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o\input texinfo @c -*-texinfo-*-

@c %**start of header
@setfilename libcdio.info
@settitle The GNU Compact Disc Input and Control library
@setchapternewpage on
@c %**end of header

@include version.texi

@paragraphindent 0
@exampleindent 0

@set libcdio @code{libcdio}
@set program @kbd{libcdio}

@c A macro for defining terms variables.
@macro term{varname}
@c @cindex{\varname\}
@emph{\varname\}
@end macro

@dircategory Libraries
@direntry
* libcdio: (libcdio).      Compact Disc Input and Control Library.
@end direntry

@ifinfo
This file documents GNU CD Input and Control Library

Copyright (C) 2003, 2004, 2005 Rocky Bernstein @email{<rocky@@panix.com>}
and Herbert Valerio Riedel @email{<hvr@@gnu.org>}

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``Free Software'' and ``Free Software Needs
Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,''
and with the Back-Cover Texts as in (a) below.

(a) The Free Software Foundation's Back-Cover Text is: ``You have
freedom to copy and modify this GNU Manual, like GNU software.  Copies
published by the Free Software Foundation raise funds for GNU
development.''
@end ifinfo

@titlepage
@title GNU libcdio library
@subtitle $Id: libcdio.texi,v 1.45 2005/07/11 00:36:56 rocky Exp $
@author Rocky Bernstein et al.
@page

@vskip 0pt plus 1filll

Copyright @copyright{} 2003, 2004 Herbert Valerio Riedel
@email{<hvr@@gnu.org>} and Rocky Bernstein @email{<rocky@@panix.com>}
@sp 1
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``Free Software'' and ``Free Software Needs
Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,''
and with the Back-Cover Texts as in (a) below.

(a) The Free Software Foundation's Back-Cover Text is: ``You have
freedom to copy and modify this GNU Manual, like GNU software.  Copies
published by the Free Software Foundation raise funds for GNU
development.''
@end titlepage
@page

@ifnottex
@node Top, History, (dir), (dir)

@top The GNU Compact Disc Input and Control Library (@value{program})

This file documents GNU CD input and control library

Copyright (C) 2003, 2004, 2005 Rocky Bernstein and Herbert Valerio Riedel

@menu
* History::           How this came about
* Previous Work::     The problem and previous work
* Purpose::           What is in this package (and what's not)
* CD Formats::        A tour through the CD-specification spectrum
* CD Image Formats::  A tour through various CD-image formats
* CD Units::          The units that make up a CD
* How to use::        Okay enough babble, lemme at the library!
* Utility Programs::  Diagnostic programs that come with this library
* CD-ROM Access and Drivers::     CD-ROM Access and Drivers
* Internal Program Organization:: Looking under the hood

Appendices
* ISO-9660 Character Sets::
* Glossary::          
* GNU General Public License::
* GNU Free Documentation License::

Indices
* General Index::       Overall index
@end menu
@end ifnottex

@contents

@node History
@chapter History

As a result of the repressive Digital Millennium Copyright Act (DMCA)
I became aware of Video CD's (VCD's). Video CD's are not subject to
the DMCA and therefore enjoy the protection afforded by copyright but
no more. But in order for VCD's to be competitive with DVD's, good
tools (including GPL tools) are needed for authoring and playing
them. And so through VCD's I became aware of the excellent Video CD
tools by Herbert Valerio Riedel which form the @kbd{vcdimager} package.

Although vcdimager is great for authoring, examining and extracting
parts of a Video CD, it is not a VCD player. And when I looked at the
state of Video CD handling in existing VCD players: @code{xine},
@code{MPlayer}, and @code{vlc}, I was a bit disappointed. None handled
playback control, menu selections, or playing still frames and
segments from track 1.

Version 0.7.12 of vcdimager was very impressive, however it lacked
exportable libraries that could be used in other projects. So with the
blessing and encouragement of Herbert Valerio Riedel, I took to
extract and create libraries from this code base. The result was two
libraries: one to extract information from a VCD which I called
libvcdinfo, and another to do the reading and control of a VCD. Well,
actually, at this point I should say that a Video CD is really just
Video put on a existing well-established Compact Disc or CD format. So
the library for this is called @value{libcdio} rather than
@kbd{libvcdio}.

While on the topic of the name @value{libcdio}, I should also explain that
the library really doesn't handle writing or output (the final "o" in
the name). However it was felt that if I put libcdi that might be
confused with a particular CD format called CD-I.

Later on, the ISO-9660 filesystem handling component from
@kbd{vcdimager} was extracted, expanded and made a separate
library. Next the ability to add MMC commands was added, and then
CD paranoia support. And from there, the rest is history.

@node Previous Work
@chapter The problem and previous work

If around the year 2002 you were to look at the code for a number of
open-source CD or media players that work on several platforms such as
vlc, MPlayer, xine, or xmms to name but a few, you'd find the code to
read a CD sprinkled with conditional compilation for this or that
platform. That is there was @emph{no} OS-independent programmer
library for CD reading and control even though the technology was over
10 years old; yet there are media players which strive for OS
independence.

One early CD player, @kbd{xmcd} by Ti Kan, was I think a bit better
than most in that it tried to @emph{encapsulate} the kinds of CD
control mechanisms (SCSI, Linux ioctl, Toshiba, etc.) in a "CD Audio
Device Interface Library" called libdi.  However this library is for
Audio CD's only and I don't believe this library has been used outside
of xmcd.

Another project, Simple DirectMedia Layer also encapsulates CD
reading. 

@quotation
SDL is a library that allows you portable low-level access to a video
framebuffer, audio output, mouse, and keyboard. With SDL, it is easy
to write portable games which run on ...
@end quotation

Many of the media players mentioned above do in fact can make use of
the SDL library but for @emph{video} output only. Because the encapsulation
is over @emph{many} kinds of I/O (video, joysticks, mice, as well as CD's),
I believe that the level of control provided for CD a little bit
limited. (However to be fair, it may have only been intended for games
and may be suitable for that).  Applications that just want the CD
reading and control portion I think will find quite a bit overhead.

Another related project is J@"org Schilling's SCSI library. You can
use that to make a non-SCSI CD-ROM act like one that understands SCSI
MMC commands which is a neat thing to do. However it is a little weird
to have to install drivers just so you can run a particular user-level
program. Installing drivers often requires special privileges and
permissions and it is pervasive on a system. It is a little sad that
along the way to creating such a SCSI library a library similar to
@value{libcdio} wasn't created which could be used. Were that the
case, this library certainly never would have been written.

At the OS level there is the ``A Linux CD-ROM Standard'' by David van
Leeuwen from around 1999. This defines a set of definitions and
ioctl's that mask hardware differences of various Compact Disc
hardware. It is a great idea, however this ``standard'' lacked
adoption on OS's other than GNU/Linux. Or maybe it's the case that the
standard on other OS's lacked adoption on GNU/Linux. For example on
FreeBSD there is a ``Common Access Method'' (CAM) used for all SCSI
access which seems not to be adopted in GNU/Linux.@footnote{And I'm
thankful for that since, at least for MMC commands, it is
inordinately complicated and in some places arcane.}

Finally at the hardware level where a similar chaos exists, there has
been an attempt to do something similar with the MMC (multimedia
commands). This attempts to provide a uniform command set for CD
devices PostScript does for printer commands.@footnote{I wrote
``attempts'' because over time the command set has changed and now
there are several different commands to do a particular function like
read a CD table of contents and some hardware understands some of the
version of the commands set but might not others} In contrast to
PostScript where there one in theory can write a PostScript program in
a uniform ASCII representation and send that to a printer, for MMC
although there are common internal structures defined, there is no
common syntax for representing the structures or an OS-independent
library or API for issuing MMC-commands which a programmer would need
to use. Instead each Operating System has its own interface.  For
example Adaptec's ASPI or the Microsoft's DeviceIoControl on Microsoft
Windows, or IOKit for Apple's OS/X, or FreeBSD's CAM. I've been
positively awed at how many different variations and differing levels
of complexity there are for doing basically the same thing. How easy
it is to issue an MMC command from a program varies from easy to very
difficult. And mastering the boilerplate code to issue an MMC command
on one OS really doesn't help much in figuring out how to do it on
another OS. So in @value{libcdio} we provide a common (and hopefully
simple) API to issue MMC commands.

@node Purpose
@chapter What is in this package (and what's not)

The library, @command{libcdio}, encapsulates CD-ROM reading and
control. Applications wishing to be oblivious of the OS- and
device-dependent properties of a CD-ROM can use this library.

Also included is a library, @command{libiso9660}, for working with
ISO-9660 filesystems, @command{libcdio_paranoia}, and
@command{libcdio_cdda} libraries for applications which want to use
cdparanoia's error-correction and jitter detection.

Some support for disk-image types like cdrdao's TOC, CDRWIN's BIN/CUE
and Ahead Nero's NRG format is available, so applications that use this
library also have the ability to read disc images as though they were
CDs.

@command{libcdio} also provides a way to issue SCSI ``MultiMedia
Commands'' (MMC).  MMC is supported by many hardware CD-ROM
manufacturers; and in some cases where a CD-ROM doesn't understand MMC
directly, some Operating Systems (such as GNU/Linux, Solaris, or
FreeBSD or Microsoft Windows ASPI to name a few) provide the MMC
emulation.@footnote{This concept of software emulation of a common
hardware command language is common for printers such as using
ghostscript to private postscript emulation for a non-postscript
printer.}

Immediate of the library in this package are the Video CD authoring
and ripping tools, VCDImager (@url{http://vcdimager.org}), a
navigation-capable Video CD plugin and CD-DA plugins for the media
players xine (@url{http://xinehq.de}) and videolan's vlc
(@url{http://videolan.org/vlc}).

A version of the CD-DA extraction tool cdparanoia
(@url{http://www.xiph.org/paranoia} and its library which corrects
for CD-ROM jitter are part of the distribution.

Also included in the libcdio package is a utility program
@command{cd-info} which displays CD information: number of tracks,
CD-format and if possible basic information about the format.  If
libcddb (@url{http://libcddb.sourceforge.net}) is available, the
@command{cd-info} program will display CDDB matches on CD-DA
discs. And if a new enough version of libvcdinfo is available (from
the vcdimager project), then @command{cd-info} shows basic VCD
information.

