av/rtmp/rtmp.go

/*
NAME
  rtmp.go

DESCRIPTION
  See Readme.md

AUTHORS
  Saxon Nelson-Milton <saxon@ausocean.org>
  Dan Kortschak <dan@ausocean.org>

LICENSE
  rtmp.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License
  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.

  Derived from librtmp under the GNU Lesser General Public License 2.1
  Copyright (C) 2005-2008 Team XBMC http://www.xbmc.org
  Copyright (C) 2008-2009 Andrej Stepanchuk
  Copyright (C) 2009-2010 Howard Chu
*/

package rtmp

/*
#include <stdlib.h>
#include <unistd.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>

typedef struct sockaddr_in sockaddr_in;
typedef struct sockaddr sockaddr;
*/
import "C"

import (
	"bytes"
	"errors"
	"fmt"
	"log"
	"math/rand"
	"strconv"
	"strings"
	"time"
	"unsafe"

	"github.com/chamaken/cgolmnl/inet"
)

const _Gi = 1 << 30

const (
	minDataSize = 11
	debugMode   = false
	length      = 512
)

const (
	// av_setDataFrame is a static const global in rtmp.c
	setDataFrame = "@setDataFrame"

	av__checkbw                         = "_checkbw"
	av__onbwcheck                       = "_onbwcheck"
	av__onbwdone                        = "_onbwdone"
	av__result                          = "_result"
	av_app                              = "app"
	av_audioCodecs                      = "audioCodecs"
	av_capabilities                     = "capabilities"
	av_close                            = "close"
	av_code                             = "code"
	av_connect                          = "connect"
	av_createStream                     = "createStream"
	av_deleteStream                     = "deleteStream"
	av_FCPublish                        = "FCPublish"
	av_FCUnpublish                      = "FCUnpublish"
	av_flashVer                         = "flashVer"
	av_fpad                             = "fpad"
	av_level                            = "level"
	av_live                             = "live"
	av_NetConnection_Connect_InvalidApp = "NetConnection.Connect.InvalidApp"
	av_NetStream_Failed                 = "NetStream.Failed"
	av_NetStream_Pause_Notify           = "NetStream.Pause.Notify"
	av_NetStream_Play_Complete          = "NetStream.Play.Complete"
	av_NetStream_Play_Failed            = "NetStream.Play.Failed"
	av_NetStream_Play_PublishNotify     = "NetStream.Play.PublishNotify"
	av_NetStream_Play_Start             = "NetStream.Play.Start"
	av_NetStream_Play_Stop              = "NetStream.Play.Stop"
	av_NetStream_Play_StreamNotFound    = "NetStream.Play.StreamNotFound"
	av_NetStream_Play_UnpublishNotify   = "NetStream.Play.UnpublishNotify"
	av_NetStream_Publish_Start          = "NetStream.Publish.Start"
	av_NetStream_Seek_Notify            = "NetStream.Seek.Notify"
	av_nonprivate                       = "nonprivate"
	av_objectEncoding                   = "objectEncoding"
	av_onBWDone                         = "onBWDone"
	av_onFCSubscribe                    = "onFCSubscribe"
	av_onFCUnsubscribe                  = "onFCUnsubscribe"
	av_onStatus                         = "onStatus"
	av_pageUrl                          = "pageUrl"
	av_ping                             = "ping"
	av_play                             = "play"
	av_playlist_ready                   = "playlist_ready"
	av_publish                          = "publish"
	av_releaseStream                    = "releaseStream"
	av_secureToken                      = "secureToken"
	av_set_playlist                     = "set_playlist"
	av_swfUrl                           = "swfUrl"
	av_tcUrl                            = "tcUrl"
	av_type                             = "type"
	av_videoCodecs                      = "videoCodecs"
	av_videoFunction                    = "videoFunction"
)

var RTMPT_cmds = []string{
	"open",
	"send",
	"idle",
	"close",
}

var (
	packetSize               = [...]int{12, 8, 4, 1}
	RTMPProtocolStringsLower = [...]string{
		"rtmp",
		"rtmpt",
		"rtmpe",
		"rtmpte",
		"rtmps",
		"rtmpts",
		"",
		"",
		"rtmfp",
	}
)

func startSession(rtmp *C_RTMP, u string, timeout uint32) (*C_RTMP, error) {
	connect_timeout := int32(timeout)
	rtmp = C_RTMP_Alloc()
	C_RTMP_Init(rtmp)
	rtmp.Link.timeout = connect_timeout
	if !C_RTMP_SetupURL(rtmp, u) {
		C_RTMP_Close(rtmp)
		//C.RTMP_Free(rtmp)
		return nil, errors.New("rtmp startSession: Failed to setup URL!")
	}

	C_RTMP_EnableWrite(rtmp)
	C_RTMP_SetBufferMS(rtmp, 3600*1000)
	if !C_RTMP_Connect(rtmp, nil) {
		C_RTMP_Close(rtmp)
		//C.RTMP_Free(rtmp)
		return nil, errors.New("rtmp startSession: Failed to connect!")
	}

