// extractID3 attempts to extract MusicBrainz Picard tags from m.Raw(), where m.Format
// is assumed to be a supported version of ID3.
func extractID3(m tag.Metadata) Info {
var txxx, ufid string
switch m.Format() {
case tag.ID3v2_2:
txxx, ufid = "TXX", "UFI"
case tag.ID3v2_3, tag.ID3v2_4:
txxx, ufid = "TXXX", "UFID"
}
i := Info{}
for k, v := range m.Raw() {
switch {
case strings.HasPrefix(k, txxx):
if str, ok := v.(*tag.Comm); ok {
i.set(str.Description, str.Text)
}
case strings.HasPrefix(k, ufid):
if id, ok := v.(*tag.UFID); ok {
if id.Provider == UFIDProviderURL {
i.set(Recording, string(id.Identifier))
}
}
}
}
return i
}
// Extract tags created by MusicBrainz Picard which can be used with with the MusicBrainz and LastFM APIs.
// See https://picard.musicbrainz.org/docs/mappings/ for more information.
func Extract(m tag.Metadata) Info {
switch m.Format() {
case tag.ID3v2_2, tag.ID3v2_3, tag.ID3v2_4:
return extractID3(m)
}
return extractMP4Vorbis(m)
}
// extractMP4Vorbis attempts to extract MusicBrainz Picard tags from m.Raw(), where m.Format
// is assumed to be MP4 or VORBIS.
func extractMP4Vorbis(m tag.Metadata) Info {
i := Info{}
for t, v := range m.Raw() {
if s, ok := v.(string); ok {
i.set(t, s)
}
}
return i
}
func dataURL(m tag.Metadata) string {
p := m.Picture()
if p == nil {
return ""
}
if p.MIMEType == "-->" {
return string(p.Data)
}
return fmt.Sprintf("data:%s;base64,%s", p.MIMEType, base64.StdEncoding.EncodeToString(p.Data))
}
// Get the new folder name
func getNewFolderName(m tag.Metadata) (string, error) {
artist := m.AlbumArtist()
if artist == "" {
artist = m.Artist()
}
year := strconv.Itoa(m.Year())
album := m.Album()
if len(artist) == 0 {
return "", errors.New("Artist not found")
}
if year == "0" {
return "", errors.New("Year not found")
}
if len(album) == 0 {
return "", errors.New("Album not found")
}
folder := artist + " - " + year + " - " + album
return folder, nil
}
// Open the given file and return an http.File which contains the artwork, and hence
// the Name() of the returned file will have an extention for the artwork, not the
// media file.
func (afs artworkFileSystem) Open(ctx context.Context, path string) (http.File, error) {
f, err := afs.FileSystem.Open(ctx, path)
if err != nil {
return nil, err
}
defer f.Close()
stat, err := f.Stat()
if err != nil {
return nil, err
}
var m tag.Metadata
m, err = tag.ReadFrom(f)
if err != nil {
return nil, fmt.Errorf("error extracting picture from '%v': %v", path, err)
}
p := m.Picture()
if p == nil {
return nil, fmt.Errorf("no picture attached to '%v'", path)
}
name := stat.Name()
if p.Ext != "" {
name += "." + p.Ext
}
return &file{
ReadSeeker: bytes.NewReader(p.Data),
stat: &fileInfo{
name: name,
size: int64(len(p.Data)),
modTime: stat.ModTime(),
},
}, nil
}
func printMetadata(m tag.Metadata) {
fmt.Printf("Metadata Format: %v\n", m.Format())
fmt.Printf("File Type: %v\n", m.FileType())
fmt.Printf(" Title: %v\n", m.Title())
fmt.Printf(" Album: %v\n", m.Album())
fmt.Printf(" Artist: %v\n", m.Artist())
fmt.Printf(" Composer: %v\n", m.Composer())
fmt.Printf(" Genre: %v\n", m.Genre())
fmt.Printf(" Year: %v\n", m.Year())
track, trackCount := m.Track()
fmt.Printf(" Track: %v of %v\n", track, trackCount)
disc, discCount := m.Disc()
fmt.Printf(" Disc: %v of %v\n", disc, discCount)
fmt.Printf(" Picture: %v\n", m.Picture())
fmt.Printf(" Lyrics: %v\n", m.Lyrics())
}