diff --git a/README.md b/README.md
index 56dc33c..f5f9a17 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,97 @@
-go-av
+
+joy4: A modern multimedia library for Golang
 ==
 
-Golang audio and video manipulation library
+* Well-designed API, easy to use, write a media server in 1 minute:
 
- * h264/aac encoder and decoder (using libav) ([HERE](http://github.com/go-av/codec))
- * mp4 reader and writer ([HERE](http://github.com/go-av/mp4))
- * rtmp server ([HERE](http://github.com/go-av/rtmp))
+  ```go
+  import (
+    "github.com/nareix/av"
+  )
+
+  func main() {
+    demuxer, _ := rtsp.Open("rtsp://xxooxo")
+    outfile, _ := os.Create("out.mp4")
+    muxer := mp4.Create(outfile, demuxer.Streams())
+    av.CopyPackets(muxer, demuxer)
+    muxer.WriteTrailer()
+    outfile.Close()
+  }
+  ```
+
+  ​
+
+
+* Support MPEG-TS/MP4/FLV muxer/demuxer and RTSP client
+* Support H264/AAC parser/encoder/decoder and transcode (cgo ffmpeg binding)
+
+
+* high performance RTSP/RTMP/HLS/MPEG-DASH streaming server
+* AV Database: store audio/video packets 
+
+
+
+# 简单易用的 Golang 流媒体框架
+
+* 简单易用的 API，一分钟内可以实现很多东西
+
+* 支持 MPEG-TS/MP4/FLV 格式，以及 RTSP/RTMP 客户端
+
+* 支持 H264/AAC 编解码以及转码（使用 cgo 调用 ffmpeg）
+
+* 支持输入输出设备
+
+* 高性能 RTMP/FLV/HLS/MPEG-DASH 服务器，支持 OBS/ffmpeg 推流，支持 CDN 边缘节点模式
+
+* 音视频数据库：支持录播/点播。支持分布式部署
+
+* 与其他流行流媒体框架的对比以及适用场景
+  * ffmpeg 是目前支持格式最全使用最广泛的编解码库，本框架以 Golang 的方式封装了 ffmpeg 的编解码部分，开发更方便
+
+  * live555 是 C++ 开发的流媒体框架，支持 RTSP，不支持新的流媒体协议，开发难度较大
+
+  * gstreamer 是 C 开发的流媒体框架，功能齐全，包含编解码/画面声音处理/转码。但是开发难度极大，对各插件的行为很难控制，需要学习过多的概念，除了直接调用命令行的简单应用之外，很难用在实际项目中
+
+  * nginx-rtmp 是基于 nginx 开发的 RTMP/HLS/MPEG-DASH 服务器，性能很强。但是它是一个现成的服务器不是一个库，很难利用它的代码进行二次开发
+
+  * av314 采用 Golang 语言编写，与 C/C++ 开发的其他框架相比，在保持高性能的同时没有 C/C++ 的各种问题，API 非常简单易用
+
+  * av314 支持最新的流媒体格式，对于旧的格式也能使用 ffmpeg 来支持
+
+  * av314 支持 Windows/Mac/Linux/树莓派
+
+    ​
+
+示例：
+
+- 读取文件
+- 读取文件然后格式转换保存文件
+- 新建一个 RTSP Server 并在请求时候播放文件
+- 从 RTMP Client 读取流并转移保存到文件
+- RTMP 推流并建立
+
+
+
+```go
+dec := h264dec.New(CodecData)
+dec.Write(nalu)
+dec.ReadFrame()
+
+enc := h264enc.New()
+
+stream := NewStream(type, codecData)
+
+new := &av.Transcoder{
+  R: demuxer,
+}
+new.FindEncoder = func(type av.CodecType, codecData []byte) {
+  if type == av.G722 {
+  	return av.AAC, aacenc.New(codecData)
+  }
+}
+new.ReadPacket()
+```
+
+
+
+streams, _ := muxer.ReadHeader()
\ No newline at end of file
diff --git a/av.go b/av.go
new file mode 100644
index 0000000..e242c21
--- /dev/null
+++ b/av.go
@@ -0,0 +1,163 @@
+package av
+
+type SampleFormat int
+
+const (
+	U8 = SampleFormat(iota+1)
+	S16
+	S32
+	FLT
+	DBL
+	U8P
+	S16P
+	S32P
+	FLTP
+	DBLP
+	U32
+)
+
+func (self SampleFormat) BytesPerSample() int {
+	switch self {
+	case U8,U8P:
+		return 1
+	case S16,S16P:
+		return 2
+	case FLT,FLTP,S32,S32P,U32:
+		return 4
+	case DBL,DBLP:
+		return 8
+	default:
+		return 0
+	}
+}
+
+func (self SampleFormat) IsPlanar() bool {
+	switch self {
+	case S16P,S32P,FLTP,DBLP:
+		return true
+	default:
+		return false
+	}
+}
+
+const (
