diff --git a/av/format/flv/aac_packetizer.go b/av/format/flv/aac_packetizer.go
new file mode 100644
index 0000000..5ed0e3d
--- /dev/null
+++ b/av/format/flv/aac_packetizer.go
@@ -0,0 +1,94 @@
+// Copyright (c) 2019,CAOHONGJU All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package flv
+
+import "github.com/cnotch/ipchub/av/codec"
+
+type aacPacketizer struct {
+	meta         *codec.AudioMeta
+	dataTemplate *AudioData
+	tagWriter    TagWriter
+	spsMuxed     bool
+}
+
+func NewAacPacketizer(meta *codec.AudioMeta, tagWriter TagWriter) Packetizer {
+	ap := &aacPacketizer{
+		meta:      meta,
+		tagWriter: tagWriter,
+	}
+	ap.prepareTemplate()
+	return ap
+}
+
+func (ap *aacPacketizer) prepareTemplate() {
+	audioData := &AudioData{
+		SoundFormat:   SoundFormatAAC,
+		AACPacketType: AACPacketTypeRawData,
+		Body:          nil,
+	}
+
+	switch ap.meta.SampleRate {
+	case 5512:
+		audioData.SoundRate = SoundRate5512
+	case 11025:
+		audioData.SoundRate = SoundRate11025
+	case 22050:
+		audioData.SoundRate = SoundRate22050
+	case 44100:
+		audioData.SoundRate = SoundRate44100
+	default:
+		audioData.SoundRate = SoundRate44100
+	}
+
+	if ap.meta.SampleSize == 8 {
+		audioData.SoundSize = SoundeSize8bit
+	} else {
+		audioData.SoundSize = SoundeSize16bit
+	}
+
+	if ap.meta.Channels > 1 {
+		audioData.SoundType = SoundTypeStereo
+	} else {
+		audioData.SoundType = SoundTypeMono
+	}
+
+	ap.dataTemplate = audioData
+}
+
+func (ap *aacPacketizer) PacketizeSequenceHeader() error {
+	if ap.spsMuxed {
+		return nil
+	}
+
+	ap.spsMuxed = true
+	audioData := *ap.dataTemplate
+	audioData.AACPacketType = AACPacketTypeSequenceHeader
+	audioData.Body = ap.meta.Sps
+	data, _ := audioData.Marshal()
+
+	tag := &Tag{
+		TagType:   TagTypeAudio,
+		DataSize:  uint32(len(data)),
+		Timestamp: 0,
+		StreamID:  0,
+		Data:      data,
+	}
+	return ap.tagWriter.WriteFlvTag(tag)
+}
+
+func (ap *aacPacketizer) Packetize(basePts int64, frame *codec.Frame) error {
+	audioData := *ap.dataTemplate
+	audioData.Body = frame.Payload
+	data, _ := audioData.Marshal()
+
+	tag := &Tag{
+		TagType:   TagTypeAudio,
+		DataSize:  uint32(len(data)),
+		Timestamp: uint32(frame.AbsTimestamp-basePts) + ptsDelay,
+		StreamID:  0,
+		Data:      data,
+	}
+	return ap.tagWriter.WriteFlvTag(tag)
+}
diff --git a/av/format/flv/flv_test.go b/av/format/flv/flv_test.go
index 181a190..f6a9fd7 100644
--- a/av/format/flv/flv_test.go
+++ b/av/format/flv/flv_test.go
@@ -40,7 +40,7 @@ func TestFlvWriter(t *testing.T) {
 	var audio codec.AudioMeta
 	sdp.ParseMetadata(string(sdpraw), &video, &audio)
 	writer, err := NewWriter(out, 5)
-	flvMuxer := NewMuxerAvcAac(video, audio, writer, xlog.L())
+	flvMuxer,_ := NewMuxer(&video, &audio, writer, xlog.L())
 