	// TODO: port this
	if !C_RTMP_ConnectStream(rtmp, 0) {
		C_RTMP_Close(rtmp)
		//C.RTMP_Free(rtmp)
		return nil, errors.New("rtmp startSession: Failed to connect stream!")
	}

	return rtmp, nil
}

func endSession(rtmp *C_RTMP) uint32 {
	if rtmp == nil {
		return 3
	}

	C_RTMP_Close(rtmp)
	//C.RTMP_Free(rtmp)
	return 0
}

// uint32_t RTMP_GetTime();
// rtmp.c +156
func C_RTMP_GetTime() int32 {
	return int32(time.Now().UnixNano() / 1000000)
}

// int RTMPPacket_Alloc(RTMPPacket* p, uint32_t nSize);
// rtmp.c +189
func C_RTMPPacket_Alloc(p *C_RTMPPacket, nSize uint32) (ok bool) {
	buf := make([]byte, RTMP_MAX_HEADER_SIZE+nSize)
	p.m_body = &buf[RTMP_MAX_HEADER_SIZE]
	p.m_nBytesRead = 0
	return true
}

// void RTMPPacket_Free(RTMPPacket* p);
// rtmp.c +203
func C_RTMPPacket_Free(p *C_RTMPPacket) {
	if p.m_body != nil {
		p.m_body = nil
	}
}

// RTMP* RTMP_IsConnected();
// rtmp.c +317
func C_RTMP_Alloc() *C_RTMP {
	return &C_RTMP{}
}

// void RTMP_Init(RTMP *r);
// rtmp.c +329
func C_RTMP_Init(r *C_RTMP) {
	*r = C_RTMP{}
	r.m_sb.sb_socket = -1
	r.m_inChunkSize = RTMP_DEFAULT_CHUNKSIZE
	r.m_outChunkSize = RTMP_DEFAULT_CHUNKSIZE
	r.m_nBufferMS = 30000
	r.m_nClientBW = 2500000
	r.m_nClientBW2 = 2
	r.m_nServerBW = 2500000
	r.m_fAudioCodecs = 3191.0
	r.m_fVideoCodecs = 252.0
	r.Link.timeout = 30
	r.Link.swfAge = 30
}

// void RTMP_EnableWrite(RTMP *r);
// rtmp.c +351
func C_RTMP_EnableWrite(r *C_RTMP) {
	r.Link.protocol |= RTMP_FEATURE_WRITE
}

// int RTMP_IsConnected(RTMP *r);
// rtmp.c +363
func C_RTMP_IsConnected(r *C_RTMP) int32 {
	if r.m_sb.sb_socket != -1 {
		return 1
	}
	return 0
}

// void RTMP_SetBufferMS(RTMP *r, int size);
// rtmp.c +381
func C_RTMP_SetBufferMS(r *C_RTMP, size int32) {
	r.m_nBufferMS = size
}

// void SocksSetup(RTMP *r, C_AVal* sockshost);
// rtmp.c +410
func C_SocksSetup(r *C_RTMP, sockshost string) {
	if sockshost != "" {
		p := strings.SplitN(sockshost, ":", 2)
		r.Link.sockshost = p[0]
		r.Link.socksport = 1080
		if len(p) != 1 {
			port, err := strconv.Atoi(p[1])
			if err != nil {
				port = 1080
				log.Println("C_SocksSetup: bad string conversion!")
			}
			r.Link.socksport = uint16(port)
		}
	} else {
		r.Link.sockshost = ""
		r.Link.socksport = 0
	}
}

// int RTMP_SetupURL(RTMP *r, char* url);
// rtmp.c +757
// NOTE: code dealing with rtmp over http has been disregarded
func C_RTMP_SetupURL(r *C_RTMP, addr string) (ok bool) {
	r.Link.protocol, r.Link.hostname, r.Link.port, r.Link.app, r.Link.playpath0, ok = C_RTMP_ParseURL(addr)
	if !ok {
		return false
	}
	r.Link.playpath = r.Link.playpath0

	if r.Link.tcUrl == "" {
		if r.Link.app != "" {
			r.Link.tcUrl = fmt.Sprintf("%v://%v:%v/%v",
				RTMPProtocolStringsLower[r.Link.protocol], r.Link.hostname, r.Link.port, r.Link.app)
			r.Link.lFlags |= RTMP_LF_FTCU
		} else {
			r.Link.tcUrl = addr
		}
	}

	C_SocksSetup(r, r.Link.sockshost)

	if r.Link.port == 0 {
		switch {
		case (r.Link.protocol & RTMP_FEATURE_SSL) != 0:
			r.Link.port = 433
		case (r.Link.protocol & RTMP_FEATURE_HTTP) != 0:
			r.Link.port = 80
		default:
			r.Link.port = 1935
		}
	}
	return true
}

