usually limited, and every viewer connected to a single drive/decoder must watch the same thing at the same time.

Many companies provide support for streaming video (MPEG-1, MPEG-2, MPEG-4, etc.) over LANs, but only from files or realtime encoders, not from DVD-Video discs.

The Internet is a different matter. It takes over a week to download the contents of a single-layer DVD using a 56k modem. It takes about 7 hours on a T1 line. Cable modems theoretically cut the time down to a few hours, but if other users in the same neighborhood have cable modems, bandwidth could drop significantly. [Jim's prediction: the average DVD viewing household won't have sufficiently fast Internet connections before 2007 at the earliest. Around that time there will be a new high-definition version of DVD with double the data rate, which will once again exceed the capacity of the typical Internet connection.]

[4.8] What are DeCSS and DivX;-)?

CSS (Content Scrambling System) is an encryption and authentication scheme intended to prevent DVD movies from being digitally copied. See 1.11 for details. DeCSS refers to the general process of defeating CSS, as well as to DeCSS source code and programs.

Computer software to decrypt CSS was released to the Internet in October 1999 (see Dana Parker's article at www.emediapro.net/news99/news111.html), although other "ripping" methods were available before that (see www.7thzone.com, go.to/dvdsoft, www.neophile.net, and www.dfbills.com/powerbook/dvd.html). The difference between circumventing CSS encryption with DeCSS and intercepting decrypted, decompressed video with a DVD ripper is that DeCSS can be considered illegal under the DMCA and the WIPO treaties. The DeCSS information can be used to "guess" at master keys, such that a standard PC can generate the entire list of 400 keys, rendering the key secrecy process useless. 

In any case, there's not much appeal to being able to copy a set of movie files (often without menus and other DVD special features) that would take over a week to download on a 56K modem and would fill up a 6G hard disk or a dozen CD-Rs. In March 2000, a DVD redistribution technology called DivX;-) appeared. (Yes, the smiley face is part of the name, whose creators should be drawn and quartered for the stupid joke, which has confused thousands. See 2.10.) DivX;-) is a simple hack of Microsoft's MPEG-4 video codec and MP3 audio, allowing DeCSSed video to be re-encoded for downloading and playing in Windows Media Player. The DivX;-) creators are now involved in Project Mayo developing a new version called OpenDivx (originally called Divx Deux). There's also an open-source variation called 3ivx. In spite of lower data rates (and therefore lower quality) of DivX;-) et al, the time and effort it takes to find and download the files is not worth the bother for most movie viewers. The reality is that people ripping and downloading DVDs are doing it for the challenge, not to avoid buying discs.

The supporters of DeCSS point out that it was only developed to allow DVD movies to be played on the Linux operating system, which had been excluded from CSS licensing because of its open-source nature. This is specifically allowed by DMCA and WIPO laws. However, the DeCSS.exe program posted on the Internet is a Windows application that decrypts movie files. The lack of differentiation between the DeCSS process in Linux and the DeCSS.exe Windows application is hurting the cause of DeCSS backers, since DeCSS.exe can be used in the process of copying and illegally distributing movies from DVD. See OpenDVD.org and Tom Vogt's DeCSS central for more information on DeCSS.

Worthy of note is that DVD piracy was around long before DeCSS. Serious DVD pirates can copy the disc bit for bit, including the normally unreadable lead in (this can be done with a specially modified drive), or copy the video output from a standard DVD player, or get a copy of the video from another source such as laserdisc, VHS, or a camcorder smuggled into a theater. It's certainly true that DVD piracy is a problem, but DeCSS has little to do with it.

Shortly after the appearance of DeCSS, the DVD CCA filed a lawsuit and requested a temporary injunction in an attempt to prevent Web sites from posting (or even linking to!) DeCSS information. The request was denied by a California court on December 29, 1999. On January 14, 2000, the seven top U.S. movie studios (Disney, MGM, Paramount, Sony [Columbia/TriStar], Time Warner, Twentieth Century Fox, and Universal), backed by the MPAA, filed lawsuits in Connecticut and New York in a further attempt to stop the distribution of DeCSS on Web sites in those states. On January 21, the judge for the New York suit granted a preliminary injunction, and on January 24, the judge for the CCA suit in California reversed his earlier decision and likewise granted a preliminary injunction. In both cases, the judges ruled that the injunction applied only to sites with DeCSS information, not to linking sites. (Good thing, since this FAQ links to DeCSS sites!) The CCA suit is based on misappropriation of trade secrets (somewhat shaky ground), while the MPAA suits are based on copyright circumvention. On January 24, 16-year old Jon Johansen, the Norwegian programmer who first distributed DeCSS, was questioned by local police who raided his house and confiscated his computer equipment and cell phone. Johansen says the actual cracking work was done by two anonymous programmers, one German and one Dutch, who call themselves Masters of Reverse Engineering (MoRE).

