Thomas Schmitt has made significant contributions to this glossary.
See also @uref{https://www.videohelp.com/glossary}.

@table @dfn

@item @anchor{ASPI}ASPI
@cindex ASPI
See @acronym{Win32 ASPI}

@item ATA

Advanced Technology Attachment (ATA). The same thing as IDE.

@item ATAPI

Advanced Technology Attachment (ATA) Packet Interface. The interface
provides a mechanism for transferring and executing SCSI CDBs on IDE
CD Drives and DVD Drives.

IDE (also called ATA) was originally designed for hard drives only,
but with the help of ATAPI, it is possible to connect other devices, in
particular CD-ROMS to the IDE/EIDE connections.

The ATAPI CD-ROM drives understand a subset of SCSI commands. In
particular multi-initiator commands are neither needed nor defined for
ATAPI devices.

@item BIN/CUE

A CD-image format developed by Jeff Arnold for CDRWIN software on
Microsoft Windows. Many other programs subsequently support using this
format. The @code{.CUE} file is a text file that contains CD format
and track layout information, while the @code{.BIN} file holds the
actual data of each track.

@item Blu-ray Disc (BD)
@cindex Blu-ray Disc (BD)
Optical media with a capacity of 25 GB as a single layer and 50 GB as
double layer. See also @pxref{models-profiles,,"Media models and
profiles"}.


@item CD
@cindex CD
Compact Disc. Capacity up to 900 MB. See also
@pxref{models-profiles,,"Media models and profiles"}.

@item CD-DA
@cindex CD-DA
Compact Disc Digital Audio, described in the ``Red Book'' or IEC 60908
(formerly IEC 908). This is commonly referred to as an audio @acronym{CD}
and what most people think of when you play a @acronym{CD} as it was
the first to use the @acronym{CD} medium.

See @url{http://en.wikipedia.org/wiki/Red_Book_(audio_CD_standard)}

@item CD+G
@cindex CD+G

Compact Disc + Graphics. An extension of the CD audio format contains
a limited amount of graphics in subcode channels. This disc works in
all audio players but the graphics portion is only available in a
special CD+G or Karaoke player.

@item CD-i
@cindex CD-i

Compact Disc Interactive. An extension of the CD format designed
around a set-top computer that connects to a TV to provide interactive
home entertainment, including digital audio and video, video games,
and software applications. Defined by the ``Green Book'' standard.
@uref{http://www.icdia.org/}. CD-i for video and video music has
largely (if not totally) been superseded by VCDs.

@item CD-i Bridge
@cindex CD-i Bridge

A standard allowing CD-ROM XA discs to play on CD-i.  Kodak PhotoCDs
are CD-XA Bridge discs.

@item CD-ROM
@cindex CD-ROM

Compact Disc Read Only Memory or ``Yellow Book'' described in Standards
ISO/IEC 10149. The data stored on it can be either in the form of
audio, computer, or video files.

@item CD-ROM Mode 1 and Mode2

The Yellow Book specifies two types of tracks, Mode 1 and Mode 2. Mode
1 is used for computer data and text and has an extra error correction
layer. Mode 2 is for audio and video data and has no extra correction
layer. CD-ROM/XA An expansion of the CD-ROM Mode 2 format that allows
both computer and audio/video to be mixed in the same track.

@item CD Text
@cindex CD Text

CD Text is a technology developed by Sony Corporation and Philips
Electronics in 1996 that allowed storing in an audio CD and its tracks
information such as artist name, title, songwriter, composer, or
arranger. Commercially available audio CDs sometimes contain CD Text
information.

Information on how CD Text is stored can be found in in older MMC
standards.  Specifically, try ``Annex J'' of ``mmc3r10g.pdf''.

An ``Unofficial CD Text FAQ'' is at
@url{http://web.ncf.ca/aa571/cdtext.htm}

@item @anchor{XA}CD XA
@cindex CD XA

CD-ROM EXtended Architecture. A modification to the CD-ROM
specification that defines two new types of sectors.  CD-ROM XA was
developed jointly by Sony, Philips, and Microsoft, and announced in
August 1988. Its specifications were published in an extension to the
Yellow Book.  CD-i, Photo CD, Video CD, and CD-EXTRA have all
subsequently been based on CD-ROM XA.