// int add_addr_info(struct sockaddr_in *service, AVal *host, int port)
// rtmp.c +869
func C_add_addr_info(service *C.sockaddr_in, hostname string, port uint16) (ok bool) {
	h := (*C.char)(unsafe.Pointer(goStrToCStr(hostname)))
	service.sin_addr.s_addr = C.inet_addr(h)
	if service.sin_addr.s_addr == C.INADDR_NONE {
		host := C.gethostbyname(h)
		if host == nil || *host.h_addr_list == nil {
			//RTMP_Log(RTMP_LOGERROR, "Problem accessing the DNS. (addr: %s)", hostname)
			return false
		}
		service.sin_addr = *(*C.struct_in_addr)(unsafe.Pointer(*host.h_addr_list))
	}

	service.sin_port = C.ushort(inet.Htons(port))
	return true
}

// int RTMP_Connect0(RTMP *r, struct sockaddr* service);
// rtmp.c +906
func C_RTMP_Connect0(r *C_RTMP, service *C.sockaddr) (ok bool) {
	on := 1
	r.m_sb.sb_timedout = 0
	r.m_pausing = 0
	r.m_fDuration = 0

	r.m_sb.sb_socket = int32(C.socket(C.AF_INET, C.SOCK_STREAM, C.IPPROTO_TCP))

	if r.m_sb.sb_socket != -1 {
		if C.connect(C.int(r.m_sb.sb_socket), service, C.socklen_t(unsafe.Sizeof(*service))) < 0 {
			log.Println("C_RTMP_Connect0, failed to connect socket.")
		}

		if r.Link.socksport != 0 {
			if debugMode {
				log.Println("C_RTMP_Connect0: socks negotiation.")
			}

			if !C_SocksNegotiate(r) {
				log.Println("C_RTMP_Connect0: SOCKS negotiation failed.")
				return false
			}
		}
	} else {
		log.Println("C_RTMP_Connect0: failed to create socket.")
		return false
	}

	{
		var tv int32
		SET_RCVTIMEO(&tv, r.Link.timeout)

		if C.setsockopt(C.int(r.m_sb.sb_socket), C.SOL_SOCKET, C.SO_RCVTIMEO,
			unsafe.Pointer(&tv), C.socklen_t(unsafe.Sizeof(tv))) != 0 {
			log.Println("C_RTMP_Connect0: Setting socket timeout failed")
		}
	}

	C.setsockopt(C.int(r.m_sb.sb_socket), C.IPPROTO_TCP, C.TCP_NODELAY,
		unsafe.Pointer(&on), C.socklen_t(unsafe.Sizeof(on)))

	return true
}

// int RTMP_Connect1(RTMP* r, RTMPPacket* cp);
// rtmp.c +978
func C_RTMP_Connect1(r *C_RTMP, cp *C_RTMPPacket) (ok bool) {
	if debugMode {
		log.Println("... connected, handshaking...")
	}
	if !C_HandShake(r, 1) {
		log.Println("C_RTMP_Connect1: handshake failed!")
		return false
	}
	if debugMode {
		log.Println("... handshaked...")
	}
	if !C_SendConnectPacket(r, cp) {
		log.Println("RTMP connect failed!")
		return false
	}
	return true
}

// int RTMP_Connect(RTMP *r, RTMPPacket* cp);
// rtmp.c +1032
func C_RTMP_Connect(r *C_RTMP, cp *C_RTMPPacket) (ok bool) {
	// TODO: port this
	var service C.sockaddr_in

	if r.Link.hostname == "" {
		return false
	}
	memset((*byte)(unsafe.Pointer(&service)), 0, int(unsafe.Sizeof(service)))

	// TODO: port this
	service.sin_family = C.AF_INET

	if r.Link.socksport != 0 {
		if !C_add_addr_info(&service, r.Link.sockshost, r.Link.socksport) {
			return false
		}
	} else {
		// connect directly
		if !C_add_addr_info(&service, r.Link.hostname, r.Link.port) {
			return false
		}
	}
	if !C_RTMP_Connect0(r, (*C.sockaddr)(unsafe.Pointer(&service))) {
		return false
	}

	r.m_bSendCounter = true

	return C_RTMP_Connect1(r, cp)
}

// int SocksNegotiate(RTMP* r);
// rtmp.c +1062
func C_SocksNegotiate(r *C_RTMP) (ok bool) {
	var addr int32
	var service C.sockaddr_in

	memset((*byte)(unsafe.Pointer(&service)), 0, int(unsafe.Sizeof(service)))

	C_add_addr_info(&service, r.Link.hostname, r.Link.port)
	addr = int32(inet.Htonl(uint32(service.sin_addr.s_addr)))

	{
		packet := []byte{
			4, 1,
			byte((r.Link.port >> 8) & 0xFF),
			byte((r.Link.port) & 0xFF),
			byte(addr>>24) & 0xFF, byte(addr>>16) & 0xFF,
			byte(addr>>8) & 0xFF, byte(addr) & 0xFF,
			0,
		}

		C_WriteN(r, unsafe.Pointer(&packet[0]), int(unsafe.Sizeof(packet)))

		if C_ReadN(r, &packet[0], 8) != 8 {
			return false
		}

		if packet[0] == 0 && packet[1] == 90 {
			return true
		} else {
			// TODO: use new logger here
			log.Println("C_SocksNegotitate: SOCKS returned error code!")
			return false
		}
	}
}

