bypass". If you set your Region ID to Bypass you will not encounter any problems. It has been reported that a few discs out there are very picky and will not play properly in Bypass mode.
Each TV-DVD player has it's own unlock code for playing any region(bypass) or a specific one:
for the "Apex 600A", for instance, it is [Setup] » [Preferences] » [Step] » [<<] » [>>]

For Shinco DVD players (older firmware), instead, the sequence is [stop] » [setup] » [pause] » [1] » [2] » [3]

For Thomson DTH-222 players: [1] » [6] » [7] » [1] » [9] and a text shows up with the current region. Press [0] for "All regions" and you're done.

And so on, and so on: for the DANSAI DVD-952: [SETUP] » [STOP] » [PREVIOUS] » [NEXT]
Choose now a regional code [1-6] or the [Bypass] jolly and deactivate the MacroVision crap.

Clearly it would be absurd to go through thousands of different models, and it is actually NOT necessary. Most DVD players are based on teh SAME chipset. Chances are that those same chipsets will also have analoguous unlocking codes :-)

Of course -once accessed it- through those same "loophole" menu you can also disable the macrovision copy protection crap.

For COMPUTERS, the problem is solved in a much easier way using any good software that will allow you to to change the region of the player so it will recognize all discs, for instance the commercial (but easy to find regged on the web) DVDX player professional: "the first region-free/code-free software DVD player in the world. Through this player you can play all region DVDs on all DVD drives even if you have changed the region code 5 times. You needn't hack DVD drive (flash firmware) which is very dangerous. DVD X Player's Macrovision-free feature allowing you view DVDs through your TV-out device without obstruction or distortion. You can skip the FBI warnning easily when enable the Operation-free option in DVD X Player. DVD X Player is also a full-featured and easy to use DVD player integrating all functions of a standard DVD player" (their own blabbering :-)


Differences between DVD-R and DVD+R   
Must know technicalities


DVD-R:
Benefits: Better DVD playback compatiblity within home DVD players.
Drawbacks: Older technology and less money behind the format means that they come out with faster media and burner technology slower. You will frequently see DVD burners that will support (for instance) 16X DVD+R and only 8X DVD-R.

DVD+R:
Benefits: Faster speeds, more inovations like Double Layer discs (8.5 GB)
Drawbacks: Will not play is some home DVD players. If you know your home DVD player will play DVD+Rs then there is no reason to not use them.



Bastards: Macrovision clowns and DVD GPL thiefs   
The evil within


Macrovision scrambled eggs


The NTSC video standard (the broadcast standard used in North America and Japan) is defined with a 525-line vertical resolution. However, only 480 of those lines are used for transmitting video information. The extra 45 lines are used to carry control codes (such as interlace information), closed captions, and other similar non-video content. Macrovision copy protection works by adding certain codes to these control lines that are interpreted by an Automatic Gain Control chip in a VCR or DVD to scramble the video signal if the video is being recorded.

Now, unfortunately, despite all the claims that DVD produces the best quality image available, it is well known in technical circles that the image quality from DVDs could be even better. Most TVs use a technique called interlacing: rather than drawing each of the 480 visible scan lines every frame, only 240 are drawn in an alternating pattern. Since DVD is a digital format, it is actually possible to output all 480 scan lines at once, and on high-quality TVs (which have Progressive inputs, in addition to composite and S-Video), such images are much more stable than interlaced images. DVDs implement Macrovision by attaching a small code to the video stream indicating whether or not to enable Macrovision protection. Then, when the DVD player outputs the frame, it adds Macrovision codes to the frame; however, due to technical limitations, it has proven extremely difficult to create a DVD player that can output 480 scan lines per frame in addition to Macrovision control codes. Because this could potentially allow unscrupulous users to connect their DVD players to computer-based recording devices and create perfect copies, the MPAA and DVD Copy Control Association bastards (DVD CCA) stalled for years the release of progressive-scan DVD players.

