diff --git a/rtmp/rtmp.go b/rtmp/rtmp.go
index 2c6300d5..ea5d05cb 100644
--- a/rtmp/rtmp.go
+++ b/rtmp/rtmp.go
@@ -130,7 +130,7 @@ var (
 	errTinyPacket    = errors.New("rtmp: packet too small")
 	errEncoding      = errors.New("rtmp: encoding error")
 	errDecoding      = errors.New("rtmp: decoding error")
-	errCopying       = errors.New("rtmp: copying error")
+	errUnimplemented = errors.New("rtmp: unimplemented feature")
 )
 
 // setupURL parses the RTMP URL.
@@ -861,76 +861,22 @@ func handshake(s *Session) error {
 
 // write prepares data to write then sends it.
 func (s *Session) write(buf []byte) error {
+	if buf[0] == RTMP_PACKET_TYPE_INFO || (buf[0] == 'F' && buf[1] == 'L' && buf[2] == 'V') {
+		return errUnimplemented
+	}
+	if len(buf) < minDataSize {
+		return errTinyPacket
+	}
+
 	pkt := packet{
-		channel: RTMP_CHANNEL_SOURCE,
-		info:    s.streamID,
+		packetType: buf[0],
+		bodySize:   C_AMF_DecodeInt24(buf[1:4]),
+		timestamp:  C_AMF_DecodeInt24(buf[4:7]) | uint32(buf[7])<<24,
+		channel:    RTMP_CHANNEL_SOURCE,
+		info:       s.streamID,
 	}
-	var enc []byte
 
-	for len(buf) != 0 {
-		if pkt.bytesRead == 0 {
-			if len(buf) < minDataSize {
-				return errTinyPacket
-			}
-
-			if buf[0] == 'F' && buf[1] == 'L' && buf[2] == 'V' {
-				buf = buf[13:]
-			}
-
-			pkt.packetType = buf[0]
-			buf = buf[1:]
-			pkt.bodySize = C_AMF_DecodeInt24(buf[:3])
-			buf = buf[3:]
-			pkt.timestamp = C_AMF_DecodeInt24(buf[:3])
-			buf = buf[3:]
-			pkt.timestamp |= uint32(buf[0]) << 24
-			buf = buf[4:]
-
-			headerType := uint8(RTMP_PACKET_SIZE_MEDIUM)
-			switch pkt.packetType {
-			case RTMP_PACKET_TYPE_VIDEO, RTMP_PACKET_TYPE_AUDIO:
-				if pkt.timestamp == 0 {
-					headerType = RTMP_PACKET_SIZE_LARGE
-				}
-			case RTMP_PACKET_TYPE_INFO:
-				headerType = RTMP_PACKET_SIZE_LARGE
-				pkt.bodySize += 16
-			}
-
-			resizePacket(&pkt, pkt.bodySize, headerType)
-
-			enc = pkt.body[:pkt.bodySize]
-			if pkt.packetType == RTMP_PACKET_TYPE_INFO {
-				enc = C_AMF_EncodeString(enc, setDataFrame)
-				if enc == nil {
-					return errEncoding
-				}
-				pkt.bytesRead = uint32(len(pkt.body) - len(enc))
-			}
-
-		} else {
-			enc = pkt.body[:pkt.bodySize][pkt.bytesRead:]
-		}
-		num := int(pkt.bodySize - pkt.bytesRead)
-		if num > len(buf) {
-			num = len(buf)
-		}
-
-		copy(enc[:num], buf[:num])
-		pkt.bytesRead += uint32(num)
-		buf = buf[num:]
-		if pkt.bytesRead == pkt.bodySize {
-			err := sendPacket(s, &pkt, false)
-			pkt.body = nil
-			pkt.bytesRead = 0
-			if err != nil {
-				return err
-			}
-			if len(buf) < 4 {
-				return nil
-			}
-			buf = buf[4:]
-		}
-	}
-	return nil
+	resizePacket(&pkt, pkt.bodySize, RTMP_PACKET_SIZE_AUTO)
+	copy(pkt.body, buf[minDataSize:minDataSize+pkt.bodySize])
+	return sendPacket(s, &pkt, false)
 }