Merge pull request #24 from hanafizaki/patch-3

Update main.go

main.go

@@ -734,6 +734,11 @@ func writeM4a(w *mp4.Writer, info *SongInfo, meta *AutoGenerated, data []byte, t
 						return err
 					}
 
+					err = addExtendedMeta("ITUNESALBUMID", meta.Data[0].ID)
+					if err != nil {
+						return err
+					}
+
 					err = addMeta(mp4.BoxType{'\251', 'w', 'r', 't'}, meta.Data[0].Relationships.Tracks.Data[index].Attributes.ComposerName)
 					if err != nil {
 						return err
@@ -749,6 +754,11 @@ func writeM4a(w *mp4.Writer, info *SongInfo, meta *AutoGenerated, data []byte, t
 						return err
 					}
 
+					err = addExtendedMeta("RELEASETIME", meta.Data[0].Relationships.Tracks.Data[index].Attributes.ReleaseDate)
+					if err != nil {
+						return err
+					}
+
 					cnID, err := strconv.ParseUint(meta.Data[0].Relationships.Tracks.Data[index].ID, 10, 32)
 					if err != nil {
 						return err