CD-XA defines another way of formatting sectors on a CD-ROM, including
headers in the sectors that describe the type (audio, video, data) and
some additional info (markers, resolution in case of a video or audio
sector, file numbers, etc).

The data written on a CD-XA is consistent with and can be in ISO-9660
file system format and therefore be readable by ISO-9660 file system
translators. But also a CD-I player can read CD-XA discs even if
its own `Green Book' file system only resembles ISO 9660 and isn't
fully compatible.

@item DVD
@cindex DVD
Digital Versatile Disc. Capacity up to 4.5 GB as single-layer and 8.5
GB as double-layer media. See also @pxref{models-profiles,,"Media
models and profiles"}.

@item Defect management
@cindex Defect management
A method to compensate small amounts of bad spots on media by replacing
them out of a pool of reserve blocks and performing address translation.
The necessary check reading slows down write performance by a factor of 2 or 3.
Defect management applies by default to DVD-RAM and BD-RE. Optionally it
can be formatted onto CD-RW and DVD+RW, where it has the name "Mount Rainier".
Sequential BD-R can be formatted for defect management too.

@item Command Packet
@cindex Command Packet

The data structure that is used to issue an ATAPI command. It contains
a SCSI Command Descriptor Block (CDB).

@item ECMA-119 (ISO-9660)
@cindex ECMA-119

@uref{http://www.ecma-international.org/publications/standards/Ecma-119.htm}
is a freely available specification that is technically identical to ISO 9660.

@item ECMA-167 (UDF)
@cindex ECMA-167

@uref{https://ecma-international.org/publications-and-standards/standards/ecma-167/}

is a freely available specification which is also approved as ISO 13346.
It serves as the base for UDF.

@item ECMA-168
@cindex ECMA-168

@uref{https://ecma-international.org/publications-and-standards/standards/ecma-168/}
is a freely available specification which is also approved as ISO 13490.

@item FSF
@cindex FSF

Free Software Foundation, @uref{http://www.fsf.org/}

@item GNU
@cindex GNU

@acronym{GNU} is not @acronym{UNIX}, @uref{http://www.gnu.org/}

@item IDE

Integrated Drive Electronics. This is a commonly used interface for
hard disk drives and CD-ROM drives. It is less expensive than SCSI,
but offers slightly less performance.

@item ISO
@cindex ISO

International Standards Organization.

@item ISO 13346
@cindex ISO 13346

ISO 13346 / ECMA-167 is a filesystem framework for data exchange on
overwriteable or pseudo-overwritable media. It serves as the base of UDF.

@item ISO 13490
@cindex ISO 13490

ISO 13490 / ECMA-168 is an attempt to replace ISO 9660 with a format that
allows finer write granularity and representation of typical disk file
properties. It resembles ECMA-167 which led to UDF.

@item ISO 9660
@cindex ISO 9660

ISO 9660 / ECMA-119 is an operating-system-independent filesystem format
originally intended for CD-ROM media. It was standardized in 1988 and
replaced the High Sierra standard for the logical format on CD-ROM media
(ISO 9660 and High Sierra are identical in content, but the exact format is
different). ISO 9660 and ECMA-119 are technically identical meanwhile.

There are several specification levels. In Level 1, file names must be
in the 8.3 format (no more than eight characters in the name, no more
than three characters in the suffix) and in capital letters. Directory
names can be no longer than eight characters. There can be no more
than eight nested directory levels. Level 2 and 3 specifications allow
file names up to 32 characters long. Level 3 allows data file sizes to be
4 GB or larger. File data content is stored in extents, i.e. contiguous
sequences of blocks. A single extent can hold only up to 2 exp 32 - 1 bytes.
So files of 4 GB or larger need more than one extent to be stored.
Older operating systems might have trouble with multi-extent files.

@item Joliet extensions
@cindex Joliet extensions

This ISO-9660 upward-compatible standard was developed for Windows 95
and Windows NT by Microsoft as an extension of ISO 9600 which allows
the use of Unicode characters and supports file names up to 64
characters.

See @uref{https://pismotec.com/cfs/jolspec.html} for
the Joliet Specification.

The name Joliet comes from the city in Illinois (U.S) where the
standard was defined.