// int RTMP_ConnectStream(RTMP* r, int seekTime);
// rtmp.c +1099
func C_RTMP_ConnectStream(r *C_RTMP, seekTime int32) (playing bool) {
	var packet C_RTMPPacket

	if seekTime > 0 {
		r.Link.seekTime = seekTime
	}

	r.m_mediaChannel = 0

	// TODO: read packet
	for !r.m_bPlaying && C_RTMP_IsConnected(r) != 0 && C_RTMP_ReadPacket(r, &packet) {
		// TODO: port is ready
		if C_RTMPPacket_IsReady(&packet) {
			if packet.m_nBodySize == 0 {
				continue
			}

			if packet.m_packetType == RTMP_PACKET_TYPE_AUDIO ||
				packet.m_packetType == RTMP_PACKET_TYPE_VIDEO ||
				packet.m_packetType == RTMP_PACKET_TYPE_INFO {
				log.Println("C_RTMP_ConnectStream: got packet before play()! Ignoring.")
				C_RTMPPacket_Free(&packet)
				continue
			}

			C_RTMP_ClientPacket(r, &packet)
			C_RTMPPacket_Free(&packet)
		}
	}
	return r.m_bPlaying
}

// int RTMP_ClientPacket()
// rtmp.c +1226
// NOTE cases have been commented out that are not currently used by AusOcean
func C_RTMP_ClientPacket(r *C_RTMP, packet *C_RTMPPacket) int32 {
	var bHasMediaPacket int32
	switch packet.m_packetType {

	case RTMP_PACKET_TYPE_CHUNK_SIZE:
		// TODO: port this
		C_HandleChangeChunkSize(r, packet)

	case RTMP_PACKET_TYPE_BYTES_READ_REPORT:
		// TODO: usue new logger here
		//RTMP_Log(RTMP_LOGDEBUG, "%s, received: bytes read report", __FUNCTION__);

	case RTMP_PACKET_TYPE_CONTROL:
		panic("Unsupported packet type RTMP_PACKET_TYPE_CONTROL")
		/*
			log.Println("RTMP_PACKET_TYPE_CONTROL")
			// TODO: port this
			C.HandleCtrl(r, packet)
		*/
	case RTMP_PACKET_TYPE_SERVER_BW:
		// TODO: port this
		C_HandlServerBW(r, packet)

	case RTMP_PACKET_TYPE_CLIENT_BW:
		// TODO: port this
		C_HandleClientBW(r, packet)

	case RTMP_PACKET_TYPE_AUDIO:
		panic("Unsupported packet type RTMP_PACKET_TYPE_AUDIO")

	case RTMP_PACKET_TYPE_VIDEO:
		panic("Unsupported packet type RTMP_PACKET_TYPE_VIDEO")

	case RTMP_PACKET_TYPE_FLEX_MESSAGE:
		panic("Unsupported packet type RTMP_PACKET_TYPE_FLEX_MESSAGE")

	case RTMP_PACKET_TYPE_INFO:
		panic("Unsupported packet type RTMP_PACKET_TYPE_INFO")

	case RTMP_PACKET_TYPE_INVOKE:
		log.Println("RTMP_PACKET_TYPE_INVOKE:")
		// TODO use new logger here
		//RTMP_Log(RTMP_LOGDEBUG, "%s, received: invoke %u bytes", __FUNCTION__,packet.m_nBodySize);

		if C_HandleInvoke(r, packet.m_body, packet.m_nBodySize) {
			// This will never happen with the methods we implement.
			log.Println("HasMediaPacket")
			bHasMediaPacket = 2
		}

	case RTMP_PACKET_TYPE_FLASH_VIDEO:
		panic("Unsupported packet type RTMP_PACKET_TYPE_FLASH_VIDEO")

	default:
		// TODO use new logger here
		// RTMP_Log(RTMP_LOGDEBUG, "%s, unknown packet type received: 0x%02x", __FUNCTION__,packet.m_packetType);
	}
	return bHasMediaPacket
}

// int ReadN(RTMP* r, char* buffer, int n);
// rtmp.c +1390
func C_ReadN(r *C_RTMP, buffer *byte, n int) int {
	nOriginalSize := n
	var avail int
	var ptr *byte

	r.m_sb.sb_timedout = 0

	ptr = buffer

	for n > 0 {
		nBytes := 0
		var nRead int

		avail = int(r.m_sb.sb_size)
		if avail == 0 {
			if C_RTMPSockBuf_Fill(&r.m_sb) < 1 {
				if r.m_sb.sb_timedout == 0 {
					return 0
				}
			}
			avail = int(r.m_sb.sb_size)
		}

		if n < avail {
			nRead = n
		} else {
			nRead = avail
		}

		if nRead > 0 {
			memmove(unsafe.Pointer(ptr), unsafe.Pointer(r.m_sb.sb_start), uintptr(nRead))
			r.m_sb.sb_start = (*byte)(incBytePtr(unsafe.Pointer(r.m_sb.sb_start),
				nRead))
			r.m_sb.sb_size -= int32(nRead)
			nBytes = nRead
			r.m_nBytesIn += int32(nRead)
			if r.m_bSendCounter && r.m_nBytesIn > (r.m_nBytesInSent+r.m_nClientBW/10) {
				if !C_SendBytesReceived(r) {
					return 0
				}
			}
		}

