Extended Metadata

hAudiotagger provides access to 60+ extended metadata fields commonly used by music libraries, tagging services, and professional audio tools.

Overview

Extended metadata is kept separate from the core Tag to maintain a clean separation between basic metadata (title, artist, album) and metadata provider data (MusicBrainz IDs, ISRC codes, etc.).

// Basic metadata
final tag = await Haudiotagger.read('/path/to/song.mp3');
print(tag?.title);  // Basic field

// Extended metadata
final ext = await Haudiotagger.getExtended('/path/to/song.mp3');
print(ext.isrc);    // Extended field

Available Fields

MusicBrainz

Field	Description
musicBrainzRecordingId	Unique identifier for this recording
musicBrainzTrackId	Unique identifier for this track
musicBrainzReleaseId	Unique identifier for this release
musicBrainzReleaseGroupId	Unique identifier for this release group
musicBrainzArtistId	Unique identifier for this artist
musicBrainzReleaseArtistId	Unique identifier for the release artist
musicBrainzWorkId	Unique identifier for this work
musicBrainzReleaseType	Release type (album, single, EP, etc.)

AcoustID

Field	Description
acoustId	AcoustID identifier for this recording
acoustIdFingerprint	AcoustID audio fingerprint

Identifiers

Field	Description
isrc	International Standard Recording Code
barcode	Product barcode
catalogNumber	Catalog number

People & Roles

Field	Description
arranger	Arranger
conductor	Conductor
director	Director
engineer	Engineer
lyricist	Lyricist
mixDj	DJ who mixed
mixEngineer	Mix engineer
performer	Performer
producer	Producer
publisher	Publisher
label	Record label
remixer	Remixer
writer	Writer
composer	Composer
originalLyricist	Original lyricist

Dates

Field	Description
recordingDate	When the recording was made
releaseDate	When this release was published
originalReleaseDate	Original release date

Style

Field	Description
initialKey	Initial key (musical key)
color	Color associated with this release
mood	Mood of the track

URLs

Field	Description
audioFileUrl	URL to the audio file
audioSourceUrl	URL to the audio source
commercialInformationUrl	Commercial information URL
copyrightUrl	Copyright URL
trackArtistUrl	Track artist URL
radioStationUrl	Radio station URL
paymentUrl	Payment URL
publisherUrl	Publisher URL

Legal

Field	Description
copyrightMessage	Copyright message
license	License information

Podcast

Field	Description
podcastDescription	Podcast description
podcastSeriesCategory	Podcast category
podcastUrl	Podcast URL
podcastGlobalUniqueId	Podcast unique identifier
podcastKeywords	Podcast keywords

Other

Field	Description
setSubtitle	Set subtitle
showName	Show name
contentGroup	Content group
trackSubtitle	Track subtitle
language	Language
script	Script
parentalAdvisory	Parental advisory status
fileOwner	File owner
originalFileName	Original file name
originalMediaType	Original media type
encodedBy	Encoded by
encoderSoftware	Encoder software
encoderSettings	Encoder settings

Usage

Read Extended Metadata

final ext = await Haudiotagger.getExtended('/path/to/song.mp3');

print('ISRC: ${ext.isrc}');
print('MusicBrainz Recording ID: ${ext.musicBrainzRecordingId}');
print('Mood: ${ext.mood}');
print('Producer: ${ext.producer}');

Write Extended Metadata

Replaces all extended fields:

await Haudiotagger.setExtended('/path/to/song.mp3', ExtendedTag(
  isrc: 'US-S1Z-99-00001',
  mood: 'upbeat',
  catalogNumber: 'CAT-12345',
  producer: 'Dr. Dre',
  musicBrainzRecordingId: 'abc-123-def-456',
));

Partial Update

Only set fields are modified — everything else stays intact:

await Haudiotagger.updateExtended('/path/to/song.mp3', ExtendedChanges(
  mood: 'chill',  // Only mood changes
));

Remove All Extended Fields

await Haudiotagger.removeExtended('/path/to/song.mp3');

Web Usage

All extended metadata methods have *FromBytes variants for web support:

// Read
final ext = await Haudiotagger.getExtendedFromBytes(fileBytes);

// Write
final modified = await Haudiotagger.setExtendedFromBytes(fileBytes, ext);

// Partial update
final updated = await Haudiotagger.updateExtendedFromBytes(fileBytes, changes);

// Remove
final cleaned = await Haudiotagger.removeExtendedFromBytes(fileBytes);

Format Support

Extended metadata support varies by format:

Format	Support
MP3 (ID3v2)	Full
FLAC (Vorbis)	Full
MP4/M4A (ilst)	Partial
Ogg Vorbis	Full
Opus	Full
AAC	Full

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