Microsoft recalls Xbox 360

Microsoft recalls Xbox 360 wireless racing wheel
Hot wheels add immersion with smoke and burning smell

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Microsoft is to provide customers with a free retrofit to its Xbox 360 Wireless Racing Wheel.

The action follows a very small number of incidents of a malfunction in the device, in which a component in the wheel chassis may overheat and release smoke when the AC/DC power supply is used to charge the wheel.

Microsoft has stressed that the action is precautionary and voluntary, and that there have been no reported incidences of fire, personal injury or property damage resulting from the failure.

A spokesman for the Xbox team told vnunet.com that the problem lies within the power supply and not the wheel itself. Customers who contact Microsoft will be sent a replacement power supply to rectify the problem.

Owners of the peripheral should stop using the AC/DC power supply until they have obtained their retrofit. They may continue to operate the wheel using battery power.

However, while operating in battery mode the force feedback feature will not be available. But once retrofitted, owners may run the wheel using AC power and reactivate this feature.

Microsoft has created a Wireless Racing Wheel recall web page which contains information about the problem and a link to a form that users can fill out and send in to Microsoft, at which point they will receive further details about the retrofit.

The company is working with the relevant regulatory agencies such as the US Consumer Product Safety Commission to make sure that the malfunction is properly dealt with, and has warned that this may affect delivery dates to suppliers.

By : Ian Williams, vnunet.com 24 Aug 2007
Keyword : Microsoft,xbox 360

7 Ways To Save On Your InkJet Printing Costs

7 Ways To Save On Your InkJet Printing Costs

Inkjet printers are not only getting better, they're also getting less expensive. Why is that?

The inkjet printer manufacturers have built their business around the supplies rather than the printer itself. They make the printers as inexpensive as possible, sometimes selling them at cost, or less and making long term profits from the inkjet cartridges.

Manufacturers regularly warn about using generic cartridges, and highly recommend their own. Truth be told, there is very little difference between the two and you can regularly save over half of your current manufacturer branded cartridge purchases.

To help keep your inkjet supply costs low, here are seven tips that will keep you under budget:

1. When printing inter-office, internal, personal or draft documents, use the "draft" and "grayscale" options in your printer settings. This will save on both black ink was well as color ink. Save color and standard black for your final document print.

2. Select inkjet printers that use separate black and color inkjet cartridges like the Canon "i" series. Many of these printers have 2 black and 4 color cartridges that allow you to replace only the colors that are running low, not just the one 'color' cartridge as many printers often do. This saves on long term cartridge costs and lengthens the time between cartridge replacements.

3. Purchase "generic" cartridges made for your printer. These are of similar quality to the manufacturer's brand, and often at less than half the price.

4. Purchase "remanufactured" cartridges compatible with your printer. These are cartridges collected from the original owner, cleaned and re-filled with the same ink.

5. Purchase a cartridge "refill kit". You'll receive a kit that will allow you to refill the ink in your cartridge rather than a new cartridge. This is a great way to recycle and the quality is high and costs low.

6. Purchase your cartridges in bulk to save on shipping costs and discounts are sometimes available on larger single purchases.

7. Order your cartridges online to save time and money. Many local stores don't carry the generic versions and costs are normally substantially lower online.

Using any combination of the tips above will save you both time and money and help you manage your inkjet printing supply needs easily.

By : Mark Idzik
Keyword : inkjet, cartridges, refill, ink, jet, inkjets, money, save

Adding USB 2.0

Adding USB 2.0

The process of adding USB 2.0 ports took no time and the backup system is mighty fast. If you add USB 2.0 ports with a PCI port card, then you'll still have your USB 1.1 ports, so whatever is plugged into those can stay.

Rob Foster from the UK sent me a port PCI USB card since he had a few extras. Thanks again, Rob. When installing hardware or devices, most situations require loading the software FIRST before doing anything else. This one didn't - so be sure to check this out before attempting to put the card in. Before starting the process, be sure you have an open PCI slot, a standard slot that has one big connector with a small one behind it.

Turn off the computer, if it is not already. Take off the CPU case. How this is done depends on the CPU. If you lost or misplaced the manual, I'm sure your computer manufacturer has info online. Google it, if needed. Slide the PCI card into the open PCI slot.

At this point, you can cover up the CPU, but some people leave it off until turning on the computer and checking all is OK. When turning on this little feller, it found the new card right away and worked. I didn't even have to run the software. The card came with four USB ports, one of which holds the backup system. It took under two hours to back up the computer (get size), faster and easier than the tape back up.

Well, it only took a year or so to get around to adding the USB 2.0 ports as that's about how long the back up system has been sitting here taunting me.

By : Meryl K. Evans
Keyword : usb computer hardware upgrade

All About DVD Part 4: DVD-Audio and SACD

All About DVD Part 4: DVD-Audio and SACD

New sound formats: DVD-Audio and SACD

When Audio-CD format emerged, most music producers and music lovers were absolutely sure that Audio CD provides the best quality sound possible and nothing else will ever be required. However, some audiophiles instantly refused to accept new Audio CD and reverted back to old vinyl disks. At first no-one took them seriously, however, as the time passed an increasing number of listeners started to notice, especially when comparing CD albums with the same records on vinyl, that CDs are not capable to transmit full range of sound. Eventually it becomes clear that there are scientific reasons behind this, namely dynamic range and sampling rate.

Dynamic range is the difference between the loudest and softest sounds in audio record. Sound data is recorded on CD in 16-bit PCM format and therefore its dynamical range does not exceed 96 decibels. And the upper range for human ear is 120Db. The difference is obvious. While the lack of dynamic range might be hard to notice for the pop music, but for something like symphony orchestra sound engineers often have a problem with too soft or too loud instruments which are beyond dynamical range and therefore lost in record.