 	rtpDemuxer,_ := rtp.NewDemuxer(&video,&audio,flvMuxer, xlog.L())
 	channels := []int{int(rtp.ChannelVideo), int(rtp.ChannelVideoControl), int(rtp.ChannelAudio), int(rtp.ChannelAudioControl)}
diff --git a/av/format/flv/h264_packetizer.go b/av/format/flv/h264_packetizer.go
new file mode 100644
index 0000000..0ca65fe
--- /dev/null
+++ b/av/format/flv/h264_packetizer.go
@@ -0,0 +1,111 @@
+// Copyright (c) 2019,CAOHONGJU All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package flv
+
+import (
+	"github.com/cnotch/ipchub/av/codec"
+	"github.com/cnotch/ipchub/av/codec/h264"
+)
+
+type h264Packetizer struct {
+	meta      *codec.VideoMeta
+	tagWriter TagWriter
+	spsMuxed  bool
+	nextDts   float64
+	dtsStep   float64
+}
+
+func NewH264Packetizer(meta *codec.VideoMeta, tagWriter TagWriter) Packetizer {
+	h264p := &h264Packetizer{
+		meta:      meta,
+		tagWriter: tagWriter,
+	}
+
+	if meta.FrameRate > 0 {
+		h264p.dtsStep = 1000.0 / meta.FrameRate
+	}
+	return h264p
+}
+
+func (h264p *h264Packetizer) PacketizeSequenceHeader() error {
+	if h264p.spsMuxed {
+		return nil
+	}
+
+	if !h264.MetadataIsReady(h264p.meta) {
+		// not enough
+		return nil
+	}
+
+	h264p.spsMuxed = true
+
+	if h264p.meta.FixedFrameRate {
+		h264p.dtsStep = 1000.0 / h264p.meta.FrameRate
+	} else { // TODO:
+		h264p.dtsStep = 1000.0 / 30
+	}
+
+	record := NewAVCDecoderConfigurationRecord(h264p.meta.Sps, h264p.meta.Pps)
+	body, _ := record.Marshal()
+
+	videoData := &VideoData{
+		FrameType:       FrameTypeKeyFrame,
+		CodecID:         CodecIDAVC,
+		AVCPacketType:   AVCPacketTypeSequenceHeader,
+		CompositionTime: 0,
+		Body:            body,
+	}
+	data, _ := videoData.Marshal()
+
+	tag := &Tag{
+		TagType:   TagTypeVideo,
+		DataSize:  uint32(len(data)),
+		Timestamp: 0,
+		StreamID:  0,
+		Data:      data,
+	}
+
+	return h264p.tagWriter.WriteFlvTag(tag)
+}
+
+func (h264p *h264Packetizer) Packetize(basePts int64, frame *codec.Frame) error {
+	if frame.Payload[0]&0x1F == h264.NalSps {
+		return h264p.PacketizeSequenceHeader()
+	}
+
+	if frame.Payload[0]&0x1F == h264.NalPps {
+		return h264p.PacketizeSequenceHeader()
+	}
+
+	dts := int64(h264p.nextDts)
+	h264p.nextDts += h264p.dtsStep
+	pts := frame.AbsTimestamp - basePts + ptsDelay
+	if dts > pts {
+		pts = dts
+	}
+
+	videoData := &VideoData{
+		FrameType:       FrameTypeInterFrame,
+		CodecID:         CodecIDAVC,
+		AVCPacketType:   AVCPacketTypeNALU,
+		CompositionTime: uint32(pts - dts),
+		Body:            frame.Payload,
+	}
+
+	if frame.Payload[0]&0x1F == h264.NalIdrSlice {
+		videoData.FrameType = FrameTypeKeyFrame
+	}
+	data, _ := videoData.Marshal()
+
+	tag := &Tag{
+		TagType:   TagTypeVideo,
+		DataSize:  uint32(len(data)),
+		Timestamp: uint32(dts),
+		StreamID:  0,
+		Data:      data,
+	}
+
+	return h264p.tagWriter.WriteFlvTag(tag)
+}
diff --git a/av/format/flv/muxer.go b/av/format/flv/muxer.go
new file mode 100644
index 0000000..69bf7fb
--- /dev/null
+++ b/av/format/flv/muxer.go
@@ -0,0 +1,222 @@
+// Copyright (c) 2019,CAOHONGJU All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package flv
+
+import (
+	"fmt"
+	"runtime/debug"
+	"time"
+
+	"github.com/cnotch/ipchub/av/codec"
+	"github.com/cnotch/ipchub/av/format/amf"
+	"github.com/cnotch/queue"
+	"github.com/cnotch/xlog"
+)
+
+// Packetizer 封包器
+type Packetizer interface {
+	PacketizeSequenceHeader() error
+	Packetize(basePts int64, frame *codec.Frame) error
+}
+
+type emptyPacketizer struct{}
+
+func (emptyPacketizer) PacketizeSequenceHeader() error                    { return nil }
+func (emptyPacketizer) Packetize(basePts int64, frame *codec.Frame) error { return nil }
+
+// 网络播放时 PTS（Presentation Time Stamp）的延时
+// 影响视频 Tag 的 CTS 和音频的 DTS（Decoding Time Stamp）
+const (
+	ptsDelay = 1000
+)
+
+// Muxer flv muxer from av.Frame(H264[+AAC])
+type Muxer struct {
+	videoMeta *codec.VideoMeta
+	audioMeta *codec.AudioMeta
+	vp        Packetizer
+	ap        Packetizer
+	typeFlags byte
+	recvQueue *queue.SyncQueue
+	tagWriter TagWriter
+	closed    bool
+
+	logger *xlog.Logger // 日志对象
+}
+
+// NewMuxer .
+func NewMuxer(videoMeta *codec.VideoMeta, audioMeta *codec.AudioMeta, tagWriter TagWriter, logger *xlog.Logger) (*Muxer, error) {
+	muxer := &Muxer{
+		recvQueue: queue.NewSyncQueue(),
+		videoMeta: videoMeta,
+		audioMeta: audioMeta,
+		vp:        emptyPacketizer{},