Other utility programs in the libcdio package are:

@table @code 

@item @code{cdda-player}

shows off @value{libcdio} audio and CD-ROM control commands. It can
play a track, eject or load media and show the the status of a CD-DA
that is might be currently played via the audio control commands.  It
can be run in batch mode or has a simple curses-based interface.

If libcddb is available or a CD has CD-Text and your CD-ROM drive
supports CD-Text, track/album information about the CD can be shown.

@item @code{cd-drive}

shows what drivers are available and some basic properties of
cd-drives attached to the system. (But media may have to be inserted
in order to get this info.)  lists out drive capabilities

@item cd-read
performs low-level block reading of a CD or CD image,

@item @code{iso-info} 

displays ISO-9660 information from an ISO-9660 image. Below is some
sample output

@smallexample
iso-info version 0.72
Copyright (c) 2003, 2004, 2005 R. Bernstein
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
__________________________________
ISO 9660 image: ../test/joliet.iso
Application: K3B THE CD KREATOR VERSION 0.11.12 (C) 2003 SEBASTIAN TRUEG AND THE K3B TEAM
Preparer   : K3b - Version 0.11.12
Publisher  : Rocky Bernstein
System     : LINUX           
Volume     : K3b data project
Volume Set : K3b data project
__________________________________
ISO-9660 Information
/:
 Oct 22 2004 19:44  .
 Oct 22 2004 19:44  ..
 Oct 22 2004 19:44  libcdio

/libcdio/:
 Oct 22 2004 19:44  .
 Oct 22 2004 19:44  ..
 Mar 12 2004 02:18  COPYING
 Jun 26 2004 07:01  README
 Aug 12 2004 06:22  README.libcdio
 Oct 22 2004 19:44  test

/libcdio/test/:
 Oct 22 2004 19:44  .
 Oct 22 2004 19:44  ..
 Jul 25 2004 06:52  isofs-m1.cue
@end smallexample

@item @code{iso-read} 

extracts files from an ISO-9660 image.

@end table

At present, there is no support for writing CD's. Nor is there any
support for reading or writing DVDs. For some of these, there are
other libraries (e.g. libdi, libscg, or libdvdread) may be helpful.

I'm not theoretically opposed to putting support like this into
libcdio. However at present there are already many gaps in this
package, so narrowing its scope in order to focus on these things I
think is a good idea.

@node CD Formats
@chapter CD Formats

Much of what I write in this section can be found elsewhere. See for
example @url{http://www.pctechguide.com/08cd-rom.htm} or
@url{http://www.pcguide.com/ref/cd/format.htm}

We give just enough background here to cover Compact Discs and Compact
Disc formats that are handled by this library.

The Sony and Philips Corporations invented and Compact Disc (CD) in
the early 1980s. The specifications for the layout is often referred
to by the color of the cover on the specification. 

@menu
* Red Book::        Red Book (CD-DA) CD Text, CDDB
* Yellow Book::     Yellow Book (CD-ROM Digital Data)
* Green Book::      Green Book (CD-i)
* White Book::      White Book (DV, Video CD)
@end menu

@node Red Book
@section Red Book (CD-DA)
@cindex Red Book

@menu
* CD Text::         CD Text and CD+G
* CDDB::            Internet CD Database (CDDB)
@end menu

The first type of CD that was produced was the Compact Disc Digital
Audio (CD-DA) or just plain ``audio CD''. The specification, ICE 908,
is commonly called the ``Red Book''. Music CD's are recorded in this
format which basically allows for around 74 minutes of audio per disc
and for that information to be split up into tracks. Tracks are broken
up into "sectors" and each sector contains up to 2,352 bytes. To play
one 44.1 kHz CD-DA sampled audio second, 75 sectors are used. 

The minute/second/frame numbering of sectors or MSF format is based on
the fact that 75 sectors are used in a second of playing of
sound. (And for almost every other CD format and application the MSF
format doesn't make that much sense).

In @value{libcdio} when you you want to read an audio sector, you call 
@code{cdio_read_audio_sector()} or @code{cdio_read_audio_sectors()}.

@cindex subchannel
In addition the the audio data ``channel'' a provision for other
information or @term{subchannel} information) can be stored in a
sector. Other subchannels include a Media Catalog Number (also
abbreviated as MCN and sometimes a UPC), or album meta data (also
called CD-Text). Karioke graphics can also be stored in a format
called @term{CD+G}.

@node CD Text
@subsection CD Text, CD+G
@cindex CD Text
@cindex CD+G

CD Text is an extension to the CD-DA standard that adds the ability to
album and track meta data (titles, artist/performer names, song
titles) and and graphical (e.g. Karioke) information.  For an
alternative way to get album and track meta-data see @xref{CDDB}.

Information is stored in such a way that it doesn't interfere with the
normal operation of any CD players or CDROM drives. There are two
different parts of the CD where the data can be stored.

The first place the information can be recorded is in the R-W sub
codes in the lead in area of the CD giving a data capacity of about
5,000 ASCII characters (or 2,500 Kanji or Unicode characters).  This
information is stored as a single block of data and is the format used
in virtually all of the CD Text CDs shipping today. The method for
reading this data from a CDROM drive is covered under the Sony
proposal to the MMC specification. The format of the data is partially
covered in the MMC specification.

The second place the information can be recorded is in the R-W sub
codes in the program area of the CD giving a data capacity of roughly
31MB. This information is stored in a format that follows the
Interactive Text Transmission System (ITTS) which is the same data
transmission standard used by such things as Digital Audio
Broadcasting (DAB), and virtually the same as the data standard for
the MiniDisc. Traditionally the R-W sub codes have been used for text
and graphics in applications such as CD+G (CD w/graphics) or in the
case of most audio CDs, not at all. The methods for reading this data
from a CD-ROM drive is covered by the programming specs from the
individual drive manufacturers. In the case of ATAPI drives, the
SFF8020 spec covers the reading of the RW subcodes.

Not all drives support reading the RW subcodes from the program
area. However for those that do, @value{libcdio} provides a way to get
at this information via @code{cdtext_get()} and its friends.

@node CDDB
@subsection Internet CD Database (CDDB)
@cindex CDDB

CDDB is an database on the Internet of of CD album/track, artist, and
genre information similar to CD Text information. Using track
information (number of tracks and length of the tracks), devices that
have access to the Internet can query for meta information and
contribute information for CD's where there is no existing
information.  When storage is available (such as you'd expect for any
program using @value{libcdio}, the information is often saved for
later use when the Internet is not available; people tend request the
same information since they via programs play the same music.

Obtaining CD meta information when none is encoded in an audio CD is
useful in media players or making one's own compilations from audio
CDs. 

There are currently two popular CDDB services on the Internet. The
original database has been renamed Gracenote and is a profit making
entity. FreeDB (@url{http://freedb.org} is an open source CD
information resource that is free for developers and the public to
use.

As there already is an excellent library for handling CDDB libcddb
(@url{http://libcddb.sourceforge.net} we suggest using that. Our
utility program @command{cd-info} will make use it if it is available
and it's what we use in our applications that need it.

@node Yellow Book
@section Yellow Book (CD-ROM Digital Data)
The CD-ROM specification or the ``Yellow Book'' followed a few years
later (Standards ISO/IEC 10149), and describes the extension of CD's
to store computer data, i.e. CD-ROM (Compact Disk Read Only Memory).

The specification in the Yellow Book defines two modes: Mode 1 and
Mode 2.

@menu
* ISO 9660::
* Mode 1::           Mode 1 Format
* Mode 2::           Mode 2 Format
@end menu

@node ISO 9660
@subsection ISO 9660
@cindex ISO 9660

@menu
* ISO 9660 Level 1::
* ISO 9660 Level 2::
* ISO 9660 Level 3::
* Joliet Extensions::
* Rock Ridge Extensions::
@end menu

The Yellow Book doesn't specify how data is to be stored on a CD-ROM.
It was feared that different companies would implement proprietary
data storage formats using this specification, resulting in
incompatible data CDs. To prevent this, representatives of major
manufacturers met at the High Sierra Hotel and Casino in Lake Tahoe,
NV, in 1985, to define a standard for storing data on CDs. This format
was nicknamed High Sierra Format. In a slightly modified form it was
later adopted as ISO the ISO 9660 standard. This standard is further
broken down into 3 "levels", the higher the level, the more
permissive.

@node ISO 9660 Level 1
@subsubsection ISO 9660 Level 1
Level 1 ISO 9660 defines names in the 8+3 convention so familiar to
MS-DOS: eight characters for the filename, a period, and then three
characters for the file type, all in upper case. The allowed
characters are A-Z, 0-9, ".", and "_".Level 1 ISO 9660 requires that
files occupy a contiguous range of sectors. This allows a file to be
specified with a start block and a count. The maximum directory depth
is 8. For a table of the characters, see @xref{ISO-9660 Character
Sets}.

@node ISO 9660 Level 2
@subsubsection ISO 9660 Level 2
Level 2 ISO 9660 allows far more flexibility in filenames, but isn't
usable on some systems, notably MS-DOS.

@node ISO 9660 Level 3
@subsubsection ISO 9660 Level 3
Level 3 ISO-9660 allows non-contiguous files, useful if the file was
written in multiple packets with packet-writing software.

There have been a number of extensions to the ISO 9660 CD-ROM file
format. One extension is Microsoft's Joliet specification, designed to
resolve a number of deficiencies in the original ISO 9660 Level 1 file
system, and in particular to support the long file names used in
Windows 95 and subsequent versions of Windows.

Another extension is the Rock Ridge Interchange Protocol (RRIP), which
enables the recording of sufficient information to support POSIX File
System semantics.

@node Joliet Extensions
@subsubsection Joliet Extensions
@cindex Joliet extensions

Joliet extensions were an upward-compatible extension to the ISO 9660
specification that removes the limitation initially put in to deal
with the limited filename conventions found in Microsoft DOS OS. In
particular, the Joliet specification allows for long filenames and
allows for UCS-BE (Big-endian Unicode) encoding of filenames which
include mixed case letter, accented characters spaces and various
symbols. 

