diff --git a/av/pack.go b/av/pack.go
index efe1944..eb93fd9 100644
--- a/av/pack.go
+++ b/av/pack.go
@@ -15,7 +15,17 @@ type Packet struct {
 	Data       []byte
 }
 
-func (p *Packet) NewPacketData() *Packet {
+func (p *Packet) Type() int {
+	if p.IsVideo {
+		return TAG_VIDEO
+	} else if p.IsMetadata {
+		return TAG_SCRIPTDATAAMF0
+	} else {
+		return TAG_AUDIO
+	}
+}
+
+func (p *Packet) Clone() *Packet {
 	var tp = *p
 	tp.Data = make([]byte, len(p.Data))
 	copy(tp.Data, p.Data)
diff --git a/container/flv/writer.go b/container/flv/writer.go
index 4c3f9c1..590bf7f 100755
--- a/container/flv/writer.go
+++ b/container/flv/writer.go
@@ -23,7 +23,7 @@ const (
 )
 
 type Writer struct {
-	t         *utils.Timestamp
+	t         utils.Timestamp
 	headerBuf []byte
 	w         *stream.Writer
 	inited    bool
@@ -43,7 +43,6 @@ func WithWriterBuffer(size int) WriterConf {
 
 func NewWriter(w io.Writer, conf ...WriterConf) *Writer {
 	writer := &Writer{
-		t:         utils.NewTimestamp(),
 		headerBuf: make([]byte, headerLen),
 		bufSize:   1024,
 	}
@@ -75,7 +74,7 @@ func (w *Writer) Write(p *av.Packet) error {
 	} else if p.IsMetadata {
 		var err error
 		typeID = av.TAG_SCRIPTDATAAMF0
-		p = p.NewPacketData()
+		p = p.Clone()
 		p.Data, err = amf.MetaDataReform(p.Data, amf.DEL)
 		if err != nil {
 			return err
@@ -86,8 +85,7 @@ func (w *Writer) Write(p *av.Packet) error {
 		return nil
 	}
 	dataLen := len(p.Data)
-	timestamp := p.TimeStamp + w.t.BaseTimeStamp()
-	w.t.RecTimeStamp(timestamp, uint32(typeID))
+	timestamp := w.t.RecTimeStamp(p.TimeStamp, uint32(typeID))
 
 	preDataLen := dataLen + headerLen
 	timestampExt := timestamp >> 24
@@ -95,7 +93,7 @@ func (w *Writer) Write(p *av.Packet) error {
 	return w.w.
 		U8(typeID).
 		U24(uint32(dataLen)).
-		U24(uint32(timestamp)).
+		U24(timestamp).
 		U8(uint8(timestampExt)).
 		U24(0).
 		Bytes(p.Data).
diff --git a/protocol/hls/source.go b/protocol/hls/source.go
index a30c060..b3cf62b 100644
--- a/protocol/hls/source.go
+++ b/protocol/hls/source.go
@@ -11,6 +11,7 @@ import (
 	"github.com/zijiren233/livelib/container/flv"
 	"github.com/zijiren233/livelib/container/ts"
 	"github.com/zijiren233/livelib/protocol/hls/parser"
+	"github.com/zijiren233/livelib/utils"
 )
 
 const (
@@ -23,6 +24,7 @@ const (
 
 type Source struct {
 	seq         int
+	t           utils.Timestamp
 	bwriter     *bytes.Buffer
 	btswriter   *bytes.Buffer
 	demuxer     *flv.Demuxer
@@ -79,7 +81,7 @@ func (source *Source) SendPacket() error {
 		if p.IsMetadata {
 			continue
 		}
-		p = p.NewPacketData()
+		p = p.Clone()
 		err := source.demuxer.Demux(p)
 		if err != nil {
 			if err == flv.ErrAvcEndSEQ {
@@ -92,6 +94,7 @@ func (source *Source) SendPacket() error {
 		if err != nil || isSeq {
 			continue
 		}
+		p.TimeStamp = source.t.RecTimeStamp(p.TimeStamp, uint32(p.Type()))
 		if source.btswriter != nil {
 			source.stat.update(p.IsVideo, p.TimeStamp)
 			source.calcPtsDts(p.IsVideo, p.TimeStamp, uint32(compositionTime))
diff --git a/protocol/httpflv/writer.go b/protocol/httpflv/writer.go
index 1026d2e..01439a1 100755
--- a/protocol/httpflv/writer.go
+++ b/protocol/httpflv/writer.go
@@ -19,7 +19,7 @@ const (
 )
 
 type HttpFlvWriter struct {
-	t         *utils.Timestamp
+	t         utils.Timestamp
 	headerBuf []byte
 	w         *stream.Writer
 	inited    bool
@@ -41,7 +41,6 @@ func WithWriterBuffer(size int) HttpFlvWriterConf {
 
 func NewHttpFLVWriter(w io.Writer, conf ...HttpFlvWriterConf) *HttpFlvWriter {
 	writer := &HttpFlvWriter{
-		t:           utils.NewTimestamp(),
 		headerBuf:   make([]byte, headerLen),
 		bufSize:     1024,
 		packetQueue: make(chan *av.Packet, maxQueueNum),
@@ -73,6 +72,7 @@ func (w *HttpFlvWriter) Write(p *av.Packet) (err error) {
 }
 
 func (w *HttpFlvWriter) SendPacket() error {
+	var typeID uint8
 	for p := range w.packetQueue {
 		if !w.inited {
 			if err := w.w.Bytes(flv.FlvFirstHeader).Error(); err != nil {
@@ -81,14 +81,12 @@ func (w *HttpFlvWriter) SendPacket() error {
 			w.inited = true
 		}
 
