diff --git a/example/test.go b/example/test.go
index 7666aed..b279abc 100644
--- a/example/test.go
+++ b/example/test.go
@@ -16,9 +16,25 @@ type Stream struct {
 	Title string
 	Data bytes.Buffer
 	Type uint
+	PTS uint
+	PCR uint
 }
 
-func main() {
+type Sample struct {
+	Type uint
+	PCR uint64
+	PTS uint64
+	DTS uint64
+	Data []byte
+}
+
+func readSamples(ch chan Sample) {
+	defer func() {
+		close(ch)
+	}()
+
+	debug := false
+
 	var file *os.File
 	var err error
 	if file, err = os.Open("/tmp/out.ts"); err != nil {
@@ -66,8 +82,14 @@ func main() {
 			return
 		}
 		if stream.Data.Len() == int(stream.Header.DataLength) {
-			fmt.Println(stream.Type, stream.Title, stream.Data.Len(), "total")
-			fmt.Println(hex.Dump(stream.Data.Bytes()))
+			if debug {
+				fmt.Println(stream.Type, stream.Title, stream.Data.Len(), "total")
+				fmt.Println(hex.Dump(stream.Data.Bytes()))
+			}
+			ch <- Sample{
+				Type: stream.Type,
+				Data: stream.Data.Bytes(),
+			}
 		}
 		return
 	}
@@ -76,7 +98,9 @@ func main() {
 		if header, n, err = ts.ReadTSPacket(file, data[:]); err != nil {
 			return
 		}
-		fmt.Println(header, n)
+		if debug {
+			fmt.Println(header, n)
+		}
 
 		payload = data[:n]
 		pr := bytes.NewReader(payload)
@@ -94,7 +118,7 @@ func main() {
 					return
 				}
 				//fmt.Println("pmt", pmt)
-				if true {
+				if debug {
 					fmt.Println(hex.Dump(payload))
 				}
 			}
@@ -109,3 +133,18 @@ func main() {
 	}
 }
 
+func main() {
+	ch := make(chan Sample)
+	go readSamples(ch)
+
+	for {
+		var sample Sample
+		var ok bool
+		if sample, ok = <-ch; !ok {
+			break
+		}
+		if sample.Type == ts.ElementaryStreamTypeH264 {
+		}
+	}
+}
+
diff --git a/reader.go b/reader.go
index 347481e..c50a719 100644
--- a/reader.go
+++ b/reader.go
@@ -56,7 +56,7 @@ func ReadTSHeader(r io.Reader) (self TSHeader, err error) {
 	}
 
 	if debug {
-		fmt.Printf("ts: %s\n", FieldsDumper{
+		fmt.Printf("ts: flags %s\n", FieldsDumper{
 			Fields: []struct{
 				Length int
 				Desc string
@@ -100,7 +100,7 @@ func ReadTSHeader(r io.Reader) (self TSHeader, err error) {
 		}
 
 		if debug {
-			fmt.Printf("ts: %s\n", FieldsDumper{
+			fmt.Printf("ts: ext_flags %s\n", FieldsDumper{
 				Fields: []struct{
 					Length int
 					Desc string
diff --git a/ts.go b/ts.go
index bfebd1b..30b830d 100644
--- a/ts.go
+++ b/ts.go
@@ -18,6 +18,7 @@ type TSHeader struct {
 	OPCR uint64
 	ContinuityCounter uint
 	PayloadUnitStart bool
+	RandomAccessIndicator bool
 }
 
 type PATEntry struct {
@@ -74,6 +75,12 @@ func UIntToPCR(v uint64) uint64 {
 	return base*300+ext
 }
 
+func PCRToUInt(pcr uint64) uint64 {
+	base := pcr/300
+	ext := pcr%300
+	return base<<15|0x3f<<9|ext
+}
+
 type FieldsDumper struct {
 	Fields []struct {
 		Length int
diff --git a/writer.go b/writer.go
index 6b5405c..8bce989 100644
--- a/writer.go
+++ b/writer.go
@@ -8,6 +8,103 @@ import (
 
 type TSWriter struct {
 	W io.Writer
+	ContinuityCounter uint
+	PayloadUnitStart bool
+}
+
+func WriteUInt64(w io.Writer, val uint64, n int) (err error) {
+	var b [8]byte
+	for i := n-1; i >= 0; i-- {
+		b[i] = byte(val)
+		val >>= 8
+	}
+	if _, err = w.Write(b[:]); err != nil {
+		return
+	}
+	return
+}
+
+func WriteUInt(w io.Writer, val uint, n int) (err error) {
+	return WriteUInt64(w, uint64(val), n)
+}
+
+func WriteTSHeader(w io.Writer, self TSHeader) (err error) {
+	var flags, extFlags uint
+
+	// sync(8)
+	// transport_error_indicator(1)
+	// payload_unit_start_indicator(1)
+	// transport_priority(1)
+	// pid(13)
+	// Scrambling control(2)
+	// Adaptation field flag(1) 0x20
+	// Payload flag(1) 0x10
+	// Continuity counter(4)
+
+	flags = 0x47<<24
+	flags |= 0x10
+	if self.PayloadUnitStart {
+		flags |= 0x400000
+	}
+	flags |= (self.PID&0x1fff00)<<8
+	flags |= self.ContinuityCounter&0xf
+
+	if self.PCR != 0 {
+		extFlags |= 0x20
+	}
+	if self.OPCR != 0 {
+		extFlags |= 0x08
+	}
+	if self.RandomAccessIndicator {
+		extFlags |= 0x40
+	}
+
+	if extFlags != 0 {
+		flags |= 0x20
+	}
+
+	if err = WriteUInt(w, flags, 4); err != nil {
+		return
+	}
+
+	if flags & 0x20 != 0 {
+		var length uint
+
+		// Discontinuity indicator	1	0x80	
+		// Random Access indicator	1	0x40	
+		// Elementary stream priority indicator	1	0x20	
+		// PCR flag	1	0x10
+		// OPCR flag	1	0x08	
+
+		length = 1
+		if extFlags & 0x10 != 0 {
+			length += 6
+		}
+		if extFlags & 0x08 != 0 {
+			length += 6
+		}
+
+		if err = WriteUInt(w, length, 1); err != nil {
+			return
+		}
+		if err = WriteUInt(w, extFlags, 1); err != nil {
+			return
+		}
+
+		if extFlags & 0x10 != 0 {
+			if err = WriteUInt64(w, PCRToUInt(self.PCR), 6); err != nil {
+				return
+			}
+		}
+
+		if extFlags & 0x08 != 0 {
+			if err = WriteUInt64(w, PCRToUInt(self.OPCR), 6); err != nil {
+				return
+			}
+		}
+	}
+
+	return
 }
 
 type PSIWriter struct {