		if nBytes == 0 {
			log.Println("RTMP socket closed by peer")
			C_RTMP_Close(r)
			break
		}

		n -= nBytes
		ptr = (*byte)(incBytePtr(unsafe.Pointer(ptr), nBytes))
	}

	return nOriginalSize - n
}

// int WriteN(RTMP* r, const char* buffer, int n);
// rtmp.c +1502
func C_WriteN(r *C_RTMP, buffer unsafe.Pointer, n int) (ok bool) {
	ptr := buffer
	for n > 0 {
		var nBytes int

		nBytes = int(C_RTMPSockBuf_Send(&r.m_sb, (*byte)(ptr), int32(n)))

		if nBytes < 0 {
			if debugMode {
				log.Println("C_WriteN, RTMP send error")
			}

			// TODO: port this
			C_RTMP_Close(r)
			n = 1
			break
		}

		if nBytes == 0 {
			break
		}

		n -= nBytes
		ptr = incBytePtr(ptr, nBytes)
	}

	// !ok here is equivalent to io.ErrShortWrite.
	return n == 0
}

// int SendConnectPacket(RTMP* r, RTMPPacket* cp);
// rtmp.c +1579
func C_SendConnectPacket(r *C_RTMP, cp *C_RTMPPacket) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [4096]byte
	pend := (*byte)(incBytePtr(unsafe.Pointer(&pbuf[0]), int(unsafe.Sizeof(pbuf))))
	var enc *byte

	if cp != nil {
		return C_RTMP_SendPacket(r, cp, 1)
	}

	packet.m_nChannel = 0x03
	packet.m_headerType = RTMP_PACKET_SIZE_LARGE
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))

	enc = C_AMF_EncodeString(enc, pend, av_connect)

	r.m_numInvokes += 1
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))

	(*[_Gi]byte)(unsafe.Pointer(enc))[0] = AMF_OBJECT

	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))

	enc = C_AMF_EncodeNamedString(enc, pend, av_app, r.Link.app)
	if enc == nil {
		return false
	}
	if r.Link.protocol&RTMP_FEATURE_WRITE != 0 {
		enc = C_AMF_EncodeNamedString(enc, pend, av_type, av_nonprivate)
		if enc == nil {
			return false
		}
	}

	if r.Link.flashVer != "" {
		enc = C_AMF_EncodeNamedString(enc, pend, av_flashVer, r.Link.flashVer)
		if enc == nil {
			return false
		}
	}
	if r.Link.swfUrl != "" {
		enc = C_AMF_EncodeNamedString(enc, pend, av_swfUrl, r.Link.swfUrl)
		if enc == nil {
			return false
		}
	}

	if r.Link.tcUrl != "" {
		enc = C_AMF_EncodeNamedString(enc, pend, av_tcUrl, r.Link.tcUrl)
		if enc == nil {
			return false
		}
	}

	if r.Link.protocol&RTMP_FEATURE_WRITE == 0 {
		enc = C_AMF_EncodeNamedBoolean(enc, pend, av_fpad, false)
		if enc == nil {
			return false
		}
		enc = C_AMF_EncodeNamedNumber(enc, pend, av_capabilities, 15)
		if enc == nil {
			return false
		}
		enc = C_AMF_EncodeNamedNumber(enc, pend, av_audioCodecs, r.m_fAudioCodecs)
		if enc == nil {
			return false
		}
		enc = C_AMF_EncodeNamedNumber(enc, pend, av_videoCodecs, r.m_fVideoCodecs)
		if enc == nil {
			return false
		}
		enc = C_AMF_EncodeNamedNumber(enc, pend, av_videoFunction, 1)
		if enc == nil {
			return false
		}
		if r.Link.pageUrl != "" {
			enc = C_AMF_EncodeNamedString(enc, pend, av_pageUrl, r.Link.pageUrl)
			if enc == nil {
				return false
			}
		}
	}

	if r.m_fEncoding != 0.0 || r.m_bSendEncoding {
		enc = C_AMF_EncodeNamedNumber(enc, pend, av_objectEncoding, r.m_fEncoding)
		if enc == nil {
			return false
		}
	}

	if int(uintptr(incBytePtr(unsafe.Pointer(enc), 3))) >= int(uintptr(
		unsafe.Pointer(pend))) {
		return false
	}

	(*[_Gi]byte)(unsafe.Pointer(enc))[0] = 0
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	(*[_Gi]byte)(unsafe.Pointer(enc))[0] = 0
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	(*[_Gi]byte)(unsafe.Pointer(enc))[0] = AMF_OBJECT_END
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))

