diff --git a/example/test.go b/example/test.go
index f305a34..e97bb2e 100644
--- a/example/test.go
+++ b/example/test.go
@@ -195,23 +195,48 @@ func main() {
 		return
 	}
 
+	var w *ts.TSWriter
+	var sample Sample
+	writePES := func() (err error) {
+		pes := ts.PESHeader{
+			StreamId: ts.StreamIdH264,
+			PTS: sample.PTS,
+			DTS: sample.DTS,
+		}
+		w.PCR = sample.PCR
+		bw := &bytes.Buffer{}
+		if err = ts.WritePES(bw, pes, sample.Data); err != nil {
+			return
+		}
+		if err = w.Write(bw.Bytes(), false); err != nil {
+			return
+		}
+		return
+	}
+
 	if file != nil {
 		writePAT()
 		writePMT()
-		file.Close()
+		w = &ts.TSWriter{
+			W: file,
+			PID: 0x100,
+		}
 	}
 
 	for {
-		var sample Sample
 		var ok bool
 		if sample, ok = <-ch; !ok {
 			break
 		}
 		if sample.Type == ts.ElementaryStreamTypeH264 {
-			if false {
+			if true {
 				fmt.Println("sample: ", len(sample.Data), "PCR", sample.PCR)
 				//fmt.Print(hex.Dump(sample.Data))
 			}
+
+			if file != nil {
+				writePES()
+			}
 		}
 	}
 }
diff --git a/reader.go b/reader.go
index 23972de..648eff7 100644
--- a/reader.go
+++ b/reader.go
@@ -449,6 +449,10 @@ func ReadPESHeader(r io.Reader) (res *PESHeader, err error) {
 		return
 	}
 
+	if DebugReader {
+		fmt.Printf("pes: StreamId=%x\n", self.StreamId)
+	}
+
 	if length, err = ReadUInt(r, 2); err != nil {
 		return
 	}
diff --git a/ts.go b/ts.go
index c0e943e..da6e546 100644
--- a/ts.go
+++ b/ts.go
@@ -53,6 +53,11 @@ type PSI struct {
 	LastSecNum uint
 }
 
+const (
+	StreamIdH264 = 0xe0
+	StreamIdAAC = 0xc0
+)
+
 type PESHeader struct {
 	StreamId uint // H264=0xe0 AAC=0xc0
 	DataLength uint
diff --git a/writer.go b/writer.go
index d3945b5..368bb24 100644
--- a/writer.go
+++ b/writer.go
@@ -46,25 +46,29 @@ func WriteTSHeader(w io.Writer, self TSHeader) (err error) {
 	flags |= (self.PID&0x1fff00)<<8
 	flags |= self.ContinuityCounter&0xf
 
+	const PCR = 0x10
+	const OPCR = 0x08
+	const EXT = 0x20
+
 	if self.PCR != 0 {
-		extFlags |= 0x20
+		extFlags |= PCR
 	}
 	if self.OPCR != 0 {
-		extFlags |= 0x08
+		extFlags |= OPCR
 	}
 	if self.RandomAccessIndicator {
 		extFlags |= 0x40
 	}
 
 	if extFlags != 0 {
-		flags |= 0x20
+		flags |= EXT
 	}
 
 	if err = WriteUInt(w, flags, 4); err != nil {
 		return
 	}
 
-	if flags & 0x20 != 0 {
+	if flags & EXT != 0 {
 		var length uint
 
 		// Discontinuity indicator	1	0x80	
@@ -74,10 +78,10 @@ func WriteTSHeader(w io.Writer, self TSHeader) (err error) {
 		// OPCR flag	1	0x08	
 
 		length = 1
-		if extFlags & 0x10 != 0 {
+		if extFlags & PCR != 0 {
 			length += 6
 		}
-		if extFlags & 0x08 != 0 {
+		if extFlags & OPCR != 0 {
 			length += 6
 		}
 
@@ -88,13 +92,13 @@ func WriteTSHeader(w io.Writer, self TSHeader) (err error) {
 			return
 		}
 
-		if extFlags & 0x10 != 0 {
+		if extFlags & PCR != 0 {
 			if err = WriteUInt64(w, PCRToUInt(self.PCR), 6); err != nil {
 				return
 			}
 		}
 
-		if extFlags & 0x08 != 0 {
+		if extFlags & OPCR != 0 {
 			if err = WriteUInt64(w, PCRToUInt(self.OPCR), 6); err != nil {
 				return
 			}