fix artistid

main.go

@@ -818,15 +818,17 @@ func writeM4a(w *mp4.Writer, info *SongInfo, meta *AutoGenerated, data []byte, t
 						}
 					}
 
-					if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID) > 0 {
-						atID, err := strconv.ParseUint(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID, 10, 32)
-						if err != nil {
-							return err
-						}
+					if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data) > 0 {
+						if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID) > 0 {
+							atID, err := strconv.ParseUint(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID, 10, 32)
+							if err != nil {
+								return err
+							}
 
-						err = addMeta(mp4.BoxType{'a', 't', 'I', 'D'}, uint32(atID))
-						if err != nil {
-							return err
+							err = addMeta(mp4.BoxType{'a', 't', 'I', 'D'}, uint32(atID))
+							if err != nil {
+								return err
+							}
 						}
 					}
 					trkn := make([]byte, 8)

main_select.go

@@ -812,16 +812,17 @@ func writeM4a(w *mp4.Writer, info *SongInfo, meta *AutoGenerated, data []byte, t
 							}
 						}
 					}
+					if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data) > 0 {
+						if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID) > 0 {
+							atID, err := strconv.ParseUint(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID, 10, 32)
+							if err != nil {
+								return err
+							}
 
-					if len(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID) > 0 {
-						atID, err := strconv.ParseUint(meta.Data[0].Relationships.Tracks.Data[index].Relationships.Artists.Data[0].ID, 10, 32)
-						if err != nil {
-							return err
-						}
-
-						err = addMeta(mp4.BoxType{'a', 't', 'I', 'D'}, uint32(atID))
-						if err != nil {
-							return err
+							err = addMeta(mp4.BoxType{'a', 't', 'I', 'D'}, uint32(atID))
+							if err != nil {
+								return err
+							}
 						}
 					}
 					trkn := make([]byte, 8)