CD ripper
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ACD ripper,CD grabber,orCD extractorissoftwarethatripsrawdigital audioinCompact Disc Digital Audio(CD-DA) format tracks on acompact discto standard computer sound files, such asWAVorMP3.
A more formal term used for the process of ripping audio CDs isdigital audio extraction(DAE).
History
[edit]In the early days of computer CD-ROM drives and audio compression mechanisms (such as MP2), CDrippingwas considered undesirable by copyright holders, with some attempting to retrofit copy protection into the simple ISO9660 standard. As time progressed, most music publishers became more open to the idea that since individuals had bought the music, they should be able to create a copy for their own personal use on their own computer. This is not yet entirely true; even with some current digital music delivery mechanisms, there are considerable restrictions on what an end user can do with their paid for (and therefore personally licensed) audio. Windows Media Player's default behavior is to add copy protection measures to ripped music, with a disclaimer that if this is not done, the end user is held entirely accountable for what is done with their music. This suits most users who simply want to store their music on a memory stick, MP3 player or portable hard disk and listen to it on any PC or compatible device.
Etymology
[edit]TheJargon Fileentry forripnotes that the term originated inAmigaslang, where it referred to the extraction of multimedia content from program data.[1]
Design
[edit]As an intermediate step, some ripping programs save the extracted audio in alosslessformat such asWAV,FLAC,or even rawPCMaudio. The extracted audio can then be encoded with alossycodeclikeMP3,Vorbis,WMAorAAC.The encoded files are more compact and are suitable for playback ondigital audio players.They may also be played back in amedia playerprogram on a computer.
Most ripping programs will assist in tagging the encoded files withmetadata.The MP3 file format, for example, allowstagswith title, artist, album and track number information. Some will try to identify the disc being ripped by looking up network services likeAMG'sLASSO,FreeDB,Gracenote'sCDDB,GD3[1]orMusicBrainz,or attempt text extraction ifCD-Texthas been stored.
Some all-in-one ripping programs can simplify the entire process by ripping andburningthe audio to disc in one step, possibly re-encoding the audio on-the-fly in the process.
Some CD ripping software is specifically intended to provide an especially accurate or "secure" rip, includingExact Audio Copy,cdda2wav,CDexandcdparanoia.
Compact disc seek jitter
[edit]In the context ofdigital audio extractionfromcompact discs,seek jittercauses extractedaudio samplesto be doubled-up or skipped entirely if the Compact Disc drive re-seeks. The problem occurs because theRed Bookdoes not require block-accurate addressing during seeking.[a]As a result, the extraction process may restart a few samples early or late, resulting in doubled or omitted samples. These glitches often sound like tiny repeating clicks during playback. A successful approach to correction in software involves performing overlapping reads and fitting the data to find overlaps at the edges. Most extraction programs perform seek jitter correction. CD manufacturers avoid seek jitter by extracting the entire disc in one continuous read operation, using special CD drive models at slower speeds so the drive does not re-seek.
Optical drive properties
[edit]Properties of an optical drive helping in achieving a perfect rip are a small sample offset (at best zero), nojitter,no or deactivatablecaching,and a correct implementation and feed-back of the C1 andC2error states. There are databases listing these features for multiple brands and versions of optical drives. Also,EAChas the ability to autodetect some of these features by a test-rip of a known reference CD.[2]
Examples
[edit]Notable CD ripper applications include the following ones:
See also
[edit]Notes
[edit]- ^Due to additional sector level addressing added in theYellow Book,CD-ROMdata discs are not subject to seek jitter.
References
[edit]- ^"rip".The Jargon File (version 4.4.3).catb.org. 2003-07-01. Archived fromthe originalon 2009-02-24.
- ^DAE Drive Features Database - FAQArchived2006-01-16 at theWayback Machine(2007)
- ^"cdparanoia".
- ^"fre:ac".
External links
[edit]- "Recommended Secure Digital Audio Extraction software".Archivedfrom the original on 2013-05-18.
- "Comparison of CD rippers".Retrieved2021-07-19.