Apart from dynamic range it also became clear that Audio CDs have insufficient sampling rate. Digital record consists of small pieces called samples, each of them contains information about sound in particular point in time. The more samples are per unit of time, the higher is the quality of record. Basically, sample is a digital analogue of sound oscillation and for that reason they are measured by using the same unit, hertz (Hz). The maximum frequency of sound that humans can hear is around 20 thousands hertz (20 kHz). To reproduce sound accurately, the sound information have to be digitized with sampling rate higher than a human can hear.

During Audio-CD development it was believed that doubling this rate - up to 44.1 kHz would be sufficient. But for some records part of sound was lost and turned into noise. Especially often that happened for classical music and jazz, with high-frequency instruments such as violin and flute being the most unlucky ones. It is scientifically proven now that for the most accurate sound the sampling rate has to be not lower than 64 kHz. This, of course, is far beyond Audio CD capabilities.

To address these issues the DVD-Audio format was developed. It took more time to approve than DVD-Video, as DVD-Forum had to justify between two alternative technologies: one from Toshiba and the other from Sony-Philips (they also developed Audio CD) alliance. The problem was to decide, which format was better. Both of them successfully solved the drawbacks of Audio CD.

Toshiba simply improved existing PCM standard and turned it into 24-bit one. The dynamic range grew to 144db and sampling rate soared up to 192 kHz. These values exceed human ear capabilities by a good margin. This format also had support for multi-channel sound.

Sony and Philips took another route and invented new single-bit audio format called DSD (Direct Stream Digital). The idea was to read data from disk in significantly smaller quantities (one bit at a time, compared to 16 bits for Audio CD and 20-24 bits for DVD-Audio) but with insane sampling rate - 2.8224 MHz. Similar principle is actually employed in the vinyl audio pickup. Due to this the dynamical range for new format grew to 120db. Apart from that multi-channel support was added along with compatibility with Audio CD. The latter was achieved by adding second layer with sound in Audio CD format. If such disk is inserted in generic Audio-CD player, it will be played just like any Audio CD, with all limitations of that format.

At the end, in 1999 Toshiba finally prevailed. This was due to several reasons. First of all, DSD soundtrack is hard to make even in studio environment. Second, when this technology first appeared, there was no special equipment that could support it. All existing devices were able to work with PCM sound only, and DSD required conversion. This eventually reduced the benefits of DSD to zero. Toshiba, however, selected DVD as a medium for the new format, which made it possible to create audio disks in this format even at home. The situation with Sony-Philips creation was completely different. It had to be recorded on special disks, which were similar in appearance and sizes to normal DVD, but totally different otherwise. These disks also required special equipment for printing and recording. All of these were the reasons why Toshiba received rights for the DVD-Audio brand-name.

But that didn't stop Sony and Philips and they decided to introduce their own format - regardless of DVD-Forum decision. The new format was called Super Audio Compact Disc. As a result, there was no single standard and neither SACD nor DVD-Audio managed to even get close to ordinary Audio-CD sales volumes.

The difference in sound between SACD and DVD-Audio wasn't spotted even by most "advanced" audiophiles.

Let's examine each of the technologies in details:

DVD-Audio

Since DVD-Audio standard is based on ordinary DVD, such disk can be double-sided or double-layered or a combination of these two. Unlike SACD, a sound can be recorded on DVD-Audio in different quality and in various formats, stereo or multi-channel. Sampling rate for DVD-Audio can vary from 44.1 kHz up to 192 kHz (however sound can only be stereo at 192 kHz, as it is simply not enough space for multi-channel sound of that quality). Generally, DVD-Audio is able to deliver 1000 times more accurate sound when compared with Audio CD!

To be able to fit multi-channel uncompressed sound (which usually takes lots of space) developers have used special lossless compression technology called MLP (Meridian Lossless Packing), which in some ways is similar to PC archiving packages such as Zip or RAR.

In order to be compatible with generic DVD players, DVD-Audio disks can contain copy of the soundtrack encoded in Dolby Digital and DTS on the other side of the disk. Such disks are known as Hybrid DVD-Audio disc - HDAD. Sometimes it is possible to encounter disks that have only Dolby Digital or DTS encoded soundtracks, however, such disks hardly have anything to do with DVD-Audio.

Apart from this, several sound-recording companies have developed in 2004 a new format called DualDisc. Essentially it is a double sided disc, one side of which is single- or double layer DVD and the other side is plain CD. The CD format used in such disk is slightly different form normal CD. Standard thickness of CD or DVD disk is 1.2mm. Audio CD layer occupies all that space, and DVD requires only half of it, or 0.6mm. Therefore it is not possible to create a disk with both proper DVD and CD layers as it would be 2mm thick and won't fit in any drive. Due to this reason the developers decided to cheat a little bit and reduced thickness of Audio CD layer to 0.9mm. As a result, it is possible to play DualDisc on most players, but it is still too thick and doesn't fit in most cars CD. In addition to this it can damage some Hi-End equipment, and will also void the warranty. Another interesting effect of making Audio CD layer thinner is the inability to record anything to it via normal CD recording methods due to spherical aberrations. This means that laser is not able to focus on data pits and "see" only blurred image which cannot provide any actual data. The problem was solved my making pits bigger, however their amount reduced. As a result, the capacity of disc has dropped and instead of standard 74 minutes such disks contain only 60, and there are only 525 MB available instead of 650.

