Media Descriptor File (MDF) is a proprietary disc image

file format A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...

developed for Alcohol 120%, an optical disc authoring program. Daemon Tools,

CDemu CDemu is a free and open-source virtual drive software, designed to emulate an optical drive and optical disc (including CD-ROMs and DVD-ROMs) on the Linux operating system. , CDemu is not available in the official repositories of Debian, Ubuntu ...

, MagicISO, PowerDVD, and

WinCDEmu WinCDEmu is an open-source utility for mounting disk image files in Microsoft Windows. It installs a Windows device driver which allows a user to access an image of a CD or DVD as if it were a physical drive. WinCDEmu supports ISO ISO is the most ...

can also read the MDF format. A ''disc image'' is a

computer file A computer file is a computer resource for recording data in a computer storage device, primarily identified by its file name. Just as words can be written to paper, so can data be written to a computer file. Files can be shared with and trans ...

replica of the

s and

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...

of an

optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...

. Unlike an

ISO image An optical disc image (or ISO image, from the ISO 9660 file system used with CD-ROM media) is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. I ...

, a Media Descriptor File can contain multiple layers (as used in dual-layer recording) and multiple optical disc tracks. Like the IMG file format, a Media Descriptor File is a "raw" image of an optical disc. The word ''raw'' implies that the copy is precise,

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented a ...

-for-bit, including (where appropriate) file-system metadata. A Media Descriptor File may be accompanied by a Media Descriptor Sidecar file. This optional

binary file A binary file is a computer file that is not a text file. The term "binary file" is often used as a term meaning "non-text file". Many binary file formats contain parts that can be interpreted as text; for example, some computer document fi ...

(with

file extension A filename extension, file name extension or file extension is a suffix to the name of a computer file (e.g., .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically ...

.mds) contains metadata about an imaged optical disc, including a delineation of where disc layers begin and end ("layer breaks"), and which portions of the MDF belong in which disc layer. The MDS file also stores the location and value of the layer breach bit, a CD/DVD copy protection mechanism. The MDS file is comparable to the CloneCD Control File and cue sheet (.cue) file formats. However, their capabilities are not identical; also the cue sheet is a

text file A text file (sometimes spelled textfile; an old alternative name is flatfile) is a kind of computer file that is structured as a sequence of lines of electronic text. A text file exists stored as data within a computer file system. In operat ...

format. Alcohol 120%'s MDF/MDS format is one of the few formats besides Nero's NRG, BIN/CUE and CloneCD's CCD/IMG/SUB disc image formats to support

Mixed Mode CD A mixed mode CD is a Compact Disc which contains both data and audio in one session. Typically the first track is a data track while the rest are audio tracks. The most common use for mixed mode CDs is to add CD-quality audio to video games on a ...

s which contain audio CD tracks as well as data tracks.

References

{{Disk images Archive formats Computer file formats Disk image emulators Hacker culture Optical disc authoring Hardware virtualization Warez Compact Disc and DVD copy protection

See also

References