MP3/MP4/FLAC metadata parsing library

This package provides MP3 (ID3v1,2.{2,3,4}) and MP4 (ACC, M4A, ALAC) and FLAC metadata detection, parsing and artwork extraction.

Parsed metadata is exported via a single interface (giving a consistent API for all supported metadata formats).

// Metadata is an interface which is used to describe metadata retrieved by this package.
type Metadata interface {
	Format() Format

	Title() string
	Album() string
	Artist() string
	AlbumArtist() string
	Composer() string
	Year() int

	Track() (int, int) // Number, Total
	Disc() (int, int) // Number, Total

	Picture() *Picture // Artwork

	Raw() map[string]interface{} // NB: raw tag names are not consistent across formats.
}

Audio Data Checksum (SHA1)

This package also provides a metadata-invariant checksum for audio files: only the audio data is used to construct the checksum.

http://godoc.org/github.com/dhowden/tag#Sum

Example Usage

There are a simple command-line tools which demonstrate basic tag extraction and summing:

$ go get github.com/dhowden/tag/...
$ cd $GOPATH/bin
$ ./tag 11\ High\ Hopes.m4a
Metadata Format: MP4
 Title: High Hopes
 Album: The Division Bell
 Artist: Pink Floyd
 Composer: Abbey Road Recording Studios/David Gilmour/Polly Samson
 Year: 1994
 Track: 11 of 11
 Disc: 1 of 1
 Picture: Picture{Ext: jpeg, MIMEType: image/jpeg, Type: , Description: , Data.Size: 606109}

$ ./sum 11\ High\ Hopes.m4a
2ae208c5f00a1f21f5fac9b7f6e0b8e52c06da29