add duration for all formats

dsf.go

@@ -7,12 +7,13 @@ package tag
 import (
 	"errors"
 	"io"
+	"time"
 )
 
-// ReadDSFTags reads DSF metadata from the io.ReadSeeker, returning the resulting
+// ReadDSFMeta reads DSF metadata from the io.ReadSeeker, returning the resulting
 // metadata in a Metadata implementation, or non-nil error if there was a problem.
 // samples: http://www.2l.no/hires/index.html
-func ReadDSFTags(r io.ReadSeeker) (Metadata, error) {
+func ReadDSFMeta(r io.ReadSeeker) (Metadata, error) {
 	dsd, err := readString(r, 4)
 	if err != nil {
 		return nil, err
@@ -31,79 +32,53 @@ func ReadDSFTags(r io.ReadSeeker) (Metadata, error) {
 		return nil, err
 	}
 
-	_, err = r.Seek(int64(id3Pointer), io.SeekStart)
+	_, err = r.Seek(int64(28), io.SeekCurrent)
 	if err != nil {
 		return nil, err
 	}
 
-	id3, err := ReadID3v2Tags(r)
+	sampleRate, err := readUint32LittleEndian(r)
 	if err != nil {
 		return nil, err
 	}
 
-	return metadataDSF{id3}, nil
-}
-
-type metadataDSF struct {
-	id3 Metadata
-}
-
-func (m metadataDSF) Format() Format {
-	return m.id3.Format()
-}
-
-func (m metadataDSF) FileType() FileType {
-	return DSF
-}
-
-func (m metadataDSF) Title() string {
-	return m.id3.Title()
-}
-
-func (m metadataDSF) Album() string {
-	return m.id3.Album()
-}
-
-func (m metadataDSF) Artist() string {
-	return m.id3.Artist()
-}
-
-func (m metadataDSF) AlbumArtist() string {
-	return m.id3.AlbumArtist()
-}
-
-func (m metadataDSF) Composer() string {
-	return m.id3.Composer()
-}
+	_, err = r.Seek(int64(4), io.SeekCurrent)
+	if err != nil {
+		return nil, err
+	}
 
-func (m metadataDSF) Year() int {
-	return m.id3.Year()
-}
+	sampleNum, err := readUint64LittleEndian(r)
+	if err != nil {
+		return nil, err
+	}
 
-func (m metadataDSF) Genre() string {
-	return m.id3.Genre()
-}
+	duration := time.Second * (time.Duration(sampleNum) / time.Duration(sampleRate))
 
-func (m metadataDSF) Track() (int, int) {
-	return m.id3.Track()
-}
+	_, err = r.Seek(int64(id3Pointer), io.SeekStart)
+	if err != nil {
+		return nil, err
+	}
 
-func (m metadataDSF) Disc() (int, int) {
-	return m.id3.Disc()
-}
+	id3, err := ReadID3v2Tags(r)
+	if err != nil {
+		return nil, err
+	}
 
-func (m metadataDSF) Picture() *Picture {
-	return m.id3.Picture()
+	return metadataDSF{
+		metadataID3v2: id3,
+		duration:      duration,
+	}, nil
 }
 
-func (m metadataDSF) Lyrics() string {
-	return m.id3.Lyrics()
+type metadataDSF struct {
+	*metadataID3v2
+	duration time.Duration
 }
 
-func (m metadataDSF) Comment() string {
-	return m.id3.Comment()
+func (m metadataDSF) FileType() FileType {
+	return DSF
 }
 
-func (m metadataDSF) Raw() map[string]interface{} {
-	return m.id3.Raw()
+func (m metadataDSF) Duration() time.Duration {
+	return m.duration
 }

flac.go

@@ -6,26 +6,28 @@ package tag
 
 import (
 	"errors"
+	"fmt"
 	"io"
+	"time"
 )
 
 // blockType is a type which represents an enumeration of valid FLAC blocks
 type blockType byte
 
 // FLAC block types.
 const (
-	// Stream Info Block           0
 	// Padding Block               1
 	// Application Block           2
 	// Seektable Block             3
 	// Cue Sheet Block             5
+	streamInfoBlock    blockType = 0
 	vorbisCommentBlock blockType = 4
 	pictureBlock       blockType = 6
 )
 
-// ReadFLACTags reads FLAC metadata from the io.ReadSeeker, returning the resulting
+// ReadFLACMeta reads FLAC metadata from the io.ReadSeeker, returning the resulting
 // metadata in a Metadata implementation, or non-nil error if there was a problem.
-func ReadFLACTags(r io.ReadSeeker) (Metadata, error) {
+func ReadFLACMeta(r io.ReadSeeker) (Metadata, error) {
 	flac, err := readString(r, 4)
 	if err != nil {
 		return nil, err
@@ -35,11 +37,11 @@ func ReadFLACTags(r io.ReadSeeker) (Metadata, error) {
 	}
 
 	m := &metadataFLAC{
-		newMetadataVorbis(),
+		metadataVorbis: newMetadataVorbis(),
 	}
 
