Quod Libet

Rhythmbox (the music player that comes with Debian) is pretty good. Fine most of the time. But it does have a problem with compilation albums. Investigating the issue before, I'd found that Banshee will play compilation albums correctly, but in the process of installing it on Squeeze I noticed it has an obsolete dependency bug, so I gave it a miss. On a whim I tried Quod Libet again. Lenny came with version 1 which didn't impress me too much, but Squeeze has version 2 which is a big improvement. It recognised my compilation albums correctly- and what's more its excellent tag editor allowed me to fix some tagging errors I hadn't noticed before.
The default GUI is pretty basic, can be customised to show a paned browser, album covers, a search feature, playlists etc. (These features are also available in a separate window.)

The basic GUI:


Album cover view:


The Tag Editor:


The download album art plugin:


Quod Libet comes with many plugins that can be enabled if desired. I really liked the album cover search feature which works really well- no more Google searches and file saving- it's all automatic.
I also used the notify plugin to get new track notifications, and the tray icon plugin to put the music player in the notification area rather than close it completely. (I like to keep the bottom panel for documents and keep my music player separate.) This is probably the weakest feature of the player (although it is only a plugin.) Hovering over the Quod Libet icon only gives track information- not album art and track progress like other players. The panel icon is also indistinct when paused (a bug?)
[Update: not a bug. The plugin superimposes the Gnome paused icon (which depends on the theme selected) over the Quod Libet icon. Unfortunately in a dark panel, the Quod Libet icon does not display well, as it is black with a white border (so only the border shows. Editing the Quod Libet icon to white helps.]
Other plugins worth a look would be the MusicBrainz and CDDB lookup plugins for identifying audio tracks. (I looked previously at other programs using MusicBrianz and CDDB.)
Despite the minor gripe about the tray icon plugin, I'll give Quod Libet five stars for handling compilation albums, having one of the best tag editors around, a brilliant album cover finder and an elegant and customisable GUI. And I haven't looked at all the features yet- for example, Quod Libet claims to be better able to handle large music libraries than other players.

Tagging audio files using Music Brainz Picard- Some more examples

Here are some more screen shots to illustrate identifying music files by use of an acoustic fingerprint, and adding tag information, using Music Brainz Picard.
I've added a folder containing 19 music files which are not tagged with meta-information- album, artist, track etc.- and used the scan button to have Music Brainz Picard check the acoustic fingerprints of the tracks against its database. The application has suggested four possible album matches:


The first suggestion is actually the album I'd ripped to MP3.


The complete green bars indicate a match with high confidence; the incomplete green bars a slightly less confident match, and the incomplete orange bar (track 16) a tentative match. (As we saw in the previous post, matches with low confidence are shown by a red bar.)
There are three tracks (5, 15 & 19) for which the application has not found a matching file. If we select this album and save, the corresponding files will not have their tag information added. We need to tell the application that three of our files in the added folder correspond with these tracks- we'll either find them in the unmatched files, or in the three other album suggestions.
In this case, my unidentified album was a soundtrack, which included tracks originally found on other albums, so it won't be surprising if Music Brainz Picard thinks they belong on another CD.
Here is our missing track 19, track 18 on another CD: we need to drag and drop it to track 19 on the first CD suggestion.


Here is our missing track 5: again we need to drag and drop it onto track 5 in the first CD suggestion.


And here is our missing track 15: drag and drop to the first CD suggestion as before.


In this example, Music Brainz Picard had correctly identified all the tracks, but understandably not been able to tell which CD the tracks were from.
It's also possible to see the acoustic identification completely misidentify a track, it which case it's again necessary to manually drag the misidentified file to the correct CD suggestion, and drop it on the correct track number.
(If there is a way to tell Music Brainz Picard "this suggestion is the correct album, and all my files belong to that album, in the order that they appear as files in the folder", then I haven't found it. If anybody knows better, or can simply or clarify the instructions given, please leave a comment.
Update: Forgot to RTFM.

You can drag whole directories, multiple files or album clusters onto albums and Picard will attempt to match the dragged files to the album. Any track that doesn't match up well enough, will be added to an "Unmatched Files" sub-folder specific to that album. You can drag files out of this folder and into the right slots in the album to fix up the files that Picard couldn't get right.

Tagging audio files using Music Brainz Picard

As described in the previous post, I recently converted some audio files from the FLAC format to MP3 using Sound Converter. Now sound converter is very clever, and when it converts files with no tags, it goes online to look for the appropriate information: album, artist, title etc. As far as I can work out, (see a previous post), it does this using a discid calculated from track lengths and an online database of CD discid's.
For several of my CD folders, Sound Converter correctly added MP3 tag information (although it left the files without meaningful filenames). Other folder it could not identify, and I had to use a different system of file identification, an acoustic fingerprint, and a different application Music Brainz Picard (which can also take care of the file name issue, renaming files according to the track name*).
It took me a while previously to work out how to use Music Brainz Picard, and when I cam to use it again, I realised I forgotten what I'd learnt, so I thought I'd write a short tutorial.
The first step is to add a folder containing tracks you want to identify from the menu.