+		ap:        emptyPacketizer{},
+		typeFlags: byte(TypeFlagsVideo),
+		tagWriter: tagWriter,
+		closed:    false,
+		logger:    logger,
+	}
+	switch videoMeta.Codec {
+	case "H264":
+		muxer.vp = NewH264Packetizer(videoMeta, tagWriter)
+	default:
+		return nil, fmt.Errorf("flv muxer unsupport video codec type:%s", videoMeta.Codec)
+	}
+
+	if audioMeta.Codec == "AAC" {
+		muxer.typeFlags |= TypeFlagsAudio
+		muxer.ap = NewAacPacketizer(audioMeta, tagWriter)
+	}
+
+	go muxer.process()
+	return muxer, nil
+}
+
+// WriteFrame .
+func (muxer *Muxer) WriteFrame(frame *codec.Frame) error {
+	muxer.recvQueue.Push(frame)
+	return nil
+}
+
+// Close .
+func (muxer *Muxer) Close() error {
+	if muxer.closed {
+		return nil
+	}
+
+	muxer.closed = true
+	muxer.recvQueue.Signal()
+	return nil
+}
+
+// TypeFlags 返回 flv header 中的 TypeFlags
+func (muxer *Muxer) TypeFlags() byte {
+	return muxer.typeFlags
+}
+
+func (muxer *Muxer) process() {
+	defer func() {
+		defer func() { // 避免 handler 再 panic
+			recover()
+		}()
+
+		if r := recover(); r != nil {
+			muxer.logger.Errorf("flvmuxer routine panic；r = %v \n %s", r, debug.Stack())
+		}
+
+		// 尽早通知GC，回收内存
+		muxer.recvQueue.Reset()
+	}()
+
+	var basePts int64
+	for !muxer.closed {
+		f := muxer.recvQueue.Pop()
+		if f == nil {
+			if !muxer.closed {
+				muxer.logger.Warn("flvmuxer:receive nil frame")
+			}
+			continue
+		}
+
+		frame := f.(*codec.Frame)
+		if basePts == 0 {
+			basePts = frame.AbsTimestamp
+			muxer.muxMetadataTag()
+			muxer.vp.PacketizeSequenceHeader()
+			muxer.ap.PacketizeSequenceHeader()
+		}
+
+		switch frame.MediaType {
+		case codec.MediaTypeVideo:
+			if err := muxer.vp.Packetize(basePts, frame); err != nil {
+				muxer.logger.Errorf("flvmuxer: muxVideoTag error - %s", err.Error())
+			}
+		case codec.MediaTypeAudio:
+			if err := muxer.ap.Packetize(basePts, frame); err != nil {
+				muxer.logger.Errorf("flvmuxer: muxAudioTag error - %s", err.Error())
+			}
+		default:
+		}
+	}
+}
+
+func (muxer *Muxer) muxMetadataTag() error {
+	properties := make(amf.EcmaArray, 0, 12)
+
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  "creator",
+			Value: "ipchub stream media server"})
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataCreationDate,
+			Value: time.Now().Format(time.RFC3339)})
+
+	if muxer.typeFlags&TypeFlagsAudio > 0 {
+		properties = append(properties,
+			amf.ObjectProperty{
+				Name:  MetaDataAudioCodecID,
+				Value: SoundFormatAAC})
+		properties = append(properties,
+			amf.ObjectProperty{
+				Name:  MetaDataAudioDateRate,
+				Value: muxer.audioMeta.DataRate})
+		properties = append(properties,
+			amf.ObjectProperty{
+				Name:  MetaDataAudioSampleRate,
+				Value: muxer.audioMeta.SampleRate})
+		properties = append(properties,
+			amf.ObjectProperty{
+				Name:  MetaDataAudioSampleSize,
+				Value: muxer.audioMeta.SampleSize})
+		properties = append(properties,
+			amf.ObjectProperty{
+				Name:  MetaDataStereo,
+				Value: muxer.audioMeta.Channels > 1})
+	}
+
+	vcodecID := CodecIDAVC
+	if muxer.videoMeta.Codec == "H265" {
+		vcodecID = CodecIDHEVC
+	}
+
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataVideoCodecID,
+			Value: vcodecID})
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataVideoDataRate,
+			Value: muxer.videoMeta.DataRate})
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataFrameRate,
+			Value: muxer.videoMeta.FrameRate})
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataWidth,
+			Value: muxer.videoMeta.Width})
+	properties = append(properties,
+		amf.ObjectProperty{
+			Name:  MetaDataHeight,
+			Value: muxer.videoMeta.Height})
+
+	scriptData := ScriptData{
+		Name:  ScriptOnMetaData,
+		Value: properties,
+	}
+	data, _ := scriptData.Marshal()
+
+	tag := &Tag{
+		TagType:   TagTypeAmf0Data,
+		DataSize:  uint32(len(data)),
+		Timestamp: 0,
+		StreamID:  0,
+		Data:      data,
+	}
+
+	return muxer.tagWriter.WriteFlvTag(tag)
+}
diff --git a/av/format/flv/muxeravcaac.go b/av/format/flv/muxeravcaac.go
deleted file mode 100644
index 3d55377..0000000
--- a/av/format/flv/muxeravcaac.go
+++ /dev/null
@@ -1,362 +0,0 @@
-// Copyright (c) 2019,CAOHONGJU All rights reserved.
-// Use of this source code is governed by a MIT-style
-// license that can be found in the LICENSE file.
-
-package flv
-
-import (
-	"runtime/debug"
