DVD FAQs
| This DVD FAQs is collected from books, magazines, web forums as well as many other conferences and presentations, to help answer any DVD questions you may have. |
| What is DVD? |
| DVD is the new generation of optical disc storage technology. DVD is essentially a bigger, faster CD that can hold cinema-like video, better-than-CD audio, still photos, and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format. It has replaced laserdisc, is well on the way to replacing videotape and video game cartridges, and could eventually replace audio CD and CD-ROM. DVD has widespread support from all major electronics companies, all major computer hardware companies, and all major movie and music studios. With this unprecedented support, DVD became the most successful consumer electronics product of all time in less than three years of its introduction. In 2003, six years after introduction, there were over 250 million DVD playback devices worldwide, counting DVD players, DVD PCs, and DVD game consoles. This was more than half the numbers of VCRs, setting DVD up to become the new standard for video publishing.
It’s important to understand the difference between the physical formats (such as DVD-ROM and DVD-R) and the application formats (such as DVD-Video and DVD-Audio). DVD-ROM is the base format that holds data. DVD-Video (often simply called DVD) defines how video programs such as movies are stored on disc and played in a DVD-Video player or a DVD computer. The difference is similar to that between CD-ROM and Audio CD. DVD-ROM includes recordable variations: DVD-R/RW, DVD-RAM, and DVD+R/RW. The application formats include DVD-Video, DVD-Video Recording (DVD-VR), DVD+RW Video Recording (DVD+VR), DVD-Audio Recording (DVD-AR), DVD Stream Recording (DVD-SR), DVD-Audio (DVD-A), and Super Audio CD (SACD). There are also special application formats for game consoles such as Sony PlayStation 2 and Microsoft Xbox. |
| What do the letters DVD stand for? |
| All of the following have been proposed as the words behind the letters DVD.
*Delayed, very delayed (referring to the many late releases of DVD formats) And the official answer is? "Nothing." The original acronym came from "digital video disc." Some members of the DVD Forum tried to express that DVD goes far beyond video by retrofitting the painfully contorted phrase "digital versatile disc," but this has never been officially accepted by the DVD Forum as a whole. The DVD Forum decreed in 1999 that DVD, as an international standard, is simply three letters. After all, how many people ask what VHS stands for? (Guess what, no one agrees on that one either.) |
| What’s the quality of DVD-Video? |
| DVD has the capability to produce near-studio-quality video and better-than-CD-quality audio. DVD is vastly superior to consumer videotape. However, quality depends on many production factors. As compression experience and technology improves we see increasing quality, but as production costs decrease and DVD authoring software becomes widely available we also see more shoddily produced discs. A few low-budget DVDs even use MPEG-1 encoding (which is no better than VHS) instead of higher-quality MPEG-2.
DVD video is usually encoded from digital studio master tapes to MPEG-2 format. The encoding process uses lossy compression that removes redundant information (such as areas of the picture that don’t change) and information that’s not readily perceptible by the human eye. The resulting video, especially when it is complex or changing quickly, may sometimes contain visual flaws, depending on the processing quality and amount of compression. At average video data rates of 3.5 to 6 Mbps (million bits/second), compression artifacts may be occasionally noticeable. Higher data rates can result in higher quality, with almost no perceptible difference from the master at rates above 6 Mbps. As MPEG compression technology improves, better quality is being achieved at lower rates. Video from DVD sometimes contains visible artifacts such as color banding, blurriness, blockiness, fuzzy dots, shimmering, missing detail, and even effects such as a face that "floats" behind the rest of the moving picture. It’s important to understand that the term "artifact" refers to anything that is not supposed to be in the picture. Artifacts are sometimes caused by poor MPEG encoding, but artifacts are more often caused by a poorly adjusted TV, bad cables, electrical interference, sloppy digital noise reduction, improper picture enhancement, poor film-to-video transfer, film grain, player faults, disc read errors, and so on. Most DVDs exhibit few visible MPEG compression artifacts on a properly configured system.. If you think otherwise, you are misinterpreting what you see. Some early DVD demos were not very good, but this is simply an indication of how bad DVD can be if not properly processed and correctly reproduced. In-store demos should be viewed with a grain of salt, since