About
=====

Locutus is a software that compares audio files with the MusicBrainz database,
updates the metadata in the files and stores the files in a structured
directory.
This project is still quite young, there may be bugs and I won't guarantee that
it won't erase any files. That said, I still haven't lost a single file due to
Locutus, so the risk is low.

Some of Locutus' features:
- Capable of handling extremely large music archives. It still has problems with
  directories that contain a large amount of audio files (>500) that contains no
  metadata, but as long as the audio files got metadata and/or are splitted
  across multiple directories there's virtually no limit how large archives
  Locutus can handle.
- Clever metadata matching that's extensively configurable. As long as the
  metadata found in audio files are correct Locutus mismatch files very rarily.
  It is however possible to configure Locutus in a way that will cause
  mismatched files, use precaution!
- Locutus is split in 3 parts, the daemon, the database and the web interface.
  Each part can run on its own computer, or they can all run on the same
  computer. While the daemon compares files, updates metadata and store the
  files, you can manually match the files the daemon was unable to automatically
  match in the web interface.
- Albums retrieved from Musicbrainz are stored in a local cache, reducing amount
  of queries sent, and thus also reducing load generated on MusicBrainz.
- Grouping files in assumed albums. To reduce amount of queries sent to
  MusicBrainz the files are placed in groups that are assumed to be albums. This
  makes Locutus look up the first file in a group, fetch the best matching
  albums for that track and compare the other files in the group with that
  album. If some of the files have a poor match, those files will be looked up
  separately and albums returned from those will also be matched with the other
  files in the group.
- Automatically fetch tags from AudioScrobbler as "genre". Currently it only
  supports storing the most popular tag. Since it needs to look up each file
  this feature significantly slows down Locutus as it may only look up tags once
  per second at most.


Installation
============

Database:
---------
Locutus currently supports PostgreSQL version 8.3 or later (not tested on
earlier version).

1. Become the 'postgres' user:
     sudo su - postgres
2. Create a user for locutus:
     createuser -S -D -R -P -E locutus
3. Create a database for locutus
     createdb -O locutus locutus
4. Log out the 'postgres' user and goto the "sql" directory of locutus where
   you issue the following command:
     psql -h localhost -f locutus.sql -U locutus locutus
5. You'll need to grant locutus access to the database. Edit (most likely)
   "/etc/postgresql/8.3/main/pg_hba.conf" and add the following entry after
   "# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD":
     host    locutus     locutus     127.0.0.1/32          md5
   Change the IP if you're running the daemon/web interface on another computer.
6. By default PostgreSQL only listen on 127.0.0.1. If you're accessing the
   database from somewhere else, you'll need to edit
   "/etc/postgresql/8.3/main/postgresql.conf":
     listen_addresses = '*'
7. Restart PostgreSQL:
     /etc/init.d/postgresql restart

Daemon:
-------
The daemon requires GNU Common C++, TagLib (version 1.5 or later) and the
PostgreSQL C client library.
For Debian users:
  aptitude install libpq-dev libtag1-dev libcommoncpp2-dev build-essential

To build the daemon, simply enter the "daemon" directory and type "make". This
will produce an executable file called "locutus". Currently this is not a daemon
as it will only run once and exit, so for the time being you'll have to run this
manually.
The first time you run Locutus it will populate the "setting" table with default
values.

Web interface:
--------------
Perl, Apache2 and Template::Toolkit are required for the web interface.
This guide is written for Debian Linux, if you're using another distro you may
need to do things differently. I leave it as an exercise to those readers to
figure this out :)
For Debian users:
  aptitude install libapache2-mod-speedycgi libapache-dbi-perl \
  templatetoolkit-perl libdbd-pgsql libclass-dbi-pg-perl

1. Open "/etc/apache2/sites-enabled/000-default" in your favourite editor and
   add the following lines somewhere in the VirtualHost (changing the paths to
   where you got the "web" directory):
     Alias /locutus/ "/home/canidae/projects/locutus/web/"
     <Directory /home/canidae/projects/locutus/web/>
         Options ExecCGI Indexes FollowSymLinks MultiViews
         AllowOverride None
         Order allow,deny
         allow from all
         AddHandler cgi-script .pl
     </Directory>
2. Restart Apache:
     /etc/init.d/apache2 restart
3. The interface should now be up at "http://localhost/locutus/" (or another URL
   if you installed the web interface on another computer). If it isn't, then
   check logs in "/var/log/apache2/" and "/var/log/postgresql/".


Killer coding ninja monkeys (in order of appearance)
====================================================

Vidar Wahlberg, <canidae@exent.net>
  Daemon, database, web interface