Ripping

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Ripping is the process of copying audio or video content to a hard disk, typically from removable media or media streams. Digital audio extraction is a more formal phrase applied to the ripping of audio CDs. Ripping is distinct from simple file copying in that the source audio/video is not formatted for ease of use in a computer filesystem. For example, the hierarchy of files making up the audio/video data on a DVD-Video disc can be encoded into a single avi file. In addition, the copied data is often compressed with appropriate codecs. Ripping is often used to shift formats, and to edit, duplicate or backup media content. Media files released on the Internet may describe the source of the rip in their names, e.g. DVD-Rip.[1]

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[edit] Ripping Software

Main article: CD ripper

A CD ripper, CD grabber or CD extractor is a piece of software designed to extract or "rip" raw digital audio (in format commonly called CDDA) from a compact disc to a file or other output. Some all-in-one ripping programs can simplify the entire process by ripping and burning the audio to disc in one step, possibly re-encoding the audio on-the-fly in the process.

[edit] Legality

Ripping also allows content to be losslessly copied for a very low or essentially zero cost and given to those who did not purchase it, possibly substituting for sales of content. Hence it has aroused fierce opposition by the recording industry, who view it as theft.[2]

Since the music or video is transferred to a data file, the files can be shared with other computer users over the Internet.

Although it is legal in the United States to make backup copies of software, the legality of ripping music for personal use without the permission of the copyright holder is controversial. Historically, copying media for personal use was established to be Fair Use under U.S. Copyright by the Supreme Court in the Sony Betamax doctrine. On the other hand, the RIAA, which represents many music copyright holders has maintained that copying rights have not been granted to end users and that Fair Use does not apply.[3]

Depending on the outcome of the trial including the RIAA v. Jammie Thomas, even ripping a cd without permission from the owner of the copyright, even for personal use may be illegal. [4]

However, in oral arguments before the Supreme Court in MGM Studios, Inc. v. Grokster, Ltd., Don Verrilli, representing MGM stated:

"And let me clarify something I think is unclear from the amicus briefs. The record companies, my clients, have said, for some time now, and it's been on their Website for some time now, that it's perfectly lawful to take a CD that you've purchased, upload it onto your computer, put it onto your iPod. There is a very, very significant lawful commercial use for that device, going forward."[5]

In some countries selling software to circumvent copy-protection in commercial DVDs is illegal.[6]

In countries such as Spain, anyone is allowed to make a private copy of a copyrighted material for oneself and the source copy does not even have to be legal. Making copies for other people, however, is forbidden if done for profit. In the United Kingdom, making a private copy of copyrighted media without the copyright owner's consent is illegal as of January 2008: this includes ripping music from a CD to a computer or digital music player.[7][8] The UK government has made proposals to allow people to make copies of music for personal use.[9].

[edit] Obtaining an accurate rip

CD audio has two major design constraints that make it difficult to obtain accurate copies in the form of a standard digital file. First, the system is designed to provide audio in real time in order to ensure continuous playback without gaps. For this reason, it does not provide a reliable stream of data from the disc to the computer.

Secondly, the designers felt that it would be preferable for major scratches in the disc to be covered up rather than resulting in total failure. Normally, an error correction system such as Reed Solomon would provide either a perfect copy of the original error-free data, or no result at all. However, CD audio's Cross-interleaved Reed-Solomon coding includes an extra facility that interpolates across uncorrectable errors. This means that the data read from an audio CD may not in fact be a faithful reproduction of the original.

Another practical factor in obtaining faithful copies of the music data is that different CD drives have widely varying quality for reading audio. Some drives such as Plextor are thought to deliver extremely accurate copies [1] while other may do little or no error correction and even misreport error correction information.

Obtaining an accurate digital extraction or "rip" under these circumstances is difficult. iTunes includes an "error correction" mode in its CD importing system. Technical information about this mode is not available from Apple, but it probably [2] ensures that iTunes will attempt to error-correct all data it reads off the disc. However, iTunes does not report if interpolation occurred due to uncorrectable errors.

There is specialized software that will attempt to correct errors, and also attempt to report if errors could not be corrected. See Software aiming to provide an accurate/secure rip They use a variety of techniques, such as making use of error correction information, knowledge of the peculiarities of different drives, and ripping multiple times and comparing the results. All of these programs are still susceptible to some degree to poor CD drives.

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