diff --git a/rtmp/rtmp.go b/rtmp/rtmp.go
index 02ddfc05..15796e65 100644
--- a/rtmp/rtmp.go
+++ b/rtmp/rtmp.go
@@ -50,6 +50,10 @@ import (
 	"bitbucket.org/ausocean/av/tools"
 )
 
+const (
+	minDataSize = 11
+)
+
 // Session provides an interface for sending flv tags over rtmp.
 type Session interface {
 	Open() error
@@ -79,11 +83,14 @@ func NewSession(url string, connectTimeout uint) Session {
 // See #define AVC(str) {str, sizeof(str)-1} in amf.h
 func AVC(str string) C.AVal {
 	var aval C.AVal
-	aval.av_val = (*C.char)(unsafe.Pointer(&([]byte(str)[0])))
-	aval.av_len = (C.int)(int(unsafe.Sizeof([]byte(str))-1))
+	aval.av_val = C.CString(str)
+	aval.av_len = C.int(len(str))
 	return aval
 }
 
+// av_setDataFrame is a static const global in rtmp.c
+var av_setDataFrame = AVC("@setDataFrame")
+
 // Open establishes an rtmp connection with the url passed into the
 // constructor
 func (s *session) Open() error {
@@ -98,10 +105,13 @@ func (s *session) Open() error {
 	return nil
 }
 
+func byteSliceToCArr(buf []byte) *C.char {
+	return (*C.char)(unsafe.Pointer(&buf[0]))
+}
 
 func (s *session) rtmpWrite(r *C.RTMP, buf []byte) int {
 	var pkt *C.RTMPPacket = &r.m_write
-	var pend, enc *C.char
+	var pend, enc []byte
 	size := len(buf)
 	s2 := size
 	var ret, num int
@@ -111,7 +121,7 @@ func (s *session) rtmpWrite(r *C.RTMP, buf []byte) int {
 
 	for s2 > 0 {
 		if pkt.m_nBytesRead == 0 {
-			if size < 11 {
+			if size < minDataSize {
 				log.Printf("size: %d\n", size)
 				log.Printf("too small \n")
 				return 0
@@ -123,29 +133,15 @@ func (s *session) rtmpWrite(r *C.RTMP, buf []byte) int {
 				s2 -= 13
 			}
 
-			// pkt.m_packetType = *buf++
 			buf = buf[1:]
 			pkt.m_packetType = C.uchar(buf[0])
-
-			cChar := (*C.char)(unsafe.Pointer(&buf[0]))
-			pkt.m_nBodySize = C.AMF_DecodeInt24(cChar)
-
-			// C: buf+=3
+			pkt.m_nBodySize = C.AMF_DecodeInt24(byteSliceToCArr(buf))
 			buf = buf[3:]
-
-			cChar = (*C.char)(unsafe.Pointer(&buf[0]))
-			pkt.m_nTimeStamp = C.AMF_DecodeInt24(cChar)
-
-			// C: buf+=3
+			pkt.m_nTimeStamp = C.AMF_DecodeInt24(byteSliceToCArr(buf))
 			buf = buf[3:]
-
-			// C: pkt->m_nTimeStamp |= *buf++ << 24;
 			buf = buf[1:]
 			pkt.m_nTimeStamp |= C.uint( buf[0] << 24 )
-
-			// C: buf+=3
 			buf = buf[3:]
-
 			s2 -= 11
 
 			if ((pkt.m_packetType == C.RTMP_PACKET_TYPE_AUDIO ||
@@ -161,7 +157,7 @@ func (s *session) rtmpWrite(r *C.RTMP, buf []byte) int {
 			}
 
 			// C: if (!RTMPPacket_Alloc(pkt, pkt->m_nBodySize))
-			if !tools.IntToBool(int( C.RTMPPacket_Alloc(pkt, pkt.m_nBodySize))) {
+			if int( C.RTMPPacket_Alloc(pkt, pkt.m_nBodySize)) == 0 {
 				log.Println("Failed to allocated packet")
 				return 0
 			}
@@ -171,10 +167,8 @@ func (s *session) rtmpWrite(r *C.RTMP, buf []byte) int {
 			// pend = enc + pkt.m_nBodySize
 			pend = (*C.char)(unsafe.Pointer( uintptr(unsafe.Pointer(enc)) +
 				( unsafe.Sizeof(C.char(0x00)) * (uintptr(pkt.m_nBodySize)) ) ))
-			if pkt.m_packetType == C.RTMP_PACKET_TYPE_INFO {
 
-				// av_setDataFrame is a static const global in rtmp.c
-				av_setDataFrame := AVC("@setDataFrame")
+			if pkt.m_packetType == C.RTMP_PACKET_TYPE_INFO {
 				enc = C.AMF_EncodeString(enc, pend, &av_setDataFrame )
 
 				// C-code: pkt.m_nBytesRead enc - pkt.m_body