+	H264 = 0x264
+	AAC = 0xaac
+)
+
+type CodecData interface {
+	IsVideo() bool
+	IsAudio() bool
+	Type() int
+}
+
+type VideoCodecData interface {
+	CodecData
+	Width() int
+	Height() int
+}
+
+type AudioCodecData interface {
+	CodecData
+	SampleFormat() SampleFormat
+	SampleRate() int
+	ChannelCount() int
+}
+
+type H264CodecData interface {
+	VideoCodecData
+	AVCDecoderConfRecordBytes() []byte
+	SPS() []byte
+	PPS() []byte
+}
+
+type AACCodecData interface {
+	AudioCodecData
+	MPEG4AudioConfigBytes() []byte
+	MakeADTSHeader(samples int, payloadLength int) []byte
+}
+
+type Muxer interface {
+	WriteHeader([]CodecData) error
+	WritePacket(int, Packet) error
+	WriteTrailer() error
+}
+
+type Demuxer interface {
+	ReadPacket() (int, Packet, error)
+	Duration() float64
+	Streams() []CodecData
+}
+
+type Packet struct {
+	IsKeyFrame      bool
+	Data            []byte
+	Duration        float64
+	CompositionTime float64
+}
+
+type AudioFrame struct {
+	SampleFormat SampleFormat
+	ChannelCount int
+	Bytes []byte
+}
+
+type AudioEncoder interface {
+	CodecData() AudioCodecData
+	Encode(AudioFrame) ([]Packet, error)
+	Flush() ([]Packet, error)
+}
+
+type AudioDecoder interface {
+	Decode(Packet) (AudioFrame, error)
+	Flush() (AudioFrame, error)
+}
+
+/*
+在写入数据包的时候必须严格按照 V-A-A-A-V-A-A-A-.... 顺序，所有包的时间都必须正确
+如果有误，跳过错的那一段
+
+cli := rtsp.Open("xxoo")
+cli = &av.TranscodeDemuxer{
+	Demuxer: cli,
+	Transcoders: []Transcoder{ffmpeg.AudioTranscodeTo("aac")},
+}
+
+<script class="miniplayer" controls=true autoplay=true minidash-src="stream1" src="//site/minidash.min.js"></script>
+
+minidash.open('src', function(video) {
+})
+
+minidash.HandleConn(func(conn *minidash.Conn) {
+	conn.RequestSrc
+	muxer, err := conn.WriteHeader(cli.Streams())
+	muxer.WritePacket()
+})
+
+怎样转码
+av.Transconder{
+	TranscodeHeader(codecData) ok, codecData, error
+	TranscodePacket(Packet, flush) []Packet, error
+	FlushPacket() []Packet, error
+}
+
+decoder := ffmpeg.FindAudioDecoder(AudioCodecData)
+decoder := ffmpeg.FindAudioDecoderByName("aac", CodecData)
+
+av.DemuxTranscoder{
+	Demuxer Demuxer
+	Transconders []Transconder
+}
+Streams()
+ReadPacket()
+ClearPacketCache()
+
+怎样混合多个Demuxer
+DemuxerMixer{
+	demuxer
+}
+demuxer.FilterStreams()
+streams := demuxer.Streams()
+streams[0]
+*/
+
diff --git a/pktqueue/pktqueue.go b/pktqueue/pktqueue.go
new file mode 100644
index 0000000..372c6b6
--- /dev/null
+++ b/pktqueue/pktqueue.go
@@ -0,0 +1,84 @@
+package pktqueue
+
+import (
+	"github.com/nareix/av"
+)
+
+type timePacket struct {
+	time float64
+	av.Packet
+}
+
+type stream struct {
+	pkts []timePacket
+	lastDuration float64
+}
+
+func (self *stream) Read(flush bool) (ok bool, pkt timePacket) {
+	if len(self.pkts) > 1 {
+		ok = true
+		pkt := self.pkts[0]
+		pkt.Duration = self.pkts[1].time - self.pkts[0].time
+		self.lastDuration = pkt.Duration
+		self.pkts = self.pkts[1:]
+	} else if len(self.pkts) == 1 && flush {
+		ok = true
+		pkt := self.pkts[0]
+		pkt.Duration = self.lastDuration
