Ripping
Ripping is the extraction of digital content from a container, such as a CD, onto a new digital location. Originally, the term meant to rip music from Commodore 64 games. Later, the term was applied to ripping WAV or MP3 files from digital audio CDs, and after that to the extraction of contents from any storage media, including DVD and Blu-ray discs, as well as the extraction of video game sprites.
This article is about copying digital media. For other uses, see Rip.
Despite the name, neither the media nor the data is damaged after extraction. Ripping is often used to shift formats, and to edit, duplicate or back up media content. A rip is the extracted content, in its destination format, along with accompanying files, such as a cue sheet or log file from the ripping software.
To rip the contents out of a container is different from simply copying the whole container or a file. When creating a copy, nothing looks into the transferred file, nor checks if there is any encryption or not, and raw copy is also not aware of any file format. One can copy a DVD byte by byte via programs like the Linux dd command onto a hard disk, and play the resulting ISO file just as one would play the original DVD.
To rip contents is also different from grabbing an analog signal and re-encoding it, as it was done with early day CD-ROM drives not capable of digital audio extraction (DAE). Sometimes even encoding, i.e. digitizing audio and video originally stored on analog formats, such as vinyl records is incorrectly referred to as ripping.
Ripping software[edit]
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.
For example, audio CDs contain 16-bit, 44.1 kHz LPCM-encoded audio samples interleaved with secondary data streams and synchronization and error correction info. The ripping software tells the CD drive's firmware to read this data and parse out just the LPCM samples. The software then dumps them into a WAV or AIFF file, or feeds them to another codec to produce, for example, a FLAC or MP3 file. Depending on the capabilities of the ripping software, ripping may be done on a track-by-track basis, or all tracks at once, or over a custom range. The ripping software may also have facilities for detecting and correcting errors during or after the rip, as the process is not always reliable, especially when the CD or the drive containing the CD itself is damaged or defective.
There are also DVD rippers which operate in a similar fashion. Unlike audio CDs, DVDs do contain data formatted in files for use in computers. However, commercial DVDs are often encrypted (for example, using Content Scramble System/ARccOS Protection), preventing access to the files without using the ripping software's decryption ability, which may not be legal to distribute or use. DVD files are often larger than is convenient to distribute or copy to CD-R or ordinary (not dual-layer) DVD-R, so DVD ripping software usually offers the ability to re-encode the content, with some quality loss, so that it fits in smaller files.