There has been a lot of talk lately about the advances in DVD. Many claim it to be the next step beyond the CD-ROM. But, before jumping right into it, one needs to understand it. In doing so, one will find that it might not be all that it is cracked up to be. At least not yet.
The DVD acronym is a little vague. Some call it Digital Video Disk while other call it Digital Versatile Disk. It doesn’t really matter, though. It is indeed the next step beyond CD-ROM. Each disk can hold anywhere from 4.7GB to 17GB! A standard CD can hold only 650MB. While this is good, DVD also plays a big role in bringing the computer to the level of the TV. Many movies are now distributed on DVD-ROM. These movies often allow the user to select custom camera angles or view it in different languages.
The CD was a major innovation to the world of the PC. It caught on quickly because it was cheap to make and could hold quite a lot of data, especially when you consider the fact that the next best alternative for mass-distribution of software was the floppy disk. It would take 450 floppy disks to equal the capacity of a CD-ROM. But, believe it or not, the CD-ROM itself began to pose limitations for users. Data-intensive applications saw capacity issues with only 650 MB of available space. This is where DVD comes in. DVD stands for digital versatile disc. The “versatile” comes from the fact that it can hold data as well as sound and video. This is not very telling, seeing as CD-ROM can do this, too. But, however you determine to name it, DVD significantly increases capacities, with double-sided, double-density DVD discs able to hold up to 17 GB of data.
DVD is more common as a platform to distributing movies than it is as a computer data medium. Hollywood has played a major part in the rapid boom of DVD in this arena. While there is computer software distributed on DVD, it is rare when compared to CD-ROMs. Usually, only niche software that requires lots of space comes on DVD. Some programs that used to span several CD-ROMs (encyclopedias, for example) are good candidates for DVD distribution.
Movie Distribution = Code Protection
As we all know from the war of RIAA against the likes of Napster, artist groups take protection of their works very seriously. This is no different when it comes to movies, and obviously, distributing movies on DVD makes the desire of the motion picture industry to protect those movies all that much stronger. There are severals ways to go about doing this.
- Region Code Control – Hollywood studios often release movies at different times in different areas of the world. So, the industry wanted to be able to implement regional control on DVDs so that they could maintain control over timing. Each DVD player is given a code to correspond to the region in which it is sold. That code must correspond with the regional code on the DVD, or it won’t play. Region codes are optional and if a DVD has no such codes, it will play on any player.
- Macrovision 7 – This is a proprietary protection spec that takes advantage of the non-displayed portion of the video signal to prevent copying. The portion of the signal in question is that which controls the automatic gain control or a recording deck, so copying a movie with such protection would result in a blacked-out video that is not watchable.
- Content Scrambling System – Uses a method of encryption/decryption using keys to decrypt content.
- Digital Video Express (DIVX) – DIVX is like big brother, if you ask me. It is a proprietary encoding scheme that requires a special DIVX player which includes a dial-up connection to a DIVX online service. DIVX discs were cheaper than regular DVDs, but when you played it for the first time, you had 48 hours to watch it until the player disabled the disc and did not allow you to watch it. It also registers the disc with the online service, and disconnecting the player from the connection will disable the player until it is re-connected. If you wanted to view the movie again, you had to purchase additional viewing time. You could also purchase the whole disc and it would unlock. DIVX drives are more expensive than regular ones, and they were plagued with compatibility issues.
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