The way all of this is encoded is by adding a second directory and
filesystem structure in addition to or in parallels to original ISO
9600 filesystem. The root node of the ISO 9660 filesystem is found via
the @term{Primary Volume Descriptor} or @term{PVD}. The root of the
Joliet-encode filesystem is found in a Supplementary Volume
Descriptor or @term{SVD} defined in the ISO 9660 specification. The
SVD structure is almost identical to a PVD with a couple of unused
fields getting used and with the filename encoding changed to UCS-BE.

@node Rock Ridge Extensions
@subsubsection Rock Ridge Extensions
@cindex Rock Ridge extensions

Using the Joliet Extension one overcome the limitedness of the
original ISO-9660 naming scheme. But another and probably better
method is to use the Rock Ridge Extension. Not only can one store a
filename as one does in a POSIX OS, but the other file attributes,
such as the various timestamps (creation, modification, access), file
attributes (user, group, file mode permissions, device type, symbolic
links) can be stored. This is much as one would do in XA attributes;
however the two are not completely interchangeable in the information
they store: XA does @emph{not} address filename limitations, and the
Rock Ridge extensions don't indicate if a sector is in Mode 1 or Mode
2 format.

The Rock Ridge extension makes use of a hook that was defined as part
of the ISO 9660 standard.

@node Mode 1
@subsection Mode 1 (2048 data bytes per sector)
@cindex Mode 1
Mode 1 is the data storage mode used by to store computer data. There
are 3 layers of error correction. A Compact Disc using only this format can
hold at most 650 MB. The data is laid out in basically the same way as
in and audio CD format, except that the 2,352 bytes of data in each
block are broken down further. 2,048 of these bytes are for ``real''
data. The other 304 bytes are used for an additional level of error
detecting and correcting code. This is necessary because data CDs
cannot tolerate the loss of a handful of bits now and then, the way
audio CDs can.

In @value{libcdio} when you you want to read a mode1
sector you call the @code{cdio_read_mode1_sector()} or
@code{cdio_read_mode1_sectors()}.

@node Mode 2
@subsection Mode 2 (2336 data bytes per sector)
@cindex Mode 2
Mode 2 data CDs are the same as mode 1 CDs except that the error
detecting and correcting codes are omitted. So still there are 2
layers of error correction. A Compact Disc using only this mode can
thus hold at most 742 MB. Similar to audio CDs, the mode 2 format
provides a more flexible vehicle for storing types of data that do not
require high data integrity: for example, graphics and video can use
this format. But in contrast to the Red Book standard, different modes
can be mixed together; this is the basis for the extensions to the
original data CD standards known as CD-ROM Extended Architecture, or
CD-ROM XA.  CD-ROM XA formats currently in use are CD-I Bridge
formats, Photo CD and Video CD plus Sony's Playstation.

In @value{libcdio} when you you want to read a mode1
sector you call the @code{cdio_read_mode2_sector()} or
@code{cdio_read_mode2_sectors()}.

@node Green Book
@section Green Book (CD-i)
@cindex Green Book

This was a CD-ROM format developed by Philips for CD-i (an obsolete
embedded CD-ROM application allowing limited user user interaction
with films, games and educational applications). The format is ISO
9660 compliant and introduced mode 2 form 2 addressing. It also 
contains XA (Extended Architecture) attributes.

Although some Green Book discs contain CD-i applications which can
only be played on a CD-i player, others have films or music
videos. Video CDs in Green-Book format are labeled "Digital Video on
CD." The Green Book for video is largely superseded by White book
CD-ROM which draws on this specification.


@node White Book
@section White Book (DV, Video CD)
@cindex Green Book

The White Book was released by Sony, Philips, Matsushita, and JVC in
1993, defines the Video CD specification. The White Book is also known
as Digital Video (DV). 

A Video CD contains one data track recorded in CD-ROM XA Mode 2 Form
2. It is always the first track on the disc (Track 1). The ISO-9660
file structure and a CD-i application program are recorded in this
track, as well as the Video CD Information Area which gives general
information about the Video Compact Disc. After the data track, video
is written in one or more subsequent tracks within the same
session. These tracks are also recorded in Mode 2 Form 2. 

In @value{libcdio} when you you want to read a mode2 format 2 audio
sector you call the @code{cdio_read_mode2_sector()} or
@code{cdio_read_mode2_sectors()} setting @code{b_form2} to @code{true}.

@node CD Image Formats
@chapter CD Image Formats 

@menu
* CDRDAO TOC Format::           
* CDRWIN BIN/CUE Format::              
* NRG Format::              
@end menu

In both the @command{cdrdao} and bin/cue formats there is one meta-file with
extensions @code{.toc} or @code{.cue} respectively and one or more
files (often with the extension @code{.bin}) which contains the
content of tracks. The format of the track data is often
interchangeable between the two formats.  For example, in
@value{libcdio}'s regression tests we make use of this to reduce the
size of the test data and just provide alternate meta-data files
(@code{.toc} or @code{.cue}).

In contrast to the first two formats, the NRG format consists of a
single file. This has the advantage of being a self-contained
unit: in the other two formats it is possible for the meta file to
refer to a file that can't be found. A disadvantage of the NRG format
is that the meta data can't be easily viewed or modified say in a text
file as it can be with the first two formats. In conjunction with this
disadvantage is another disadvantage that the format is not
documented, so how @value{libcdio} interprets an NRG image is based on
inference. It is recommended that one of the other forms be used
instead of NRG where possible.

@node CDRDAO TOC Format
@section CDRDAO TOC Format

This is @command{cdrdao}'s CD-image description format. Since this
program is GPL and everything about it is in the open, it is the
preferred format to use. (Alas, at present it isn't as well supported
in @value{libcdio} as the BIN/CUE format.)

The @emph{toc}-file describes what data is written to the media in the
@acronym{CD-ROM}; it allows control over track/index positions,
pre-gaps and sub-channel information.  It is a text file, so a text
editor can be used to create, view or modify it.

The @cite{cdrdao(1) manual page}, contains more information about this
format.

@subsection CDRDAO Grammar

Below are the lexical tokens and grammar for a cdrdao TOC. It was
taken from the cdrdao's pacct grammar; the token and nonterminal names
are the same.

@example
#lexclass START
#token Eof		"@@"
#token                  "[\t\r\ ]+"
#token Comment          "//~[\n@@]*"
#token                  "\n"       
#token BeginString      "\""       
#token Integer          "[0-9]+"
#tokclass AudioFile     @{ "AUDIOFILE" "FILE" @}

#lexclass STRING
#token EndString        "\""
#token StringQuote      "\\\""
#token StringOctal      "\\[0-9][0-9][0-9]"
#token String           "\\"
#token String           "[ ]+"
#token String           "~[\\\n\"\t ]*"
@end example

@example

<toc>  ::= ( "CATALOG" <string> | <tocType> )* @{ <cdTextGlobal> @} 
           ( <track> )+ Eof 

<track> ::= "TRACK" <trackMode> 
    @{ <subChannelMode> @}
    (  "ISRC" <string> | @{ "NO" @} "COPY" | @{ "NO" @} "PRE_EMPHASIS" 
    | "TWO_CHANNEL_AUDIO"  | "FOUR_CHANNEL_AUDIO" )*
    @{ <cdTextTrack>  @}
    @{ "PREGAP" <msf> @}
    ( <subTrack> | "START" @{ msf @} | "END" @{ msf @} )+
    ( "INDEX" <msf> )*

<subTrack> ::= 
     AudioFile <string> @{ "SWAP"  @} @{ "#" <sLong>  @}  <samples>
     | "DATAFILE" <string> @{ "#" <sLong> @{ <dataLength> @} @}
     | "FIFO" <string> <dataLength> 
     | "SILENCE" <samples> 
     | "ZERO" @{ dataMode  @} @{ <subChannelMode>  @} <dataLength> 
  

<string> ::=  BeginString ( String | StringQuote | StringOctal )+ 
            EndString

<stringEmpty> ::= BeginString ( String | StringQuote | StringOctal )*
                EndString

<uLong> ::= Integer 

<sLong> ::= Integer 

<msf> ::= Integer ":" Integer ":" Integer 

<samples> ::= <msf> | <uLong>

<dataLength> ::= <msf> | <uLong>

<dataMode> ::=  "AUDIO" | "MODE0" | "MODE1" | "MODE1_RAW" | "MODE2" 
     | "MODE2_RAW" | "MODE2_FORM1" | "MODE2_FORM2" | "MODE2_FORM_MIX"

<trackMode> ::= "AUDIO" | "MODE1" | "MODE1_RAW" | "MODE2"
     | "MODE2_RAW"  | "MODE2_FORM1" | "MODE2_FORM2" | "MODE2_FORM_MIX"

<subChannelMode> ::= "RW" | "RW_RAW"

<tocType> ::= "CD_DA" | "CD_ROM" | "CD_ROM_XA" | "CD_I"

<packType> ::= "TITLE" | "PERFORMER" | "SONGWRITER" | "COMPOSER" | "ARRANGER"  
     | "MESSAGE" | "DISC_ID" | "GENRE" | "TOC_INFO1" | "TOC_INFO2"  
     | "RESERVED1" | "RESERVED2" | "RESERVED3" | "RESERVED4" | "UPC_EAN" |
     "ISRC" | "SIZE_INFO"

<binaryData> ::=  "@{"
    @{ Integer ( "," Integer  )* @}
    "@}"
         
<cdTextItem> ::= <packType>  ( <stringEmpty> | <binaryData> )
 
<cdTextBlock> ::=  "LANGUAGE" Integer "@{" ( <cdTextItem> )* "@}"

<cdTextLanguageMap> ::= 
    "LANGUAGE_MAP" "@{"
    ( Integer  ":" (  Integer | "EN"  ) )+
    "@}"

<cdTextTrack> ::=  "CD_TEXT" "@{" ( <cdTextBlock> )*  "@}"

<cdTextGlobal> ::= "CD_TEXT" "@{" @{ <cdTextLanguageMap> @} ( <cdTextBlock> )* "@}"
@end example



@node  CDRWIN BIN/CUE Format
@section CDRWIN BIN/CUE Format
@cindex BIN/CUE, CD Image Format

The format referred to as @emph{CDRWIN BIN/CUE Format} in this manual
is a popular CD image format used in the @acronym{PC} world. Not
unlike @command{cdrdao}'s TOC file, the @emph{cue} file describes the
track layout, i.e. how the sectors are to be placed on the CD
media. The @emph{cue} file usually contains a reference to a file
traditionally having the @file{.bin} extension in its filename, the
@emph{bin} file. This @emph{bin} file contains the sector data payload
which is to be written to the CD medium according to the description
in the @emph{cue} file.