-	"time"
-
-	"github.com/cnotch/ipchub/av/codec"
-	"github.com/cnotch/ipchub/av/codec/h264"
-	"github.com/cnotch/ipchub/av/format/amf"
-	"github.com/cnotch/queue"
-	"github.com/cnotch/xlog"
-)
-
-// 网络播放时 PTS（Presentation Time Stamp）的延时
-// 影响视频 Tag 的 CTS 和音频的 DTS（Decoding Time Stamp）
-const (
-	dtsDelay = 0
-	ptsDelay = 1000
-)
-
-// MuxerAvcAac flv muxer from av.Frame(H264[+AAC])
-type MuxerAvcAac struct {
-	videoMeta         codec.VideoMeta
-	audioMeta         codec.AudioMeta
-	typeFlags         byte
-	audioDataTemplate *AudioData
-	recvQueue         *queue.SyncQueue
-	tagWriter         TagWriter
-	closed            bool
-	spsMuxed          bool
-	basePts           int64
-	nextDts           float64
-	dtsStep           float64
-	logger            *xlog.Logger // 日志对象
-}
-
-// NewMuxerAvcAac .
-func NewMuxerAvcAac(videoMeta codec.VideoMeta, audioMeta codec.AudioMeta, tagWriter TagWriter, logger *xlog.Logger) *MuxerAvcAac {
-	muxer := &MuxerAvcAac{
-		recvQueue: queue.NewSyncQueue(),
-		videoMeta: videoMeta,
-		audioMeta: audioMeta,
-		typeFlags: byte(TypeFlagsVideo),
-		tagWriter: tagWriter,
-		closed:    false,
-		nextDts:   dtsDelay,
-		logger:    logger,
-	}
-
-	if videoMeta.FrameRate > 0 {
-		muxer.dtsStep = 1000.0 / videoMeta.FrameRate
-	}
-	if audioMeta.Codec == "AAC" {
-		muxer.typeFlags |= TypeFlagsAudio
-		muxer.prepareTemplate()
-	}
-
-	go muxer.process()
-	return muxer
-}
-
-// WriteFrame .
-func (muxer *MuxerAvcAac) WriteFrame(frame *codec.Frame) error {
-	muxer.recvQueue.Push(frame)
-	return nil
-}
-
-// Close .
-func (muxer *MuxerAvcAac) Close() error {
-	if muxer.closed {
-		return nil
-	}
-
-	muxer.closed = true
-	muxer.recvQueue.Signal()
-	return nil
-}
-
-// TypeFlags 返回 flv header 中的 TypeFlags
-func (muxer *MuxerAvcAac) TypeFlags() byte {
-	return muxer.typeFlags
-}
-
-func (muxer *MuxerAvcAac) process() {
-	defer func() {
-		defer func() { // 避免 handler 再 panic
-			recover()
-		}()
-
-		if r := recover(); r != nil {
-			muxer.logger.Errorf("flvmuxer routine panic；r = %v \n %s", r, debug.Stack())
-		}
-
-		// 尽早通知GC，回收内存
-		muxer.recvQueue.Reset()
-	}()
-
-	muxer.muxMetadataTag()
-	muxer.muxSequenceHeaderTag()
-
-	for !muxer.closed {
-		f := muxer.recvQueue.Pop()
-		if f == nil {
-			if !muxer.closed {
-				muxer.logger.Warn("flvmuxer:receive nil frame")
-			}
-			continue
-		}
-
-		frame := f.(*codec.Frame)
-		if muxer.basePts == 0 {
-			muxer.basePts = frame.AbsTimestamp
-		}
-
-		if frame.MediaType == codec.MediaTypeVideo {
-			if err := muxer.muxVideoTag(frame); err != nil {
-				muxer.logger.Errorf("flvmuxer: muxVideoTag error - %s", err.Error())
-			}
-		} else {
-			if err := muxer.muxAudioTag(frame); err != nil {
-				muxer.logger.Errorf("flvmuxer: muxAudioTag error - %s", err.Error())
-			}
-		}
-	}
-}
-
-func (muxer *MuxerAvcAac) muxVideoTag(frame *codec.Frame) error {
-	if frame.Payload[0]&0x1F == h264.NalSps {
-		if len(muxer.videoMeta.Sps) == 0 {
-			muxer.videoMeta.Sps = frame.Payload
-		}
-		return muxer.muxSequenceHeaderTag()
-	}
-
-	if frame.Payload[0]&0x1F == h264.NalPps {
-		if len(muxer.videoMeta.Pps) == 0 {
-			muxer.videoMeta.Pps = frame.Payload
-		}
-		return muxer.muxSequenceHeaderTag()
-	}
-
-	dts := int64(muxer.nextDts)
-	muxer.nextDts += muxer.dtsStep
-	pts := frame.AbsTimestamp - muxer.basePts + ptsDelay
-	if dts > pts {
-		pts = dts
-	}
-
-	videoData := &VideoData{
-		FrameType:       FrameTypeInterFrame,
-		CodecID:         CodecIDAVC,
-		AVCPacketType:   AVCPacketTypeNALU,
-		CompositionTime: uint32(pts - dts),
-		Body:            frame.Payload,
-	}
-
-	if frame.Payload[0]&0x1F == h264.NalIdrSlice {
-		videoData.FrameType = FrameTypeKeyFrame
-	}
-	data, _ := videoData.Marshal()
-
-	tag := &Tag{
-		TagType:   TagTypeVideo,
-		DataSize:  uint32(len(data)),
-		Timestamp: uint32(dts),
-		StreamID:  0,
-		Data:      data,
-	}
-
-	return muxer.tagWriter.WriteFlvTag(tag)
-}
-
-func (muxer *MuxerAvcAac) muxAudioTag(frame *codec.Frame) error {
-	audioData := *muxer.audioDataTemplate
-	audioData.Body = frame.Payload
-	data, _ := audioData.Marshal()
-
-	tag := &Tag{
-		TagType:   TagTypeAudio,
-		DataSize:  uint32(len(data)),
-		Timestamp: uint32(frame.AbsTimestamp-muxer.basePts) + ptsDelay,
-		StreamID:  0,
-		Data:      data,
-	}
-	return muxer.tagWriter.WriteFlvTag(tag)
-}
-