Most probably DualDisc technology won't last long. There actually is a new technology to replace it - Onedisc/DVDplus. German engineers managed to create hybrid medium with standard thickness - 1.2mm. More importantly, the capacity of CD side doesn't suffer; it still is able to contain 650mb of data or 74 minutes of audio. The developers of this standard, however, do not share their secrets, and how exactly did they managed to overcome obvious problems is still a mystery. Many recording studios have purchased license for this technology and Onedisc will probably soon appear on shop shelves.

Beside audio data, DVD-Audio disc is able to hold any type of DVD-Video data. It can be video, menu, slides, etc (it is also possible to put sound in DVD-Audio format on DVD-Video disk). The standard also provides new technology for storing text information, some sort of replacement for CD-Text. Disk can contain titles, lyrics, information about performers, etc. Text can be viewed on TV or audio player screen. Just as DVD-Video, DVD-Audio can provide a selection of several languages for text info.

DVD-Audio copy protection is also worth mentioning. After famous DVD-Video hack manufacturers decided to postpone DVD-Audio until better protection becomes available. This better protection was CPPM (Content Protection for Pre-recorded Media), which include several different protection measures:

1. According to the new standard, DVD-Audio data is encrypted. Unique set of keys can only be kept in legal player device (that is, DVD-Audio player that comply with CPPM requirements). In case if keys do not match the disk (for example when DVD-Audio player is manufactured without appropriate license), it will not be possible to decrypt the data and DVD-Audio disk simply won't play.

Theoretically, it is possible to copy such keys by hacking the device, but practically it is rather useless as if stolen keys would be revealed, all later releases of DVD-Audio disks simply won't support them. And most manufacturers perform monthly revision of keys.

2. Contents of DVD-Audio are also bound to the physical medium. This is achieved by recording "digital watermarks" on the disk. This hidden information contains disk details and the information about how many times this disk can be copied. Watermarks are recorded with intervals of several seconds and if the player discovers that watermarks doesn't match medium it instantly stops playback.

Apart from this, if DVD-Audio player is equipped with Firewire (iLink) digital out, it won't be possible to use it for illegal copying too. All outgoing information is encrypted and because of this it only will be possible to connect the cable to an amplifier or receiver that supports encryption. It will not be possible to connect player to the PC and therefore won't be possible to copy digital output.

SACD disks come in three flavors - single layer, double-layer and hybrid.

In case of SACD hybrid disks have two layers. Bottom layer has Audio CD data and upper semi-transparent layer contains SACD data. If such disk is inserted in normal CD player, there will be no problems with playback - the player simply won't notice the upper layer.

Single- and double-layered disks contain only SACD data, also known as HD (high definition). Each HD layer takes the same space as standard DVD layer - 4.7 GB. Sound can be recorded in mono, stereo or multi-channel formats. Some SACD player can read only mono or stereo disks, and it will take a special device to read multi-channel disks. In most cases, however, there are both multi-channel and stereo versions present. Each type of soundtrack has its own space on the disk - stereo data is recorded closer to the center of the disk, multi-channel data comes next and additional data (such as photos or lyrics) is recorded close to the edge. Each sound zone contains at least 74 minutes of sound. There are, however, purely multi-channel disks with several hours of audio on them.

In ordered to reduce size of data, SACD developers had used DST (Direct Stream Transfer) compression. This compression is similar to MPL and resembles PC archiving utility. It operates by compressing repeating sequences of bits and can achieve significant reduction in size without any losses.

Just as DVD-Audio does, SACD has complex set of copy protection measures:

1. SACD disks are not compatible with computer DVD drives, which makes illegal copying at home impossible.

2. Disk contents are inaccessible until special lead-in SACD-Mark is read. This label is located in a hidden area of the disk and contains information essential for the playback. Only certified devices can read and decrypt it.

3. Disk contents are also protected by PSP-PDM (Pit Signal Processing-Physical Disc Mark) watermarks. By changing pits (tracks) width it is possible to write additional info on the disk (for example, key from encrypted soundtrack). These watermarks can be reproduced only on special licensed equipment. Without them the playback will stop after only few seconds. Besides, it is possible to create a visible picture on working surface of the disk - for example, company logo, thus the original disk can be recognized even with naked eye. To avoid compatibility issues, the second layer in SACD is protected as much as any normal Audio CD is.

For audio output mainly analog out is used, but encrypted digital out via Firewire (iLink) is also possible, just as in DVD-Audio. Coaxial and optics outputs are not supported at all.

Summary

Most probably, both formats will still remain an expensive technology for true music fans and audiophiles. Majority of consumers already made their choice in favor of medium-independent music format - MP3. So it is highly possible that DVD-Audio and SACD will remain the top audio quality available, as any higher quality doesn't have much sense and will be too expensive to reach.

By : Artem Chlegov
Keyword : dvd-audio,sacd,super audio cd,onedisc,dsd,cppm,onedisk,pcm,mlp,meridian loseless packing

All About DVD Part 3: Blue-Ray and HD-DVD

All About DVD Part 3: Blue-Ray and HD-DVD

New storage formats: DVD-HD and Blue-Ray

On the first glance, DVDs have just finished becoming common and are the best option available. But developers do not agree, trying to invent new needs for poor users. This time HDTV (High Definition Television)is considered to be the new technology that no video lover can live without. Compared with common TV, HDVT has several times bigger screen resolution and is technically able to display much more fine details. Of course, all this is available on special HDTV-ready TV sets only. Another problem is concerned with storage of HDTV video, as even the DVD-18 standard with its largest capacity among DVD swill not be able to store several hours of HDTV quality video.

