Both
Unpopular Music Player
and
Opus 1 Music Player
use Android's media database. Unfortunately it is incomplete, error prone, and the update automatism is hardly to predict and unreliable. Sometimes it fails.
For music management the mentioned programs use their own tagger library to extract the missing and wrong information directly from the music files. This works, but the inconsistency problem remains.
The
Classical Music Scanner
creates its own database replacing that one of Android for the mentioned programs (if configured accordingly). However, this database does only contain information about audio files, neither pictures nor movies. Note that the tagger libraries in the music player applications are no longer used in this case.
The
Classical Music Scanner
is "open source", and it is also available via F-Droid (https://f-droid.org/packages/de.kromke.andreas.mediascanner/).
- Correction: Precede movement name with movement number (arabic digits).
- Correction: After renaming album pictures, write correct (new) file name to database.
- Progress and result text corrected.