-func (muxer *MuxerAvcAac) muxMetadataTag() error {
-	properties := make(amf.EcmaArray, 0, 12)
-
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  "creator",
-			Value: "ipchub stream media server"})
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataCreationDate,
-			Value: time.Now().Format(time.RFC3339)})
-
-	if muxer.typeFlags&TypeFlagsAudio > 0 {
-		properties = append(properties,
-			amf.ObjectProperty{
-				Name:  MetaDataAudioCodecID,
-				Value: SoundFormatAAC})
-		properties = append(properties,
-			amf.ObjectProperty{
-				Name:  MetaDataAudioDateRate,
-				Value: muxer.audioMeta.DataRate})
-		properties = append(properties,
-			amf.ObjectProperty{
-				Name:  MetaDataAudioSampleRate,
-				Value: muxer.audioMeta.SampleRate})
-		properties = append(properties,
-			amf.ObjectProperty{
-				Name:  MetaDataAudioSampleSize,
-				Value: muxer.audioMeta.SampleSize})
-		properties = append(properties,
-			amf.ObjectProperty{
-				Name:  MetaDataStereo,
-				Value: muxer.audioMeta.Channels > 1})
-	}
-
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataVideoCodecID,
-			Value: CodecIDAVC})
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataVideoDataRate,
-			Value: muxer.videoMeta.DataRate})
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataFrameRate,
-			Value: muxer.videoMeta.FrameRate})
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataWidth,
-			Value: muxer.videoMeta.Width})
-	properties = append(properties,
-		amf.ObjectProperty{
-			Name:  MetaDataHeight,
-			Value: muxer.videoMeta.Height})
-
-	scriptData := ScriptData{
-		Name:  ScriptOnMetaData,
-		Value: properties,
-	}
-	data, _ := scriptData.Marshal()
-
-	tag := &Tag{
-		TagType:   TagTypeAmf0Data,
-		DataSize:  uint32(len(data)),
-		Timestamp: 0,
-		StreamID:  0,
-		Data:      data,
-	}
-
-	return muxer.tagWriter.WriteFlvTag(tag)
-}
-
-func (muxer *MuxerAvcAac) muxSequenceHeaderTag() error {
-	if muxer.spsMuxed {
-		return nil
-	}
-
-	if !h264.MetadataIsReady(&muxer.videoMeta) {
-		// not enough
-		return nil
-	}
-
-	if muxer.videoMeta.FixedFrameRate {
-		muxer.dtsStep = 1000.0 / muxer.videoMeta.FrameRate
-	} else { // TODO:
-		muxer.dtsStep = 1000.0 / 30
-	}
-	muxer.spsMuxed = true
-
-	record := NewAVCDecoderConfigurationRecord(muxer.videoMeta.Sps, muxer.videoMeta.Pps)
-	body, _ := record.Marshal()
-
-	videoData := &VideoData{
-		FrameType:       FrameTypeKeyFrame,
-		CodecID:         CodecIDAVC,
-		AVCPacketType:   AVCPacketTypeSequenceHeader,
-		CompositionTime: 0,
-		Body:            body,
-	}
-	data, _ := videoData.Marshal()
-
-	tag := &Tag{
-		TagType:   TagTypeVideo,
-		DataSize:  uint32(len(data)),
-		Timestamp: 0,
-		StreamID:  0,
-		Data:      data,
-	}
-
-	if err := muxer.tagWriter.WriteFlvTag(tag); err != nil {
-		return err
-	}
-
-	return muxer.muxAudioSequenceHeaderTag()
-}
-
-func (muxer *MuxerAvcAac) muxAudioSequenceHeaderTag() error {
-	if muxer.typeFlags&TypeFlagsAudio == 0 {
-		return nil
-	}
-
-	audioData := *muxer.audioDataTemplate
-	audioData.AACPacketType = AACPacketTypeSequenceHeader
-	audioData.Body = muxer.audioMeta.Sps
-	data, _ := audioData.Marshal()
-
-	tag := &Tag{
-		TagType:   TagTypeAudio,
-		DataSize:  uint32(len(data)),
-		Timestamp: 0,
-		StreamID:  0,
-		Data:      data,
-	}
-	return muxer.tagWriter.WriteFlvTag(tag)
-}
-
-func (muxer *MuxerAvcAac) prepareTemplate() {
-	audioData := &AudioData{
-		SoundFormat:   SoundFormatAAC,
-		AACPacketType: AACPacketTypeRawData,
-		Body:          nil,
-	}
-
-	switch muxer.audioMeta.SampleRate {
-	case 5512:
-		audioData.SoundRate = SoundRate5512
-	case 11025:
-		audioData.SoundRate = SoundRate11025
-	case 22050:
-		audioData.SoundRate = SoundRate22050
-	case 44100:
-		audioData.SoundRate = SoundRate44100
-	default:
-		audioData.SoundRate = SoundRate44100
-	}
-
-	if muxer.audioMeta.SampleSize == 8 {
-		audioData.SoundSize = SoundeSize8bit
-	} else {
-		audioData.SoundSize = SoundeSize16bit
-	}
-
-	if muxer.audioMeta.Channels > 1 {
-		audioData.SoundType = SoundTypeStereo
-	} else {
-		audioData.SoundType = SoundTypeMono
-	}
-
-	muxer.audioDataTemplate = audioData
-}
diff --git a/av/format/rtp/aac_depacketizer.go b/av/format/rtp/aac_depacketizer.go
index 4f29922..069ef33 100644
--- a/av/format/rtp/aac_depacketizer.go
+++ b/av/format/rtp/aac_depacketizer.go
@@ -10,7 +10,7 @@ import (
 )
 