Fortunately, developers of DVD have mastered so-called "blue" laser, which wavelength is only 405nm. By using this laser it becomes possible to achieve much higher data density compared with DVD disks that use "red" laser with wavelength of 650nm. This new technology would allow to store up to 200 GB of data on a multi-layered disk.

Unfortunately, the new formats war has sparked even before the end of the development of actual devices, with the same old players on the field: Sony and Philips with Blue Ray standard and Toshiba, NEC and Sanyo with HD-DVD format.

HD-DVD

HD-DVD (High Definition DVD), as clearly visible from its name, is official heir to the DVD format, approved by DVD Forum. This format is 100% compatible with both CD and DVD, not only from home user perspective but also on manufacturing level. Manufacturing HD-DVD will not require huge investments in new equipment, and this was the reason why such big companies as Intel and Microsoft decided to support it. Microsoft, for example, promised full support of HD-DVD in its new Windows Vista that should be released next year.

One single layer of HD-DVD disk has the same thickness as DVD layer (0.6mm) and can contain up to15 GB of data. This means that HD-DVD won't have any troubles supporting dual-layered and double-sided disks, besides; Toshiba announced the development of triple-layer HD-DVD, where one side of the disk would contain 45GB. The theoretical capacity limit for HD-DVD is, therefore, 90GB.

Along with MPEG-2, compression technologies such as MPEG-4 and Video Codec 1 (VC1, format based on Windows Media 9) will be used. HD-DVD Video disk swill have more advanced capabilities for interactivity than DVD-Videodisks. For example, it would be possible to play several different video clips in picture-in-picture mode, and it also would be possible to connect more than one remote control to the HD-DVD player in order to play videogames together. Internet access will also be included in all HD-DVD devices, so it would be possible to follow web-links straight from disk menu or to download new soundtrack or subtitles from the net. And these are only few of new features.

Internet connectivity is also demanded by the new encryption for HD-DVD and Blue Ray disks - AACS (Advanced Access Content System). Each disk is validated with online database prior to playing. If the disk appears to be counterfeit, the playing device will be locked. It is not clear, however, what to do in countries where Internet is not available in every household. There is certain possibility, though, that Blue Ray and HD-DVD will become luxury, just as SACD and DVD-Audio before them. Alternatively, it could become common only in distant future, when Internet will be available even in African deserts.

Despite stricter copy protection, manufacturers most probably will not add regional codes to HD-DVD as it provides more troubles than benefits, and although movie production companies still insist on keeping regional protection, most of DVD-Forum officials are against it.

Recordable HD-DVD are named in the same way as DVD: HD-DVD-R (recordable) and HD-DVD-RW (rewritable).

Blue Ray Disc

Blue Ray Disc (BD) standard is promoted by Blue Ray Disc Association (BDA), an organization formed for this particular purpose. By throwing away the compatibility with CD and DVD it became possible to achieve much higher capacity than HD-DVD. One layer of BD can contain23.3GB, 25GB or 27GB of data. As the layer thickness is much lower than the one of DVD and is only 0.1 mm (compared to 0.6mm for HD-DVD), it is possible to manufacture multilayered disks with high number of layers. The theoretical capacity of Blue Ray disk is 200GB. Unfortunately, manufacturing of these disks will require purchase of brand new equipment.

Initially Blue Ray disks could only be used with cartridges (same as DVD-RAM) because of poor protection from physical damage, but now this issue seems to be solved and plastic cartridges are not needed anymore. Codecs used to store video in Blue Ray standard are the same as the ones used for HD-DVD (Mpeg-2, Mpeg-4 and VC1). This is not surprising as Blue Ray and HD-DVD were designed to store existing formats of video, while in case with DVD new codecs were developed specifically to cater for new type of disks.

Blue-Ray disks have more advanced menu compared to DVD-Video. The menu offers more functionality and is generally written in Java language. Blue Ray devices require Internet connection just as HD-DVD ones do, and Blue-Ray disk menu also supports integration with Internet. As it was said before, Internet will be also required for AACS protection. Apart from AACS, Blue Ray also implements two unique protection measures - ROM-Mark and BD+Rom-Mark. ROM-Mark is a special hidden label on the disk, similar to watermark in DVD-Audio. It can not be copied and disks couldn't be played without it. BD+ technology is designed to check whether or not Blue Ray player was hacked, and in case if it is true, it will download new firmware from Internet in order to fix in appropriate modifications.

Blue Ray disks naming is slightly different from usual. Read-only disks are called BD-ROM, recordable are called BD-R and rewritable are named BD-RE (Rewritable).

Future Perspectives

Only time will tell if one particular format will prevail or if there will be a complete mess with formats again. At the moment both alliances are trying to do something to attract customers and manufacturers. Blue Ray is leading at the moment. Due to the more advanced copy protection and higher capacity Blue Ray Association managed to attract most of film production companies. Another plus for Blue Ray lies in the fact that PlayStation 3 will use Blue Ray disks and therefore will be able to play Blue Ray Video disks too. Apple Computers is also going to include Blue Ray drives in its computer packages. Apart from all of this, Blue Ray devices appeared on the market much earlier than the competitors.

HD-DVD may attract users because of its back compatibility with previous formats. Besides, manufacturers will not have to spend much effort and money to make disks of this type. HD-DVD is also supported by some major studios, such as New Line Cinema, Paramount Pictures, Universal Studios ? Warner Bros (however some of them support both formats) and IT giants such as b>Intel and Microsoft.