The unidentified tracks should appear as unmatched files.


[Update: Anonymous has commented that it would be more efficient to use the Cluster and Lookup features here first- see comment for details.]
I can then select the unmatched files and use the Scan option from the menu, which will create an acoustic fingerprint and check it against the Music Brainz database. Suggested matches will appear in the right-hand window. In this case, there are only two hits- the red bars show that the confidence in a match is low, but the result is correct.

In the case of a more certain match, the bars will be green. If the track appears on more than one album, or the acoustic fingerprint created matches more than one track, alternative album or track suggestions will be displayed.
This is where some manual work comes in- I have to drag the unmatched file to the appropriate track (on the appropriate album, if applicable). (In the case of mismatched files, I have to drag those from the wrongly suggested album to the correct album.)
[Update: From reading the Music Brainz Picard documentation, it seems I can drag all of my unmatched files and drop them on the identified album, and Music Brainz Picard will attempt to sort them out.]
Note: If I click Save above, Music Brainz Picard will only add tag information for two tracks in the folder. I have to do some dragging and dropping:

Now I have matched all the tracks, I can click Save.

The correct tags have been appended to my files. (To change the file names to something more meaningful, select Options>Rename Files.)
In the event that acoustic fingerprinting can't suggest an album match, enter album, artist or track details and click the search icon. This will open a web page in your default browser. Check the suggested hits and click the green Tagger button to return details to Music Brainz Picard.

* To change file names to match tag information, select a folder and use the Lookup button to match tag information against Music Brainz Picard's database, select Options>Rename Files and save.)
Update: More example screen shots in this post.

Linux MP3 tag editors- a review

The story so far. In the beginning, the universe was created...
OK, skip that bit. I have a collection of MP3 files, and the tags attached to some of the files are causing errors in the way albums are displayed in some music players. I want to view and edit MP3 tags. My last post on the subject ended with some confusion as to which tag editors can do what, so here is a quick review.


Kid3 is the clear winner in KDE. (It's perfectly usable in Gnome- but the KDE dependencies make it a little slow to load, and it uses the KDE theme.) The Gnome alternative, Audio Tag Tool, produces errors when reading ID3v2 Version 2.3 tags, and cannot read ID3v2 Version 2.4 tags- the default used by such applications as Sound Juicer.
Applications using the Mutagen backend are a very usable alternative in Gnome, only lacking the ability to see which ID3 standard is being used, and if an ID3v2 tag exists, to see which version, and to switch view between tag standards if both exist.
UPDATE: A comment points out that there is a version of Kid3 for Gnome (kid3-qt) which doesn't have the KDE dependencies- a tip of the hat there.

Music file tags

Rip a CD and the ripping program will often go online and look up the album, artist and track information, and append this information to the audio file as a tag. Sound Juicer does this in Ubuntu. But how does it work, and is it possible to automatically tag audio files that have been ripped without tagging? This issue caused me some confusion recently.
I used Audiograbber to rip some CD's into MP3 on a Windows computer. The program didn't prompt me to add the tag information, so I assumed it didn't have this facility (looking at the website now, I see it does). The result was several folders of MP3 files with no meaningful file names or tag information.
I decided to look for a way to automatically tag and name the files. I found EasyTAG. The program gave me an option to search the something called the CDDB database to look up the CD details. For several of my folders of MP3's, this worked. For one folder, the program found the CD in the database, but one track didn't match up. In frustration, I tried MP3Tag in Windows. Using the same CDDB database (freedb.org) and entry, the program correctly tagged the folder. (Ho hum.)
But I was left in some confusion. Apart from not seeing that I could have used Audiograbber to look up the files when I ripped them, I hadn't really understood what how EasyTAG and MP3Tag found the metadata for my files, as this post to the Ubuntu Forum proves.
So how does CDDB work? Wikipedia has a good explanation. The CDDB database uses a "discid" created from track duration information stored in the table-of-contents of the CD.
So how had EasyTAG recognised my already-ripped MP3 files without a table-of-contents? I'd assumed it must have used an "audio fingerprint", but I was obviously wrong. I can only guess that EasyTAG and MP3Tag use track length information to create a discid.
So is there a way to identify audio files using an "acoustic fingerprint"? Yes, MusicBrainz Picard can do it in Linux. (Winamp in Windows uses Gracenote.)