	/* add auth string */
	if r.Link.auth != "" {
		enc = C_AMF_EncodeBoolean(enc, pend, r.Link.lFlags&RTMP_LF_AUTH != 0)
		if enc == nil {
			return false
		}
		enc = C_AMF_EncodeString(enc, pend, r.Link.auth)
		if enc == nil {
			return false
		}
	}

	if r.Link.extras.o_num != 0 {
		for i := 0; i < int(r.Link.extras.o_num); i++ {
			enc = C_AMF_PropEncode((*C_AMFObjectProperty)(incPtr(unsafe.Pointer(
				&r.Link.extras.o_props), int(unsafe.Sizeof(r.Link.extras.o_props)), i)),
				enc, pend)

			if enc == nil {
				return false
			}
		}
	}

	packet.m_nBodySize = uint32(uintptr(decBytePtr(unsafe.Pointer(enc),
		int(uintptr(unsafe.Pointer(packet.m_body))))))

	return C_RTMP_SendPacket(r, &packet, 1)
}

// int RTMP_SendCreateStream(RTMP* r);
// rtmp.c +1725
func C_RTMP_SendCreateStream(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [256]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_createStream)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))

	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 1)
}

// int SendReleaseStream(RTMP* r);
// rtmp.c +1816
func C_SendReleaseStream(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [1024]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_releaseStream)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	enc = C_AMF_EncodeString(enc, pend, r.Link.playpath)
	if enc == nil {
		return false
	}
	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 0)
}

// int SendFCPublish(RTMP* r);
// rtmp.c +1846
func C_SendFCPublish(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [1024]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_FCPublish)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	enc = C_AMF_EncodeString(enc, pend, r.Link.playpath)
	if enc == nil {
		return false
	}
	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 0)
}

// int SendFCUnpublish(RTMP *r);
// rtmp.c +1875
func C_SendFCUnpublish(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [1024]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_FCUnpublish)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	enc = C_AMF_EncodeString(enc, pend, r.Link.playpath)

	if enc == nil {
		return false
	}

	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 0)
}

// int SendPublish(RTMP* r);
// rtmp.c +1908
func C_SendPublish(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [1024]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x04 /* source channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_LARGE
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = r.m_stream_id
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_publish)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	enc = C_AMF_EncodeString(enc, pend, r.Link.playpath)

	if enc == nil {
		return false
	}

	enc = C_AMF_EncodeString(enc, pend, av_live)
	if enc == nil {
		return false
	}

	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 1)
}

// int
// SendDeleteStream(RTMP *r, double dStreamId)
// rtmp.c +1942
func C_SendDeleteStream(r *C_RTMP, dStreamId float64) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [256]byte
	pend := (*byte)(incBytePtr(unsafe.Pointer(&pbuf[0]), 256))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av_deleteStream)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))
	enc = C_AMF_EncodeNumber(enc, pend, dStreamId)

	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	/* no response expected */
	return C_RTMP_SendPacket(r, &packet, 0)
}

// int SendBytesReceived(RTMP* r);
// rtmp.c +2080
func C_SendBytesReceived(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [256]byte
	pend := (*byte)(incBytePtr(unsafe.Pointer(&pbuf[0]), 256))

	packet.m_nChannel = 0x02 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM
	packet.m_packetType = RTMP_PACKET_TYPE_BYTES_READ_REPORT
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	packet.m_nBodySize = 4

	C_AMF_EncodeInt32(packet.m_body, pend, r.m_nBytesIn)

	r.m_nBytesInSent = r.m_nBytesIn

	return C_RTMP_SendPacket(r, &packet, 0)
}

// int SendCheckBW(RTMP* r);
// rtmp.c +2105
func C_SendCheckBW(r *C_RTMP) (ok bool) {
	var packet C_RTMPPacket
	var pbuf [256]byte
	var pend *byte = (*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&pbuf[0])) +
		unsafe.Sizeof(pbuf)))
	var enc *byte

	packet.m_nChannel = 0x03 /* control channel (invoke) */
	packet.m_headerType = RTMP_PACKET_SIZE_LARGE
	packet.m_packetType = RTMP_PACKET_TYPE_INVOKE
	packet.m_nTimeStamp = 0
	packet.m_nInfoField2 = 0
	packet.m_hasAbsTimestamp = false
	packet.m_body = &pbuf[RTMP_MAX_HEADER_SIZE]

	enc = (*byte)(unsafe.Pointer(packet.m_body))
	enc = C_AMF_EncodeString(enc, pend, av__checkbw)
	r.m_numInvokes++
	enc = C_AMF_EncodeNumber(enc, pend, float64(r.m_numInvokes))
	*enc = AMF_NULL
	enc = (*byte)(incBytePtr(unsafe.Pointer(enc), 1))

	packet.m_nBodySize = uint32(uintptr(unsafe.Pointer(enc)) - uintptr(
		unsafe.Pointer(packet.m_body)))

	return C_RTMP_SendPacket(r, &packet, 0)
}

// void AV_erase(C_RTMP_METHOD* vals, int* num, int i, int freeit);
// rtmp.c +2393
func C_AV_erase(m []C_RTMP_METHOD, i int) []C_RTMP_METHOD {
	copy(m[i:], m[i+1:])
	m[len(m)-1] = C_RTMP_METHOD{}
	return m[:len(m)-1]
}