 type aacDepacketizer struct {
-	audio       *codec.AudioMeta
+	meta       *codec.AudioMeta
 	w           codec.FrameWriter
 	sizeLength  int
 	indexLength int
@@ -19,14 +19,14 @@ type aacDepacketizer struct {
 }
 
 // NewAacDepacketizer 实例化 AAC 解包器
-func NewAacDepacketizer(audio *codec.AudioMeta, w codec.FrameWriter) depacketizer {
+func NewAacDepacketizer(meta *codec.AudioMeta, w codec.FrameWriter) Depacketizer {
 	fe := &aacDepacketizer{
-		audio:       audio,
+		meta:       meta,
 		w:           w,
 		sizeLength:  13,
 		indexLength: 3,
 	}
-	fe.syncClock.RTPTimeUnit = 1000.0 / float64(audio.SampleRate)
+	fe.syncClock.RTPTimeUnit = 1000.0 / float64(meta.SampleRate)
 	return fe
 }
 
diff --git a/av/format/rtp/demuxer.go b/av/format/rtp/demuxer.go
index 83680d4..a1b1714 100644
--- a/av/format/rtp/demuxer.go
+++ b/av/format/rtp/demuxer.go
@@ -13,8 +13,8 @@ import (
 	"github.com/cnotch/xlog"
 )
 