@item LBA
@cindex LBA

Logical Block Addressing. Mapped integer numbers from CD Red Book
Addressing MSF.  The starting sector is -150 and the ending sector is
449849, which correlates directly to MSF: 00:00:00 to 99:59:74.
Because an LBA is a single number it is often easier to work with in
programming than an MSF.

@item Lead in
@cindex lead in

The area of a CD where the Table Of Contents (TOC) and CD Text are
stored.  I think it is supposed to be around 4500 (1 min) or more
sectors in length.  On a CDR(W) the lead-in length is variable,
because manufacturers have a different starting position
indicated by the ATIP start of lead-in position that is recorded in
the ATIP groove on the disk. For example:

@table @dfn
@item Ricoh Company Limited
97:27:00, 97:27:06, 97:27:66
@item Mitsubishi Chemical (Verbatim)
97:34:21 to 97:34:25
@end table

@item LSN
@cindex LSN

Logical Sector Number. Mapped integer numbers from CD Red Book
Addressing MSF.  The starting sector is 0 and the ending sector is 449699,
which correlates to MSF: 00:00:00 to 99:59:74.  Because an LSN is a
single number it is often easier to work with in programming than an
MSF. Because it starts at 0 rather than -150 as is the case of an LBA
it can be represented as an unsigned value.

@item MCN
@cindex MCN

Media Catalog Number. An identification number on an audio CD.  Also
called a UPC. Another identification number is ISRC.

@item @anchor{MMC}MMC
@cindex MMC (Multimedia Commands)

MMC (Multimedia Commands).

MMC are raw commands for communicating with CDROM drives,
CD-Rewriters, DVD-Rewriters, etc. They are a subset of the larger SCSI
command set. See also @pxref{SCSI,,@acronym{SCSI}}.

Many manufacturers have adopted this standard and it also applies to
ATAPI versions of their drives.

The documents @code{libcdio} makes use of are described in the
Multi-Media Commands standard (MMC). This document generally has a
numeric level number appended. For example, MMC-6 refers to
``Multi-Media Commands - 6.

@item @anchor{models-profiles}Media models and profiles
@cindex Media models and profiles

MMC classifies media as models, which describe their logical structure,
and as profiles, which describe the capabilities of the drive with the
particular media. So both are closely related but not identical.

There are three model families: CD, DVD, Blu-ray.
CD allows special sector formats like audio as well as data
sectors of 2048 bytes. DVD and Blu-ray only record data sectors.
@table @dfn
@item Non-writable media: CD-ROM, DVD-ROM, BD-ROM.
@item Write-once media: CD-R, DVD-R, DVD+R, BD-R.
@item Reusable media: CD-RW, DVD-RW, DVD+RW, DVD-RAM, BD-RE.
@end table

Profiles depend on drive type and media state. They are expressed as
numbers. It is unfortunate that formatted CD-RW have the same
profile number as unformatted ones.

ROM drives often announce all media as ROM profiles.
Some writer drives show closed sequential media as ROM profile.
@table @dfn
@item CD-ROM     0x08
@item DVD-ROM    0x10
@item BD-ROM     0x40
@end table

Sequentially recordable profiles allow multisession in most cases.
Special burn programs are needed for writing to them.
@table @dfn
@item CD-R       0x09
@item CD-RW      0x0a (unformatted)
@item DVD-R      0x11
@item DVD-RW     0x14 (unformatted)
@item DVD-R DL   0x15 (double layer)
@item DVD-R DL   0x16 (double layer, jump recording)
@item DVD+R      0x1a
@item DVD+RW DL  0x2a (double layer)
@item DVD+R DL   0x2b (double layer)
@item BD-R       0x41 (single or double layer, formatted or not)
@item HD DVD-ROM 0x50
@item HD DVD-R   0x51
@item HD DVD-RAM 0x52
@end table
They can assume three states:
@table @dfn
@item "Blank" is not readable but writeable from scratch
@item "Appendable" is readable and after the readable part still writeable
@item "Closed" is only readable
@end table
CD-RW and DVD-RW can be brought back to a blank state,
or they can be formatted to become overwritable.