// int HandleInvoke(RTMP* r, const char* body, unsigned int nBodySize);
// rtmp.c +2912
func C_HandleInvoke(r *C_RTMP, body *byte, nBodySize uint32) (ok bool) {

	if *body != 0x02 {
		// TODO use new logger here
		//RTMP_Log(RTMP_LOGWARNING, "%s, Sanity failed. no string method in invoke packet",
		//__FUNCTION__);
		return false
	}
	var obj C_AMFObject
	nRes := C_AMF_Decode(&obj, body, int32(nBodySize), 0)
	if nRes < 0 {
		// TODO use new logger here
		//RTMP_Log(RTMP_LOGERROR, "%s, error decoding invoke packet", __FUNCTION__);
		return false
	}

	// NOTE we don't really need this ?? still functions without it
	//C.AMF_Dump(&obj)
	//C.AMFProp_GetString(C_AMF_GetProp(&obj, nil, 0), &method)
	method := C_AMFProp_GetString(C_AMF_GetProp(&obj, "", 0))
	txn := C_AMFProp_GetNumber(C_AMF_GetProp(&obj, "", 1))
	// TODO use new logger here
	// RTMP_Log(RTMP_LOGDEBUG, "%s, server invoking <%s>", __FUNCTION__, method.av_val);

	switch method {
	case av__result:
		var methodInvoked string
		for i, m := range r.m_methodCalls {
			if float64(m.num) == txn {
				methodInvoked = m.name
				r.m_methodCalls = C_AV_erase(r.m_methodCalls, i)
				break
			}
		}
		if methodInvoked == "" {
			// TODO use new logger here
			//RTMP_Log(RTMP_LOGDEBUG, "%s, received result id %f without matching request",
			//__FUNCTION__, txn);
			goto leave
		}
		// TODO use new logger here
		//RTMP_Log(RTMP_LOGDEBUG, "%s, received result for method call <%s>", __FUNCTION__,
		//methodInvoked.av_val);
		switch methodInvoked {
		case av_connect:
			if r.Link.token != "" {
				panic("No support for link token")

			}
			if (r.Link.protocol & RTMP_FEATURE_WRITE) != 0 {
				C_SendReleaseStream(r)
				C_SendFCPublish(r)
			} else {
				panic("Link protocol has no RTMP_FEATURE_WRITE")
			}

			C_RTMP_SendCreateStream(r)
			if (r.Link.protocol & RTMP_FEATURE_WRITE) == 0 {
				panic("Link protocol has no RTMP_FEATURE_WRITE")
			}

		case av_createStream:
			r.m_stream_id = int32(C_AMFProp_GetNumber(C_AMF_GetProp(&obj, "", 3)))

			if r.Link.protocol&RTMP_FEATURE_WRITE != 0 {
				C_SendPublish(r)
			} else {
				panic("Link protocol has no RTMP_FEATURE_WRITE")
			}

		case av_play, av_publish:
			panic("Unsupported method av_play/av_publish")
		}
		//C.free(unsafe.Pointer(methodInvoked.av_val))

	case av_onBWDone:
		if r.m_nBWCheckCounter == 0 {
			C_SendCheckBW(r)
		}

	case av_onFCUnsubscribe, av_onFCSubscribe:
		panic("Unsupported method av_onFCUnsubscribe/av_onFCSubscribe")

	case av_ping:
		panic("Unsupported method av_ping")

	case av__onbwcheck:
		panic("Unsupported method av_onbwcheck")

	case av__onbwdone:
		panic("Unsupported method av_onbwdone")

	case av_close:
		panic("Unsupported method av_close")

	case av_onStatus:
		var obj2 C_AMFObject
		C_AMFProp_GetObject(C_AMF_GetProp(&obj, "", 3), &obj2)
		code := C_AMFProp_GetString(C_AMF_GetProp(&obj2, av_code, -1))

		level := C_AMFProp_GetString(C_AMF_GetProp(&obj2, av_level, -1)) // Not used.
		_ = level

		// TODO use new logger
		// RTMP_Log(RTMP_LOGDEBUG, "%s, onStatus: %s", __FUNCTION__, code.av_val);

		switch code {
		case av_NetStream_Failed, av_NetStream_Play_Failed,
			av_NetStream_Play_StreamNotFound, av_NetConnection_Connect_InvalidApp:
			panic("Unsupported method av_NetStream/av_NetStream_Play_Failed/av_netSTream_Play_StreamNotFound/av_netConnection_Connect_invalidApp")

		case av_NetStream_Play_Start, av_NetStream_Play_PublishNotify:
			panic("Unsupported method av_NetStream_Play_Start/av_NetStream_Play_PublishNotify")

		case av_NetStream_Publish_Start:
			r.m_bPlaying = true
			for i, m := range r.m_methodCalls {
				if m.name == av_publish {
					r.m_methodCalls = C_AV_erase(r.m_methodCalls, i)
					break
				}
			}

		case av_NetStream_Play_Complete, av_NetStream_Play_Stop, av_NetStream_Play_UnpublishNotify:
			panic("Unsupported method av_NetStream_Play_Complete/av_NetStream_Play_Stop/av_NetStream_Play_UnpublishNotify")

		case av_NetStream_Seek_Notify:
			panic("Unsupported method av_netStream_Seek_Notify")

		case av_NetStream_Pause_Notify:
			panic("Unsupported method av_NetStream_Pause_Notify")
		}

	case av_playlist_ready:
		panic("Unsupported method av_playlist_ready")

	default:
		panic(fmt.Sprintf("unknown method: %q", method))
	}
leave:
	C_AMF_Reset(&obj)
	// None of the methods we implement will result in a true return.
	return ok
}

