CD ripper

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fre:ac, a CD extractor and audio converter

A CD ripper, CD grabber, or CD extractor is software that rips raw digital audio in Compact Disc Digital Audio (CD-DA) format tracks on a compact disc to standard computer sound files, such as WAV or MP3.

Contents

A more formal term used for the process of ripping audio CDs is digital audio extraction (DAE).

History

In the early days of computer CD-ROM drives and audio compression mechanisms (such as MP2), CD ripping was 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

The Jargon File entry for rip notes that the term originated in Amiga slang, where it referred to the extraction of multimedia content from program data. [1]

Design

As an intermediate step, some ripping programs save the extracted audio in a lossless format such as WAV, FLAC, or even raw PCM audio. The extracted audio can then be encoded with a lossy codec like MP3, Vorbis, WMA or AAC. The encoded files are more compact and are suitable for playback on digital audio players. They may also be played back in a media player program on a computer.

Most ripping programs will assist in tagging the encoded files with metadata. The MP3 file format, for example, allows tags with title, artist, album and track number information. Some will try to identify the disc being ripped by looking up network services like AMG's LASSO, FreeDB, Gracenote's CDDB, GD3 or MusicBrainz, or attempt text extraction if CD-Text has been stored.

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.

Some CD ripping software is specifically intended to provide an especially accurate or "secure" rip, including Exact Audio Copy, cdda2wav, CDex and cdparanoia.

Compact disc seek jitter

In the context of digital audio extraction from compact discs, seek jitter causes extracted audio samples to be doubled-up or skipped entirely if the Compact Disc drive re-seeks. The problem occurs because the Red Book does not require block-accurate addressing during seeking. [lower-alpha 1] 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

Properties of an optical drive helping in achieving a perfect rip are a small sample offset (at best zero), no jitter, no or deactivatable caching, and a correct implementation and feed-back of the C1 and C2 error states. There are databases listing these features for multiple brands and versions of optical drives. Also, EAC has the ability to autodetect some of these features by a test-rip of a known reference CD. [2]

Examples

Notable CD ripper applications include the following ones:

BSD and Linux
Mac OS X
Windows

See also

Notes

  1. Due to additional sector level addressing added in the Yellow Book, CD-ROM data discs are not subject to seek jitter.

Related Research Articles

<span class="mw-page-title-main">Compact disc</span> Digital optical disc data storage format

The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in October 1982 in Japan and branded as Digital Audio Compact Disc.

<span class="mw-page-title-main">MP3</span> Digital audio format

MP3 is a coding format for digital audio developed largely by the Fraunhofer Society in Germany under the lead of Karlheinz Brandenburg, with support from other digital scientists in other countries. Originally defined as the third audio format of the MPEG-1 standard, it was retained and further extended — defining additional bit-rates and support for more audio channels — as the third audio format of the subsequent MPEG-2 standard. A third version, known as MPEG-2.5 — extended to better support lower bit rates — is commonly implemented, but is not a recognized standard.

<span class="mw-page-title-main">Compact Disc Digital Audio</span> Data format used for audio compact discs

Compact Disc Digital Audio, also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the Red Book, one of a series of Rainbow Books that contain the technical specifications for all CD formats.

<span class="mw-page-title-main">Video CD</span> CD-based format meant for digital video distribution

Video CD is a home video format and the first format for distributing films on standard 120 mm (4.7 in) optical discs. The format was widely adopted in Southeast Asia, South Asia, East Asia, Central Asia and West Asia, superseding the VHS and Betamax systems in the regions until DVD-Video finally became affordable in the first decade of the 21st century.

<span class="mw-page-title-main">MiniDisc</span> Magneto-optical storage medium, mainly for audio (1992–2013)

MiniDisc (MD) is an erasable magneto-optical disc-based data storage format offering a capacity of 60, 74, and later, 80 minutes of digitized audio.

<span class="mw-page-title-main">DVD-Audio</span> DVD format for storing high-fidelity audio

DVD-Audio is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio uses most of the storage on the disc for high-quality audio and is not intended to be a video delivery format.