Note also that the sale, purchase, or manufacture of any device that disables Macrovision copy protection has been rendered illegal since 2002 (under section 1201a of the Digital Millenium Copyright Act) by the political lackeys of the commercial powers that be.


DVD GPL thiefs

There is also -for dvd related programs- a plethora of bastard soidisant programmers which take open source programs and simply modify a little their appearance in order to scrap money from the zombies. More than a dozen open source programs were ripped off, from DVDx to CDEx. This underlines the importance of pointing people to the REAL open source programs, bypassing the commercial vultures (and the same time the importance of reverse engineering software to individuate the bastards).



Comments and additions   

Winky's comment, January 2006: "a little more info for people to search


A very large subject.
Essay is a good essay.

A good book for a superfical view of how dvd is organized is McGraw-Hill DVD Demystified. It shows the arrangement of dvd. Etc. It offers atleast some background info.

From a user perspective the problem is using a commerical dvd player.
A possible solution would be to use a puter based dvd player such as videolan,
xine or a gstreamer based one. Get a TV out card, or buy a lcd projector and hook it up to ur puter and you are in buisness.

videolan has the advantage it runs on the most platforms. Xine is the best for linux. And gstreamer, the new guy on the block, is basically making pipelines for media (DVD support for 0.10 version is still not available).
For all of the above programes they work with libdvdnav to read the dvd. (libdvdcss is used to break the encryption). The cvs version of dvdnav emulates a dvdplayer.

The data from the libdvdnav has to be demuxed (split in the various streams which make up a dvd)

Dvds are very complex.
Video on DVDs is stored in Mpeg1 or Mpeg2. (video)
Audio in older dvds was stored in Mpeg1 or Mpegs (audio) but in most modern dvd is in dts or ac3. (ussually there are other encodings).
Subtitles are also in another stream.
(Codecs and above list a far from complete, just to give reader an idea)

Demuxer is responsible for splitting into the various streams.

After the data is demuxed it is fed into the appropriate codec, (Mpeg Video) ac3 etc.

Then the decoded data is fed into the appropriate output device.

If you wish to examine a byte to byte basis how demuxing occurs take a look at the xine source code for the mpegdemuxer.
If you wish to see how dvd is encoded look at libdvdnav and libdvdread (which is what dvdnav is based on)

Another point I should have mentioned is DVD is based on a subset of mpeg. (Not sure which one :) ). Mpeg standards are very large. They cover storage of muxed streams, and also how each individual stream is encoded.

There is also -for dvd related programs- a plethora of bastard soidisant programmers which take open source programs and simply modify a little their appearance in order to scrap money from the zombies. More than a dozen open source programs were ripped off, from DVDx to CDEx. This underlines the importance of pointing people to the REAL open source programs, bypassing the commercial vultures (and the same time the importance of reverse engineering software to individuate the bastards).

It is a correct statement, but an unfair one. Downloading libdvdnav from cvs, recompiling etc, is beyond most peoples abilities. Also for legal reasons libdvdcss has to be compiled seperately and linked into libdvdnav (not a simple task on windoze). The only way I personally was able to do it was by making my own scons (a python form of make) for libdvdnav. Linux it is easier :).

Comercial programs wrap things in a nice self contained package. There are exceptions but more open-source programs to be used, the user has to have some experience with autoconfig make gcc etc :).

Anyway it was a good essay. The ammount of info on dvd could fill several books.

Also could be mentioned is other formats for storing media. Matroska (i like this one the best, most flexable, and has idea of titles/chapters etc. Ogg etc.

Also could mention video codec (theora, vidx, x264) and audio codec (vorbis is best, speex is best for audio).

Avi is a shit format made by MS. Do not use it :). Avi is also not suitable for variable rate codecs.

Anyway the above just is off the top of my head. Hopefully it will give a little more info for people to search.

;) (Winky)


Comments, suggestions and addenda are welcome, awaited and required

Petit image

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