Contents
1. Authors
2. Description
3. Arguments
4. Options in mpdknotifierrc file
5. Album art search algorithm
6. Troubleshooting
7. See also

1. Authors

Developer of MpdKNotifier v1.0: Jakub Horák <kubahorak@gmail.com>
Further development: xaizek <xaizek@gmail.com>

2. Description

This small program shows notifications with short information about current
track of MPD using libnotify (http://www.galago-project.org/news/index.php). It
can:
- display album art
- use external application to get cover (format is supported)
- resize album art if its bigger than needed
- display custom list of commands (format is supported)

3. Arguments

    -d, --debug
Use this argument to enable debug mode (which is disabled by default) if you
want to see what happens at runtime. All debug messages will be printed out on
stderr, not to log. So, you may want to redirect messages to a file like this:  
    mpdknotifier --debug 2> debug.out

4. Options in mpdknotifierrc file

In configuration file mpdknotifierrc (that should be copied into
~/.kde/share/config/) in group "General" you can use options from the list
below:
1. MPDHost
2. MPDPort
3. MusicDir
4. CommandsNames
5. Commands
6. Format
7. ArtFindCmd
8. LogFile
9. PreferredCoverWidth
10. PreferredCoverHeight
11. ArtResizeCmd
12. NoCoverImg

Note: 
There is a default value for each option. So you can skip some of theme in your
configuration file. You can see them below in brackets after equals ('=')
symbol. Here is full format of each entry:
    n) parameter_name [=default_value]
    Description.

1) MPDHost [=localhost]
Sets IP address or DNS name of MPD server host and host password in the
following format: [password@]host, where password is optional.

2) MPDPort [=6600]
Sets number of port to connect to MPD server.

3) MusicDir [=/mnt/music/]
Sets path to the music collection, should be same as one in mpd.conf. Needed for
getting album art.

4) CommandsNames [=Open ncmpcpp]
List of semicolon (';') separated command names.

5) Commands [=terminal -x ncmpcpp]
List of semicolon (';') commands. Next special sequences can be used:
- '%a' - full path to album art
- '%f' - full path to current track
- '%d' - full path to parent directory of current track
- '%с' - name of album art file
- '%%' - percent symbol

6) Format [=%Artist% - %Title%{\n%Album%} {(%Date%)}]
Format string for text message in the notification. You can use any tags that
are supported by your version of MPD server. Just surround them with percent
('%') symbol.
Also you can use conditional blocks using curly brackets ('{' and '}').
Conditional block will be displayed only if all tags it includes had been
expanded. For additional formating HTML tags (<b></b>, <i></i>, <br>, ...) and
escape sequences ('\t', '\n', ...) can be used. But depending on your notify
daemon you can use both types together or only one at a time.

7) ArtFindCmd [=<empty string>]
If MPDKNotifier can't find album art, then this command is executed and search
is repeated.

8) LogFile [=~/.mpdknotifier/log.txt]
Log file name. You can use '~' symbol to refer to your home directory. 

9) PreferredCoverWidth [=200]
Preferred width of album art in pixels. This option is used for scaling album
art and to decide if we need to call ArtResizeCmd.

10) PreferredCoverHeight [=200]
Preferred height of album art in pixels. This option is also used for scaling
album art and to decide if we need to call ArtResizeCmd.

11) ArtResizeCmd [=<empty string>]
Contains command for resizing images bigger than PreferredCoverWidth x
PreferredCoverHeight. You can use all special sequences like in Commands option.

12) NoCoverImg [=/usr/share/apps/mpdknotifier/nocover.jpg]
Path to the image file, that would be used when no cover was found.

5. Album art search algorithm

Firstly a search for any jpg, png or gif file in parent directory of current
track is performed. If we found nothing than executing command from ArtFindCmd
option and repeating this algorithm from start (but only once). If we found only
1 image, then use it as a cover. Otherwise try to find best match. Perform the
second search using next patterns:
    [fF]ront.jpg
    [fF]ront.png
    [cC]over.jpg
    [cC]over.png
if we have matches take first of them and finish. Else perform third search with
this patterns:
    *[fF]ront*.jpg
    *[fF]ront*.png
    *[cC]over*.jpg
    *[cC]over*.png
if we found something take any of results and finish. Else take first image from
results of first search.

6. Troubleshooting

If you've found a bug or have some problems using this program, please inform
the developers. Thus you can help to make this software better. If you have an
account on GitHub.com you can create an issue there. Or you can always contact
developers by email (see 'Authors' section).

7. See also

For additional instructions:
http://mpd.wikia.com/wiki/Client:MpdKNotifier

For latest version:
https://github.com/xaizek/mpdknotifier

For homepage of original developer:
http://zee.cz/