Summary

Unfortunately, multi format drive that could support both Blue Ray and HD-DVD will be very expensive and difficult to manufacture due to large differences in technology behind new standards. However, several companies already have announced the development of such devices. If they succeed, we can hope that new formats will be widely accepted very soon. If not, there is a certain chance that HD-DVD and Blue Ray will share the destiny of DVD-Audio and SACD and only few chosen ones will use them. Besides, it is still not clear whether or not consumers actually need high definition image. And if you take into account that many people often transform DVD into smaller AVI files and use them for viewing at PC, it becomes possible to assume that HD-DVD and Blue Ray manufacturers will have a hard time promoting their formats. Video-on-Demand also does not add popularity to them.

So, which format will prevail still remains a mystery.

By : Artem Chlegov
Keyword : dvd,hd-dvd,HD-DVD-R,blue ray disc,blue ray,blu-ray,hdtv,high definition,high definition television

All About DVD Part 2: The Mess With Formats

All About DVD Part 2: The Mess With Formats

Getting familiar with recordable DVD formats

Probably everyone nowadays had a need to transfer information between several PC's or make a backup copy of favorite movie. Recordable DVDs (DVD-Rs) serve this purpose very well, but it could be quite hard to get familiar with all the different types of them. While in CD era there were only two formats, namely CD-R for recordable and CD-RW for rewritable disk, for DVD it is not that simple. The fight between manufacturers to enforce their own formats led to the mess of the biblical scale. Besides DVD-R and DVD-RW, in most shops it is possible to encounter DVD+R, DVD+RW and even mysterious DVD-RAM. And there is no guarantee that your DVD drive will be able to work with newly purchased disk.

In this article we will try and help users to get familiar with this mess.

DVD-ROM

(DVD Read Only Memory). Generic factory-printed DVD. All mass-production DVDs with movies, software etc are printed on DVD-ROM.

DVD-R

(DVD-Recordable - pronounced as "DVD Are" or "DVD Dash Are"). This is the first format for recordable DVDs. It was developed in 1995 by Pioneer and was approved by DVD-Forum as a main standard for recordable DVD. Basically, this formatis direct analogue of CD-R but with bigger capacity and, respectively, smaller track size. As with CD-R, record is made by altering the structure of organic polymer in reflective layer with powerful laser. DVD-R can be recorded only once, but it is compatible with most DVD players and computer DVD drives. Properly stored and unscratched DVD is believed to remain readable for hundreds of years.

Initially DVD-R was only single-layered, but recently double-layer DVD-R DL (dual layer) becomes available. They are also known as DVD-R9, however, they are still uncommon and they can be recorded only on newest models of DVD burners. Trying to record these disks in non-compatible drive can actually lead to the DVD burner damage.

There are two types of DVD-R disks: DVD-R Authoring (DVD-R (A)) and DVD-R General (DVD-R (G)).DVD-R (A) type of disks appears first and was used only for professional needs. This type of disk allows recording of anything, including hidden area and keys, which means that It can be used as a master-copy for mass-production.

Devices and disks compatible with DVD-R(A) are professional equipment and therefore very expensive and uncommon.

DVD-R General (G) is much more common. It was developed later specifically for the needs of common users. This type of disks does not allow making a full copy of protected DVD - no keys will be recorded and resulting disk simply will not play. On the other hand, there are lots of devices and blank DVD-R son the market for this type of disks, and they also quite inexpensive. DVD-R (G) devices can read DVD-R (A) disks but cannot record anything on them.

Unlike CD-R, DVD-R shave a special copy protection called CPRM, which stands for Content Protection for Recordable Media. Each blank DVD-R has inerasable encrypted entry (lead in) in hidden area of the disk, which contains information about type of medium and manufacturer. When backup copy of protected DVD is made, copy program will re-encode the information again, but this time using this hidden information, so twill not be possible to copy the resulting disk again as it will require hidden information from specific medium. This type of copy protection also supported by other DVD-Forum formats, namely DVD-RW and DVD-RAM.

DVD-RW

DVD-RW (DVD ReWritable) was also developed by the Pioneer and essentially is the same DVD-R with only difference that reflective layer's state can be transformed by the laser more than once. The specifications for DVD-RW states that each DVD-RW medium should withstand up to 1000 rewriting cycles. The reflectivity of < b>DVD-RWs is much less then of DVD-R and some DVD drives can mistake them for dual-layer DVD. For this reason DVD-RW are compatible with only approximately 70% of existing DVD players.

Early models of DVD-drives required DVD-RW to be finalized in order to read it properly; however, with the appearance of new drives this is not necessary anymore in most cases. It is also not necessary to write at least 1 GB on a disk. Files of any size, no matter how small can be recorded now.

Dual layer DVD-RW, called DVD-RW DL with capacity up to 8.54GB of data is about to appear soon. Currently it is being developed by Ricoh; unfortunately, it won't be compatible with current DVD-drives and for this reason is unlikely to ever become popular. Besides, high capacity Blue-Ray and HD DVD are also coming soon.

DVD+RW

Despite the decision of DVDForum, DVD+RW (DVD ReWritable, pronounced as DVD plus R) format was founded and promoted by coalition of developers called DVD+RW Alliance. First version of DVD+RW, presented in 1997, was able to hold only 2.8 GB of data (compared with 4.7 for DVD-RW). These disks also weren't compatible with normal DVD players and, basically, all of these were the reasons for DVD Forum not to accept this standard.

later developers managed to improve both flaws but even after this, DVD+RW didn't become a standard. As a result, DVD+RW can only reviewed a potential alternative to DVD-RW. However, DVD+RW is not without some pleasant features that DVD-RW misses:

1. Lossless linking technology allows editing of the recorded disk on sector level, which means that, unlike in DVD-RW, there is no need to rewrite whole disk when only certain parts of it needs to be changed.