The following is an attempt to describe the subset of the @file{.cue}
file syntax used in @value{libcdio} and vcdimager in an EBNF-like
notation:

@subsection BIN/CUE Grammar

@example
@cartouche
<cue-document> ::= +( <file-line> +<track-expr> )

<digit> ::= "0" | "1" ... "8" | "9"
<number> ::= +<digit>
<msf> ::= <digit><digit> ":" <digit><digit> ":" <digit><digit>

<file-line> ::= "FILE" <pathname-expr> <file-type> <EOL>

<pathname-expr> ::= [ "\"" ] <pathname-str-without-spaces> [ "\"" ] 
                  | "\"" <pathname-str> "\""  

<file-type> ::= "BINARY" 

<track-expr> ::= <track-line> [ <flag-line> ]
                 [ <pregap-line> ] *<index-line> [ <postgap-line> ]

<flag-line> ::= "FLAGS" *<flag-type> <EOL>
<flag-type> ::= "DCP"

<track-line> ::= "TRACK" <number> <track-type> <EOL>

<pregap-line> ::= "PREGAP" <msf> <EOL>

<index-line> ::= "INDEX" <number> <msf> <EOL>

<postgap-line> ::= "POSTGAP" <msf> <EOL>

<track-type> ::= "AUDIO" | "MODE1/2048" | "MODE1/2352" 
               | "MODE2/2336" | "MODE2/2352"

<comment-line> ::= "REM" *<char> <EOL>
@end cartouche
@end example

@node  NRG Format
@section NRG Format
@cindex Nero NRG, CD-Image format

The format referred to as @emph{NRG Format} in this manual is another
popular CD image format. It is available only on Nero software
on a Microsoft Windows Operating System. It is proprietary and not
generally published, so the information we have comes from guessing
based on sample CD images. So support for this is incomplete and using
this format is not recommended.

Unlike @command{cdrdao}'s TOC file the BIN/CUE format everything is
contained in one file. that one can edit Meta information such as the
number of tracks and track format is contained at the end of the
file. This information is not intended to be edited through a text
editor.

@node CD Units
@chapter The units that make up a CD

@menu
* Tracks::   Tracks
* Sectors::  Block addressing (MSF, LSN, LBA)
@end menu

@node Tracks
@section tracks --- disc subdivisions
@cindex track

In this section we describe CD properties and terms that we make use
of in @value{libcdio}.

A CD is formated into a number of @term{tracks}, and a CD can hold at
most 99 such tracks. This is defined by @code{CDIO_CD_MAX_TRACKS} in
@file{cdio/sector.h}. Between the tracks CD specifications require a
``2 second'' in gap (called a @term{lead-in gap}. This is unused space
with no ``data'' similar to the space between tracks on an old
phonograph. The word ``second'' here really refers to a measure of
space and not really necessarily an amount of time. However in the
special case that the CD encodes an audio CD or CD-DA, the amount of
time to play a gap of this size will take 2 seconds.

@cindex lead out
The beginning (or inner edge) of the CD is supposed to have a ``2
second'' lead-in gap and there is supposed to be another ``2 second''
@term{lead-out} gap at the end (or outer edge) of the CD.

People have discovered that they can put useful data in the various
gaps and their equipment can read this, violating the standards but
allowing a CD to store more data.

In order to determine the number of tracks on a CD and where they
start, commands are used to get this table-of-contents or @term{TOC}
information. Asking about the start of the @term{lead-out track}
gives the amount of data stored on the Compact Disk. To make it easy
to specify this leadout track, special constant 0xAA (decimal 170) is
used to indicate it. This is safe since this is higher than the
largest legal track position. In @value{libcdio},
@code{CDIO_CDROM_LEADOUT_TRACK} is defined to be this special value.

@node Sectors
@section block addressing (MSF, LSN, LBA)
@cindex MSF
@cindex LSN
@cindex LBA
@cindex sectors
@cindex frames

A track is broken up into a number of 2352-byte @emph{blocks} which we
sometimes call @emph{sectors} or @emph{frames}. Whereas tracks have to
have a gap between them, a block or sector does not. (In
@value{libcdio} the block size constant is defined using
@code{CDIO_CD_FRAMESIZE_RAW}).

A Compact Disc has a limit on the number of blocks or sectors.  This
values is defined by constant @code{CDIO_CD_MAX_LSN} in
@file{cdio/sector.h}.

One can addressing a block in one of three formats. The oldest format
is by it's minute/second/frame number, also referred to as @term{MSF}
and written in time-like format MM:SS:FF (e.g. 30:01:40). It is best
suited in audio (Red Book) applications. In @value{libcdio}, the type
@code{msf_t} can be used to declare variables to hold such
values. Minute, second and frame values are one byte @emph{and stored
BCD notation}.@footnote{Perhaps this is a @value{libcdio} design
flaw. It was originally done I guess because it was convenient for
VCDs.} There are @value{libcdio} conversion routines
@code{cdio_from_bcd8()} and @code{cdio_to_bcd8()} to convert the
minute, second, and frame values into or out of integers. If you want
to print a field in a BCD-encoded MSF, one can use the format
specifier @code{%x} @emph{(not @code{%d})} and things will come out
right.

In the MSF notation, there are 75 ``frames'' in a ``second,'' and the
familiar (if awkward) 60 seconds in a minute. @emph{Frame} here is
what we called a @emph{block} above. The CD specification defines
``frame'' to be @emph{another} unit which makes up a block. Very
confusing. A frame is also sometimes called a sector, analogous to
hard-disk terminalogy.

Even more confusing is using this time-like notation for an address or
for a length. Too often people confuse the MSF notation this with an
amount of time. A ``second'' (or @code{CDIO_CD_FRAMES_PER_SEC} blocks)
in this notation is only a second of playing time for something
encoded as CD-DA. It does @emph{not} necessarily represent the amount
time that it will take to play a of Video CD---usually you need more
blocks than this. Nor does it represent the amount of data used to
play a second of an MP3---usually you need fewer blocks than this. It
is also not the amount of time your CD-ROM will take to read a
``second'' of data off a Compact Disc: for example a 12x CD player
will read 12x @code{CDIO_CD_FRAMES_PER_SEC}
@code{CDIO_CD_FRAMSIZE_RAW}-byte blocks in a one second of time.

When programming, unless one is working with a CD-DA (and even here,
only in a time-like fashion), is generally more cumbersome to use an
MSF rather than a LBA or LSN described below, since subtraction of two
MSF's has the awkwardness akin to subtraction using Roman Numerals.

Probably the simplest way to address a block is to use its @term{LSN}
or ``logical sector number.'' This just numbers the blocks usually
from 0 on. @emph{fix me: LSNs can be negative up to the pregap size?}
The Lead-in and Lead-out gaps described above have LSNs just like any
other space on a CD. The last unit of address is a @term{LBA}. It is
the same as a LSN but the 150 blocks associated with the initial
lead-in is are not counted. So to convert a LBA into an LSN you just
add 150. Why the distinction between LBA and LSN? I don't know,
perhaps this has something to do with ``multisession'' CDs.

@node How to use
@chapter How to use

The @value{libcdio} package comes with a number of small example
programs in the directory @file{example} which demonstrate different
aspects of the library and show how to use the library. The source
code to all of the examples here are contained on the package.

Other sources for examples would be the larger utility programs
@command{cd-drive}, @command{cd-info}, @command{cd-read},
@command{iso-info}, and @command{iso-read} which are all in the
@file{src} directory of the @value{libcdio} package.  See also
@xref{Utility Programs}.

@menu
* Example 1::        list out tracks and LSNs
* Example 2::        list drivers available and default CD device 
* Example 3::        figure out what kind of CD (image) we've got
* Example 4::        use libiso9660 to extract a file from an ISO-9660 image
* Example 5::        list CD-Text and CD disc mode info
* Example 6::        run a MMC INQUIRY command
* Example 7::        using the CD Paranoia library for CD-DA reading
* All sample programs:: list of all programs in the example directory
@end menu

@node Example 1
@section Example 1: list out tracks and LSNs
Here we will give an annotated example which can be found in the
distribution as @file{example/tracks.c}.

@smallexample
 1: #include <stdio.h>
 2: #include <sys/types.h>
 3: #include <cdio/cdio.h>
 4: int
 5: main(int argc, const char *argv[])
 6: @{
 7:  CdIo_t *p_cdio = cdio_open ("/dev/cdrom", DRIVER_DEVICE);
 8:  track_t first_track_num = cdio_get_first_track_num(p_cdio);
 9:  track_t i_tracks        = cdio_get_num_tracks(p_cdio);
10:  int j, i=first_track_num;
11:
12:  printf("CD-ROM Track List (%i - %i)\n", first_track_num, i_tracks);
13
14:  printf("  #:  LSN\n");
15:  
16:  for (j = 0; j < i_tracks; i++, j++) @{
17:    lsn_t lsn = cdio_get_track_lsn(p_cdio, i);
18:    if (CDIO_INVALID_LSN != lsn)
19:      printf("%3d: %06d\n", (int) i, lsn);
20:  @}
21:  printf("%3X: %06d  leadout\n", CDIO_CDROM_LEADOUT_TRACK, 
22:         cdio_get_track_lsn(p_cdio, CDIO_CDROM_LEADOUT_TRACK));
23:  cdio_destroy(p_cdio);
24:  return 0;
25: @}
@end smallexample 

Already from the beginning on line 2 we see something odd. The
@code{#include <sys/types.h>} is needed because @value{libcdio}
assumes type definitions exist for @code{uint32_t}, @code{uint16_t}
and so on.  Alternatively you change line 2 to:

@smallexample
#define HAVE_SYS_TYPES_H
@end smallexample 

and @code{<cdio/cdio.h>} will insert line 2. If you use GNU autoconf
to configure your program, add @code{sys/types.h} to
@code{AC_HAVE_HEADERS} and @emph{it} will arrange for
@code{HAVE_SYS_TYPES_H} to get defined. If you don't have
@code{<sys/types.h>} but have some other include that defines these
types, put that instead of line 2. Or you could roll your own
typedefs. (Note: In the future, this will probably get ``fixed'' by
requiring glib.h.)