most salespeople are incapable of properly adjusting a television set. Most TVs have the sharpness set too high for the clarity of DVD. This exaggerates high-frequency video and causes distortion, just as the treble control set too high on a stereo causes the audio to sound harsh. For best quality the sharpness control should be set very low. Brightness should also not be set too high. Some DVD players output video with a black-level setup of 0 IRE (Japanese standard) rather than 7.5 IRE (US standard). On TVs that are not properly adjusted this can cause some blotchiness in dark scenes. There may be an option in the player menu to use standard black level. DVD video has exceptional color fidelity, so muddy or washed-out colors are almost always a problem in the display (or the original source), not in the DVD player or disc. DVD audio quality is superb. DVD includes the option of PCM (pulse code modulation) digital audio with sampling sizes and rates higher than audio CD. Alternatively, audio for most movies is stored as discrete, multi-channel surround sound using Dolby Digital or DTS audio compression similar to the digital surround sound formats used in theaters. As with video, audio quality depends on how well the processing and encoding was done. In spite of compression, Dolby Digital and DTS can be close to or better than CD quality. |
| How do I put a PowerPoint presentation on DVD? |
| There’s not yet a feature in PowerPoint to export directly to video on DVD, but you can convert a PowerPoint presentation to stills or video for import into a DVD authoring program. Recent versions of PowerPoint allow you to save your slides as graphic images (JPEG or PNG files) that can be imported into a DVD authoring program that supports slideshows. The advantage of using the slideshow feature is that you can have the DVD player pause indefinitely on each still until you press the Enter or Play key on the remote control. (Note: make sure the authoring software supports true slideshows with "infinite stills," since many programs just render slides as video.) The disadvantage of using stills is that you won’t get animations and other fancy PowerPoint effects. Alternatively you can record the PowerPoint presentation as a video file (use a PowerPoint add-in or a motion screen capture program) and import the video file into the DVD authoring program. This preserves the full visual effect but locks you into the timing you used when recording the presentation. Another alternative is 321 Studio’s DVD X Point, which directly converts PowerPoint presentations (version 2002 only) to DVD slideshows. |
| How do I copy my home video/film/photos to DVD? |
| This used to be almost impossible, but luckily for you it’s getting cheaper and easier all the time.
For a simple video-to-DVD transfer you can buy a DVD video recorder ($500 to $3,000) and connect it to your VCR or camcorder. It works just like a VCR but it records onto a disc instead of tape. For transferring photos or music, or for making a customized DVD with menus and chapters and other fun stuff, you’ll need the following: *A computer Note: You must use authoring software. You can’t just copy MPEG or AVI or JPEG files onto a disc and expect it to play in DVD players. Then take the following steps *If the video and pictures are not already in digital form (AVI, WMV, DivX, QuickTime, JPEG, and so on) you need to transfer them to your computer. For analog video, such as VHS and Hi8, you need a video capture device or a computer with built-in analog video input; for digital video such as DV or D8 you need a 1394/FireWire input on the computer. For film, first have it transferred to tape or digital video at a camera shop or video company (see a list at HomeMovieDay.com). For slides or photos, use a scanner (or rent scanning time at a place such as Kinkos). Another option is to us do all the work for you at a reasonable fee. |
| How much does it cost to produce a DVD? Isn’t it more expensive than VHS? |
| VHS 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 extra features of DVD 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 $50/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 $300/hour. A simple two-hour DVD-Video title with menus and various video clips can cost as low as $2,000. If you want to do it yourself, authoring and encoding systems can be purchased at prices from $50 to over $2 million. Another option is to have us author your next DVD project, at a reasonable fee of $250 – $500. Videotapes don’t really have a mastering cost, and they run about $2.40 for duplication. CDs cost about $490 to master and $0.50 to replicate by us. |
| How is DVD doing? Where can I get statistics? |
| DVD did not take off quite as fast as some early predictions, but it has sold faster than videotape, CD, and laserdisc. In fact, before its third birthday in March 2000, DVD had become the most successful consumer electronics entertainment product ever.
