Provided by: libcddb-perl_1.222-1_all 
NAME
CDDB.pm - a high-level interface to cddb protocol servers (freedb and CDDB)
VERSION
version 1.222
SYNOPSIS
use CDDB;
### Connect to the cddbp server.
my $cddbp = new CDDB(
Host => 'freedb.freedb.org', # default
Port => 8880, # default
Login => $login_id, # defaults to %ENV's
) or die $!;
### Retrieve known genres.
my @genres = $cddbp->get_genres();
### Calculate cddbp ID based on MSF info.
my @toc = (
'1 0 2 37', # track, CD-i MSF (space-delimited)
'999 1 38 17', # lead-out track MSF
'1000 0 0 Error!', # error track (don't include if ok)
);
my (
$cddbp_id, # used for further cddbp queries
$track_numbers, # padded with 0's (for convenience)
$track_lengths, # length of each track, in MM:SS format
$track_offsets, # absolute offsets (used for further cddbp queries)
$total_seconds # total play time, in seconds (for cddbp queries)
) = $cddbp->calculate_id(@toc);
### Query discs based on cddbp ID and other information.
my @discs = $cddbp->get_discs($cddbp_id, $track_offsets, $total_seconds);
foreach my $disc (@discs) {
my ($genre, $cddbp_id, $title) = @$disc;
}
### Query disc details (usually done with get_discs() information).
my $disc_info = $cddbp->get_disc_details($genre, $cddbp_id);
my $disc_time = $disc_info->{'disc length'};
my $disc_id = $disc_info->{discid};
my $disc_title = $disc_info->{dtitle};
my @track_offsets = @{$disc_info->{offsets}};
my @track_seconds = @{$disc_info->{seconds}};
my @track_titles = @{$disc_info->{ttitles}};
# other information may be returned... explore!
### Submit a disc via e-mail. (Requires MailTools)
die "can't submit a disc (no mail modules; see README)"
unless $cddbp->can_submit_disc();
# These are useful for prompting the user to fix defaults:
print "I will send mail through: ", $cddbp->get_mail_host(), "\n";
print "I assume your e-mail address is: ", $cddbp->get_mail_address(), "\n";
# Actually submit a disc record.
$cddbp->submit_disc(
Genre => 'classical',
Id => 'b811a20c',
Artist => 'Various',
DiscTitle => 'Cartoon Classics',
Offsets => $disc_info->{offsets}, # array reference
TrackTitles => $disc_info->{ttitles}, # array reference
From => 'login@host.domain.etc', # will try to determine
);
DESCRIPTION
CDDB protocol (cddbp) servers provide compact disc information for programs that need it.
This allows such programs to display disc and track titles automatically, and it provides
extended information like liner notes and lyrics.
This module provides a high-level Perl interface to cddbp servers. With it, a Perl
program can identify and possibly gather details about a CD based on its "table of
contents" (the disc's track times and offsets).
Disc details have been useful for generating CD catalogs, naming mp3 files, printing CD
liners, or even just playing discs in an automated jukebox.
Despite the module's name, it connects to FreeDB servers by default. This began at
version 1.04, when cddb.com changed its licensing model to support end-user applications,
not third-party libraries. Connections to cddb.com may still work, and patches are
welcome to maintain that functionality, but it's no longer officially supported.
PUBLIC METHODS
new PARAMETERS
Creates a high-level interface to a cddbp server, returning a handle to it. The
handle is not a filehandle. It is an object. The new() constructor provides defaults
for just about everything, but everything is overrideable if the defaults aren't
appropriate.
The interface will not actually connect to a cddbp server until it's used, and a
single cddbp interface may actually make several connections (to possibly several
servers) over the course of its use.
The new() constructor accepts several parameters, all of which have reasonable
defaults.
Host and Port describe the cddbp server to connect to. These default to
'freedb.freedb.org' and 8880, which is a multiplexor for all the other freedb servers.
