I thought the nepomuk backend has changed in 4.10. If so, I was wondering whether I should delete all my data and re-index everything anew using the new backend. I ask because presently nepomuk reports wrong mp3 track length (usually not more than 5 seconds a track) which makes the nepomuk plugin for Amarok useless (since scanning becomes impossible). I was led to believe that reindexing on the new backend would fix this.

Thanks!

Reindexing your files could possibly solve the situation. I'm not sure if there is a way to force reindexing other than deleting the database though.

I'll give it a try and see whether it works. Thanks.

This turned out to be unhelpful. After stopping nepomuk, deleting the database, and restarting nepomuk, it continued to crash and restart repeatedly. I found this is a 4.10 bug fixed upstream. So I patched my system and rebooted. Nepomuk is running and reindexed everything, but mp3 track times are not part of the metadata. It doesn't show anything concerning track time. And the nepomuk plugin for Amarok now shows only 7 of my 4000+ tracks. Yet nepomuk shows that it's indexed all my songs (at least for some first pass?)

The first pass is a very basic filename, type and times index, while the second run extracts metadata from the files.
You should be able to see a "nepomukindexer" process indexing files if the second run is still in progress (this information should also be offered by the Nepomuk Controller application in your system tray).

Well the second pass has gone through. Track length is still misreported--all under 10 seconds. But the amarok plugin is at least showing nearly all of my tracks. Definitely not in a usable state, not until they sort out track length, or have the plugin get track length from the file, rather than nepomuk.

just an added note: it should be possible to just re-index specific folders, see http://trueg.wordpress.com/2011/12/05/m ... s-is-easy/

google01103 wrote:just an added note: it should be possible to just re-index specific folders, see http://trueg.wordpress.com/2011/12/05/m ... s-is-easy/

Thanks. That's actually quite useful.

I would suggest filing a bug regarding the incorrect track lengths, against Nepomuk. Nepomuk may not be storing the information it is retrieving correctly (I think it uses Taglib like Amarok does, not 100% sure though) or it is not retrieving the information correctly.

I've reported the bug here: https://bugs.kde.org/show_bug.cgi?id=315676

Seems to be related to this: https://bugs.kde.org/show_bug.cgi?id=310057