Here are some predictions: *InfoTech (1995): Worldwide sales of DVD players in 1997 will be 800,000. Worldwide sales of DVD-ROM drives in 1997 will be 1.2 million, with sales of 39 million drives in 2000. Here’s reality: *1997 For comparison, there were about 700 million audio CD players and 160 million CD-ROM drives worldwide in 1997. 1.2 billion CD-ROMs were shipped worldwide in 1997 from a base of about 46,000 different titles. There were about 80 million VCRs in the U.S. (89% of households) and about 400 million worldwide. 110,000 VCRs shipped in the first two years after release. Nearly 16 million VCRs were shipped in 1998. In 2000 there were about 270 million TVs in the U.S. and 1.3 billion worldwide. When DVD came out in 1997 there were under 3 million laserdisc players in the U.S. For latest U.S. player sales statistics, see the CEA page at The Digital Bits. Other DVD statistics and forecasts can be found at IRMA, MediaLine, Twice. Industry analyses and forecasts can be purchased from Adams Media Research, Alexander & Associates, British Video Association, Cahners In-stat, Centris, Datamonitor, Dataquest, DVD Intelligence, eBrain, International Data Corporation (IDC), InfoTech, Jon Peddie Associates (JPA), Paul Kagan Associates, Screen Digest, SIMBA Information, Strategy Analytics, Understanding & Solutions and others. |
| What are "regional codes," "country codes," or "zone locks"? |
| Motion picture studios want to control the home release of movies in different countries because theater releases aren’t simultaneous (a movie may come out on video in the U.S. when it’s just hitting screens in Europe). Also, studios sell distribution rights to different foreign distributors and would like to guarantee an exclusive market. Therefore they required that the DVD standard include codes to prevent playback of certain discs in certain geographical regions. Each player is given a code for the region in which it’s sold. The player will refuse to play discs that are not coded for its region. This means that a disc bought in one country may not play on a player bought in another country. Some people believe that region codes are an illegal restraint of trade, but no legal cases have established this.
Regional codes are entirely optional for the maker of a disc. Discs without region locks will play on any player in any country. It’s not an encryption system, it’s just one byte of information on the disc that the player checks. Some studios originally announced that only their new releases would have regional codes, but so far almost all Hollywood releases play in only one region. Region codes are a permanent part of the disc, they won’t "unlock" after a period of time. Region codes don’t apply to DVD-Audio, DVD-ROM, or recordable DVD (see below for more detail). Seven regions (also called locales or zones) have been defined, and each one is assigned a number. Players and discs are often identified by their region number superimposed on a world globe. If a disc plays in more than one region it will have more than one number on the globe. Region 01 Region 02 Region 03 Region 04 Region 05 Region 06 Region 07 Region 08 |
| Notation and units |
| There’s an unfortunate confusion of units of measurement in the DVD world. For example, a single-layer DVD holds 4.7 billion bytes (G bytes), not 4.7 gigabytes (GB). It only holds 4.37 gigabytes. Likewise, a double-sided, dual-layer DVD holds only 15.90 gigabytes, which is 17 billion bytes.