2. DVD+RW format has better facility for error handling. If certain sector wasn't recorded properly, it is rewritten again, more carefully. Also during the process of disk creation DVD Burner is able to determine the address of sector that is being recorded, so if the record process is interrupted, it is possible to resume it from the same position where it stopped.

3. DVD+RW format supports EasyWrite(Mt. Rainier) technology, which in conjunction with special software such as DirectCD or InCD allows using DVD+RW medium as a normal floppy or hard drive via Explorer or other file manager. The support for EasyWrite also will be included in new Microsoft Windows Vista as a standard option.

4. In addition to everything above, maximum writing speed for DVD+RW is about twice faster than for DVD-RW.

However, DVD+RW format also has some drawbacks.For example, DVD+RW is less compatible compared to DVD-RW, and the probability of running into incompatible DVD drive is higher, no matter what the press-releases and advertisements claim. Compatibility becomes even bigger issue for old DVD drives.

DVD+RW and DVD+R have a special protection system designed for them, called VCPS (Video Content Protection System for DVD+R/+RW). It has all the features of CPRM (which is for DVD-RRW) and also supports limitations in copying of protected digital broadcasts. However, such innovations are usually welcomed only by movie and video producers and generally provide only nuisance for users.

DVD+R

Although it might seem strange, DVD+R was introduced by the same DVD+RWAlliance later than DVD+RW, namely in 2002, which is the reason why it is possible to encounter DVD drives that can work with DVD+RW but are totally incompatible with DVD+R. The introduction of DVD+R was more of a step back for the developers, as the only thing they have to do to create DVD+R is to change the substance in reflective layer of DVD+RW from rewritable to the one that support only one cycle of writing. Due to this, DVD+R is actually missing some of useful features of DVD+RW, such as improved error handling. There is also dual layer version of DVD+R, called DVD+R DL or DVD+R9 (actually, it appeared earlier thanDVD-R9). In general, DVD+R does not differ much from DVD-R.

DVD-RAM

Initially DVD-RAM (DVD-Random Access Memory) was developed for back-up storage, but later it's capabilities in handling video became evident, so now there are many home DVD-RAM camcorders and DVD-RAM recorders which are aimed to replace VHS.

Although DVD-RAM format was developed by Panasonic in compliance with DVD Forum, it is much different from DVD-R and DVD-RW. The chemical part of the process is essentially the same as in DVD-RW, but the logical part more resembles the operation of hard disk drive. From the very beginning DVD-RAM is divided into several sectors. Data is recorded not in circular track as in normal DVD and CD but is directed in certain sector, without particular order. During reading of the disk this allows to find the desired file fast and easily by addressing appropriate sector. Besides, this layout allows reading and writing information simultaneously. Interestingly enough, DVD-RAM does not require any special software for recording; it can be accessed in the same manner as normal hard drive or floppy disk.

Although DVD-RAM can withstand more writing cycles (about 100000) than DVD-RW, it is substantially more fragile and have to be handled with much greater care. For this reason many DVD-RAMs are being sold in special cartridges, however, if disk is single-sided, it can be removed from cartridge temporarily as some DVD-RAM recorders have normal CD tray instead of cartridge loader.

Some DVD-RAM disks are actually sold without any case at all. These disks require extreme caution during use.

However, despite being extremely fragile, DVD-RAM has most reliable error checking. If error is discovered during burning process, data is simply recorder in different sector; while in any other DVD format disk will become completely unreadable.

Speaking of compatibility, any DVD-RAM recorder will have no troubles reading DVD-R and DVD-RW formats. However, only few drives will be able to read DVD-RAM format. Unfortunately, DVD-RAM is much less common compared to other formats of recordable DVD's and therefore the price for both drives and disks is still relatively high.

DVD+VR, DVD-VR

DVDs can be recorded in two modes - Video Format and Video Recording Format (DVD-VR). First one is compliant with DVD-Video standard and is compatible with any equipment (this format is used for factory DVD-Video disks and for video data on DVD-R). DVD-RV mode can be altered after recording and does not require copy to hard drive in order to edit disk contents. It is possible to add, cut and delete video data for the disks written in DVD-VR mode, it is also possible to add more chapters or change menu. This can be done for both DVD-RW and DVD-RAM (for DVD-RAM it is actually the only available mode).

For DVD+RW there exists slightly better version of DVD-VR called DVD+VR. Some of the positive differences from DVD-VR are the possibility of creation of full-fledged menus up to 30megabytes in size, while DVD-VR can only generate standard play-lists. It is also possible to delete data from DVD+VR anytime, while in DVD-VR it has to be done only prior to recording of new data. And the most important thing - DVD-VR disks can only be played on DVD Burner or home DVD Recorder, while DVD+VR can be viewed on any device capable of reading DVD+RW.

Not long ago the selection of preferred format was an important question, as after selecting, for example, DVD-R compatible device the user have to live with the fact that the device won't be able to read or write DVD+R. It was also dangerous to use DVD-RW or DVD+RW as a floppy to transfer data, because, unlike CD-RW, there was a chance that there will be incompatible drive in other computer.

Luckily enough, these problems are now gone.

Summary

After the appearance of first multi-format device on the market, any modern DVD drive now supports almost all of available formats, and the selection of desired type of DVD can be made several times a day, depending on particular task. The only sad thing that the mess with DVD formats was sorted too late, as completely new formats of disks are already emerging.

