diff --git a/example/test.go b/example/test.go
index 3a033fd..0fe5750 100644
--- a/example/test.go
+++ b/example/test.go
@@ -216,7 +216,7 @@ func main() {
 		}
 		w.PCR = sample.PCR
 		bw := &bytes.Buffer{}
-		if err = ts.WritePES(bw, pes, sample.Data); err != nil {
+		if err = ts.WritePES(bw, pes, bytes.NewReader(sample.Data)); err != nil {
 			return
 		}
 		if err = w.Write(bw.Bytes(), false); err != nil {
@@ -253,5 +253,6 @@ func main() {
 			}
 		}
 	}
+
 }
 
diff --git a/writer.go b/writer.go
index c949603..3ec0d1f 100644
--- a/writer.go
+++ b/writer.go
@@ -274,11 +274,13 @@ func bswap32(v uint) uint {
 	return (v>>24)|((v>>16)&0xff)<<8|((v>>8)&0xff)<<16|(v&0xff)<<24
 }
 
-func WritePES(w io.Writer, self PESHeader, data []byte) (err error) {
+func WritePES(w io.Writer, self PESHeader, data io.ReadSeeker) (err error) {
 	// http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
 
 	var pts_dts_flags, header_length, packet_length uint
 
+	dataLen := getSeekerLength(data)
+
 	// start code(24) 000001
 	// StreamId(8)
 	// packet_length(16)
@@ -315,7 +317,7 @@ func WritePES(w io.Writer, self PESHeader, data []byte) (err error) {
 	if pts_dts_flags & DTS != 0 {
 		header_length += 5
 	}
-	packet_length = 3+header_length+uint(len(data))
+	packet_length = 3+header_length+uint(dataLen)
 
 	if DebugWriter {
 		fmt.Printf("pesw: packet_length=%d\n", packet_length)
@@ -359,7 +361,7 @@ func WritePES(w io.Writer, self PESHeader, data []byte) (err error) {
 	}
 
 	// data
-	if _, err = w.Write(data); err != nil {
+	if _, err = io.Copy(w, data); err != nil {
 		return
 	}
 
@@ -475,14 +477,124 @@ func WritePMT(w io.Writer, self PMT) (err error) {
 
 type SimpleH264Writer struct {
 	W io.Writer
-	headerHasWritten bool
+	TimeScale int
+
+	SPS []byte
+	PPS []byte
+
+	tsw *TSWriter
+	pts uint64
+	pcr uint64
+	prepared bool
 }
 
-func (self *SimpleH264Writer) WriteSample(data []byte) (err error) {
+func (self *SimpleH264Writer) prepare() (err error) {
+	writePAT := func() (err error) {
+		w := &TSWriter{
+			W: self.W,
+			PID: 0,
+			DisableHeaderPadding: true,
+		}
+		pat := PAT{
+			Entries: []PATEntry{
+				{ProgramNumber: 1, ProgramMapPID: 0x1000},
+			},
+		}
+		bw := &bytes.Buffer{}
+		if err = WritePAT(bw, pat); err != nil {
+			return
+		}
+		if err = w.Write(bw.Bytes(), false); err != nil {
+			return
+		}
+		return
+	}
+
+	writePMT := func() (err error) {
+		w := &TSWriter{
+			W: self.W,
+			PID: 0x1000,
+			DisableHeaderPadding: true,
+		}
+		pmt := PMT{
+			PCRPID: 0x100,
+			ElementaryStreamInfos: []ElementaryStreamInfo{
+				{StreamType: ElementaryStreamTypeH264, ElementaryPID: 0x100},
+			},
+		}
+		bw := &bytes.Buffer{}
+		if err = WritePMT(bw, pmt); err != nil {
+			return
+		}
+		if err = w.Write(bw.Bytes(), false); err != nil {
+			return
+		}
+		return
+	}
+
+	if err = writePAT(); err != nil {
+		return
+	}
+
+	if err = writePMT(); err != nil {
+		return
+	}
+
+	self.tsw = &TSWriter{
+		W: self.W,
+		PID: 0x100,
+	}
+	self.pts = PTS_HZ
+	self.pcr = PCR_HZ
+
 	return
 }
 
-func (self *SimpleH264Writer) WriteNALU(data []byte) (err error) {
+func (self *SimpleH264Writer) writeData(data io.ReadSeeker, duration int) (err error) {
+	pes := PESHeader{
+		StreamId: StreamIdH264,
+		PTS: self.pts,
+	}
+	self.tsw.PCR = self.pcr
+
+	self.pts += uint64(duration)*PTS_HZ/uint64(self.TimeScale)
+	self.pcr += uint64(duration)*PCR_HZ/uint64(self.TimeScale)
+
+	bw := &bytes.Buffer{}
+	if err = WritePES(bw, pes, data); err != nil {
+		return
+	}
+	if err = self.tsw.Write(bw.Bytes(), false); err != nil {
+		return
+	}
+
 	return
 }
 
+func (self *SimpleH264Writer) writeNALUs(nalus [][]byte, duration int) (err error) {
+	readers := []io.ReadSeeker{}
+	for _, nalu := range nalus {
+		startCode := bytes.NewReader([]byte{0,0,1})
+		readers = append(readers, startCode)
+		readers = append(readers, bytes.NewReader(nalu))
+	}
+	return self.writeData(&multiReadSeeker{readers: readers}, duration)
+}
+
+func (self *SimpleH264Writer) WriteNALU(sync bool, duration int, nalu []byte) (err error) {
+	nalus := [][]byte{}
+
+	if !self.prepared {
+		if err = self.prepare(); err != nil {
+			return
+		}
+		self.prepared = true
+		nalus = append(nalus, self.SPS)
+		nalus = append(nalus, self.PPS)
+	}
+
+	nalus = append(nalus, nalu)
+
+	return self.writeNALUs(nalus, duration)
+}
+