+		self.pkts = self.pkts[1:]
+	}
+	return
+}
+
+type Queue struct {
+	streams []*stream
+	Poll func() error
+	err error
+	time float64
+}
+
+func (self *Queue) CurrentTime() float64 {
+	return self.time
+}
+
+func (self *Queue) Alloc(n int) {
+	self.streams = make([]*stream, n)
+}
+
+func (self *Queue) Clear() {
+	self.Alloc(len(self.streams))
+	self.time = 0.0
+}
+
+func (self *Queue) ReadPacket() (i int, pkt av.Packet, err error) {
+	for {
+		flush := self.err != nil
+		var tpkt timePacket
+		var ok bool
+		var stream *stream
+		for i, stream = range self.streams {
+			if ok, tpkt = stream.Read(flush); ok {
+				break
+			}
+		}
+		if ok {
+			pkt = tpkt.Packet
+			self.time = tpkt.time
+			return
+		} else {
+			if self.err == nil {
+				self.err = self.Poll()
+			} else {
+				err = self.err
+				return
+			}
+		}
+	}
+	return
+}
+
+func (self *Queue) WriteTimePacket(i int, time float64, pkt av.Packet) {
+	stream := self.streams[i]
+	stream.pkts = append(stream.pkts, timePacket{Packet: pkt, time: time})
+}
+
diff --git a/proxy/proxy.go b/proxy/proxy.go
new file mode 100644
index 0000000..58462d0
--- /dev/null
+++ b/proxy/proxy.go
@@ -0,0 +1,225 @@
+package proxy
+
+import (
+	"github.com/nareix/av"
+	"hash/fnv"
+	"encoding/binary"
+	"sync/atomic"
+	"sync"
+	"io"
+	"fmt"
+)
+
+func hashParams(params []interface{}) uint64 {
+	f := fnv.New64()
+	for _, p := range params {
+		if s, ok := p.(string); ok {
+			io.WriteString(f, s)
+		} else {
+			binary.Write(f, binary.LittleEndian, p)
+		}
+	}
+	return f.Sum64()
+}
+
+type Publisher struct {
+	h uint64
+	Params []interface{}
+	proxy *Proxy
+	streams []av.CodecData
+	closed bool
+	lock *sync.RWMutex
+	cond *sync.Cond
+	subscribersCount int32
+	pkt struct {
+		av.Packet
+		i int
+	}
+	ondemand bool
+}
+
+func newPublisher() *Publisher {
+	pub := &Publisher{}
+	pub.lock = &sync.RWMutex{}
+	pub.cond = sync.NewCond(pub.lock.RLocker())
+	return pub
+}
+
+func (self *Publisher) addSubscriber() (sub *Subscriber, err error) {
+	self.cond.L.Lock()
+	for len(self.streams) == 0 && !self.closed {
+		self.cond.Wait()
+	}
+	self.cond.L.Unlock()
+
+	if self.closed {
+		err = fmt.Errorf("publisher closed")
+		return
+	}
+
+	atomic.AddInt32(&self.subscribersCount, 1)
+	sub = &Subscriber{}
+	sub.pub = self
+
+	return
+}
+
+func (self *Publisher) WriteHeader(streams []av.CodecData) (err error) {
+	self.lock.Lock()
+	self.streams = streams
+	self.lock.Unlock()
+	self.cond.Broadcast()
+	return
+}
+
+func (self *Publisher) WritePacket(i int, pkt av.Packet) (err error) {
+	var closed bool
+
+	self.lock.Lock()
+	if !self.closed {
+		self.pkt.Packet = pkt
+		self.pkt.i = i
+	} else {
+		closed = true
+	}
+	self.lock.Unlock()
+
+	if closed {
+		err = io.EOF
+		return
+	}
+
+	self.cond.Broadcast()
+	return
+}
+
+func (self *Publisher) Close() (err error) {
+	self.lock.Lock()
+	self.closed = true
+	self.lock.Unlock()
+	self.cond.Broadcast()
+	return
+}
+
+func (self *Publisher) removeSubscriber() {
