The Edit Track Details window can be displayed from a couple places.
Select a track from the Track window, right-click and select "Edit Track Details" from the popup.
Make a selection in any of the categories, eg. Album, Genre, and right-clicking "Edit Track Details will display the window and allow all tracks in that category to be edited.
Right-clicking "Edit Track Details" from the popup menu on the CoverArt Display displays the window , allowing all tracks belonging to the album to be edited.
The window allows multiple tracks to be edited at the same time. By selecting the "Change all Tracks Simulaneously" check box **BEFORE** making any edits, all the selected tracks can be updated with the new information.
The coverart can be dragged n dropped on from a web browser in the same way as the Cover Art Display. However, dropping a new cover onto this window will update the cover art of the tracks and not the album! This is an important distinction as it is possible to have different cover art for tracks in the same album! (why anyone would but its possible)!
If you have changed the ID3 tags of your original file, you can update the ID3 tags stored in gtkpod without removing and re-adding the track. Simply select the track to be updated and press "Ctrl-u" or choose "Update Track Info From File" from the Edit menu. Since gtkpod needs to know the filename of the track, the "Extended Information File" (see here) is needed.
"Update" will also re-read the replay-gain tags from disk, if available, and set the soundcheck field. If no replay-gain tag is available, the soundcheck field will be erased. You can also select entries in the filter tab or entire playlists for refresh.
If you have added files to directories or changed files in directories you have previously added tracks from, you can use the "Synchronize Dirs" utility to update your iTunesDB.
"Synchronize with Dir(s)" will use the selected tracks to make a list of directories to update, so you should activate the "Write Extended Information" option in the export section of the Preferences dialogue.
It will then add all non-existing tracks in those directories and update all existing tracks. The tracks are also added to the currently selected playlist, if they aren't already a member.
Tracks that have been removed from the directory will only be removed from the iTunesDB if this option is checked in the option dialogue.
For best results you should also activate duplicate detection. This avoids unnecessary copying of unchanged tracks.
There are two fields in the iTunes Database (iTunesDB) that allow for the adjustment of the volume of an individual track:
The volume is always active, whereas the soundcheck field is only active when you select 'soundcheck' on the iPod. Further, the soundcheck field only affects the earphone output but not the line output of the iPod.
gtkpod will set the soundcheck according to the replay-gain tag set in your mp3 file. Newer versions of 'lame' automatically include the replay-gain tag when encoding. In that case the soundcheck field will be filled in when you first import a track.
If no replay-gain tag is set, you can use the function 'Normalize Volume' to call mp3gain (mp3gain.sourceforge.net) to calculate the gain and write a replay-gain tag. Since this procedure is very time consuming, it is not done automatically during import. You need to install mp3gain in the default path or set the full path in the 'Tools' section of the preferences dialog. If the iPod is connected, the tag is written to the file stored on the iPod.
At this time "album gain" functionality is not supported. "Album gain" means that the volume of all tracks of one album is adjusted by the same gain, such that the relative volume level remains the same. It is planned to realize this in one of the next versions.
Also, please be aware that tracks are not normalized on a 'per playlist' fashion. If a track is normalized, it's normalized in all playlists it is a member of.
Once the replay-gain tag has been read, it is stored in the extended information file 'iTunesDB.ext'. When you call 'Normalize volume' again, the stored value will be used to re-populate the soundcheck field. Use 'Update Track' to re-read the tag from the file.