diff --git a/flv.go b/flv.go
index a0df656..00eca33 100644
--- a/flv.go
+++ b/flv.go
@@ -14,6 +14,7 @@ import (
 
 type Muxer struct {
 	pw *pio.Writer
+	streams []av.CodecData
 }
 
 func NewMuxer(w io.Writer) *Muxer {
@@ -22,6 +23,14 @@ func NewMuxer(w io.Writer) *Muxer {
 	return self
 }
 
+func Create(w io.Writer, streams []av.CodecData) (muxer *Muxer, err error) {
+	muxer = NewMuxer(w)
+	if err = muxer.WriteHeader(streams); err != nil {
+		return
+	}
+	return
+}
+
 func (self *Muxer) WriteHeader(streams []av.CodecData) (err error) {
 	var flags uint8
 	for _, stream := range streams {
@@ -36,6 +45,67 @@ func (self *Muxer) WriteHeader(streams []av.CodecData) (err error) {
 		return
 	}
 
+	for _, stream := range streams {
+		var _tag flvio.Tag
+
+		switch stream.Type() {
+		case av.H264:
+			h264 := stream.(h264parser.CodecData)
+			tag := &flvio.Videodata{
+				AVCPacketType: flvio.AVC_SEQHDR,
+				CodecID: flvio.VIDEO_H264,
+				Data: h264.AVCDecoderConfRecordBytes(),
+			}
+			_tag = tag
+
+		case av.AAC:
+			aac := stream.(aacparser.CodecData)
+			tag := flvio.MakeAACAudiodata(aac, aac.MPEG4AudioConfigBytes())
+			tag.AACPacketType = flvio.AAC_SEQHDR
+			_tag = &tag
+
+		default:
+			err = fmt.Errorf("flv: unspported codecType=%v", stream.Type())
+			return
+		}
+
+		if err = flvio.WriteTag(self.pw, _tag, 0); err != nil {
+			return
+		}
+	}
+
+	self.streams = streams
+	return
+}
+
+func (self *Muxer) WritePacket(pkt av.Packet) (err error) {
+	stream := self.streams[pkt.Idx]
+	var _tag flvio.Tag
+
+	switch stream.Type() {
+	case av.H264:
+		tag := &flvio.Videodata{
+			AVCPacketType: flvio.AVC_NALU,
+			CodecID: flvio.VIDEO_H264,
+			Data: pkt.Data,
+			CompositionTime: timeToTs(pkt.CompositionTime),
+		}
+		if pkt.IsKeyFrame {
+			tag.FrameType = flvio.FRAME_KEY
+		} else {
+			tag.FrameType = flvio.FRAME_INTER
+		}
+		_tag = tag
+
+	case av.AAC:
+		tag := flvio.MakeAACAudiodata(stream.(av.AudioCodecData), pkt.Data)
+		_tag = &tag
+	}
+
+	if err = flvio.WriteTag(self.pw, _tag, timeToTs(pkt.Time)); err != nil {
+		return
+	}
+
 	return
 }
 
@@ -138,6 +208,10 @@ func tsToTime(ts int32) time.Duration {
 	return time.Millisecond*time.Duration(ts)
 }
 
+func timeToTs(tm time.Duration) int32 {
+	return int32(tm / time.Millisecond)
+}
+
 func (self *Demuxer) ReadPacket() (pkt av.Packet, err error) {
 	var timestamp int32
 	var stream *flvStream
diff --git a/flvio/flvio.go b/flvio/flvio.go
index de5f462..19f6f7a 100644
--- a/flvio/flvio.go
+++ b/flvio/flvio.go
@@ -3,6 +3,7 @@ package flvio
 import (
 	"fmt"
 	"github.com/nareix/pio"
+	"github.com/nareix/av"
 	"io"
 )
 
@@ -64,6 +65,28 @@ const (
 	AAC_RAW    = 1
 )
 
+func MakeAACAudiodata(codec av.AudioCodecData, data []byte) Audiodata {
+	tag := Audiodata{
+		SoundFormat: SOUND_AAC,
+		SoundRate: SOUND_44Khz,
+		AACPacketType: AAC_RAW,
+		Data: data,
+	}
+	switch codec.SampleFormat().BytesPerSample() {
+	case 1:
+		tag.SoundSize = SOUND_8BIT
+	default:
+		tag.SoundSize = SOUND_16BIT
+	}
+	switch codec.ChannelLayout().Count() {
+	case 1:
+		tag.SoundType = SOUND_MONO
+	case 2:
+		tag.SoundType = SOUND_STEREO
+	}
+	return tag
+}
+
 type Audiodata struct {
 	/*
 		SoundFormat: UB[4]