<span class="mw-page-title-main">CD+G</span> Compact disc format used primarily for karaoke discs

CD+G is an extension of the compact disc standard that can present low-resolution graphics alongside the audio data on the disc when played on a compatible device. CD+G discs are often used for karaoke machines, which use this functionality to present on-screen lyrics for the song contained on the disc. The CD+G specifications were published by Philips and Sony as an extension of the Red Book specifications.

Ripping is extracting all or parts of digital content from a container. Originally, it meant to rip music out of Commodore 64 games. Later, the term was used to mean to extract WAV or MP3 format files from digital audio CDs, but got applied as well to extract the contents of any media, including DVD and Blu-ray discs, and video game sprites.

The digital sound revolution refers to the widespread adoption of digital audio technology in the computer industry beginning in the 1980s.

<span class="mw-page-title-main">Copy Control</span>

Copy Control was the generic name of a copy prevention system, used from 2001 until 2006 on several digital audio disc releases by EMI Group and Sony BMG Music Entertainment in several regions. It should not be confused with the CopyControl computer software copy protection system introduced by Microcosm Ltd in 1989.

<span class="mw-page-title-main">Sound Juicer</span> CD ripper

Sound Juicer is the official CD ripper program of GNOME. It is based on GTK, GStreamer, and libburnia for reading and writing optical discs. It can extract audio tracks from optical audio discs and convert them into audio files that a personal computer or digital audio player can play. It supports ripping to any audio codec supported by a GStreamer plugin, such as Opus, MP3, Ogg Vorbis, FLAC and uncompressed PCM formats. Versions after 2.12 implement CD playing capability. Last versions produce lossy formats with default GStreamer settings.

CD/DVD copy protection is a blanket term for various methods of copy protection for CDs and DVDs. Such methods include DRM, CD-checks, Dummy Files, illegal tables of contents, over-sizing or over-burning the CD, physical errors and bad sectors. Many protection schemes rely on breaking compliance with CD and DVD standards, leading to playback problems on some devices.

<span class="mw-page-title-main">Exact Audio Copy</span>

Exact Audio Copy (EAC) is a CD ripping program for Microsoft Windows. The program has been developed by Andre Wiethoff since 1998. Wiethoff's motivation for creating the program was that other such software only performed jitter correction while scratched CDs often produced distortion.

Cactus Data Shield (CDS) is a form of CD/DVD copy protection for audio compact discs developed by Israeli company Midbar Technologies. It has been used extensively by EMI, BMG and their subsidiaries. CDS relies on two components: Erroneous Disc Navigation and Data Corruption.

A hybrid disc is a disc, such as CD-ROM or Blu-ray, which contains multiple types of data which can be used differently on different devices. These include CD-ROM music albums containing video files viewable on a personal computer, or feature film Blu-rays containing interactive content when used with a PlayStation 3 game console.

<span class="mw-page-title-main">Compressed audio optical disc</span>

A compressed audio optical disc, MP3 CD, or MP3 CD-ROM or MP3 DVD is an optical disc that contains digital audio in the MP3 file format. Discs are written in the "Yellow Book" standard data format, as opposed to the Red Book standard audio format.

<span class="mw-page-title-main">Audiograbber</span>

Audiograbber is a proprietary freeware CD audio extractor/converter program for Microsoft Windows. It was one of the first programs in the genre to become popular. The data extraction algorithm was designed by Jackie Franck and was included in the Xing Technology software package Xing Audio Catalyst in the mid-1990s.

<span class="mw-page-title-main">CD-ROM</span> Pre-pressed compact disc containing computer data

A CD-ROM is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer.

fre:ac Audio converter and CD ripper

fre:ac is a free audio converter and CD extractor for Windows, Linux, macOS, and FreeBSD, distributed under the GPL-2.0-or-later.

References

  1. "rip". The Jargon File (version 4.4.3). catb.org. 2003-07-01. Archived from the original on 2009-02-24.
  2. DAE Drive Features Database - FAQ Archived 2006-01-16 at the Wayback Machine (2007)
  3. "cdparanoia".
  4. "fre:ac".