This all seems to be a losing battle, since the DeCSS source code is available on a T-shirt and was made publicly available by the DVD CCA itself in court records--oops! See Fire, Work With Me for a facetious look at the broad issue.

[4.9] How do I play DVD video in HTML, PowerPoint, Director, VB, etc.?

A variety of multimedia development/authoring programs can be extended to play video from a DVD, either as titles and chapters from a DVD-Video volume, or as MPEG-2 files. In Windows, this is usually done with ActiveX controls. On the Mac, until DVD-Video support is added to QuickTime, the options are limited. Newer versions of the Apple DVD Player can be controlled with AppleScript.

DVD-Video and MPEG-2 video can be played back in an HTML page in Microsoft Internet Explorer using many different ActiveX controls (see table). Some ActiveX controls also work in PowerPoint, Visual Basic, and other ActiveX hosts. Netscape Navigator is out of the game until it supports ActiveX objects. Simple MPEG-2 playback can be done in PowerPoint using the Inert Movie feature (requires a DirectShow-compatible MPEG-2 decoder). DVD and MPEG-2 playback can be integrated into Macromedia Director using specialized Xtras. 

  Price HTML (IE only) PowerPoint ActiveX host Director
Microsoft MSWebDVD (DirectX 8, docs at MSDN) free yes yes yes no
Microsoft Windows Media Player (docs in Windows Media SDK) free yes no no no
InterActual PC Friendly not available certain versions no no no
InterActual Player 2.0 $2000 and up yes yes yes yes?
SpinWare iControl $1200 and up Web version PE version no no
Visible Light Onstage DVD $500 and up ActiveX version ActiveX version ActiveX version Director version
Zuma ActiveDVD (InterActual engine) $400 and up no yes no no
Sonic EDK (InterActual engine) $4000 yes no no no
Sonic DVD Presenter (InterActual engine) $40 no yes no no
Tabuleiro DirectMediaXtra $200 no no no MPEG-2/VOB files, but not DVD-Video volumes
LBO Xtra DVD $500? no no no yes
Matinée Presenter ? Separate presentation application. Plays MPEG-2 files (not DVD-Video).

Of course, if you simply treat DVD-ROM as a bigger, faster CD-ROM, you can create projects using traditional tools (Director, Flash, Toolbook, HyperCard, VB, HTML, etc.) and traditional media types (CinePak, Sorenson, Indeo, Windows Media, etc. in QuickTime or AVI format) and they'll work just fine from DVD. You can even raise the data rate for bigger or better quality video. But it still won't look as good as MPEG-2.

[4.10] What are .IFO, .VOB, and .AOB files? How can I play them?

The DVD-Video and DVD-Audio specifications define how audio and video data are stored in specialized files. The .IFO (and backup .BUP) files contain menus and other information about the video and audio. The .VOB files (for DVD-Video) and .AOB files (for DVD-Audio) are MPEG-2 program streams with additional packets containing navigation and search information. 

Since a .VOB file is just a specialized MPEG-2 file, most MPEG-2 decoders and players can play them. However, any special features such as angles or branching will cause strange effects. The best way to play a .VOB file is to use a DVD player application to play the entire volume (or to open the VIDEO_TS.IFO file), since this will make sure all the DVD-Video features are used properly.

The DVD Video Recording format will introduce .SOB files <snigger>.

Most .VOB files won't play when copied to your hard drive. See 4.5.

[4.11] How do I get the Microsoft Windows DVD player application to run?

Windows 98 and Windows 2000 include a simple player application. It requires that a DirectShow-compatible DVD decoder be installed (see 4.1). During setup, Windows installs the player application if it finds a compatible hardware decoder. You must install the player by hand if you want to use it with a software decoder or an unrecognized hardware decoder. Using WinZip or other utility that can extract from cab files, extract dvdplay.exe from driver17.cab (on the original Windows disc). This is the only file you need, but you can also extract the help file from driver11.cab, and you can extract dvdrgn.exe from driver17.cab if you intend to change the drive region.)