Okay after getting over the hurdle of line 2, the next line pretty
straightforward: you need to include this to get cdio definitions. One
of the types that is defined via line 3 is @code{CdIo_t} and a pointer
that is used pretty much in all operations. Line 6 initializes the
variable @code{cdio} which we will be using in all of the subsequent
libcdio calls. It does this via a call to @code{cdio_open()}. 

The second parameter of @code{cdio_open} is DRIVER_UNKNOWN. For any
given installation a number of Compact Disc device drivers may be
available. In particular it's not uncommon to have several drivers
that can read CD disk-image formats as well as a driver that handles
some CD-ROM piece of hardware. Using DRIVER_UNKNOWN as that second
parameter we let the library select a driver amongst those that are
available; generally the first hardware driver that is available is
the one selected. 

If there is no CD in any of the CD-ROM drives or one does not have
access to the CD-ROM, it is possible that @value{libcdio} will find a
CD image in the directory you run this program and will pick a
suitable CD-image driver. If this is not what you want, but always
want some sort of CD-ROM driver (or failure if none), then use
DRIVER_DEVICE instead of DRIVER_UNKNOWN.

Note that in contrast to what is typically done using ioctls to read a
CD, you don't issue any sort of CD-ROM read TOC command---that is all
done by the driver. Of course, the information that you get from
reading the TOC is often desired: many tracks are on the CD, or what
number the first one is called. This is done through calls on lines 8
and 9.

For each track, we call a cdio routine to get the logical sector
number, @code{cdio_get_track_lsn()} on line 17 and print the track
number and LSN value. Finally we print out the ``lead-out track''
information and we finally call @code{cdio_destroy()} in line 23 to
indicate we're done with the CD.

@node Example 2
@section Example 2: list drivers available and default CD device 

One thing that's a bit hoaky in Example 1 is hard-coding the name of
the device used: @code{/dev/cdrom}. Although often this is the name of
a CD-ROM device on GNU/Linux and possibly some other Unix derivatives,
there are many OSs for which use a different device name.

In the next example, we'll let the driver give us the name of the CD-ROM
device that is right for it. 

@smallexample
 1: #include <stdio.h>
 2: #include <sys/types.h>
 3: #include <cdio/cdio.h>
 4: int
 5: main(int argc, const char *argv[])
 6: @{
 7:   CdIo_t *p_cdio = cdio_open (NULL, DRIVER_DEVICE);
 8:   driver_id_t driver_id;
 9:  
10:  if (NULL != p_cdio) @{
11:    printf("The driver selected is %s\n", cdio_get_driver_name(p_cdio));
12:    printf("The default device for this driver is %s\n\n", 
13:           cdio_get_default_device(p_cdio));
14:    cdio_destroy(p_cdio);
15:  @} else @{
16:    printf("Problem in trying to find a driver.\n\n");
17:  @}
18:
19:  for (driver_id=CDIO_MIN_DRIVER; driver_id<=CDIO_MAX_DRIVER; driver_id++)
20:    if (cdio_have_driver(driver_id))
21:      printf("We have: %s\n", cdio_driver_describe(driver_id));
22:    else
23:      printf("We don't have: %s\n", cdio_driver_describe(driver_id));
24:  return 0;
25: @}
@end smallexample


@node Example 3
@section Example 3: figure out what kind of CD (image) we've got

In this example is a somewhat simplified program to show the use of
@command{cdio_guess_cd_type()} to  figure out the kind of CD image
we've got. This can be found in the distribution as @file{example/sample3.c}.

@smallexample
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <cdio/cdio.h>
#include <cdio/cd_types.h>

static void
print_analysis(cdio_iso_analysis_t cdio_iso_analysis, 
	       cdio_fs_anal_t fs, int first_data, unsigned int num_audio, 
	       track_t i_tracks, track_t first_track_num, CdIo_t *cdio)
@{
  switch(CDIO_FSTYPE(fs)) @{
  case CDIO_FS_AUDIO:
    break;
  case CDIO_FS_ISO_9660:
    printf("CD-ROM with ISO 9660 filesystem");
    if (fs & CDIO_FS_ANAL_JOLIET) @{
      printf(" and joliet extension level %d", cdio_iso_analysis.joliet_level);
    @}
    if (fs & CDIO_FS_ANAL_ROCKRIDGE)
      printf(" and rockridge extensions");
    printf("\n");
    break;
  case CDIO_FS_ISO_9660_INTERACTIVE:
    printf("CD-ROM with CD-RTOS and ISO 9660 filesystem\n");
    break;
  case CDIO_FS_HIGH_SIERRA:
    printf("CD-ROM with High Sierra filesystem\n");
    break;
  case CDIO_FS_INTERACTIVE:
    printf("CD-Interactive%s\n", num_audio > 0 ? "/Ready" : "");
    break;
  case CDIO_FS_HFS:
    printf("CD-ROM with Macintosh HFS\n");
    break;
  case CDIO_FS_ISO_HFS:
    printf("CD-ROM with both Macintosh HFS and ISO 9660 filesystem\n");
    break;
  case CDIO_FS_UFS:
    printf("CD-ROM with Unix UFS\n");
    break;
  case CDIO_FS_EXT2:
    printf("CD-ROM with Linux second extended filesystem\n");
	  break;
  case CDIO_FS_3DO:
    printf("CD-ROM with Panasonic 3DO filesystem\n");
    break;
  case CDIO_FS_UNKNOWN:
    printf("CD-ROM with unknown filesystem\n");
    break;
  @}
  switch(CDIO_FSTYPE(fs)) @{
  case CDIO_FS_ISO_9660:
  case CDIO_FS_ISO_9660_INTERACTIVE:
  case CDIO_FS_ISO_HFS:
    printf("ISO 9660: %i blocks, label `%.32s'\n",
	   cdio_iso_analysis.isofs_size, cdio_iso_analysis.iso_label);
    break;
  @}
  if (first_data == 1 && num_audio > 0)
    printf("mixed mode CD   ");
  if (fs & CDIO_FS_ANAL_XA)
    printf("XA sectors   ");
  if (fs & CDIO_FS_ANAL_MULTISESSION)
    printf("Multisession");
  if (fs & CDIO_FS_ANAL_HIDDEN_TRACK)
    printf("Hidden Track   ");
  if (fs & CDIO_FS_ANAL_PHOTO_CD)
    printf("%sPhoto CD   ", 
		      num_audio > 0 ? " Portfolio " : "");
  if (fs & CDIO_FS_ANAL_CDTV)
    printf("Commodore CDTV   ");
  if (first_data > 1)
    printf("CD-Plus/Extra   ");
  if (fs & CDIO_FS_ANAL_BOOTABLE)
    printf("bootable CD   ");
  if (fs & CDIO_FS_ANAL_VIDEOCD && num_audio == 0) @{
    printf("Video CD   ");
  @}
  if (fs & CDIO_FS_ANAL_SVCD)
    printf("Super Video CD (SVCD) or Chaoji Video CD (CVD)");
  if (fs & CDIO_FS_ANAL_CVD)
    printf("Chaoji Video CD (CVD)");
  printf("\n");
@}

int
main(int argc, const char *argv[])
@{
  CdIo_t *p_cdio = cdio_open (NULL, DRIVER_UNKNOWN);
  cdio_fs_anal_t fs=0;
  
  track_t i_tracks;
  track_t first_track_num;
  lsn_t start_track;          /* first sector of track */
  lsn_t data_start =0;        /* start of data area */

  int first_data = -1;        /* # of first data track */
  int first_audio = -1;       /* # of first audio track */
  unsigned int num_data  = 0; /* # of data tracks */
  unsigned int num_audio = 0; /* # of audio tracks */
  unsigned int i;

  if (NULL == p_cdio) @{
    printf("Problem in trying to find a driver.\n\n");
    return 1;
  @}

  first_track_num = cdio_get_first_track_num(p_cdio);
  i_tracks      = cdio_get_num_tracks(p_cdio);

  /* Count the number of data and audio tracks. */
  for (i = first_track_num; i <= i_tracks; i++) @{
    if (TRACK_FORMAT_AUDIO == cdio_get_track_format(p_cdio, i)) @{
      num_audio++;
      if (-1 == first_audio) first_audio = i;
    @} else @{
      num_data++;
      if (-1 == first_data)  first_data = i;
    @}
  @}

  /* try to find out what sort of CD we have */
  if (0 == num_data) @{
    printf("Audio CD\n");
  @} else @{
    /* we have data track(s) */
    int j;
    cdio_iso_analysis_t cdio_iso_analysis; 

    memset(&cdio_iso_analysis, 0, sizeof(cdio_iso_analysis));
    
    for (j = 2, i = first_data; i <= i_tracks; i++) @{
      lsn_t lsn;
      track_format_t track_format = cdio_get_track_format(p_cdio, i);
      
      lsn = cdio_get_track_lsn(p_cdio, i);
      
      switch ( track_format ) @{
      case TRACK_FORMAT_AUDIO:
      case TRACK_FORMAT_ERROR:
	break;
      case TRACK_FORMAT_CDI:
      case TRACK_FORMAT_XA:
      case TRACK_FORMAT_DATA: 
      case TRACK_FORMAT_PSX: 
	;
      @}
      
      start_track = (i == 1) ? 0 : lsn;
      
      /* save the start of the data area */
      if (i == first_data) 
	data_start = start_track;
      
      /* skip tracks which belong to the current walked session */
      if (start_track < data_start + cdio_iso_analysis.isofs_size)
	continue;
      
      fs = cdio_guess_cd_type(p_cdio, start_track, i, &cdio_iso_analysis);
      
      print_analysis(cdio_iso_analysis, fs, first_data, num_audio,
		     i_tracks, first_track_num, p_cdio);
      
      if ( !(CDIO_FSTYPE(fs) == CDIO_FS_ISO_9660 ||
	     CDIO_FSTYPE(fs) == CDIO_FS_ISO_HFS  ||
	     CDIO_FSTYPE(fs) == CDIO_FS_ISO_9660_INTERACTIVE) )
	/* no method for non-ISO9660 multisessions */
	break;	
    @}
  @}
  cdio_destroy(p_cdio);
  return 0;
@}
@end smallexample

@node Example 4
@section Example 4: use libiso9660 to extract a file from an ISO-9660 image

Next a program to show using @command{libiso9660} to extract a file
from an ISO-9660 image.  This can be found in the distribution as
@file{example/iso3.c}. A more complete and expanded version of this
is @command{iso-read}, part of this distribution.