-// depacketizer 解包器
-type depacketizer interface {
+// Depacketizer 解包器
+type Depacketizer interface {
 	Control(p *Packet) error
 	Depacketize(p *Packet) error
 }
@@ -37,15 +37,14 @@ func NewDemuxer(video *codec.VideoMeta, audio *codec.AudioMeta, fw codec.FrameWr
 		logger:    logger,
 	}
 
-	var videoDepacketizer, audioDepacketizer depacketizer
+	var videoDepacketizer, audioDepacketizer Depacketizer
 	switch video.Codec {
 	case "H264":
 		videoDepacketizer = NewH264Depacketizer(video, fw)
 	case "H265":
 		videoDepacketizer = NewH265Depacketizer(video, fw)
-	}
-	if videoDepacketizer == nil {
-		return nil, fmt.Errorf("Unsupport video codec type:%s", video.Codec)
+	default:
+		return nil, fmt.Errorf("rtp demuxer unsupport video codec type:%s", video.Codec)
 	}
 
 	fc.depacketizeFuncs[ChannelVideo] = videoDepacketizer.Depacketize
diff --git a/av/format/rtp/h264_depacketizer.go b/av/format/rtp/h264_depacketizer.go
index 1b1d4a4..021fee8 100644
--- a/av/format/rtp/h264_depacketizer.go
+++ b/av/format/rtp/h264_depacketizer.go
@@ -13,19 +13,19 @@ import (
 
 type h264Depacketizer struct {
 	fragments []*Packet // 分片包
-	video     *codec.VideoMeta
+	meta     *codec.VideoMeta
 	w         codec.FrameWriter
 	syncClock SyncClock
 }
 
 // NewH264Depacketizer 实例化 H264 帧提取器
-func NewH264Depacketizer(video *codec.VideoMeta, w codec.FrameWriter) depacketizer {
+func NewH264Depacketizer(meta *codec.VideoMeta, w codec.FrameWriter) Depacketizer {
 	fe := &h264Depacketizer{
-		video:     video,
+		meta:     meta,
 		fragments: make([]*Packet, 0, 16),
 		w:         w,
 	}
-	fe.syncClock.RTPTimeUnit = 1000.0 / float64(video.ClockRate)
+	fe.syncClock.RTPTimeUnit = 1000.0 / float64(meta.ClockRate)
 	return fe
 }
 
