/mp3agic

A java library for reading mp3 files and reading / manipulating the ID3 tags (ID3v1 and ID3v2.2 through ID3v2.4).

Primary LanguageJavaMIT LicenseMIT

mp3agic

A java library for reading mp3 files and reading / manipulating the ID3 tags (ID3v1 and ID3v2.2 through ID3v2.4).

A simple set of command-line tools built on top of the library are included which perform tasks such including printing mp3 and ID3 details, renaming mp3 files using details from the ID3 tags, retagging mp3 files, attaching images to mp3 files and extracting images from mp3 files.

Some features

  • 100% Java
  • read low-level mpeg frame data
  • read, write, add and remove ID3v1 and ID3v2 tags (ID3v2.3 and ID3v2.4)
  • read obsolete 3-letter ID3v2.2 tags (but not write them)
  • correctly read VBR files by looking at the actual mpeg frames
  • read and write embedded images (such as album art)
  • add or remove custom messages between the end of the mpeg frames and the ID3v1 tag
  • unicode support

Building

You will need:

  • JDK 5 or higher
  • ant 1.6 or higher
  • junit 3.8.1 or higher OR maven
  • A bash shell to run the command-line scripts (if you're on MacOS or a flavor of Unix, you're set, if you're on Windows, try Cygwin or rewrite the bash scripts as bat/cmd files).

Settings you might need to change in ant.properties if you are using ant:

  • junit-jar should point to junit.jar on your local system
  • deploy-dir should point to the directory on your local system you wish to deploy to

Useful ant targets:

  • clean - remove binaries, docs and temporary build files
  • build - compiles the library and applications, runs all unit tests
  • deploy - copies the jar and scripts to the deploy directory defined in ant.properties
  • doc - generate the javadocs

How to use it

Some sample code follows for performing common operations; it is not an exhaustive list of all the functionality. More can be learned from looking at the javadocs, and at the code itself or at the included command-line applications in the com.mpatric.mp3agic.app package.

Opening an mp3 file

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    System.out.println("Length of this mp3 is: " + mp3file.getLengthInSeconds() + " seconds");
    System.out.println("Bitrate: " + mp3file.getLengthInSeconds() + " kbps " + (mp3file.isVbr() ? "(VBR)" : "(CBR)"));
    System.out.println("Sample rate: " + mp3file.getSampleRate() + " Hz");
    System.out.println("Has ID3v1 tag?: " + (mp3file.hasId3v1Tag() ? "YES" : "NO"));
    System.out.println("Has ID3v2 tag?: " + (mp3file.hasId3v2Tag() ? "YES" : "NO"));
    System.out.println("Has custom tag?: " + (mp3file.hasCustomTag() ? "YES" : "NO"));

Saving an mp3 file

    mp3file.save("MyMp3File.mp3");

Removing ID3 and custom tags from an mp3 file

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    if (mp3file.hasId3v1Tag()) {
      mp3file.removeId3v1Tag();
    }
    if (mp3file.hasId3v2Tag()) {
      mp3file.removeId3v2Tag();
    }
    if (mp3file.hasCustomTag()) {
      mp3file.removeCustomTag();
    }
    mp3file.save("Mp3FileWithoutTags.mp3");

Getting ID3v1 values

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    if (mp3file.hasId3v1Tag()) {
      ID3v1 id3v1Tag = mp3file.getId3v1Tag();
      System.out.println("Track: " + id3v1Tag.getTrack());
      System.out.println("Artist: " + id3v1Tag.getArtist());
      System.out.println("Title: " + id3v1Tag.getTitle());
      System.out.println("Album: " + id3v1Tag.getAlbum());
      System.out.println("Year: " + id3v1Tag.getYear());
      System.out.println("Genre: " + id3v1Tag.getGenre() + " (" + id3v1Tag.getGenreDescription() + ")");
      System.out.println("Comment: " + id3v1Tag.getComment());
    }

Setting ID3v1 values

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    ID3v1 id3v1Tag;
    if (mp3file.hasId3v1Tag()) {
      id3v1Tag =  mp3file.getId3v1Tag();
    } else {
      // mp3 does not have an ID3v1 tag, let's create one..
      id3v1Tag = new ID3v1Tag();
      mp3file.setId3v1Tag(id3v1Tag);
    }
    id3v1Tag.setTrack("5");
    id3v1Tag.setArtist("An Artist");
    id3v1Tag.setTitle("The Title");
    id3v1Tag.setAlbum("The Album");
    id3v1Tag.setYear("2001");
    id3v1Tag.setGenre(12);
    id3v1Tag.setComment("Some comment");
    mp3file.save("MyMp3File.mp3");

Getting ID3v2 frame values

Convenience methods are included to easily get common ID3v2 frames. If you wish to get frame data that does not have convenience methods, or if you wish to access meta-data on frames, direct reading of frames is possible (see further down on this page).