Windows Me includes a much improved player. It is always installed, but it usually does not appear in the Start menu. To use the player, choose Run... from the Start menu, then enter dvdplay.

[5] DVD production

DVD production has two basic phases: development and replication. Development is different for DVD-ROM and DVD-Video, replication is essentially the same for both.

DVD-ROMs can be developed with traditional software development tools such as Macromedia Director, Asymetrix Toolbook, HyperCard, Quark mTropolis, and C++. Discs, including DVD-R check discs, can be created with UDF formatting software (see 5.3). DVD-ROMs that take advantage of DVD-Video's MPEG-2 video and multichannel Dolby Digital or MPEG-2 audio require video and audio encoding (see 5.3).

DVD-Video development has three basic parts: encoding, authoring (design, layout, and testing), and premastering (formatting a disc image). The entire development process is sometimes referred to as authoring. Development facilities are provided by many service bureaus (see 5.5). If you intend to produce numerous DVD-Video titles (or you want to set up a service bureau), you may want to invest in encoding and authoring systems (see 5.3 and 5.4).

Replication (including mastering) is usually a separate job done by large plants that also replicate CDs (see 5.5). DVD replication equipment typically costs millions of dollars. A variety of machines are used to create a glass master, create metal stamping masters, stamp substrates in hydraulic molds, apply reflective layers, bond substrates together, print labels, and insert discs in packages. Most replication plants provide "one-off" or "check disc" services, where one to a hundred discs are made for testing before mass duplication. Unlike DVD-ROM mastering, DVD-Video mastering may include an additional step for CSS encryption, Macrovision, and regionalization. There is more information on mastering and replication at Panasonic Disc Services and Technicolor.

For projects requiring less than 50 copies, it can be cheaper use DVD-R. Automated machines can feed DVD-R blanks into a recorder, and even print labels on each disc. This is called duplication, as distinguished from replication.

[5.1] How much does it cost to produce a DVD? Isn't it more expensive than videotape, laserdisc, and CD-ROM?

Videotape, laserdisc, and CD-ROM can't be compared to DVD in a straightforward manner. There are basically three stages of costs: production, pre-mastering (authoring, encoding, and formatting), and mastering/replication.

DVD video production costs are not much higher than for VHS and similar video formats unless the extra features of such as multiple sound tracks, camera angles, seamless branching, etc. are employed.

Authoring and pre-mastering costs are proportionately the most expensive part of DVD. Video and audio must be encoded, menus and control information have to be authored and encoded, it all has to be multiplexed into a single data stream, and finally encoded in low level format. Typical charges for compression are $60/min for video, $20/min for audio, $6/min for subtitles, plus formatting and testing at about $30/min. A ballpark cost for producing a Hollywood-quality two-hour DVD movie with motion menus, multiple audio tracks, subtitles, trailers, and a few info screens is about $20,000. Alternatively, many facilities charge for time, at rates of around $400/hour. A simple two-hour DVD-Video title with menus and various video clips can cost as low as $3,000. If you want to do it yourself, authoring and encoding systems can be purchased at prices from $400 to over $2 million. Prices for software and hardware will drop very rapidly in the next few years to where DVDs can be produced on a desktop computer system that costs less than $20,000.

Videotapes don't really have a mastering cost, and they run about $2.40 for replication. CDs cost about $1,000 to master and $0.50 to replicate. Laserdiscs cost about $3,000 to master and about $8 to replicate. As of the beginning of 2000, DVDs cost about $1000 to master and about $1.60 to replicate. Since DVD production is based mostly on the same equipment used for CD production, mastering and replication costs will drop to CD levels. Double-sided or dual-layer discs cost about $1 more to replicate, since all that's required is stamping data on the second substrate (and using transparent glue for dual layers). Double-sided, dual-layer discs (DVD-18s) are more difficult and more expensive. (See 3.3.1.)

[5.2] What DVD-ROM formatting tools are available?

Features to look for in DVD formatters:

[5.3] What DVD production tools are available?

[5.3.1] Video encoding tools

[5.3.2] Audio encoding tools

[5.3.3] Other production tools

[5.3.4] Other production services

[5.4] What DVD authoring systems are available?

[5.5] Who can produce a DVD for me?

[A] = authoring (including encoding, DVD-R duplication, and premastering).
[R] = replication (mastering, check discs, and mass production).

Also see 5.8 for companies specializing in video-to-DVD-R transfers.