diff --git a/audio/format/aac/mp4.go b/audio/format/aac/mp4.go
index d0ce7d9..603cfdc 100644
--- a/audio/format/aac/mp4.go
+++ b/audio/format/aac/mp4.go
@@ -87,13 +87,14 @@ func (d *mp4Decoder) Read() (samples [][]byte) {
 
 		return
 	} else {
+		workSpace := make([]byte, 1024)
 		if d.mp4.Mdat.Data == nil {
 			return nil
 		}
 		for _, trak := range d.mp4.Moov.Traks {
 			if trak.Tkhd.TrackID == d.trackId {
 				buf := new(bytes.Buffer)
-				if err := d.mp4.CopySampleData(buf, d.reader, trak, d.currentSample, d.currentSample); err != nil || buf.Len() == 0 {
+				if err := d.mp4.CopySampleData(buf, d.reader, trak, d.currentSample, d.currentSample, workSpace); err != nil || buf.Len() == 0 {
 					return nil
 				}
 				d.currentSample++
diff --git a/audio/format/alac/mp4.go b/audio/format/alac/mp4.go
index 4d0f736..7b118f4 100644
--- a/audio/format/alac/mp4.go
+++ b/audio/format/alac/mp4.go
@@ -90,10 +90,11 @@ func (d *mp4Decoder) Read() (samples [][]byte) {
 
 		return
 	} else {
+		workSpace := make([]byte, 1024)
 		for _, trak := range d.mp4.Moov.Traks {
 			if trak.Tkhd.TrackID == d.trackId {
 				buf := new(bytes.Buffer)
-				if err := d.mp4.CopySampleData(buf, d.reader, trak, d.currentSample, d.currentSample); err != nil {
+				if err := d.mp4.CopySampleData(buf, d.reader, trak, d.currentSample, d.currentSample, workSpace); err != nil {
 					return nil
 				}
 				d.currentSample++