The problem is that the SI prefixes "kilo," "mega," and "giga" normally represent multiples of 1000 (10^3, 10^6, and 10^9), but when used in the computer world to measure bytes they generally represent multiples of 1024 (2^10, 2^20, and 2^30). Both Windows and Mac OS list volume capacities in "true" megabytes and gigabytes, not millions and billions of bytes Most DVD figures are based on multiples of 1000, in spite of using notation such as GB and KB that traditionally have been based on 1024. The "G bytes" notation does seem to consistently refer to 10^9. The closest I have been able to get to an unambiguous notation is to use "kilobytes" for 1024 bytes, "megabytes" for 1,048,576 bytes, "gigabytes" for 1,073,741,824 bytes, and "BB" for 1,000,000,000 bytes. This may seem like a meaningless distinction, but it’s not trivial to someone who prepares 4.7 gigabytes of data (according to the OS) and then wastes a DVD-R or two learning that the disc really holds only 4.3 gigabytes! Here’s an analogy that might help. A standard mile is 5,280 feet, whereas a nautical mile is roughly 6,076 feet. If you measure the distance between two cities you will get a smaller number in nautical miles, since nautical miles are longer. For example, the distance from Seattle to San Francisco is about 4,213,968 feet, which is 798 standard miles but only 693 nautical miles. DVD capacities have similarly confusing units of measurement: a billion bytes (1,000,000,000 bytes) or a gigabyte (1,073,741,824 bytes). DVD capacities are usually given in billions of bytes, such as 4.7 billion bytes for a recordable disc. Computer files are measured in gigabytes. Unfortunately, both types of measurements are often labeled as "GB." So a 4.5-GB file (4.5 gigabytes) from a computer will not fit on a 4.7-GB disc (4.7 billion bytes), since the file contains 4.8 billion bytes. To make things worse, data transfer rates when measured in bits per second are almost always multiples of 1000, but when measured in bytes per second are sometimes multiples of 1024. For example, a 1x DVD drive transfers data at 11.08 million bits per second (Mbps), which is 1.385 million bytes per second, but only 1.321 megabytes per second. The 150 KB/s 1x data rate commonly listed for CD-ROM drives is "true" kilobytes per second, since the data rate is actually 153.6 thousand bytes per second. This FAQ uses "kbps" for thousands of bits/sec, "Mbps" for millions of bits/sec (note the small "k" and big "M"). In December 1998, the IEC produced new prefixes for binary multiples: kibibytes (KiB), mebibytes (MiB), gibibytes (GiB), tebibytes (TiB), and so on. (More details at NIST, also released as IEEE Std 1541-2002) These prefixes may never catch on, or they may cause even more confusion, but they are a valiant effort to solve the problem. The big strike against them is that they sound rather silly. |
| Who invented DVD and who owns it? Whom to contact for specifications and licensing? |
| DVD is the work of many companies and many people. DVD evolved from CD and related technologies. Some of the early proposals for "high-density CD" were made in 1993, and these efforts gradually coalesced into two competing proposed formats. The MMCD format was backed by Sony, Philips, and others. The SD format was backed by Toshiba, Matsushita, Time Warner, and others. A group of computer companies led by IBM insisted that the factions agree on a single standard. The combined DVD format was announced in September of 1995, avoiding a confusing and costly repeat of the VHS vs. Betamax videotape battle or the quadraphonic sound battle of the 1970s.
