As Daniel mentioned, lots of work has gone into metadata support lately. The new editor is looking good, file writing unit tests are passing, and there are only a few bugs left for this release. Thanks for all your help!

Here is a quick summary for fellow metadata nerds:
 

FORMATS

Songbird uses TagLib 1.5 on all platforms to read from FLAC, Ogg Vorbis, MP3, M4A, MusePack, TrueAudio, and WavPack files. This includes all versions of ID3, APE, and Vorbis comments.

On Windows/Mac the QuickTime extension adds AMR, M4P, and M4B reading.

On Windows only, Windows Media Player adds WMA, WMV, ASF, ASX, and AVI reading support.

As of this release our TagLib wrapper also supports writing the following formats:

• MP3 - ID3v2.4, leaving existing ID3v1 as-is.
• FLAC - Vorbis comments, updating ID3 tags if they exist.
• MusePack - APE, updating ID3 tags if they exist.
• Ogg Vorbis - Vorbis comments.
• TrueAudio - ID3v2.4, updating ID3v1 tags if they exist.
• WavPack - APE and ID3v1.

Further support can be added with TagLib plugins, and the clunky but functional sbIMetadataHandler interface. At the moment there are open bugs to add Ogg FLAC, Speex, and M4A support.

Note that writing is currently disabled by default, and a prompt is shown on first edit. The plan is to enable writing by default in the final released build.
 

TAGS

Currently Songbird tries to write title, artist, album-artist, album, comment, lyrics, genre, producer, composer, conductor, lyricist, record label, language, key, license, license URL, year, track number, total tracks, disc number, total discs, and BPM tags.

Rather than add custom logic mapping Songbird properties to various metadata tags, Peter, aka pvh, has been working on enhancing the generic interface provided by TagLib. The new interface exposes all common tags, and leaves format specific handling to each implementation. Where possible, he’s been following the mappings used by PicardQt.

While this functionality is working quite well, there are a few peculiarities worth mentioning:

• The non-standard part of compilation flag is not yet supported (Bug 9090).
• Total tracks and total discs are not supported by some formats, and are being written as a single string of number/total.
• Songbird currently only supports one genre tag per item, where some formats support multiple.
• Play count and rating are not written by default, but may be available with a preference option (Bug 9084, 9236).
• Reading and writing album artwork is not yet supported (Bug 9033).
• Some properties cannot be unset at the moment (Bug 8530).
• The producer tag is not handled correctly in ID3v2 (Bug 9086).
• Lyrics and lyricist tags are not handle correctly in ID3v2 (Bug 9091).
• Comments are truncated in some cases when writing ID3v2 (Bug 9088).

EDITOR UI

This release will ship with a basic, but extensible, modal metadata editing dialog. To try it out, select some tracks, then press CTRL/CMD-E, or select Tools -> Metadata Editor from the main menu.

While a modal dialog is less than ideal for power users, it significantly reduces user experience complexity. If you are outraged by this decision, don’t worry, we’ll also be releasing an extension with a non-modal editor and display pane.

It is now much easier to overlay new functionality into the editor, so if there is something you’d like to see, stop by irc.mozilla.org#songbird. If time permits, we’ll add some additional panes such as an advanced property viewer, lyrics editor, and summary page.

Finally, yes, you’re right, nobody wants to edit tags by hand. Now that we have writing support and an extensible editor though, MusicBrainz support shouldn’t be too far off (Hint: gstofa in gst-plugins-bad).