Utf8 is a boolean flag. If true, utf-8 will be used when submitting CD info, and for
interpreting the data reveived. This requires the Encode module (and probably perl
version at least 5.8.0). The default is true if the Encode module can be loaded.
Otherwise, it will be false, meaning we fall back to ASCII.
Protocol_Version sets the cddbp version to use. CDDB.pm will not connect to servers
that don't support the version specified here. The requested protocol version
defaults to 1 if Utf8 is off, and to 6 if it is on.
Login is the login ID you want to advertise to the cddbp server. It defaults to the
login ID your computer assigns you, if that can be determined. The default login ID
is determined by the presence of a LOGNAME or USER environment variable, or by the
getpwuid() function. On Windows systems, it defaults to "win32usr" if no default
method can be found and no Login parameter is set.
Submit_Address is the e-mail address where new disc submissions go. This defaults to
'freedb-submit@freedb.org'. Note, that testing submissions should be done via
"test-submit@freedb.org".
Client_Name and Client_Version describe the client software used to connect to the
cddbp server. They default to 'CDDB.pm' and CDDB.pm's version number. If developers
change this, please consult freedb's web site for a list of client names already in
use.
Debug enables verbose operational information on STDERR when set to true. It's
normally not needed, but it can help explain why a program is failing. If someone
finds a reproduceable bug, the Debug output and a test program would be a big help
towards having it fixed. In case of submission, if this flag is on, a copy of the
submission e-mail will be sent to the From address.
get_genres
Takes no parameters. Returns a list of genres known by the cddbp server, or undef if
there is a problem retrieving them.
calculate_id TOC
The cddb protocol defines an ID as a hash of track lengths and the number of tracks,
with an added checksum. The most basic information required to calculate this is the
CD table of contents (the CD-i track offsets, in "MSF" [Minutes, Seconds, Frames]
format).
Note however that there is no standard way to acquire this information from a CD-ROM
device. Therefore this module does not try to read the TOC itself. Instead,
developers must combine CDDB.pm with a CD library which works with their system. The
AudioCD suite of modules is recommended: it has system specific code for MacOS, Linux
and FreeBSD. CDDB.pm's author has used external programs like dagrab to fetch the
offsets. Actual CDs aren't always necessary: the author has heard of people
generating TOC information from mp3 file lengths.
That said, see parse_cdinfo() for a routine to parse "cdinfo" output into a table of
contents list suitable for calculate_id().
calculate_id() accepts TOC information as a list of strings. Each string contains
four fields, separated by whitespace:
offset 0: the track number
Track numbers start with 1 and run sequentially through the number of tracks on a
disc. Note: data tracks count on hybrid audio/data CDs.
CDDB.pm understands two special track numbers. Track 999 holds the lead-out
information, which is required by the cddb protocol. Track 1000 holds information
about errors which have occurred while physically reading the disc.
offset 1: the track start time, minutes field
Tracks are often addressed on audio CDs using "MSF" offsets. This stands for Minutes,
Seconds, and Frames (fractions of a second). The combination pinpoints the exact disc
frame where a song starts.
Field 1 contains the M part of MSF. It is ignored for error tracks, but it still must
contain a number. Zero is suggested.
offset 2: the track start time, seconds field
This field contains the S part of MSF. It is ignored for error tracks, but it still
must contain a number. Zero is suggested.
offset 3: the track start time, frames field
This field contains the F part of MSF. For error tracks, it contains a description of
the error.
Example track file. Note: the comments should not appear in the file.
1 0 2 37 # track 1 starts at 00:02 and 37 frames
2 1 38 17 # track 2 starts at 01:38 and 17 frames
3 11 57 30 # track 3 starts at 11:57 and 30 frames
...