Overwritable profiles allow random read-write access with a
granularity of 2 kB or 32 kB.
One can hope for having read-write access via the normal
POSIX operations lseek(), read(), write() of the operating system.
@table @dfn
@item CD-RW      0x0a (formatted)
@item DVD-RAM    0x12
@item DVD-RW     0x13 (formatted, 32 kB write granularity)
@item DVD+RW     0x1a
@item BD-R       0x42 (formatted for pseudo-random recording)
@item BD-RE      0x43 (single or double layer)
@end table
BD-R profile 0x42 is defined by MMC but not implemented by the consumer
priced Blu-ray burners as of the year 2010.

@item Mixed Mode CD
@cindex Mixed Mode CD

A Mixed Mode is a CD that contains tracks of differing CD-ROM Mode
formats. In particular, the first track may contain both computer data
(Yellow Book) CD ROM data while the remaining tracks are audio or
video data. Video CD's can be Mixed Mode CDs.

@item Multisession
@cindex Multisession

A way of writing to a CD, DVD, or Blu-ray Disc that allows more data to be
added to readable discs at a later time. The media must not have been closed
by the previous writing session. This applies originally to unformatted CD-R,
CD-RW, DVD-R, DVD-RW, DVD+R, and sequential BD-R which all can record more
than one session. They hold a table of contents with sessions and tracks.
Formatted CD-RW, DVD-RAM, DVD+RW, DVD-RW, and BD-RE have only one track.
Multisession on these media needs help from the recorded data formats.

Multisession can be used to add a changeset to an existing ISO 9660
filesystem. Typically the add-on session contains a whole new filesystem tree
with old and new files. It also contains the data blocks of the newly
introduced or freshly overwritten files.
The convention for mounting multisession ISO 9660 images is to load the
superblock from the start of the first track in the last session as listed
in the media table of contents. Formatted media are assumed to have a single
track starting at block 0. So ISO 9660 multisession on formatted media has
to overwrite the volume descriptors at block 16 ff. with every new session.
A chain of recognizable sessions can be achieved by starting the first
ISO 9660 image at block 32 so that its descriptors are not overwritten later.

@item Nero NRG format file
@cindex Nero NRG, CD-Image format

A proprietary CD image file format used by a popular program for
Microsoft Windows, Ahead Nero. The specification of this format is
not to our knowledge published.

@item Rock Ridge Extensions
@cindex Rock Ridge extensions

An extension to the ISO-9660 standard which adds POSIX information to files.
It allows long file names, owner, group, access permissions @code{ugo+-rwx},
inode numbers, hard-link count, and file types other than directory or regular
file. Rock Ridge is described by unapproved standard IEEE P1282 / RRIP-1.12
and based on unapproved IEEE P1281 / SUSP-1.10. It has become a de-facto
standard on X/Open systems like GNU/Linux, FreeBSD, Solaris, et.\ al.

@item @anchor{SCSI}SCSI
@cindex SCSI

Small Computer System Interface.  A set of ANSI standard electronic
interfaces (originally developed at Apple Computer) that allow
personal computers to communicate with peripheral hardware such as
CD-ROM drives, disk drives, printers, etc.

Although the original hardware has been outdated for years, the SCSI command
set nowadays controls most storage devices including all optical disc drives.
The contemporary electronic technologies that transport SCSI commands
to optical drives are P-ATA, SATA, and USB.

A SCSI programming specification made by the SCSI committee T10
organization @url{http://www.t10.org/}.

The documents @code{libcdio} makes use of are described in SCSI
standards documents SCSI Primary Commands (SPC), SCSI Block Commands
(SBC), and Multi-Media Commands (MMC). These documents generally have
a numeric level number appended. For example, SPC-3 refers to
``SCSI Primary Commands - 3'.

In year 2025, the current versions were SPC-7 (@url{https://www.t10.org/members/w_spc7.htm}), SBC-5 (@url{https://www.t10.org/members/w_sbc5.htm}), MMC-6 (@url{https://t10.org/members/w_mmc6.htm}).

@item SCSI CDB
@cindex SCSI CDB

SCSI Command Descriptor Block. The data structure that is used to
issue a SCSI command.

@item SCSI Pass Through Interface.
@cindex SCSI Pass Through Interface.

Yet another way of issuing MMC commands for accessing a CD-ROM. As
with MMC or ASPI, the CD-ROM doesn't necessarily have to be a
SCSI-attached drive. See also @pxref{MMC,,@acronym{MMC}} and
@pxref{ASPI,,@acronym{ASPI}}.