No single company "owns" DVD. The official specification was developed by a consortium of ten companies: Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and Toshiba. Representatives from many other companies also contributed in various working groups. In May 1997, the DVD Consortium was replaced by the DVD Forum, which is open to all companies, and as of February 2000 had over 220 members. Time Warner originally trademarked the DVD logo, and has since assigned it to the DVD Format/Logo Licensing Corporation (DVD FLLC). The written term "DVD" is too common to be trademarked or owned. See section 6.2 and visit Robert’s DVD Info page for links to Web sites of companies working with DVD. The official DVD specification books are available after signing a nondisclosure agreement and paying a $5,000 fee. One book is included in the initial fee; additional books are $500 each. Manufacture of DVD products and use of the DVD logo requires additional format and logo licenses, for a one-time fee of $10,000 per format, minus $5,000 if you have already paid for the specification. (E.g., a DVD-Video player manufacturer must license DVD-ROM and DVD-Video for $20,000, or $15,000 if they have the spec.) Allowances are made for production houses and content providers to use the logo in conjunction with a licensed replicator, and for non-licensees to use the DVD logo in publications or presentations (with an option to request logo art). For more spec and logo information contact DVD Format/Logo Licensing Corporation (DVD FLLC), Shiba Shimizu Building 5F, Shiba-daimon 2-3-11, Minato-ku, Tokyo 105-0012, tel: +81-3-5777-2881, fax: +81-3-5777-2882. Before April 14, 2000, logo/format licensing was administered by Toshiba. ECMA has developed international standards for DVD-ROM (part 1, the smallest part of the DVD spec), available for free download as ECMA-267 and ECMA-268 from www.ecma-international.org. ECMA has also standardized DVD-R in ECMA-279, DVD-RAM in ECMA-272 and ECMA-273, and DVD+RW as ECMA-274. Unfortunately, ECMA has the annoying habit of spelling "disc" wrong. Also confusing, if you’re not from Europe, is ECMA’s use of a comma instead of a period for the decimal point. The specification for the UDF file system used by DVD is available from www.osta.org. Many technical details of the DVD-Video format are available at the DVD-Video Information page. Any company making DVD products must license essential technology patents from the "3C’ pool (LG, Philips, Pioneer, Sony: 3.5% per player/drive, minimum $3.50; additional $0.75 for Video CD compatibility; 3.75 cents per disc), the "6C" pool (Hitachi, IBM, Matsushita, Mitsubishi, Time Warner, Toshiba, Victor: 4% per player/drive, minimum $3, maximum $8; 4% per "DVD Video decoder", minimum $1; 4.5 cents per ROM/Video/Audio disc; 4% of DVD-R/RW/RAM disc, minimum 6.5 cents) and from Thomson (~$1 per player/drive). Patent royalties of 20 cents per disc are also owed to Discovision Associates, which owns about 1300 optical disc patents. Per disc costs are paid by the replicator. The licensor of CSS encryption technology is DVD CCA (Copy Control Association), a non-profit trade association with offices at 225 B Cochrane Circle, Morgan Hill, CA. There is a $20,000 annual licensing fee, but no per-product royalties. Send license requests to css-license@lmicp.com, technical info requests to css-info@lmicp.com. Before December 15, 1999, CSS licensing was administered on an interim basis by Matsushita. Macrovision licenses its analog anti-recording technology to hardware makers. There is a $30,000 initial charge, with a $15,000 yearly renewal fee. The fees support certification of players to ensure widest compatibility with televisions. There are no royalty charges for player manufacturers. Macrovision charges a royalty to content publishers (approximately 4 to 10 cents per disc, compared to 2 to 5 cents for a VHS tape). Dolby licenses 2-channel Dolby Digital decoders or encoders for $0.66. The fee for a system with both a 2-channel decoder and 2-channel encoder is $0.71. Multichannel decoders are approximately $1.50. Philips, on behalf of CCETT and IRT, also charges $0.20 per channel (maximum of $0.60 per player) for Dolby Digital patents, along with $0.003 per disc. DTS licenses optional DTS decoders. Dolby licenses MLP decoders for DVD-Audio players. An MPEG-2 patent license is required from MPEG LA (MPEG Licensing Adminstrator). Cost is $2.50 for a DVD player or decoder card and 4 cents for each DVD disc, although there seems to be disagreement on whether content producers owe royalties for discs. Many DVD players are also Video CD (VCD) players. Philips licenses the Video CD format and patents on behalf of themselves, Sony, JVC, Matsushita, CNETT, and IRT for $25,000 initial payment plus royalties of 2.5% per player or $2.50 minimum. Nissim claims 25 cents per player and 78/100ths of a cent for parental management and other DVD-related patents. Various essential licensing fees add up to over $14 in royalties, and about $0.20 per disc. Disc royalties are paid by the replicator. Royalties for DVD+R patents are charged by Philips (approximately $0.06 per disc) and Sony (1.5 to 3.5% of disc price). |
Leave a Reply