999 75 16 5 # leadout starts at 75:16 and 5 frames
Track 1000 should not be present if everything is okay:
1000 0 0 Error reading TOC: no disc in drive
In scalar context, calculate_id() returns just the cddbp ID. In a list context, it
returns an array containing the following values:
(
$cddbp_id,
$track_numbers,
$track_lengths,
$track_offsets,
$total_seconds
) = $cddbp->calculate_id(@toc);
print(
"cddbp ID = $cddbp_id\n", # b811a20c
"track numbers = @$track_numbers\n", # 001 002 003 ...
"track lengths = @$track_lengths\n", # 01:36 10:19 04:29 ...
"track offsets = @$track_offsets\n", # 187 7367 53805 ...
"total seconds = $total_seconds\n", # 4514
);
CDDBP_ID
The 0th returned value is the hashed cddbp ID, required for any queries or submissions
involving this disc.
TRACK_NUMBERS
The 1st returned value is a reference to a list of track numbers, one for each track
(excluding the lead-out), padded to three characters with leading zeroes. These
values are provided for convenience, but they are not required by cddbp servers.
TRACK_LENGTHS
The 2nd returned value is a reference to a list of track lengths, one for each track
(excluding the lead-out), in HH:MM format. These values are returned as a
convenience. They are not required by cddbp servers.
TRACK_OFFSETS
The 3rd returned value is a reference to a list of absolute track offsets, in frames.
They are calculated from the MSF values, and they are required by get_discs() and
submit_disc().
TOTAL_SECONDS
The 4th and final value is the total playing time for the CD, in seconds. The
get_discs() function needs it.
get_discs CDDBP_ID, TRACK_OFFSETS, TOTAL_SECONDS
get_discs() asks the cddbp server for a summary of all the CDs matching a given cddbp
ID, track offsets, and total playing time. These values can be retrieved from
calculade_id().
my @id_info = $cddbp->calculate_id(@toc);
my $cddbp_id = $id_info->[0];
my $track_offsets = $id_info->[3];
my $total_seconds = $id_info->[4];
get_discs() returns an array of matching discs, each of which is represented by an
array reference. It returns an empty array if the query succeeded but did not match,
and it returns undef on error.
my @discs = $cddbp->get_discs( $cddbp_id, $track_offsets, $total_seconds );
foreach my $disc (@discs) {
my ($disc_genre, $disc_id, $disc_title) = @$disc;
print(
"disc id = $disc_id\n",
"disc genre = $disc_genre\n",
"disc title = $disc_title\n",
);
}
DISC_GENRE is the genre this disc falls into, as determined by whoever submitted or
last edited the disc. The genre is required when requesting a disc's details. See
get_genres() for how to retrieve a list of cddbp genres.
CDDBP_ID is the cddbp ID of this disc. Cddbp servers perform fuzzy matches, returning
near misses as well as direct hits on a cddbp ID, so knowing the exact ID for a disc
is important when submitting changes or requesting a particular near-miss' details.
DISC_TITLE is the disc's title, which may help a human to pick the correct disc out of
several close mathches.
get_discs_by_toc TOC
This function acts as a macro, combining calculate_id() and get_discs() calls into one
function. It takes the same parameters as calculate_id(), and it returns the same
information as get_discs().
get_discs_by_query QUERY_STRING
Fetch discs by a pre-built cddbp query string. Some disc querying programs report
this string, and get_discs_by_query() is a convenient way to use that.
Cddb protocol query strings look like:
cddb query $cddbp_id $track_count @offsets $total_seconds
get_disc_details DISC_GENRE, CDDBP_ID
This function fetches a disc's detailed information from a cddbp server. It takes two
parameters: the DISC_GENRE and the CDDP_ID. These parameters usually come from a call
to get_discs().
The disc's details are returned in a reference to a fairly complex hash. It includes
information normally stored in comments. The most common entries in this hash
include:
$disc_details = get_disc_details( $disc_genre, $cddbp_id );
$disc_details->{"disc length"}
The disc length is commonly stored in the form "### seconds", where ### is the disc's
total playing time in seconds. It may hold other time formats.
