A tag editor is a piece of software that supports editing metadata of multimediafile formats, rather than the actual file content. These are mainly taggers for common audio tagging formats like ID3, APE, and Vorbis comments, but can also be taggers for JPEG, PDF and TIFF metadata. A common purpose of tag editors is to correct or update metadata and enable sorting and grouping of multimedia files, for example music collections. This often happens in a batch processing mode so that one doesn't have to manually edit every file on its own.
Media players such as iTunes, Foobar2000 or Winamp, as well as dedicated tag editing programs allow users to manually edit tag and song file information, including composer and release year. Dedicated tag editors may feature batch processing and creating tags from file names and vice versa.
One type of tag editor compares the existing metadata in an audio file's tags with the information from online music databases, such as Gracenote, Discogs, freedb, Zortam Music Internet Database or MusicBrainz. Once a match is found, complementary metadata information may be downloaded. This process is semi-automatic because more than one match may be found.
Acoustic fingerprinting
An acoustic fingerprint is a unique code generated from an audio waveform. Depending upon the particular algorithm, acoustic fingerprints can be used to automatically categorize or identify an audio sample. Practical uses of acoustic fingerprinting include broadcast monitoring, identification of music and ads being played, peer-to-peer network monitoring, sound effect library management, and video identification.
Hash function
In hash function, for audio identification, such as finding out whether an MP3 file matches one of a list of known items, one could use a conventional hash function such as MD5, but this would be very sensitive to highly likely perturbations such as time-shifting, CD read errors, different compression algorithms or implementations or changes in volume. Using something like MD5 is useful as a first pass to find exactly-identical files, but another, more advanced algorithm is required to find all items that would nonetheless be interpreted as identical by a human listener.
*Ex Falso – Supports MP3, Ogg, FLAC, Musepack, Wavpack, MP4, WMA, MIDI, Monkey’s Audio. Available for Windows, Linux, Mac OS, and FreeBSD.
*Kid3 – Supports MP3, Ogg/Vorbis, FLAC, MPC, MP4/AAC, MP2, Opus, Speex, TrueAudio, WavPack, WMA, WAV, AIFF files and tracker modules formats. Available for FreeBSD, Linux, Mac OS and Windows.
*MusicBrainz Picard – Supports MP3, Ogg, FLAC, Musepack, WavPack, OptimFROG, Monkey's Audio, MP4, Windows Media Audio. Available for FreeBSD, Linux, Mac OS and Windows.
*puddletag – Supports FLAC, APE, MP3, MPEG-4, MPC, OGG, OptimFROG, TAK, WMA, WavPack. Available for FreeBSD and Linux.
Proprietary software:
*File Explorer – has limited tag editing capabilities on supported file formats such as MP3 and WMA
*Jaikoz – Commercial package, available for Windows, Linux and OS X that uses the MusicBrainz database for auto-tagging. Supports embedded album art and auto-lyrics.
*Mp3tag – Freeware for Windows. Supports FLAC, APE, MP3, MPEG-4, MPC, OGG, OptimFROG, TAK, WMA, WavPack.
Image files
Free and open-source:
* ExifTool – Available for Windows, Linux and OS X
* DigiKam – Available for Linux, FreeBSD, OS X and Windows