tagfile

TagFile

TagFile is a simple Class for building objects from binary audio files. It currently supports .flac, .mp3, & .ogg file formats. Using the ultra-fast TagLib2, TagFile extracts embedded metadata and builds a hash from user-defined values. This hash can be easily serialized and persisted in a database or document store.

Example usage

class Track < TagFile::Document
  extract_tag_for :artist, :album
end

track = Track.new('valid_file.flac')
track.tags => {artist: 'artist', album: 'album'}

Extractions

In order to build '#tags' you must specify which tags to use. The following tags can be extracted:

Embedded tags (from TagLib2)

• album
• artist
• genre
• title
• track
• year

Custom tags (from TagFile)

• path
• filename
• format

class Track < TagFile::Document
  extract_tag_for :artist

  # extract_tag_for :artist, :path, :title
  # extract_tag_for :all
  # extract_tag_for :all, except: [:artist, :album]
end

Verifications

TagFile includes several user-specified verifications. While path and format have built-in verifications, format can be customized to verify a subset of formats. Note: all valid TagFile objects will have a filename, length, path, and format attribute by default.

class Track < TagFile::Document
  extract_tag_for :artist

  verify_tag_for :artist
end

class Track < TagFile::Document
  extract_tags_for :all

  verify_tag_for :artist, :album
  # verify_tag_for :all
  # verify_tag_for :all, except: [:artist, :genre]
  # verify_format_is :flac, :mp3
end

Errors

With custom verifications in place, all errors are written to '#errors'.

class Track < TagFile::Document
  extract_tag_for :artist
  verify_tag_for  :artist
  verify_format_is  :mp3
end

track = Track.new('missing_artist.flac')
track.errors => ["Missing artist tag: missing_artist.flac", "File not of format :mp3: missing_artist.flac"]