@@ -199,12 +199,12 @@ func (h264dp *h264Depacketizer) writeFrame(frame *codec.Frame) error {
 	nalType := frame.Payload[0] & 0x1f
 	switch nalType {
 	case h264.NalSps:
-		if len(h264dp.video.Sps) == 0 {
-			h264dp.video.Sps = frame.Payload
+		if len(h264dp.meta.Sps) == 0 {
+			h264dp.meta.Sps = frame.Payload
 		}
 	case h264.NalPps:
-		if len(h264dp.video.Pps) == 0 {
-			h264dp.video.Pps = frame.Payload
+		if len(h264dp.meta.Pps) == 0 {
+			h264dp.meta.Pps = frame.Payload
 		}
 	case h264.NalFillerData: // ?ignore...
 		return nil
diff --git a/av/format/rtp/h265_depacketizer.go b/av/format/rtp/h265_depacketizer.go
index 805fae2..08bee2e 100644
--- a/av/format/rtp/h265_depacketizer.go
+++ b/av/format/rtp/h265_depacketizer.go
@@ -11,19 +11,19 @@ import (
 
 type h265Depacketizer struct {
 	fragments []*Packet // 分片包
-	video     *codec.VideoMeta
+	meta     *codec.VideoMeta
 	w         codec.FrameWriter
 	syncClock SyncClock
 }
 
 // NewH265Depacketizer 实例化 H265 帧提取器
-func NewH265Depacketizer(video *codec.VideoMeta, w codec.FrameWriter) depacketizer {
+func NewH265Depacketizer(meta *codec.VideoMeta, w codec.FrameWriter) Depacketizer {
 	fe := &h265Depacketizer{
-		video:     video,
+		meta:     meta,
 		fragments: make([]*Packet, 0, 16),
 		w:         w,
 	}
-	fe.syncClock.RTPTimeUnit = 1000.0 / float64(video.ClockRate)
+	fe.syncClock.RTPTimeUnit = 1000.0 / float64(meta.ClockRate)
 	return fe
 }
 
@@ -178,16 +178,16 @@ func (h265dp *h265Depacketizer) writeFrame(frame *codec.Frame) error {
 	nalType := (frame.Payload[0] >> 1) & 0x3f
 	switch nalType {
 	case hevc.NalVps:
-		if len(h265dp.video.Vps) == 0 {
-			h265dp.video.Vps = frame.Payload
+		if len(h265dp.meta.Vps) == 0 {
+			h265dp.meta.Vps = frame.Payload
 		}
 	case hevc.NalSps:
-		if len(h265dp.video.Sps) == 0 {
-			h265dp.video.Sps = frame.Payload
+		if len(h265dp.meta.Sps) == 0 {
+			h265dp.meta.Sps = frame.Payload
 		}
 	case hevc.NalPps:
-		if len(h265dp.video.Pps) == 0 {
-			h265dp.video.Pps = frame.Payload
+		if len(h265dp.meta.Pps) == 0 {
+			h265dp.meta.Pps = frame.Payload
 		}
 	}
 	return h265dp.w.WriteFrame(frame)
diff --git a/media/stream.go b/media/stream.go
index 2758ff7..758252d 100755
--- a/media/stream.go
+++ b/media/stream.go
@@ -105,7 +105,7 @@ func (s *Stream) prepareOtherStream() {
 	s.flvCache = emptyCache{}
 	s.flvMuxer = emptyFlvMuxer{}
 
-	// prepare rtp.Packet -> av.Frame
+	// prepare rtp.Packet -> codec.Frame
 	var err error
 	if s.rtpDemuxer, err = rtp.NewDemuxer(&s.Video, &s.Audio,
 		s, s.logger.With(xlog.Fields(xlog.F("extra", "rtp2frame")))); err != nil {
@@ -113,14 +113,15 @@ func (s *Stream) prepareOtherStream() {
 		return
 	}
 
-	// prepare av.Frame -> flv.Tag
-	if s.Video.Codec == "H264" {
+	// prepare codec.Frame -> flv.Tag
+	var flvMuxer *flv.Muxer
+	if flvMuxer, err = flv.NewMuxer(&s.Video, &s.Audio,
+		s, s.logger.With(xlog.Fields(xlog.F("extra", "frame2flv")))); err == nil {
 		s.flvCache = cache.NewFlvCache(config.CacheGop())
-		s.flvMuxer = flv.NewMuxerAvcAac(s.Video, s.Audio,
-			s, s.logger.With(xlog.Fields(xlog.F("extra", "frame2flv"))))
+		s.flvMuxer = flvMuxer
 	}
 
-	// prepare av.Frame -> mpegts.Frame
+	// prepare codec.Frame -> mpegts.Frame
 	if s.Video.Codec == "H264" {
 		hlsPlaylist := hls.NewPlaylist()
 		sg, err := hls.NewSegmentGenerator(hlsPlaylist, s.path,