+	count := atomic.AddInt32(&self.subscribersCount, -1)
+	if count == 0 && self.ondemand {
+		self.Close()
+	}
+}
+
+type Subscriber struct {
+	pub *Publisher
+}
+
+func (self *Subscriber) Streams() (streams []av.CodecData) {
+	pub := self.pub
+	pub.lock.RLock()
+	streams = pub.streams
+	pub.lock.RUnlock()
+	return
+}
+
+func (self *Subscriber) ReadPacket() (i int, pkt av.Packet, err error) {
+	pub := self.pub
+	cond := pub.cond
+	cond.L.Lock()
+	ppkt := &pub.pkt
+	if pub.closed {
+		ppkt = nil
+	} else{
+		cond.Wait()
+	}
+	cond.L.Unlock()
+
+	if ppkt == nil {
+		err = io.EOF
+		return
+	}
+	i, pkt = ppkt.i, ppkt.Packet
+	return
+}
+
+func (self *Subscriber) Close() (err error) {
+	if self.pub != nil {
+		self.pub.removeSubscriber()
+		self.pub = nil
+	}
+	return
+}
+
+type Proxy struct {
+	publishers map[uint64]*Publisher
+	lock *sync.RWMutex
+	onSubscribe func(*Publisher)
+}
+
+func New() *Proxy {
+	proxy := &Proxy{}
+	proxy.lock = &sync.RWMutex{}
+	proxy.publishers = make(map[uint64]*Publisher)
+	return proxy
+}
+
+func (self *Proxy) HandleSubscribe(fn func(*Publisher)) {
+	self.onSubscribe = fn
+}
+
+func (self *Proxy) Publish(params ...interface{}) (pub *Publisher, err error) {
+	h := hashParams(params)
+
+	self.lock.Lock()
+	pub, exists := self.publishers[h]
+	if !exists {
+		pub = newPublisher()
+		pub.Params = params
+		pub.h = h
+		pub.proxy = self
+		self.publishers[h] = pub
+	}
+	self.lock.Unlock()
+
+	if exists {
+		err = fmt.Errorf("publisher already exist")
+		return
+	}
+
+	return
+}
+
+func (self *Proxy) Subscribe(params ...interface{}) (sub *Subscriber, err error) {
+	h := hashParams(params)
+	needcb := false
+
+	self.lock.RLock()
+	pub := self.publishers[h]
+	if pub == nil && self.onSubscribe != nil {
+		pub = newPublisher()
+		pub.Params = params
+		pub.h = h
+		pub.proxy = self
+		self.publishers[h] = pub
+		pub.ondemand = true
+		needcb = true
+	}
+	self.lock.RUnlock()
+
+	if pub == nil {
+		err = fmt.Errorf("publisher not found")
+		return
+	}
+
+	if needcb {
+		go func() {
+			self.onSubscribe(pub)
+			pub.Close()
+		}()
+	}
+
+	if sub, err = pub.addSubscriber(); err != nil {
+		return
+	}
+
+	return
+}
+
diff --git a/proxy/proxy_test.go b/proxy/proxy_test.go
new file mode 100644
index 0000000..16f1c55
--- /dev/null
+++ b/proxy/proxy_test.go
@@ -0,0 +1,80 @@
+package proxy
+
+import (
+	"testing"
+	"fmt"
+	"time"
+	"github.com/nareix/av"
+)
+
+func TestProxy(t *testing.T) {
+	proxy := New()
+	pub, _ := proxy.Publish("abc")
+	pub.WriteHeader([]av.CodecData{nil, nil})
+
+	done := make(chan int)
+
+	for n := 0; n < 3; n++ {
+		go func(n int) {
+			sub, _ := proxy.Subscribe("abc")
+			if sub == nil {
+				done <- n
+				return
+			}
+			for {
+				i, pkt, err := sub.ReadPacket()
+				if err != nil {
+					break
+				}
+				fmt.Println(i, pkt)
+			}
+			fmt.Println("close", n)
+			sub.Close()
+			done <- n
+		}(n)
+	}
+
+	go func() {
+		pub.WritePacket(1, av.Packet{})
+		pub.WritePacket(2, av.Packet{})
+		pub.WritePacket(3, av.Packet{})
+		if false {