-		var typeID uint8
-
 		if p.IsVideo {
 			typeID = av.TAG_VIDEO
 		} else if p.IsMetadata {
 			var err error
 			typeID = av.TAG_SCRIPTDATAAMF0
-			p = p.NewPacketData()
+			p = p.Clone()
 			p.Data, err = amf.MetaDataReform(p.Data, amf.DEL)
 			if err != nil {
 				return err
@@ -99,8 +97,7 @@ func (w *HttpFlvWriter) SendPacket() error {
 			return errors.New("not allowed packet type")
 		}
 		dataLen := len(p.Data)
-		timestamp := p.TimeStamp + w.t.BaseTimeStamp()
-		w.t.RecTimeStamp(timestamp, uint32(typeID))
+		timestamp := w.t.RecTimeStamp(p.TimeStamp, uint32(typeID))
 
 		preDataLen := dataLen + headerLen
 		timestampExt := timestamp >> 24
@@ -108,7 +105,7 @@ func (w *HttpFlvWriter) SendPacket() error {
 		if err := w.w.
 			U8(typeID).
 			U24(uint32(dataLen)).
-			U24(uint32(timestamp)).
+			U24(timestamp).
 			U8(uint8(timestampExt)).
 			U24(0).
 			Bytes(p.Data).
diff --git a/protocol/rtmp/writer.go b/protocol/rtmp/writer.go
index 2253c2a..0a78afd 100644
--- a/protocol/rtmp/writer.go
+++ b/protocol/rtmp/writer.go
@@ -12,7 +12,7 @@ import (
 )
 
 type Writer struct {
-	t           *utils.Timestamp
+	t           utils.Timestamp
 	conn        ChunkWriter
 	packetQueue chan *av.Packet
 	WriteBWInfo StaticsBW
@@ -24,7 +24,6 @@ type Writer struct {
 func NewWriter(conn ChunkWriter) *Writer {
 	w := &Writer{
 		conn:        conn,
-		t:           utils.NewTimestamp(),
 		packetQueue: make(chan *av.Packet, maxQueueNum),
 		WriteBWInfo: StaticsBW{0, 0, 0, 0, 0, 0, 0, 0},
 	}
@@ -79,21 +78,11 @@ func (w *Writer) SendPacket() error {
 		cs.Data = p.Data
 		cs.Length = uint32(len(p.Data))
 		cs.StreamID = p.StreamID
-		cs.Timestamp = p.TimeStamp
-		cs.Timestamp += w.t.BaseTimeStamp()
-
-		if p.IsVideo {
-			cs.TypeID = av.TAG_VIDEO
-		} else {
-			if p.IsMetadata {
-				cs.TypeID = av.TAG_SCRIPTDATAAMF0
-			} else {
-				cs.TypeID = av.TAG_AUDIO
-			}
-		}
+
+		cs.TypeID = uint32(p.Type())
 
 		w.SaveStatics(p.StreamID, uint64(cs.Length), p.IsVideo)
-		w.t.RecTimeStamp(cs.Timestamp, cs.TypeID)
+		cs.Timestamp = w.t.RecTimeStamp(p.TimeStamp, cs.TypeID)
 		if err := w.conn.Write(cs); err != nil {
 			return err
 		}
diff --git a/utils/utils.go b/utils/utils.go
index 4c7513e..0169ab2 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -3,31 +3,43 @@ package utils
 import "github.com/zijiren233/livelib/av"
 
 type Timestamp struct {
-	t                  uint32
+	videoTimestamp     uint32
+	audioTimestamp     uint32
 	lastVideoTimestamp uint32
 	lastAudioTimestamp uint32
 }
 
-func NewTimestamp() *Timestamp {
-	return new(Timestamp)
-}
-
-func (rw *Timestamp) BaseTimeStamp() uint32 {
-	return rw.t
-}
-
-func (rw *Timestamp) CalcBaseTimestamp() {
-	if rw.lastAudioTimestamp > rw.lastVideoTimestamp {
-		rw.t = rw.lastAudioTimestamp
+func (rw *Timestamp) timeStamp() uint32 {
+	if rw.audioTimestamp > rw.videoTimestamp {
+		return rw.audioTimestamp
 	} else {
-		rw.t = rw.lastVideoTimestamp
+		return rw.videoTimestamp
 	}
 }
 
-func (rw *Timestamp) RecTimeStamp(timestamp, typeID uint32) {
+func (rw *Timestamp) RecTimeStamp(timestamp, typeID uint32) uint32 {
 	if typeID == av.TAG_VIDEO {
+		if timestamp < rw.videoTimestamp {
+			if rw.lastVideoTimestamp > timestamp {
+				rw.videoTimestamp += timestamp
+			} else {
+				rw.videoTimestamp += timestamp - rw.lastVideoTimestamp
+			}
+		} else {
+			rw.videoTimestamp = timestamp
+		}
 		rw.lastVideoTimestamp = timestamp
 	} else if typeID == av.TAG_AUDIO {
+		if timestamp < rw.audioTimestamp {
+			if rw.lastAudioTimestamp > timestamp {
+				rw.audioTimestamp += timestamp
+			} else {
+				rw.audioTimestamp += timestamp - rw.lastAudioTimestamp
+			}
+		} else {
+			rw.audioTimestamp = timestamp
+		}
 		rw.lastAudioTimestamp = timestamp
 	}
+	return rw.timeStamp()
 }