Real persistent playlists in Amarok with Nepomuk

Again too long since my last blog post. For those who are new to my blog: I (DanielW in IRC) am the GSoC student working on bringing Nepomuk into Amarok.

So what has happend the last weeks? Amarok now writes statistics back to Nepomuk (playcount, last played date and so on). With the nepomuk search client and kio slave in playground you can search files for that (list for example all files played more than 10 times).

But what I really want to talk about are “real persistent playlists”:

Thanks to the new Filewatch service (already in svn (trunk and 4.1 branch))  Nepomuk can now track movements of files and update the metadata connected to them. (it uses KDirNotify and can only track file movements done from KDE applications).

I am using this in Amarok to have playlists which still work after renaming/moving files. This means you can:

• create and store a playlist


• close Amarok


• move the files around/rename them


• start Amarok and your playlist still works

Amarok also monitors changes to the data at runtime. I first planed to make a screenshot (without it, it is not real but you can not see it on a screenshot. So I made a screencast. Here it is (download in high quality (6 MB))

(sorry for poor Youtube quality, get the real one)

Now the technical part:

It works by creating and storing a uuid for every track used in Amarok. It then uses this uuid in the URL of the playlists. That works but is no perfect solution. In the long term (after SoC) I will have to create track (and album) resources (which link to the actual files) in Nepomuk. This will solve this without the uuid and bring other possibilities but also a lot of new problems.

You can try it out now (it is in svn of Amarok) but expect bugs and missing features.

And..

see you there