@item Session

A fully readable complete recording that contains one or more tracks
of computer data or audio on a CD. On a DVD or Blu-ray Disc, there are only
data sessions.

@item SVCD
@cindex Super VCD (SVCD)

Super @acronym{VCD}

An improvement of Video CD 2.0 specification which includes most
notably a switch from @acronym{MPEG}-1 (constant bit rate encoding) to
@acronym{MPEG}-2 (variable bit rate encoding) for the video stream.

Also added was higher video-stream resolution, up to 4 overlay
graphics and text (@dfn{OGT}) sub-channels for user switchable
subtitle displaying, closed caption text, and command lists for
controlling the @acronym{SVCD} virtual machine.

See @uref{https://www.videohelp.com/glossary?S#SVCD}

@item TOC
@cindex TOC (CD Table of Contents)

(Compact Disc) Table of Contents. The TOC contains a list of sessions
and their tracks. For sessions, it records the starting track
number and the last track number. For tracks, it records starting time
block address, size, copy protection, linear audio preemphasis, track format
(CDDA or data) in that order.
Session and track information is also available on sequential DVDs and
Blu-ray Discs. Several track properties are fixed to equivalents of CD data.

@item Track
@cindex track

A unit of data of a CD. The size of a track can vary; it can occupy
the entire contents of the CD. Most CD standards however require that
tracks have a 150 frame (or ``2 second'') lead-in gap.

An abstraction of tracks for CD, DVD, and Blu-ray Discs is the Logical Track
as of MMC specs. Overwritable media have a single logical track, sequential
media can have one or more logical tracks which they describe in their TOC.

@item UDF
@cindex UDF

Universal Disc Format was designed as the successor of ISO 9660. It allows recording
long file names and advanced file properties. Although intended
as a format for data exchange its main importance is with DVD video players.
Video DVDs have to bear a simple UDF filesystem with a prescribed set
of files.

@item VCD
@cindex Video CD (VCD)

The Video Compact Disc (@dfn{Video CD} or @dfn{VCD}) is a standardized
digital video storage format. It is based on the commonly available
Compact Disc technology, which allows for low-cost video authoring.
Video CD's can be played in most @acronym{DVD} standalone players,
dedicated VCD players, and finally, modern Personal Computers with
multimedia support.

A Video CD is made up of @acronym{CD-ROM XA} sectors,
i.e. @acronym{CD-ROM} mode 2 form 1 & 2 sectors. Non-@acronym{MPEG} data
is stored in mode 2 form 1 sectors with a user data area of 2048 byte,
which have a similar L2 error correction and detection
(@acronym{ECC}/@acronym{EDC}) to @acronym{CD-ROM} mode 1 sectors. While
real-time @acronym{MPEG} streams is stored in @acronym{CD-ROM} mode 2
form 2 sectors, which by have no L2 @acronym{ECC}, yield a ~14% greater
user data area consisting of 2324 bytes@footnote{actually raw mode 2
sectors have a 2336 byte user data area, but parts of it are used for
error codes and headers when using the mode 2 form 1 or form 2
configurations.}

@uref{https://www.videohelp.com/glossary?V#VCD}

@item Win32 ASPI
@cindex ASPI

The ASPI interface specification was developed by Adaptec for
sending commands to a SCSI host adapter (such as those controlling CD
and DVD drives) and used on Windows 9x/NT and later. Emulation for
ATAPI drives was added so that the same sets of commands worked in those
even though the drives might not be SCSI nor might there even be a
SCSI controller attached.

However, in Windows NT/2K/XP, Microsoft provides their Win32 ioctl
interface, and has taken steps to make using ASPI more inaccessible
(e.g. requiring administrative access to use ASPI).

See also @pxref{MMC,,@acronym{MMC}}.

@uref{https://www.videohelp.com/glossary?A#ASPI}

@item Win32 ioctl driver

Ioctl (Input Output ConTroLs). A Win32 function, implemented in all
Microsoft Windows.  It is used for sending commands to devices using
defined codes and structures.

@item XA
@cindex XA

@xref{XA,,@acronym{CD-ROM XA}}.

@end table