By : Artem Chlegov
Keyword : dvd recording,format,dvd-r,dvd-rw,dvd+r,dvd+rw,dvd-ram,dvd+vr,dvd-r,dvd-r9,dvd+r9,dl

All About DVD Part 1: DVD Format

All About DVD Part 1: DVD Format

Types of DVD and history of development

It's been a long time since DVD became common in our everyday life. However, most people don't seem to know what it is exactly. Answers to questions like "what sort of arcane symbols are printed on disk boxes", "how come DVD is different from CD if they look so similar", "what kinds of DVDs are there" and many others still remain mystery for many users. And instead of making conscious choice they just buy randomly without any knowledge of what exactly they are getting.

We will examine DVD in details, along with its history and different types available on the market. DVD-Video will get most attention as it is the most common type of DVDs.

What is DVD?

Initially DVD standard was designed for video storage only. Thus its acronym was decrypted as Digital Video Disk. Later, when DVD started to become popular for storage of all types of data, another meaning for DVD acronym was introduced - Digital Versatile Disk, which is still used nowadays.

Generally, DVD is the next generation of CD. First of all, DVD differs from CD by its significantly larger capacity. While CD disk can only contain between 650 and 800 megabytes, DVD is able to hold anywhere between 1 and 17 gigabytes, depending on disk type. This storage increase is achieved by reducing laser wavelength. But DVD capacity would never reach more than 4.7 gigabytes if it wasn't possible to make DVD disks double-layered or double-sided.

One side of double-layered disk can contain two layers of data. To avoid interlapping, outer layer is made semi-transparent. During reading, laser collects data from bottom layer first, and then switches to the second layer. This allows doubling the capacity, up to 9GB. It is easy to recognize double-layered disks - they have silver shade of working surface, while single-layered disk appears gold. Most video releases are printed on double-layered disks.

Apart from that, both sides of DVD can be used to store data. The possibility of making double-sided disks arise from the fact that the protective layer for DVD is only half of that for CD, that is, 0.6mm instead of 1.2mm. So, in order to keep compatibility with older format, single-sided DVD disks have additional plastic added to them to achieve 1.2mm thickness. Of course, it is not a problem to put additional layer instead of 0.6mm of plain plastic. This wasn't possible with CDs as they are thick enough already.

DVD - the history of conflict

In 1997 several large manufacturers of electronic equipment established organization called DVD-Forum (earlier known as DVD Consortium) in order to develop single standard for new generation of disks, as CD technology was becoming less and less sufficient.

Despite many debates and lots of technologies claiming to be the best, the final decision was made and DVD (with eight types of it) standard was established. It was soon followed by DVD-Video standard.

However, when it came to standards for recordable and rewritable disks, several large companies started to push their own formats DVD+R and DVD+RW. These companies founded their own coalition called DVD+RW Alliance. The most interesting part was the fact that different branches of formats were not compatible with each other.

Apart from that, Panasonic also contributed to the mess by developing DVD-RAM standard. This standard was faster and more reliable, but it was compatible only with DVD-RAM devices.

The ones who suffered the most from this mess were common users, as they were forced to make a difficult choice of preferred technology.

For that reason many people didn't rush for DVD and kept their data on good old CD-Rs and CD-RWs.

The war of standards was ended by Sony, which made DVD drive capable of reading both DVD-RW and DVD+RW. This device instantly became popular even in spite of its double price compared with single-standard drives. Sony soon was followed by other manufacturers and the ability to read both types of disks soon became a standard for any DVD drives. This was the beginning of the DVD era for PC users.

Unfortunately, there also were lots of disagreements during development of single standard for digital audio, DVD-Audio. Two technologies compete for the title of Audio CD heir: a partially compatible with Audio CD technology from Philips and Sony, and a standalone Toshiba's standard. Toshiba won, but Philips and Sony didn't give up and released their own format without DVD-Forum support. This format was called Super Audio CD (SACD). At the moment both formats are not selling particularly well and are not known in some countries at all.

Types of DVD

Let's move to DVD itself. DVD is the most common format nowadays. At the moment DVD comes in 8 flavors: DVD-1, DVD-2, DVD-3, DVD-4, DVD-5, DVD-9, DVD-10 and DVD-18. The difference is in the capacity, which is denoted by the number in the name (value is rounded).

The most common formats are DVD-5 and DVD-9. These are single- and double layered single sided disks, respectively. DVD-5 holds 4.7 GB of data and DVD-9 is able to contain up to 8.5 GB. These disks are used for most software and video releases.

DVD-10 is double sided single layered disk (9.4 GB) and DVD-18 is double sided double layered disk (17GB). This two types of DVD are much less common. All four formats mentioned above have same diameter of the disk - 12cm. Another type of disk to mention here is DVD-14, which is double sided disk with one side single- and the other one double-layered. This type of disk holds 12.32GB of data.

DVD-1, DVD-2, DVD-3 and DVD-4 are miniDVD. Their diameter is 8cm but otherwise they are completely compatible with standard drives. As with full-size disks there are single sided single layered disk (DVD-1, 1.36 GB), single sided double layered disk (DVD-2, 2.48 GB), double sided single layered (DVD-3, 2.72 GB) and double sided double layered disk (DVD-4, 4.95 GB). All these disks, except DVD-1, are quite uncommon.

Types of DVD data

Each DVD disk is able to hold various types of data. DVD can be used to watch movies (DVD-Video), store software (DVD-Data) and to listen to the music (DVD-Audio).

DVD-Data

DVD-DATA is used to store computer data on DVD. Basically it is the same CD-ROM, but with much bigger capacity, and it is used the same way as CD-ROM is. However DVD-DATA is more convenient as a storage medium due to its large capacity. Most modern programs doesn't fit on single CD, for example, computer games and Linux packages often need more than 10 CDs. In case with DVD one or two disks are usually more than enough. At the moment software is usually released on both CD and DVD, as not everyone has DVD drive yet. But it is clear that CD versions soon will disappear.