$disc_details->{discid}
This is a rehash (get it?) of the cddbp ID. It should match the CDDBP_ID given to
get_disc_details().
$disc_details->{dtitle}
This is the disc's title. I do not know whether it will match the one returned by
get_discs().
$disc_details->{offsets}
This is a reference to a list of absolute disc track offsets, similar to the
TRACK_OFFSETS returned by calculate_id().
$disc_details->{seconds}
This is a reference to a list of track length, in seconds.
$disc_details->{ttitles}
This is a reference to a list of track titles. These are the droids you are looking
for.
$disc_details->{"processed by"}
This is a comment field identifying the name and version of the cddbp server which
accepted and entered the disc record into the database.
$disc_details->{revision}
This is the disc record's version number, used as a sanity check (semaphore?) to
prevent simultaneous revisions. Revisions start at 0 for new submissions and are
incremented for every correction. It is the responsibility of the submitter (be it a
person or a program using CDDB.pm) to provide a correct revision number.
$disc_details->{"submitted via"}
This is the name and version of the software that submitted this cddbp record. The
main intention is to identify records that are submitted by broken software so they
can be purged or corrected.
$disc_details->{xmcd_record}
The xmcd_record field contains a copy of the entire unprocessed cddbp response that
generated all the other fields.
$disc_details->{genre}
This is merely a copy of DISC_GENRE, since it's otherwise not possible to determine it
from the hash.
parse_xmcd_file XMCD_FILE_CONTENTS, [GENRE]
Parses an array ref of lines read from an XMCD file into the disc_details hash
described above. If the GENRE parameter is set it will be included in disc_details.
can_submit_disc
Returns true or false, depending on whether CDDB.pm has enough dependent modules to
submit discs. If it returns false, you are missing Mail::Internet, Mail::Header, or
MIME::QuotedPrint.
get_mail_address
Returns what CDDB.pm thinks your e-mail address is, or what it was last set to. It
was added to fetch the default e-mail address so users can see it and have an
opportunity to correct it.
my $mail_from = $cddb->get_mail_address();
print "New e-mail address (or blank to keep <$mail_from>): ";
my $new_mail_from = <STDIN>;
$new_mail_from =~ s/^\s+//;
$new_mail_from =~ s/\s+$//;
$new_mail_from =~ s/\s+/ /g;
$mail_from = $new_mail_from if length $new_mail_from;
$cddbp->submit_disc(
...,
From => $mail_from,
);
get_mail_host
Returns what CDDB.pm thinks your SMTP host is, or what it was last set to. It was
added to fetch the default e-mail transfer host so users can see it and have an
opportunity to correct it.
my $mail_host = $cddb->get_mail_host();
print "New e-mail host (or blank to keep <$mail_host>): ";
my $new_mail_host = <STDIN>;
$new_mail_host =~ s/^\s+//;
$new_mail_host =~ s/\s+$//;
$new_mail_host =~ s/\s+/ /g;
$mail_host = $new_mail_host if length $new_mail_host;
$cddbp->submit_disc(
...,
Host => $mail_host,
);
parse_cdinfo CDINFO_FILE
Generates a table of contents suitable for calculate_id() based on the output of a
program called "cdinfo". CDINFO_FILE may either be a text file, or it may be the
cdinfo program itself.
my @toc = parse_cdinfo("cdinfo.txt"); # read cdinfo.txt
my @toc = parse_cdinfo("cdinfo|"); # run cdinfo directly
The table of contents can be passed directly to calculate_id().
submit_disc DISC_DETAILS
submit_disc() submits a disc record to a cddbp server. Currently it only uses e-mail,
although it will try different ways to send that. It returns true or false depending
on whether it was able to send the submission e-mail.