@smallexample
/* This is the ISO 9660 image. */
#define ISO9660_IMAGE_PATH "../"
#define ISO9660_IMAGE ISO9660_IMAGE_PATH "test/copying.iso"

#define LOCAL_FILENAME "copying"

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <sys/types.h>
#include <cdio/cdio.h>
#include <cdio/iso9660.h>

#include <stdio.h>

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#define my_exit(rc)				\
  fclose (p_outfd);				\
  free(p_statbuf);				\
  iso9660_close(p_iso);				\
  return rc;					\

int
main(int argc, const char *argv[])
@{
  iso9660_stat_t *p_statbuf;
  FILE *p_outfd;
  int i;
  
  iso9660_t *p_iso = iso9660_open (ISO9660_IMAGE);
  
  if (NULL == p_iso) @{
    fprintf(stderr, "Sorry, couldn't open ISO 9660 image %s\n", ISO9660_IMAGE);
    return 1;
  @}

  p_statbuf = iso9660_ifs_stat_translate (p_iso, LOCAL_FILENAME);

  if (NULL == p_statbuf) 
    @{
      fprintf(stderr, 
	      "Could not get ISO-9660 file information for file %s\n",
	      LOCAL_FILENAME);
      iso9660_close(p_iso);
      return 2;
    @}

  if (!(p_outfd = fopen (LOCAL_FILENAME, "wb")))
    @{
      perror ("fopen()");
      free(p_statbuf);
      iso9660_close(p_iso);
      return 3;
    @}

  /* Copy the blocks from the ISO-9660 filesystem to the local filesystem. */
  for (i = 0; i < p_statbuf->size; i += ISO_BLOCKSIZE)
    @{
      char buf[ISO_BLOCKSIZE];

      memset (buf, 0, ISO_BLOCKSIZE);
      
      if ( ISO_BLOCKSIZE != iso9660_iso_seek_read (p_iso, buf, p_statbuf->lsn 
						   + (i / ISO_BLOCKSIZE),
						   1) )
      @{
	fprintf(stderr, "Error reading ISO 9660 file at lsn %lu\n",
		(long unsigned int) p_statbuf->lsn + (i / ISO_BLOCKSIZE));
	my_exit(4);
      @}
      
      
     fwrite (buf, ISO_BLOCKSIZE, 1, p_outfd);
      
     if (ferror (p_outfd))
        @{
          perror ("fwrite()");
          my_exit(5);
        @}
    @}
  
  fflush (p_outfd);

  /* Make sure the file size has the exact same byte size. Without the
     truncate below, the file will a multiple of ISO_BLOCKSIZE.
   */
  if (ftruncate (fileno (p_outfd), p_statbuf->size))
    perror ("ftruncate()");

  my_exit(0);
@}
@end smallexample

@node Example 5
@section Example 5: list CD-Text and disc mode info

Next a program to show using @command{libcdio} to list CD-TEXT data.
This can be found in the distribution as @file{example/cdtext.c}.

@smallexample
/* Simple program to list CD-Text info of a Compact Disc using libcdio. */
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <sys/types.h>
#include <cdio/cdio.h>
#include <cdio/cdtext.h>


static void 
print_cdtext_track_info(CdIo_t *p_cdio, track_t i_track, const char *message) @{
  const cdtext_t *cdtext    = cdio_get_cdtext(p_cdio, 0);
  if (NULL != cdtext) @{
    cdtext_field_t i;
    
    printf("%s\n", message);
    
    for (i=0; i < MAX_CDTEXT_FIELDS; i++) @{
      if (cdtext->field[i]) @{
        printf("\t%s: %s\n", cdtext_field2str(i), cdtext->field[i]);
      @}
    @}
  @}
  
@}
    
static void 
print_disc_info(CdIo_t *p_cdio, track_t i_tracks, track_t i_first_track) @{
  track_t i_last_track = i_first_track+i_tracks;
  discmode_t cd_discmode = cdio_get_discmode(p_cdio);

  printf("%s\n", discmode2str[cd_discmode]);
  
  print_cdtext_track_info(p_cdio, 0, "\nCD-Text for Disc:");
  for ( ; i_first_track < i_last_track; i_first_track++ ) @{
    char psz_msg[50];
    sprintf(msg, "CD-Text for Track %d:", i_first_track);
    print_cdtext_track_info(p_cdio, i_first_track, psz_msg);
  @}
@}

int
main(int argc, const char *argv[])
@{
  track_t i_first_track;
  track_t i_tracks;
  CdIo_t *p_cdio;
  cdio = cdio_open (NULL, DRIVER_UNKNOWN);
  i_first_track = cdio_get_first_track_num(p_cdio);
  i_tracks      = cdio_get_num_tracks(p_cdio);

  if (NULL == p_cdio) @{
    printf("Couldn't find CD\n");
    return 1;
  @} else @{
    print_disc_info(p_cdio, i_tracks, i_first_track);
  @}

  cdio_destroy(p_cdio);
  
  return 0;
@}
@end smallexample 

@node Example 6
@section Example 6: Using MMC to run an @code{INQURY} command

Now a program to show issuing a simple MMC command
(@code{INQUIRY}). This MMC command retrieves the vendor, model and
firmware revision number of a CD drive. For this command to work,
usually a CD to be loaded into the drive; odd since the CD itself is
not used.

This can be found in the distribution as @file{example/mmc1.c}.

@smallexample
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <sys/types.h>
#include <cdio/cdio.h>
#include <cdio/scsi_mmc.h>
#include <string.h>

/* Set how long to wait for MMC commands to complete */
#define DEFAULT_TIMEOUT_MS 10000

int
main(int argc, const char *argv[])
@{
  CdIo_t *p_cdio;

  p_cdio = cdio_open (NULL, DRIVER_UNKNOWN);

  if (NULL == p_cdio) @{
    printf("Couldn't find CD\n");
    return 1;
  @} else @{
    int i_status;                  /* Result of MMC command */
    char buf[36] = @{ 0, @};         /* Place to hold returned data */
    scsi_mmc_cdb_t cdb = @{@{0, @}@};  /* Command Descriptor Buffer */

    CDIO_MMC_SET_COMMAND(cdb.field, CDIO_MMC_GPCMD_INQUIRY);
    cdb.field[4] = sizeof(buf);

    i_status = scsi_mmc_run_cmd(p_cdio, DEFAULT_TIMEOUT_MS, 
				&cdb, SCSI_MMC_DATA_READ, 
				sizeof(buf), &buf);
    if (i_status == 0) @{
      char psz_vendor[CDIO_MMC_HW_VENDOR_LEN+1];
      char psz_model[CDIO_MMC_HW_MODEL_LEN+1];
      char psz_rev[CDIO_MMC_HW_REVISION_LEN+1];
      
      memcpy(psz_vendor, buf + 8, sizeof(psz_vendor)-1);
      psz_vendor[sizeof(psz_vendor)-1] = '\0';
      memcpy(psz_model,
	     buf + 8 + CDIO_MMC_HW_VENDOR_LEN, 
	     sizeof(psz_model)-1);
      psz_model[sizeof(psz_model)-1] = '\0';
      memcpy(psz_rev,
	     buf + 8 + CDIO_MMC_HW_VENDOR_LEN +CDIO_MMC_HW_MODEL_LEN,
	     sizeof(psz_rev)-1);
      psz_rev[sizeof(psz_rev)-1] = '\0';

      printf("Vendor: %s\nModel: %s\nRevision: %s\n",
	     psz_vendor, psz_model, psz_rev);
    @} else @{
      printf("Couldn't get INQUIRY data (vendor, model, and revision\n");
    @}
  @}
  
  cdio_destroy(p_cdio);
  
  return 0;
@}
@end smallexample 

@node Example 7
@section Example 7: Using the CD Paranoia library for CD-DA reading

@smallexample
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <cdio/cdda.h>
#include <cdio/cd_types.h>
#include <stdio.h>

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

int
main(int argc, const char *argv[])
@{
  cdrom_drive_t *d = NULL; /* Place to store handle given by cd-paranoia. */
  char **ppsz_cd_drives;   /* List of all drives with a loaded CDDA in it. */

  /* See if we can find a device with a loaded CD-DA in it. */
  ppsz_cd_drives = cdio_get_devices_with_cap(NULL, CDIO_FS_AUDIO, false);

  if (ppsz_cd_drives) @{
    /* Found such a CD-ROM with a CD-DA loaded. Use the first drive in
       the list. */
    d=cdio_cddap_identify(*ppsz_cd_drives, 1, NULL);
  @} else @{
    printf("Unable find or access a CD-ROM drive with an audio CD in it.\n");
    exit(1);
  @}

  /* Don't need a list of CD's with CD-DA's any more. */
  cdio_free_device_list(ppsz_cd_drives);

  /* We'll set for verbose paranoia messages. */
  cdio_cddap_verbose_set(d, CDDA_MESSAGE_PRINTIT, CDDA_MESSAGE_PRINTIT);

  if ( 0 != cdio_cddap_open(d) ) @{
    printf("Unable to open disc.\n");
    exit(1);
  @}