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    if (mp3file.hasId3v2Tag()) {
      ID3v2 id3v2Tag = mp3file.getId3v2Tag();
      System.out.println("Track: " + id3v2Tag.getTrack());
      System.out.println("Artist: " + id3v2Tag.getArtist());
      System.out.println("Title: " + id3v2Tag.getTitle());
      System.out.println("Album: " + id3v2Tag.getAlbum());
      System.out.println("Year: " + id3v2Tag.getYear());
      System.out.println("Genre: " + id3v2Tag.getGenre() + " (" + id3v2Tag.getGenreDescription() + ")");
      System.out.println("Comment: " + id3v2Tag.getComment());
      System.out.println("Composer: " + id3v2Tag.getComposer());
      System.out.println("Publisher: " + id3v2Tag.getPublisher());
      System.out.println("Original artist: " + id3v2Tag.getOriginalArtist());
      System.out.println("Album artist: " + id3v2Tag.getAlbumArtist());
      System.out.println("Copyright: " + id3v2Tag.getCopyright());
      System.out.println("URL: " + id3v2Tag.getUrl());
      System.out.println("Encoder: " + id3v2Tag.getEncoder());
      byte[] albumImageData = id3v2Tag.getAlbumImage();
      if (albumImageData != null) {
        System.out.println("Have album image data, length: " + albumImageData.length + " bytes");
        System.out.println("Album image mime type: " + id3v2Tag.getAlbumImageMimeType());
      }
    }

Getting ID3v2 album artwork

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    if (mp3file.hasId3v2Tag()) {
      ID3v2 id3v2Tag = mp3file.getId3v2Tag();
      byte[] imageData = id3v2Tag.getAlbumImage();
      if (imageData != null) {
        String mimeType = id3v2Tag.getAlbumImageMimeType();
        // Write image to file - can determine appropriate file extension from the mime type
        RandomAccessFile file = new RandomAccessFile("album-artwork", "rw");
        file.write(data);
        file.close();
      }
    }

Setting ID3v2 field values

Convenience methods are included to easily set common ID3v2 tags. Text encoding is chosen appropriately for strings (generally ISO8859-1 or UTF-16). If you wish to set frame data that does not have convenience methods, or if you wish to specify text encoding, or set meta-data on frames, direct writing of frames is possible (see further down on this page).

    Mp3File mp3file = new Mp3File("SomeMp3File.mp3");
    ID3v2 id3v2Tag;
    if (mp3file.hasId3v2Tag()) {
      id3v2Tag = mp3file.getId3v2Tag();
    } else {
      // mp3 does not have an ID3v2 tag, let's create one..
      id3v2Tag = new ID3v24Tag();
      mp3file.setId3v2Tag(id3v2Tag);
    }
    id3v2Tag.setTrack("5");
    id3v2Tag.setArtist("An Artist");
    id3v2Tag.setTitle("The Title");
    id3v2Tag.setAlbum("The Album");
    id3v2Tag.setYear("2001");
    id3v2Tag.setGenre(12);
    id3v2Tag.setComment("Some comment");
    id3v2Tag.setComposer("The Composer");
    id3v2Tag.setPublisher("A Publisher");
    id3v2Tag.setOriginalArtist("Another Artist");
    id3v2Tag.setAlbumArtist("An Artist");
    id3v2Tag.setCopyright("Copyright");
    id3v2Tag.setUrl("http://foobar");
    id3v2Tag.setEncoder("The Encoder");
    mp3file.save("MyMp3File.mp3");

Reading and writing ID3v2 frames directly

Frame IDs are defined in the ID3v2 specification. Frames can be read from an ID3v2 tag using these.

For now, the best approach to access frames not yet supported by convenience methods is to extend the AbstractID3v2Tag class, following the pattern for other frames already done. Please fork the project in github and submit a patch request if you add anything useful.

Code to read and write these frames more easily is coming soon. Watch this space.

Submitting pull requests

If you have added a feature or fixed a bug in mp3agic and want to share it, please submit a pull request as follows:

  • Fork the project
  • Write the code for your feature or bug fix
  • Please don't auto-format the code or make wholesale whitespace changes as it makes seeing what has changed more difficult
  • Add tests! This is important so the code you've added doesn't get unintentionally broken in the future
  • Make sure the existing tests all pass
  • Commit and do not mess with version, or history
  • Send me a pull request

Thanks for sharing!

Copyright

Copyright (c) 2006-2012 Michael Patricios. See mit-license.txt for details.