DVD-Video

Currently this is the most common type of DVD data, the one that DVD was initially designed for. Compared with VHS tapes DVD-Video is a giant leap into the future. There are heaps of features there that most people have no idea about.

First of all, DVD-Video is interactive - any place on the disk is instantly accessible and it is possible to have more than one ending for the movie. And parents can limit viewing of naughty parts of movies for their children. Apart from that disks can have additional bonus materials, such as interviews, promotion trailers, slides, text info and even videogames. In addition to all this DVD-Video is capable to have multi angle view option, when camera angle can be changed during playback. However, this feature mostly used in porno movies and live concert records.

Video data on DVD-Video disks is compressed by using MPEG-2 compression. This compression algorithm allows shrinking video stream approximately ten times, without loss of picture quality. As a result, each disk is able to hold up to 4 hours of video with 720x576 resolution at 24 frames per second (PAL) or 720x480 at 30 frames per second (NTSC). The streaming speed is usually between 3 and 10 MBit per second.

Video can be recorded in different screen ratios. For example, it can have ratio of 4:3, which is a standard television ratio, or widescreen - 16:9. Widescreen image have two types: Letterbox and anamorphic. In the first case image is simply cropped at the top and at the bottom to achieve desired format. In anamorphic mode the image is initially recorded in stretched form and then shrinked to the desired size. This method is much more effective as whole frame is used for useful data, while in Letterbox large part of the frame is used to store black pixels only. As a result, anamorphic mode has better details and sharper picture.

Audio data can be stored in various formats: LPCM, Dolby Pro Logic, Dolby Digital, Dolby Digital EX and DTS.

LPCM (linear pulse code modulation) is uncompressed stereo or mono soundtrack. It is usually used in musical video clips and movies where sound clarity is important. Same format is used for generic Audio CD

Dolby Pro Logic is special type of soundtrack that can be split into 4 channels for surround sound. Nowadays this format is uncommon.

Dolby Digital (AC-3) is fully digital sound compression format; it can be split into up to 6 independent channels. Unlike Dolby Pro Logic, each channel is recorded on separate physical track.

Dolby Digital EX is more advanced version of Dolby Digital. Supports up to 8 independent channels.

DTS (Digital Theater System) is another digital audio compression format, introduced by Steven Spielberg as an alternative to Dolby Digital. DTS provides more quality than Dolby Digital due to lower compression. That, of course, leads to bigger size of the soundtrack itself, which occupy more disk space. It also requires special receiver to be decoded. Because of these reasons DTS disks usually does not have any bonus materials but have LPCM soundtrack. This soundtrack is included to allow users without special receiver to listen to the sound (stereo only, though). Because of all these DTS disks are much less common compared to Dolby Digital. Usually DTS disks with improved video quality (and without bonus materials) are called SuperBit. Both DTS and Dolby Digital (EX) are also used in cinemas.

Some of the largest drawbacks of DVD-Video are its various copy protection measures, which were added because of the pressure from film companies. At first these measures provided lots of nuisance for users, but eventually every DVD protection was hacked. This process was also assisted by equipment manufacturers who simply didn't support most annoying protection measures.

One of the most annoying of such measures was "Regional Protection" . The world was divided into 8 zones, and each DVD player was supposed to have information about its zone. The same was made for DVDs, and thus DVDs from one zone could only be played on players from the same zone. User was allowed to change zone for the player few times only, and the last of selected zones was locked in the player forever.

This trick was invented in order to be able to assign different price in each region, depending on income level. Besides, movie might be released in different times in different countries. For example, in Africa the movie might just hit cinemas and in USA it might already be available on DVD. So regional protection was supposed to stop people from buying DVDs in USA and selling them in Africa.

Unfortunately, this protection didn't bring anything but troubles. Many travelers were not able to play disk purchased overseas. Buying disks over the internet or from EBay also became a problem. Apart from that, some movies were released in certain countries only.

Many manufacturers considered these implications and started to provide means of switching off regional protection for their devices. Chinese manufacturers basically abandon this protection at all.

But uncontrolled distribution of DVDs wasn't the only thing that movie makers were against. Illegal copying was much bigger problem for them, especially given the fact that digital information can be copied endlessly without any loss of quality. To prevent that from happening, manufacturers included special CSS (content scrambling system) technology in DVD-Video standard. CSS basically encrypt all disks content and the key for decryption is available only for DVD-Player or special viewing program. Simply copying the disk will make the copy completely useless.

But manufacturers forgot to include support for Unix system and playback was available only for Windows and MacOS. This issue was solved by Jon Johansen, who wrote DeCSS program for Unix that easily bypassed CSS protection. Developers of CSS were enraged with that and sued Jon. They wanted to stop DeCSS from spreading and put Jon in prison, however, this case sparked lots of support movements around the world. Activists even printed DeCSS code on t-shirts. Finally, Jon was declared not guilty and his program laid a foundation for many DVD copy utilities all over the world.

In general, DVD format was successful and, despite some issues with regional protection, has spread all over the world and almost replaced VHS tapes.

Summary

DVD is not a new format anymore and there are actually new formats already that aim to replace it. Someone could ask why does he or she needs to be familiar with DVD if there is something new coming? The answer to this lies in the fact that DVD provides foundation for most new technologies, for example HD-DVD or Blue Ray. And if someone became familiar with underlying principles once, it won't be a problem to switch to something new later.

By : Artem Chlegov
Keyword : all about dvd,dvd-hd,blue ray,audio-cd,dvd-video,dolby digital,dts,formats,dvd-data,micro-d