+			time.Sleep(time.Second/100)
+		}
+		pub.Close()
+		done <- 4
+	}()
+
+	for i := 0; i < 4; i++ {
+		fmt.Println(<-done)
+	}
+
+	fmt.Println("complete")
+
+	done = make(chan int)
+
+	proxy = New()
+	proxy.HandleSubscribe(func(pub *Publisher) {
+		fmt.Println(pub.Params)
+		pub.WriteHeader([]av.CodecData{nil, nil})
+		for {
+			if err := pub.WritePacket(0, av.Packet{}); err != nil {
+				break
+			}
+		}
+		done <- 1
+	})
+
+	subs := []*Subscriber{}
+	for i := 0; i < 3; i++ {
+		sub, _ := proxy.Subscribe("xxoo")
+		subs = append(subs, sub)
+	}
+
+	for _, sub := range subs {
+		sub.Close()
+	}
+
+	<-done
+}
+
diff --git a/segment.go b/segment.go
new file mode 100644
index 0000000..3336ee0
--- /dev/null
+++ b/segment.go
@@ -0,0 +1,100 @@
+package av
+
+import (
+	"fmt"
+)
+
+type PacketWithIdx struct {
+	Idx int
+	Packet
+}
+
+type Segment struct {
+	Pkts []PacketWithIdx
+	duration float64
+}
+
+func (self Segment) Duration() float64 {
+	return self.duration
+}
+
+func (self Segment) Concat(seg Segment) (out Segment) {
+	out.Pkts = append(self.Pkts, seg.Pkts...)
+	out.duration = self.duration+seg.duration
+	return
+}
+
+func WriteSegment(muxer Muxer, seg Segment) (err error) {
+	for _, pkt := range seg.Pkts {
+		if err = muxer.WritePacket(pkt.Idx, pkt.Packet); err != nil {
+			return
+		}
+	}
+	return
+}
+
+type SegmentReader struct {
+	Demuxer Demuxer
+	streams []CodecData
+	vi int
+	lastpkt *Packet
+}
+
+func (self *SegmentReader) ClearCache() {
+	self.lastpkt = nil
+}
+
+func (self *SegmentReader) prepare() (err error) {
+	self.streams = self.Demuxer.Streams()
+	self.vi = -1
+	for i, stream := range self.streams {
+		if stream.IsVideo() {
+			self.vi = i
+			break
+		}
+	}
+	if self.vi == -1 {
+		err = fmt.Errorf("video stream not found")
+		return
+	}
+	return
+}
+
+func (self *SegmentReader) ReadGop() (seg Segment, err error) {
+	if len(self.streams) == 0 {
+		if err = self.prepare(); err != nil {
+			return
+		}
+	}
+
+	n := 0
+	if self.lastpkt != nil {
+		n++
+		seg.Pkts = append(seg.Pkts, PacketWithIdx{Idx:self.vi, Packet:*self.lastpkt})
+		seg.duration += self.lastpkt.Duration
+		self.lastpkt = nil
+	}
+
+	for {
+		var i int
+		var pkt Packet
+		if i, pkt, err = self.Demuxer.ReadPacket(); err != nil {
+			return
+		}
+		if i == self.vi && pkt.IsKeyFrame {
+			n++
+		}
+		if n == 1 {
+			seg.Pkts = append(seg.Pkts, PacketWithIdx{Idx:i, Packet:pkt})
+			if i == self.vi {
+				seg.duration += pkt.Duration
+			}
+		} else if n > 1 {
+			self.lastpkt = &pkt
+			break
+		}
+	}
+
+	return
+}
+
diff --git a/util.go b/util.go
deleted file mode 100644
index 44c5636..0000000
--- a/util.go
+++ /dev/null
@@ -1,158 +0,0 @@
-package av
-
-import (
-	"fmt"
-	"github.com/nareix/codec/aacparser"
-	"github.com/nareix/codec/h264parser"
-)
-
-type CodecType int
-
-const (
-	H264 = CodecType(1)
-	AAC  = CodecType(2)
-)
-
-func (self CodecType) String() string {
-	switch self {
-	case H264:
-		return "H264"
-	case AAC:
-		return "AAC"
-	}
-	return "?"