  /* Okay now set up to read up to the first 300 frames of the first
     audio track of the Audio CD. */
  @{ 
    cdrom_paranoia_t *p = cdio_paranoia_init(d);
    lsn_t i_first_lsn = cdio_cddap_disc_firstsector(d);

    if ( -1 == i_first_lsn ) @{
      printf("Trouble getting starting LSN\n");
    @} else @{
      lsn_t   i_cursor;
      track_t i_track    = cdio_cddap_sector_gettrack(d, i_first_lsn);
      lsn_t   i_last_lsn = cdio_cddap_track_lastsector(d, i_track);

      /* For demo purposes we'll read only 300 frames (about 4
	 seconds).  We don't want this to take too long. On the other
	 hand, I suppose it should be something close to a real test.
       */
      if ( i_last_lsn - i_first_lsn > 300) i_last_lsn = i_first_lsn + 299;

      printf("Reading track %d from LSN %ld to LSN %ld\n", i_track, 
	     (long int) i_first_lsn, (long int) i_last_lsn);

      /* Set reading mode for full paranoia, but allow skipping sectors. */
      paranoia_modeset(p, PARANOIA_MODE_FULL^PARANOIA_MODE_NEVERSKIP);

      paranoia_seek(p, i_first_lsn, SEEK_SET);

      for ( i_cursor = i_first_lsn; i_cursor <= i_last_lsn; i_cursor ++) @{
	/* read a sector */
	int16_t *p_readbuf=cdio_paranoia_read(p, NULL);
	char *psz_err=cdio_cddap_errors(d);
	char *psz_mes=cdio_cddap_messages(d);

	if (psz_mes || psz_err)
	  printf("%s%s\n", psz_mes ? psz_mes: "", psz_err ? psz_err: "");

	if (psz_err) free(psz_err);
	if (psz_mes) free(psz_mes);
	if( !p_readbuf ) @{
	  printf("paranoia read error. Stopping.\n");
	  break;
	@}
      @}
    @}
    cdio_paranoia_free(p);
  @}

  cdio_cdda_close(d);

  exit(0);
@}
@end smallexample 

Those who are die-hard cdparanoia programmers will notice that the
@value{libcdio} paranoia names are similar but a little bit
different. In particular instead of @code{paranoia_read} we have above
@code{cdio_paranoia_read} and instead of @code{cdda_open} we have
@code{cdio_cddap_open}.

This was done intentionally so that it is possible for the original
paranoia program can co-exist both in source code and linked libraries
and not conflict with @value{libcdio}'s paranoia source and libraries.

In general in place of any paranoia routine that begins
@code{paranoia_}, use @code{cdio_paranoia_} and in place of any
paranoia routine that begins @code{cdda_}, use @code{cdio_cddap_}. But
for a limited time @value{libcdio} will accept the old paranoia names
which may be useful for legacy paranoia code. The way this magic works
is by defining the old paranoia name to be the @value{libcdio} name.

In the unusual case where you do want to use both the original
paranoia and @value{libcdio} routines in a single source, the C
preprocessor symbol @code{DO_NOT_WANT_PARANOIA_COMPATIBILITY} can be
@code{define}'d and this disables the @code{#define} substitution done
automatically. The may still be a problem with conflicting structure
definitions like @code{cdrom_drive_t}.

@node All sample programs
@section A list of all sample programs in the @code{example} directory

The @code{example} directory contains some simple examples of the use
of the @value{libcdio} library.

A larger more-complicated example are the @command{cd-drive},
@command{cd-info}, @command{cd-read}, @command{iso-info} and
@command{iso-info} programs in the @command{src} directory.

Descriptions of the sample are as follows...

@table @code 

@item @code{iso1.c}

A program to show using @code{libiso9660} to list files in a
	directory of an ISO-9660 image.

@item @code{C++/iso1.cpp}

The same program as @code{iso1.c} written in C++.

@item @code{iso2.c}

A program to show using @code{libiso9660} to extract a file from a
CDRWIN cue/bin CD image.

@item @code{C++/iso2.cpp}

The same program as @code{iso2.c} written in C++.

@item @code{iso3.c}

A program to show using libiso9660 to extract a file from an ISO-9660
image.

@item @code{C++/iso3.cpp}

The same program as @code{iso3.c} written in C++.

@item @code{cdtext.c}

A program to show CD-Text and CD disc mode info.

@item @code{drives.c}

A program to show drivers installed and what the default CD-ROM drive
is and what CD drives are available.

@item @code{paranoia.c}

A program to show using libcdio's version of the CD-DA paranoia. 

@item @code{paranoia2.c}

A program to show using libcdio's version of the CD-DA paranoia
library. But in this version, we'll open a cdio object before calling
paranoia's open. I imagine in many cases such as media players this
may be what will be done since, one may want to get CDDB/CD-Text info
beforehand. 

@item @code{mmc1.c}

A program to show issuing a simple MMC command (@code{INQUIRY}).

@item @code{C++/mmc1.cpp}

The same program as @code{mmc1.c} written in C++.

@item @code{mmc2.c}

A more involved MMC command to list CD and drive features from a
SCSI-MMC @code{GET_CONFIGURATION} command.

@item @code{C++/mmc2.cpp}

The same program as @code{mmc2.c} written in C++.

@item @code{tracks.c}

A simple program to list track numbers and logical sector numbers of a
Compact Disc using @value{libcdio}.

@item @code{sample2.c}

A simple program to show drivers installed and what the default CD-ROM
drive is.

@item @code{sample3.c}

A simple program to show the use of @code{cdio_guess_cd_type()}.  Figures out
the kind of CD image we've got.

@item @code{sample4.c}

 A slightly improved sample3 program: we handle cdio logging and take
an optional CD-location.

@end table

@node Utility Programs
@chapter Diagnostic programs (@samp{cd-drive}, @samp{cd-info}, @samp{cd-read}, @samp{iso-info}, @samp{iso-read})

@menu
* cd-drive::       list out CD-ROM drive information
* cd-info::        list out CD or CD-image information
* cd-read::        read blocks of a CD or CD image
* iso-info::       list out ISO-9600 image information
* iso-read::       extract a file from an ISO 9660 image
@end menu

@node cd-drive
@section @samp{cd-drive}

@samp{cd-drive} lists out drive information, what features drive
supports, and information about what hardware drivers are available.

@node cd-info
@section @samp{cd-info}

@samp{cd-info} will print out the structure of a CD medium which could
either be a Compact Disc in a CD ROM or an CD image. It can try to
analyze the medium to give characteristics of the medium, such as how
many tracks are in the CD and the format of each track, whether a CD
contains a Video CD, CD-DA, PhotoCD, whether a track has an ISO-9660
filesystem.

@node cd-read
@section @samp{cd-read}

@samp{cd-info} can be used to read blocks a CD medium which could
either be a Compact Disc in a CD ROM or an CD image. You specify the
beginning and ending LSN and what mode format to use in the reading.

@node iso-info
@section @samp{iso-info}

@samp{iso-info} can be used to print out the structure of an ISO 9660 
image.

@node iso-read
@section @samp{iso-read}

@samp{iso-info} can be used to extract a file in an ISO-9660 image.

@node CD-ROM Access and Drivers
@chapter CD-ROM Access and Drivers

@menu
* MMC::  ``SCSI'' Multimedia Commands (MMC)
* GNU/Linux:: GNU/Linux ioctl
* Microsoft:: Microsoft Windows ioctl and ASPI
* Solaris:: Solaris ATAPI and SCSI
* FreeBSD:: FreeBSD ioctl and CAM
* OS X::  OSX (non-exclussive access)
@end menu

@node MMC
@section Multimedia Commands (MMC)

In contrast to the rest of the sections in this chapter, MMC
(Multimedia commands) is not a driver per se, although many of the
CD-ROM drivers do in fact issue MMC commands. MMC commands
gives (in theory) a broad and uniform way to access a CD-ROM drive.

If your CD-ROM drive understands MMC commands this is probably gives
the most flexibility in control. SCSI and ATAPI CD-ROM devices
generally support a fairly large set of MMC commands.

The name ``SCSI MMC'' is often found in the literature in
specifications and on the Internet. The ``SCSI'' part is probably a
little bit misleading because a drive can understand ``SCSI MMC''
commands but not use a SCSI interface---ATAPI CD-ROMs are one such
broad class of examples. In fact there are drivers to ``encapsulate''
non-SCSI drives or a non-MMC-compliant drives and make them act like
MMC drives. I believe that many OS SCSI ``pass-through'' mechanisms do
roughly the same thing.

The name ``SCSI MMC'' is no doubt due to the fact that these commands
grew out of the SCSI command set and thus were bundled in them. 

For clarity and precision we will use the term ``MMC'' rather than
``SCSI MMC''.

One of the problems with MMC is that there are so many different
``standards''. In particular there are MMC
@url{ftp://ftp.t10.org/t10/drafts/mmc/}, MMC 2
@url{ftp://ftp.t10.org/t10/drafts/mmc2/}, MMC 3
@url{ftp://ftp.t10.org/t10/drafts/mmc3/}, MMC 4
@url{ftp://ftp.t10.org/t10/drafts/mmc4/}, and MMC 5
@url{ftp://ftp.t10.org/t10/drafts/mmc5/} standards several ``drafts''
for each standard. The good news about ATAPI drives is that they too
understand some sort of MMC subset. The bad news (as I understand
it) is that they do not understand any full MMC command set.

Another problem with the MMC commands related to the variations in
standards is the variation in the commands themselves and there are
perhaps two or three ways to do many of the basic commands like read a
CD frame.

There seems to be a fascination with the number of bytes a command
takes in the MMC-specification world. (Size matters?) So often the
name of an operation will have a suffix with the number of bytes of
the command (actually in MMC jargon this is called a ``CDB''
@cindex CDB (Command Descriptor Block)
or command descriptor block). So for example there is a 6-byte ``MODE
SELECT'' often called ``MODE SELECT 6'' and a 10-byte ``MODE SELECT''
often called ``MODE SELECT 10''. Presumably the 6-byte command came
first and it was discovered that there was some deficiency causing the
longer command. In @value{libcdio} where there are two formats we add
the suffix in the name, e.g. @code{CDIO_MMC_GPCMD_MODE_SELECT_6} or
@code{CDIO_MMC_GPCMD_MODE_SELECT_10}.