The rest of CDDB.pm will work without the ability to submit discs. While cddbp
submissions are relatively rare, most CD collections will have one or two discs not
present in the system. Please submit new discs to the system: the amazing number of
existing discs got there because others submitted them before you needed them.
submit_disc() takes six required parameters and two optional ones. The parameters are
named, like hash elements, and can appear in any order.
Genre => DISC_GENRE
This is the disc's genre. It must be one of the genres that the server knows. See
get_genres().
Id => CDDBP_ID
This is the cddbp ID that identifies the disc. It should come from calculate_id() if
this is a new submission, or from get_disc_details() if this is a revision.
Artist => DISC_ARTIST
This is the disc's artist, a freeform text field describing the party responsible for
the album. It will need to be entered from the disc's notes for new submissions, or
it can come from get_disc_details() on subsequent revisions.
DiscTitle => DISC_TITLE
This is the disc's title, a freeform text field describing the album. It must be
entered from the disc's notes for new submissions. It can come from
get_disc_details() on subsequent revisions.
Offsets => TRACK_OFFSETS
This is a reference to an array of absolute track offsets, as provided by
calculate_id().
TrackTitles => TRACK_TITLES
This is a reference to an array of track titles, either entered by a human or provided
by get_disc_details().
From => EMAIL_ADDRESS
This is the disc submitter's e-mail address. It's not required, and CDDB.pm will try
to figure one out on its own if an address is omitted. It may be more reliable to
provide your own, however.
The default return address may not be a deliverable one, especially if CDDB.pm is
being used on a dial-up machine that isn't running its own MTA. If the current
machine has its own MTA, problems still may occur if the machine's Internet address
changes.
Host => SMTP_HOST
This is the SMTP host to contact when sending mail. It's not required, and CDDB.pm
will try to figure one out on its own. It will look at the SMTPHOSTS environment
variable is not defined, it will try 'mail' and 'localhost' before finally failing.
Revision => REVISION
The revision number. Should be 1 for new submissions, and one higher than the previous
one for updates. The previous revision number is available as the "revision" field in
the hash returned by get_disc_details().
PRIVATE METHODS
Documented as being not documented.
EXAMPLES
Please see the cddb.t program in the t (tests) directory. It exercises every aspect of
CDDB.pm, including submissions.
COMPATIBILITY
CDDB.pm uses standard Perl modules. It has been tested at one point or another on OS/2,
MacOS and FreeBSD systems, as well as the systems listed at:
http://testers.cpan.org/search?request=dist&dist=CDDB
If you want to submit disc information to the CDDB, you will need to install two other
modules:
Mail::Internet will allow CDDB.pm to send email submissions, and it
automagically includes Mail::Header.
MIME::QuotedPrint will allow CDDB.pm to send non-ASCII text
unscathed. Currently only ISO-8859-1 and ASCII are supported.
All other features will work without these modules.
KNOWN TEST FAILURES
The last test in the "make test" suite will try to send a sample submission to the CDDB if
MailTools is present. It expects to find an SMTP host in the SMTPHOST environment
variable. It will fall back to "mail" if SMTPHOST doesn't exist. If neither works, the
test will be skipped. To see why it's skipped:
make test TEST_VERBOSE=1
Some of the tests (most notably numbers 25, 27 and 29) compare data returned by a cddbp
server against a stored copy of a previous query. These tests fail occasionally since the
database is constantly in flux. Starting with version 1.00, the test program uses fuzzy
comparisons that should fail less. Version 1.04 saw even fuzzier comparisons. Please
report any problems so they can be fixed.
LINKS
BUG TRACKER
https://rt.cpan.org/Dist/Display.html?Status=Active&Queue=CDDB
REPOSITORY
http://github.com/rcaputo/cddb-perl http://gitorious.org/cddb-freedb-perl
OTHER RESOURCES
http://search.cpan.org/dist/CDDB/
CONTACT AND COPYRIGHT
Copyright 1998-2013 Rocco Caputo. All rights reserved. This program is free software;
you can redistribute it and/or modify it under the same terms as Perl itself.