-}
-
-func (self CodecType) IsAudio() bool {
-	return self == AAC
-}
-
-func (self CodecType) IsVideo() bool {
-	return self == H264
-}
-
-type Stream interface {
-	IsVideo() bool
-	IsAudio() bool
-	Type() CodecType
-	SetType(CodecType)
-	CodecData() []byte
-	SetCodecData([]byte) error
-	SampleRate() int
-	ChannelCount() int
-	Width() int
-	Height() int
-	String() string
-	FillParamsByStream(Stream) error
-}
-
-type StreamCommon struct {
-	codecType     CodecType
-	codecData     []byte
-	H264CodecInfo h264parser.CodecInfo
-	AACCodecInfo  aacparser.CodecInfo
-}
-
-type Muxer interface {
-	NewStream() Stream
-	WriteHeader() error
-	WriteTrailer() error
-	WritePacket(int, Packet) error
-	SetTime(float64)
-}
-
-type Demuxer interface {
-	ReadHeader() error
-	ReadPacket() (int, Packet, error)
-	Streams() []Stream
-	Time() float64
-}
-
-type SeekableDemuxer interface {
-	Demuxer
-	SeekToTime(float64) error
-}
-
-type Packet struct {
-	IsKeyFrame      bool
-	Data            []byte
-	Duration        float64
-	CompositionTime float64
-}
-
-func (self *StreamCommon) Type() CodecType {
-	return self.codecType
-}
-
-func (self *StreamCommon) SetType(CodecType CodecType) {
-	self.codecType = CodecType
-}
-
-func (self *StreamCommon) String() string {
-	str := self.codecType.String()
-	if self.IsAudio() {
-		str += fmt.Sprintf(" %dHz %dch", self.SampleRate(), self.ChannelCount())
-	} else if self.IsVideo() {
-		str += fmt.Sprintf(" %dx%d", self.Width(), self.Height())
-	}
-	return str
-}
-
-func (self *StreamCommon) SetCodecData(data []byte) (err error) {
-	if self.codecType == H264 {
-		if self.H264CodecInfo, err = h264parser.ParseCodecData(data); err != nil {
-			return
-		}
-	} else if self.codecType == AAC {
-		if self.AACCodecInfo, err = aacparser.ParseCodecData(data); err != nil {
-			return
-		}
-	} else {
-		err = fmt.Errorf("unknown codec type=%d", self.codecType)
-	}
-	self.codecData = data
-	return
-}
-
-func (self *StreamCommon) CodecData() (data []byte) {
-	return self.codecData
-}
-
-func (self *StreamCommon) ChannelCount() int {
-	return self.AACCodecInfo.ChannelCount
-}
-
-func (self *StreamCommon) SampleRate() int {
-	return self.AACCodecInfo.SampleRate
-}
-
-func (self *StreamCommon) Width() int {
-	return int(self.H264CodecInfo.SPSInfo.Width)
-}
-
-func (self *StreamCommon) Height() int {
-	return int(self.H264CodecInfo.SPSInfo.Height)
-}
-
-func (self *StreamCommon) IsVideo() bool {
-	if self.codecType == H264 {
-		return true
-	}
-	return false
-}
-
-func (self *StreamCommon) IsAudio() bool {
-	if self.codecType == AAC {
-		return true
-	}
-	return false
-}
-
-func (self *StreamCommon) FillParamsByStream(other Stream) (err error) {
-	self.codecType = other.Type()
-	if err = self.SetCodecData(other.CodecData()); err != nil {
-		return
-	}
-	return
-}
-