If the fascination and emphasis in the MMC specifications of CDB size
is a bit odd, equally so is the fact that this too often has bled
through at the OS programming API. However in @value{libcdio}, you
just give the opcode in @code{scsi_mmc_run_cmd()} and we'll do the
work to figure out how many bytes of the CDB are used.

Down the line it is hoped that @value{libcdio} will have a way to
remove a distinction between the various alternative and
alternative-size MMC commands. In @code{cdio/scsi-mmc.h} you will
find a little bit of this for example via the routine
@code{scsi_mmc_get_drive_cap()}. However much more work is needed.

@node GNU/Linux
@section GNU/Linux

The GNU/Linux uses a hybrid of methods. Somethings are done vai ioctl
and some things via MMC. GNU/Linux has a rather nice and complete
ioctl mechanism. On the other hand, the MMC mechanism is more
universal.  There are other ``access modes'' listed which are not
really access modes and should probably be redone/rethought.  They are
just different ways to run the read command. But for completeness
These are ``READ_CD'' and ``READ_10''.

@node Microsoft
@section Microsoft Windows ioctl and ASPI

There are two CD drive access methods on Microsoft Windows platforms:
ioctl and 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 Window 9x/NT and later. Emulation for
ATAPI drives was added so that the same sets of commands worked 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).


@node Solaris
@section Solaris ATAPI and SCSI

There is currently only one CD drive access methods in Solaris: SCSI
(called ``USCSI'' or ``user SCSI'' in Solaris). There used to be an
ATAPI method and it could be resurrected if needed. USCSI was
preferred since on newer releases of Solaris and Solaris environments
one would needs to have root access for ATAPI.

@node FreeBSD
@section FreeBSD ioctl and CAM

There are two CD drive access methods on Solaris: ioctl and CAM
(common access method). CAM is preferred when possible, especially on
newer releases. However CAM is right now sort of a hybrid and includes
some ioctl code.

More work on this driver is needed. Volunteers? 

@node OS X
@section OS X (non-exclussive access)

A problem with OS/X is that if the OS thinks it understands the drive
it gains exclusive access to it and thus prevents a library like this
to get non-exclusive access. 

Currently @value{libcdio} access the CD-ROM non-exclusively. However
in order to be able to issue MMC, the current belief is that
exclusive access is needed. Probably in a future @value{libcdio},
there will be some way to specify which kind of access is desired
(with the inherent consequences of each).

More work on this driver is needed. Volunteers?

@node Internal Program Organization
@chapter Internal Program Organization

@subsection file organization

Here is a list of @value{libcdio} directories.

@itemize

@item @code{include/cdio}

This contains the headers that are public. One that will probably be
used quite a bit is @code{<cdio/cdio.h>}.

@item @code{lib}

Code for installed libraries. See below for further breakout

@item @code{lib/driver}

Code for various OS-specific CD-ROM drivers, image drivers, and
common MMC routines. 

This code comprises @code{libcdio.a} (or the shared version of it).

@item @code{lib/iso9660}

Code for to extract or query ISO-9660 images.

This code comprises @code{libiso9660.a} (or the shared version of it).

@item @code{lib/paranoia}

This is from cdparanoia. It is the OS- and hardware- dependent code to
detect and correct jitter for CD-DA CDs.

@item @code{lib/cdda_interface}

This is also from cdparanoia. It is the OS- and hardware- independent
code to detect and correct jitter for CD-DA CDs.

@item @code{doc}

A home for fine documentation such as this masterpiece.

@item @code{example}

Here you will find various small example programs using
@value{libcdio} which are largely for pedagogical purposes. You might
be able to find one that is similar to what you want to do that could
be extended. In fact some these are contain the kernel ideas behind of
some of the larger programs in @file{src}.

@item @code{src}

Various stand-alone utility programs. See below.

@item @code{src/paranoia}

@value{libcdio}'s version of @code{cdparanoia}. Except for the fact
that the back-end CD-reading code has been replaced by
@value{libcdio}'s routines the code is pretty much identical. 

@item @code{test}

Regression tests

@end itemize

@subsection @samp{libcdio}

@value{libcdio} exports one opaque type @code{CdIo_t}. Internally this
a structure containing an enumeration for the driver, a structure
containing function pointers and a generic ``environment'' pointer
which is passed as a parameter on a function call. See
@file{lib/driver/cdio_private.h}. The initialization routine for each
driver sets up the function pointers and allocates memory for the
environment. When a particular user-level cdio routine is called (e.g
@code{cdio_get_first_track_num} for lib/driver/track.c), the
environment pointer is passed to a device-specific routine which will
then cast this pointer into something of the appropriate type.

Because function pointers are used, there can be and is quite a bit
of sharing of common routines. Some of the common routines are found
in the file @file{lib/driver/_cdio_generic.c}. 

Another set of routines that one is likely to find shared amongst
drivers are the MMC commands. These are located in
@file{lib/driver/scsi_mmc.c}. 

There is not only an attempt to share functions but we've tried to create
a generic CD structure @code{generic_img_private_t} of file
@file{lib/driver/generic.h}. By putting information into a common
structure, we increase the likelihood of being able to have a common
routine to perform some sort of function. 

The generic CD structure would also be useful in a utility to convert
one CD-image format to another. Basically the first image format is
``parsed'' into the common internal format and then from this
structure it is unparsed.

@subsection @samp{libiso9660}

To be completed....

@subsection Coding Conventions

In @value{libcdio} there are a number of conventions used. If you
understand some of these conventions it may facilitate understanding
the code a little. 

@subsubsection namespace names

For the most part, the visible external @value{libcdio} names follow
conventions so as not to be confused with other applications or
libraries. If you understand these conventions, there will be little
or no chance that the names you use will conflict with @value{libcdio}
and @code{libiso9660} and vice versa.

All of the external @value{libcdio} C routines start out with
@code{cdio_}, e.g. @code{cdio_open}; as a corollary, the
@value{libcdio} CD-Paranoia routines start @code{cdio_cddap_},
e.g. @code{cdio_cddap_open}.  @code{libiso9660} routines start
@code{iso9660_}, e.g. @code{iso9660_open}.

@value{libcdio} C-Preprocessor names generally start @code{CDIO_}, for
example @code{CDIO_CD_FRAMESIZE_RAW}; @code{libiso9660}
C-preprocessor names start @code{ISO9660_},
e.g. @code{ISO9660_FRAMESIZE}.

@subsubsection suffixes (type and structure names)

A few suffixes are used in type and structure names:

@itemize

@item @code{_e}

An enumeration tag. Generally though the same name will appear with the
@code{_t} suffix and probably that should be used instead.

@item @code{_s}

A structure tag. Generally though the same name will appear with the
@code{_t} suffix and probably that should be used instead.

@item @code{_t}

A type suffix. 

@end itemize

@subsubsection prefixes (variable names)

A number of prefixes are used in variable names here's what they mean

@itemize
@item @code{i_}

An integer type of some sort. A variable of this ilk one might find
being iterated over in @code{for} loops or used as the index of an
array for example.

@item @code{b_}

A boolean type of some sort. A variable of this ilk one might find
being in an @code{if} condition for example.

@item @code{p_}

A pointer of some sort. A variable of this ilk, say
@code{p_foo} one is like likely to see @code{*p_foo} or
@code{p_foo->...}.

@item @code{pp_}

A pointer to a pointer of some sort. A variable of this ilk, say
@code{pp_foo} one is like likely to see @code{**p_foo} or
@code{p_foo[x][y]} for example

@item @code{psz_}

A @code{char *} pointer of some sort. A variable of this ilk, say
@code{psz_foo} may be used in a string operation. For example
@code{printf(%s\n", psz_foo)} or @code{strdup(psz_foo)}.

@item @code{ppsz_}

A pointer to a @code{char *} pointer of some sort. A variable of this
ilk, say @code{ppsz_foo} is used for example to return a list of
CD-ROM device names

@end itemize

There are a some other naming conventions. Generally if a routine
name starts @code{cdio_}, e.g. @code{cdio_open}, then it is an
externally visible routine in @code{libcdio}. If a name starts
@code{iso9660_}, e.g. @code{iso9660_isdchar} then it is an externally
visible routine in @code{libiso9660}. If a name starts
@code{scsi_mmc_}, e.g. @code{scsi_mmc_get_discmode}, then it is an
externally visible MMC routine. (We don't have a separate library for
this yet.

Names using entirely capital letters and that start @code{CDIO_} are
externally visible @code{#defines}.


@node ISO-9660 Character Sets
@appendix ISO-9660 Character Sets

For a description of where are used see @xref{ISO 9660 Level 1}.

@menu
* ISO646 d-Characters::         
* ISO646 a-Characters::         
@end menu

@node ISO646 d-Characters
@appendixsec ISO646 d-Characters

@example
  | 0 1 2 3 4 5 6 7 
--+-----------------
0 |       0   P     
1 |       1 A Q     
2 |       2 B R     
3 |       3 C S     
4 |       4 D T     
5 |       5 E U     
6 |       6 F V     
7 |       7 G W     
8 |       8 H X     
9 |       9 I Y     
a |         J Z     
b |         K       
c |         L       
d |         M       
e |         N       
f |         O _     
@end example

@node ISO646 a-Characters
@appendixsec ISO646 a-Characters

@example
  | 0 1 2 3 4 5 6 7
--+-----------------
0 |       0   P                    
1 |     ! 1 A Q                    
2 |     " 2 B R                    
3 |       3 C S                    
4 |       4 D T                    
5 |     % 5 E U                    
6 |     & 6 F V                    
7 |     ' 7 G W                    
8 |     ( 8 H X                    
9 |     ) 9 I Y                    
a |     * : J Z                    
b |     + ; K                      
c |     , < L                      
d |     - = M                      
e |     . > N                      
f |     / ? O _                    
@end example

@node Glossary
@appendix Glossary

@include glossary.texi

@node GNU General Public License
@appendix GNU General Public License
@cindex GPL, GNU General Public License
@center Version 2, June 1991

@include gpl.texi

@node GNU Free Documentation License
@appendix GNU Free Documentation License
@cindex FDL, GNU Free Documentation License
@center Version 1.1, March 2000

@include fdl.texi

@node General Index
@unnumbered General Index
@printindex cp

@bye

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