Re: [Tracker] Tracker API for music player

[Ivan Frade <ivan frade nokia com>]

Hi Pavel,

El mar, 14-04-2009 a las 16:09 +0200, ext Pavel Rojtberg escribiÃ:
> I am the author of the unknown music player "YouAmp" and I am evaluation 
> whether it is possible to replace my self written indexer with tracker.

 Great! It should be possible (and recommendable). BTW, I think i saw
"YouAmp" in maemo...

> I already read that the best way to use tracker is calling it over D-bus 
> - but is there at least some D-Bus API documentation somewhere?

 Not much documentation for the API :/ If YouAmp is written in C, take a
look to libtracker. If it is written in Python, use directly dbus
(exploring the API with d-feet, for instance).

 The XML description of the DBus API is here:
http://svn.gnome.org/svn/tracker/trunk/data/dbus/

> Particularly I need methods for:
> * getting all music files below a certain directory
 
 Uhm... we have a method for that... but why to use directories? now you
have the great and wonderful metadata available!

Some hints:
 * In Tracker.Files "GetByServiceType" you can get "all music files"
 * With an RDF query you can filter "path starting with"


> * filtering by artist, album, title

 * GetUniqueValue for Audio:Artist, Audio:Album or Audio:Title will
return the list of different values on each property
 
> * sorting by artist, album, title AND mtime

 There is a "sort" parameter in the API, where you can choose how to
sort the results.

> * storing playlists

 It is extremely complicated in tracker (though you can use directly
totem-pl-parser). Tracker only recognize the duration of the playlist
and the number of tracks.


> I also read Tracker supports Cover albumart fetching - does it work 
> already? If so is there some documentation how to get the albumart?

 Tracker is able to extract the embedded album art from the files. There
is a specification about how to find it later:

http://live.gnome.org/MediaArtStorageSpec

 (Philip can answer more in detail about this)


> I am using Tracker in Ubuntu Jaunty (currently 0.6.93)

 That is the current stable version (and what you will find in
maemo/Fremantle and desktop distributions). Maybe you should also take a
look to the MAFW. It has been released as open source recently and
offers a higher level API for media applications (including UPNP
abstraction!).

Regards,

Ivan