 	for {
-		last, err := m.readFLACMetadataBlock(r)
+		last, err := m.readFLACBlock(r)
 		if err != nil {
 			return nil, err
 		}
@@ -53,9 +55,10 @@ func ReadFLACTags(r io.ReadSeeker) (Metadata, error) {
 
 type metadataFLAC struct {
 	*metadataVorbis
+	duration time.Duration
 }
 
-func (m *metadataFLAC) readFLACMetadataBlock(r io.ReadSeeker) (last bool, err error) {
+func (m *metadataFLAC) readFLACBlock(r io.ReadSeeker) (last bool, err error) {
 	blockHeader, err := readBytes(r, 1)
 	if err != nil {
 		return
@@ -78,12 +81,40 @@ func (m *metadataFLAC) readFLACMetadataBlock(r io.ReadSeeker) (last bool, err er
 	case pictureBlock:
 		err = m.readPictureBlock(r)
 
+	case streamInfoBlock:
+		err = m.readStreamingInfoBlock(r, blockLen)
+
 	default:
 		_, err = r.Seek(int64(blockLen), io.SeekCurrent)
 	}
 	return
 }
 
+func (m *metadataFLAC) readStreamingInfoBlock(r io.Reader, len int) error {
+	data := make([]byte, len)
+	if _, err := r.Read(data); err != nil {
+		return err
+	}
+
+	sampleRate, err := cutBits(data, 80, 20)
+	if err != nil {
+		return fmt.Errorf("reading sample rate: %w", err)
+	}
+
+	sampleNum, err := cutBits(data, 108, 36)
+	if err != nil {
+		return fmt.Errorf("reading sample number: %w", err)
+	}
+
+	m.duration = time.Second * (time.Duration(sampleNum) / time.Duration(sampleRate))
+
+	return nil
+}
+
 func (m *metadataFLAC) FileType() FileType {
 	return FLAC
 }
+
+func (m *metadataFLAC) Duration() time.Duration {
+	return time.Second
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/dhowden/tag
 
-go 1.20
+go 1.22
 
 require github.com/dhowden/itl v0.0.0-20170329215456-9fbe21093131
 

id3v1.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"strconv"
 	"strings"
+	"time"
 )
 
 // id3v1Genres is a list of genres as given in the ID3v1 specification.
@@ -42,7 +43,7 @@ var ErrNotID3v1 = errors.New("invalid ID3v1 header")
 
 // ReadID3v1Tags reads ID3v1 tags from the io.ReadSeeker.  Returns ErrNotID3v1
 // if there are no ID3v1 tags, otherwise non-nil error if there was a problem.
-func ReadID3v1Tags(r io.ReadSeeker) (Metadata, error) {
+func ReadID3v1Tags(r io.ReadSeeker) (metadataID3v1, error) {
 	_, err := r.Seek(-128, io.SeekEnd)
 	if err != nil {
 		return nil, err
@@ -142,3 +143,6 @@ func (metadataID3v1) Disc() (int, int)      { return 0, 0 }
 func (m metadataID3v1) Picture() *Picture   { return nil }
 func (m metadataID3v1) Lyrics() string      { return "" }
 func (m metadataID3v1) Comment() string     { return m["comment"].(string) }
+func (m metadataID3v1) Duration() time.Duration {
+	return time.Second
+}

id3v2.go

@@ -60,6 +60,7 @@ type id3v2Header struct {
 	Unsynchronisation bool
 	ExtendedHeader    bool
 	Experimental      bool
+	FooterPresent     bool
 	Size              uint
 }
 
@@ -97,6 +98,7 @@ func readID3v2Header(r io.Reader) (h *id3v2Header, offset uint, err error) {
 		Unsynchronisation: getBit(b[2], 7),
 		ExtendedHeader:    getBit(b[2], 6),
 		Experimental:      getBit(b[2], 5),
+		FooterPresent:     getBit(b[2], 4),
 		Size:              uint(get7BitChunkedInt(b[3:7])),
 	}
 
@@ -425,7 +427,7 @@ func (r *unsynchroniser) Read(p []byte) (int, error) {
 
 // ReadID3v2Tags parses ID3v2.{2,3,4} tags from the io.ReadSeeker into a Metadata, returning
 // non-nil error on failure.
-func ReadID3v2Tags(r io.ReadSeeker) (Metadata, error) {
+func ReadID3v2Tags(r io.ReadSeeker) (*metadataID3v2, error) {
 	h, offset, err := readID3v2Header(r)
 	if err != nil {
 		return nil, err
@@ -440,12 +442,13 @@ func ReadID3v2Tags(r io.ReadSeeker) (Metadata, error) {
 	if err != nil {
 		return nil, err
 	}
-	return metadataID3v2{header: h, frames: f}, nil
+
+	return &metadataID3v2{header: h, frames: f}, nil
 }
 
 var id3v2genreRe = regexp.MustCompile(`(.*[^(]|.* |^)\(([0-9]+)\) *(.*)$`)
 
-//  id3v2genre parse a id3v2 genre tag and expand the numeric genres
+// id3v2genre parse a id3v2 genre tag and expand the numeric genres
 func id3v2genre(genre string) string {
 	c := true
 	for c {