decode multi valued frames

v2/encoding.go

@@ -121,6 +121,18 @@ func decodeText(src []byte, from Encoding) string {
 	return string(result)
 }
 
+// decodeMulti decodes multi valued src from "from" encoding to UTF-8.
+func decodeMulti(src []byte, from Encoding) []string {
+	src = bytes.TrimSuffix(src, from.TerminationBytes) // See https://github.com/bogem/id3v2/issues/41
+	splitted := bytes.Split(src, from.TerminationBytes)
+
+	var res []string
+	for _, s := range splitted {
+		res = append(res, decodeText(s, from))
+	}
+	return res
+}
+
 // encodeWriteText encodes src from UTF-8 to "to" encoding and writes to bw.
 func encodeWriteText(bw *bufWriter, src string, to Encoding) error {
 	if to.Equals(EncodingUTF8) {

v2/parse_test.go

@@ -34,6 +34,45 @@ func TestParse(t *testing.T) {
 	testUnknownFrames(t, tag)
 }
 
+// TestParse compares parsed frames with expected frames.
+func TestMultiParse(t *testing.T) {
+	tag, err := Open(multiMp3Path, parseOpts)
+	if tag == nil || err != nil {
+		t.Error("Error while opening mp3 file:", err)
+	}
+	defer tag.Close()
+
+	testMultiTextFrames(t, tag)
+	testMultiTXXXFrames(t, tag)
+}
+
+func testMultiTextFrames(t *testing.T, tag *Tag) {
+	if err := compareTwoStrings(tag.Artist(), "artist1"); err != nil {
+		t.Error(err)
+	}
+	artistFrames := tag.GetFrames(tag.CommonID("Artist"))
+	if len(artistFrames) != 1 {
+		t.Fatalf("Expected artist frames: %v, got %v", 1, len(artistFrames))
+	}
+
+	artistFrame, ok := artistFrames[0].(TextFrame)
+	if !ok {
+		t.Fatal("Couldn't assert artist frame")
+	}
+
+	if len(artistFrame.Multi) != 2 {
+		t.Fatalf("Expected artist values: %v, got %v", 2, len(artistFrame.Multi))
+	}
+
+	if err := compareTwoStrings(artistFrame.Multi[0], "artist1"); err != nil {
+		t.Error(err)
+	}
+
+	if err := compareTwoStrings(artistFrame.Multi[1], "artist2"); err != nil {
+		t.Error(err)
+	}
+}
+
 func testTextFrames(t *testing.T, tag *Tag) {
 	if err := compareTwoStrings(tag.Artist(), "Artist"); err != nil {
 		t.Error(err)
@@ -173,6 +212,27 @@ func testTXXXFrames(t *testing.T, tag *Tag) {
 	}
 }
 
+func testMultiTXXXFrames(t *testing.T, tag *Tag) {
+	txxxFrames := tag.GetFrames(tag.CommonID("User defined text information frame"))
+	if len(txxxFrames) != 1 {
+		t.Fatalf("Expected TXXX frames: %v, got %v", 1, len(txxxFrames))
+	}
+
+	var parsedUserDefinedTextFrame UserDefinedTextFrame
+	for _, f := range txxxFrames {
+		txxx, ok := f.(UserDefinedTextFrame)
+		if !ok {
+			t.Fatal("Couldn't assert TXXX frame")
+		}
+		parsedUserDefinedTextFrame = txxx
+		fmt.Printf("%s\n", txxx.Description)
+	}
+
+	if err := compareTXXXFrames(parsedUserDefinedTextFrame, multiUDTF); err != nil {
+		t.Error(err)
+	}
+}
+
 func compareTXXXFrames(actual, expected UserDefinedTextFrame) error {
 	if err := compareTwoBytes(actual.Encoding.Key, expected.Encoding.Key); err != nil {
 		return err

v2/tag_test.go

@@ -18,6 +18,7 @@ import (
 
 const (
 	mp3Path        = "testdata/test.mp3"
+	multiMp3Path   = "testdata/test_multi.mp3"
 	frontCoverPath = "testdata/front_cover.jpg"
 	backCoverPath  = "testdata/back_cover.jpg"
 
@@ -62,6 +63,16 @@ var (
 		Value:       "fbd94fb6-2a74-42d0-acbc-81caf8b84984",
 	}
 
+	multiUDTF = UserDefinedTextFrame{
+		Encoding:    EncodingUTF8,
+		Description: "multi",
+		Value:       "val1",
+		Multi: []string{
+			"val1",
+			"val2",
+		},
+	}
+
 	musicBrainzUF = UFIDFrame{
 		OwnerIdentifier: "https://musicbrainz.org",
 		Identifier:      []byte("fbd94fb6-2a74-42d0-acbc-81caf8b84984"),

v2/text_frame.go

@@ -11,6 +11,7 @@ import "io"
 type TextFrame struct {
 	Encoding Encoding
 	Text     string
+	Multi    []string
 }
 
 func (tf TextFrame) Size() int {
@@ -45,9 +46,16 @@ func parseTextFrame(br *bufReader) (Framer, error) {
 		return nil, err
 	}
 
+	values := decodeMulti(buf.Bytes(), encoding)
+	var first string
+	if len(values) > 0 {
+		first = values[0]
+	}
+
 	tf := TextFrame{
 		Encoding: encoding,
-		Text:     decodeText(buf.Bytes(), encoding),
+		Text:     first,
+		Multi:    values,
 	}
 
 	return tf, nil

v2/user_defined_text_frame.go

@@ -8,6 +8,7 @@ type UserDefinedTextFrame struct {
 	Encoding    Encoding
 	Description string
 	Value       string
+	Multi       []string
 }
 
 func (udtf UserDefinedTextFrame) Size() int {
@@ -42,10 +43,17 @@ func parseUserDefinedTextFrame(br *bufReader, version byte) (Framer, error) {
 		return nil, err
 	}
 
+	values := decodeMulti(value.Bytes(), encoding)
+	var first string
+	if len(values) > 0 {
+		first = values[0]
+	}
+
 	udtf := UserDefinedTextFrame{
 		Encoding:    encoding,
 		Description: decodeText(description, encoding),
-		Value:       decodeText(value.Bytes(), encoding),
+		Value:       first,
+		Multi:       values,
 	}
 
 	return udtf, nil