Please read the following info carefully before using iDupe.
Introduction
iDupe is designed to process duplicates and dead tracks in iTunes in a smart way. Recent versions of iTunes have a "Show Duplicates" command. But it is of limited use. First, it offers no good way to remove duplicates while keeping one version of a track. Second, there is no good way to identify which tracks are actually duplicates as opposed to different versions of the same song, the same song with different bitrates, etc.
Usage
iDupe tries to deal with this problem in a smart way. When it scans a selection, it will make a number of judgement calls. Playlist entries that refer to exactly the same file and "dead tracks" (entries that point to no file) are treated as unambiguously undesirable entries. They will be removed from the playlist by default when you click the "Mark results in iTunes...." button. This can be changed in the settings.
Other potential duplicates will be ranked according to a number of criteria. It will consider whether it is likely to be a loose single track, which version of an album to keep, as well as other considerations. (See below for details.)
The duplicates that iDupe considers worthy of removal will be unchecked on the playlist when you click the "Mark Results in iTunes...." button.
It is then up to you to review the results. When you are ready to remove the unchecked items, reselect the group of tracks you want iDupe to operate on. You then have three choices: 1) remove the unchecked items from that playlist, 2) do that, but also remove those tracks from the main library playlist (if you are not working on a selection of the library playlist), or 3) do both of those things, but also move the file itself to the trash.
iDupe operates on a selection of tracks in iTunes. A recommended useage is to use the "Show Duplicates" command in iTunes and then select the results. Then use iDupe to scan that selection. It can however operate on any selection. By warned that large selections can take a long time to process. (Note that removing tracks from the library can take a particularly long time.) At this point, iDupe runs ok with a selection of up to 2,000 tracks. iDupe may get stuck with larger selections. If you sort your playlist, or the results of "show duplicates" in iTunes by artist or song name, it makes it easier to scan groups of possible matches at a time. (That is, try scanning for example only A-C first.)
For iDupe to work correctly, it depends on accurate ID3 tags. If your tags are a mess, do not expect iDupe to produce accurate results.
How iDupe ranks potential duplicates
Potential duplicates are defined first by having the same artist and song name.
Currently iDupe evalues a single as follows. If the album name is blank or contains "unknown" and there are any other potential duplicates at an equal or higher bitrate that do have an album name, it is considered a loose single. If it has no track number tag but another artist & song name match at an equal or higher bitrate does, it is considered a loose single. (This option can be turned off in the settings.) There is an option to skip consideration of reserved words here. This list can now be edited. (The default reserved words are: "live", "mix", "remix", and "re-mix". So in this example, live and remix tracks would be kept even if they have no track number and are found on another album, as long as those key words appear in the album name.)
iDupe defines a potential album by looking at the album name and track number in addition to the artist and song name. In other words, it will then consider album and track number matches within a set of matches by artist and song name.
iDupe evaluates which album to keep based on the following criteria, in this order: Which album has the most files? (This is considered the most "complete" version of an album, or perhaps a version of the album that has bonus tracks on it.) If two copies have the same number of files in their parent folder (usually the album folder), then which has the best bit rate? If they have the same bit rate, are all the potential dupes in the same (album) folder? If so, which tracks have the longest duration? (This might be useful if there is a version of the song that "cuts off".) Are there mixed mp3 and m4a files? If so, keep the ones with the greatest number over the other type. Are there signs of a copied file? ("Copy" in the file name, or a number at the end of the file name, or the character "#" at the end of the file name)? If they are not in the same album folder, which album contained in an artist folder has the most albums in it already? (Maybe you have the same artist in two different locations by mistake. This is most likely to happen if you keep MP3s on multiple disk volumes.)
If you opt to ignore albums and track numbers, the above considerations will be applied instead to artist and song name matches only. In general, this means that only one version of a song will be "kept" and the rest will be unchecked (marked for removal). You would use this option if you don't care about multiple versions of a song, or keeping complete albums, even if the same song is on more than one album. This option will tend to keep the highest bit rate version of the song first, then if bit rates are the same, the longest duration version.
After a scan is complete, a report will be shown. This report is searchable by clicking on it and using the find menu. This info is also searchable in the same way.
Special Deep Cleaning Mode
Deep Cleaning Mode is a special mode of operation that should be used with caution. In normal operation, iDupe will only consider potential duplicates within your selection. By contrast, in Deep Cleaning Mode, iDupe will first look for ANY possible matches for each song in the selection by searching the entire library. The original selection AND all found potential matches will be added to a special "iDupe" playlist. iDupe will then scan your original selection as copied to that playlist, PLUS all potential matches copied to that playlist. If the song names in the original selection are common words, this iDupe playlist can grow very large. For that reason, you should scan only a SMALL selection in this mode, perhaps only an album or two. A warning will be given if you have opted to show warnings and you try to scan more than 100 tracks in this mode. In general you should avoid using this mode, and try to select potential duplicates yourself.
The Settings
A few notes about the settings are in order. Most of what the settings do are described above and/or in the tool tips. (Mouse-over the setting to see them.)
The use fuzzier matching option will construct unique search IDs based on a stripped down character set, including stripping articles ("the", "an" ,"a"), spaces, and punctuation, while searching. This might be somewhat slower, but is expected to produce better results.
"Try to restore dead tracks" will take the information from a dead track and search possible matches. With OS X 10.4 (Tiger) or higher, you can opt to use spotlight if your MP3s are indexed. (Thanks go to Doug Adams on this one.) Otherwise, searches are done on the basis of albums that match the dead track's info already in your library, or if you use "try harder," all matching artists in your library.
If only one match is found, it will be added automatically before removing the dead track. If it finds more than one, you will be given the chance to choose one or to cancel. iDupe is smart enough to restore the dead track only when it's not already a duplicate of a track that is being kept, and to only restore one version if there are multiple dead tracks that point to the same file (so as not to wind up with more duplicates). If possible rating settings and play counts will be restored.
If not using Spotlight on Tiger, there must be at least one good (non-dead) track on the album in question in your library, or if using "try harder", at least one track by the artist in question, and potential tracks to be restored have to be located in that folder hierarchy. So, for instance, if you have an entire dead album, you can locate one track manually in iTunes, then select the rest of the dead ones, and then iDupe has a fair chance of restoring them.
The Action Menu
Most of the action menu commands are self-evident or explained above.
The Remove Dupe PL Entries and Remove Dead Tracks commands are only necessary to use if you have opted in settings not to do either or both of these steps at the mark results stage. Cancel will cancel out of some but not all long operations. Clear Status Message can be used if the progress bar gets stuck or the current status message is no longer relevant and your don't want to look at it.
Scan Dead Tracks with iGotta is designed to integrate with an "iGotta MP3 Collection" FileMaker Pro database. (a freeware FileMaker database template for iTunes by WBC.) If you have an iGotta database available and open, iDupe can search it for entries with no location, i.e. dead tracks. This is a much faster way to scan a large library for dead tracks than selecting an entire library in iTunes and having iDupe scan it. Note: there is a hidden option here. If this scan is activated with command-option-shift-M then during the scan, iDupe will strip carriage returns and line feeds from the comment field of non-dead matches. (This is done because those characters create false or blank records when importing into iGotta.)
Disclaimer
iDupe does not do exhaustive error checking, so be careful when using it! Wooden Brain Concepts assumes no responsibility for what it might do to your music libraries, so make sure you have a backup of your library!!
iDupe is Shareware
Please remember to pay your shareware fee.