// void HandleChangeChunkSize(RTMP* r, const RTMPPacket* packet);
// rtmp.c +3345
func C_HandleChangeChunkSize(r *C_RTMP, packet *C_RTMPPacket) {
	if packet.m_nBodySize >= 4 {
		//r.m_inChunkSize = int32(C.AMF_DecodeInt32((*byte)(unsafe.Pointer(packet.m_body))))
		r.m_inChunkSize = int32(C_AMF_DecodeInt32((*[_Gi]byte)(unsafe.Pointer(packet.m_body))[:4]))
		// TODO use new logger here
		// RTMP_Log(RTMP_LOGDEBUG, "%s, received: chunk size change to %d", __FUNCTION__, r.m_inChunkSize);
	}
}

// void HandleServerBW(RTMP* r, const RTMPPacket* packet);
// rtmp.c +3508
func C_HandlServerBW(r *C_RTMP, packet *C_RTMPPacket) {
	r.m_nServerBW = int32(C_AMF_DecodeInt32((*[_Gi]byte)(unsafe.Pointer(packet.m_body))[:4]))
	// TODO use new logger here
	// RTMP_Log(RTMP_LOGDEBUG, "%s: server BW = %d", __FUNCTION__, r.m_nServerBW);
}

// void HandleClientBW(RTMP* r, const RTMPPacket* packet);
// rtmp.c +3515
func C_HandleClientBW(r *C_RTMP, packet *C_RTMPPacket) {
	r.m_nClientBW = int32(C_AMF_DecodeInt32((*[_Gi]byte)(unsafe.Pointer(packet.m_body))[:4]))
	//r.m_nClientBW = int32(C.AMF_DecodeInt32((*byte)(unsafe.Pointer(packet.m_body))))

	if packet.m_nBodySize > 4 {
		r.m_nClientBW2 = (*[_Gi]byte)(unsafe.Pointer(packet.m_body))[4]
	} else {
		r.m_nClientBW2 = 0xff
	}
	// TODO use new logger here
	// RTMP_Log(RTMP_LOGDEBUG, "%s: client BW = %d %d", __FUNCTION__, r.m_nClientBW,
	//r.m_nClientBW2);
}

// static int DecodeInt32LE(const char* data);
// rtmp.c +3527
func C_DecodeInt32LE(data []byte) int32 {
	return int32(data[3])<<24 | int32(data[2])<<16 | int32(data[1])<<8 | int32(data[0])
}

// int EncodeInt32LE(char* output, int nVal);
// rtmp.c +3537
func C_EncodeInt32LE(output *byte, nVal int32) int32 {
	*output = byte(nVal)
	nVal >>= 8
	(*[_Gi]byte)(unsafe.Pointer(output))[1] = byte(nVal)
	nVal >>= 8
	(*[_Gi]byte)(unsafe.Pointer(output))[2] = byte(nVal)
	nVal >>= 8
	(*[_Gi]byte)(unsafe.Pointer(output))[3] = byte(nVal)
	return 4
}

// int RTMP_ReadPacket(RTMP* r, RTMPPacket* packet);
// rtmp.c +3550
func C_RTMP_ReadPacket(r *C_RTMP, packet *C_RTMPPacket) (ok bool) {
	var hbuf [RTMP_MAX_HEADER_SIZE]uint8
	var header *byte
	header = (*byte)(unsafe.Pointer(&hbuf[0]))
	var nSize, hSize, nToRead, nChunk int32
	var extendedTimestamp int32

	if C_ReadN(r, &hbuf[0], 1) == 0 {
		log.Println("C_RTMP_ReadPacket: failed to read RTMP packet header!")
		return false
	}

	packet.m_headerType = (hbuf[0] & 0xc0) >> 6
	packet.m_nChannel = int32(hbuf[0] & 0x3f)
	header = (*byte)(incBytePtr(unsafe.Pointer(header), 1))

	switch {
	case packet.m_nChannel == 0:
		if C_ReadN(r, &hbuf[1], 1) != 1 {
			log.Println("C_RTMP_ReadPacket: failed to read rtmp packet header 2nd byte.")
			return false
		}

		packet.m_nChannel = int32(hbuf[1])
		packet.m_nChannel += 64
		header = (*byte)(incBytePtr(unsafe.Pointer(header), 1))
	case packet.m_nChannel == 1:
		var tmp int32

		if C_ReadN(r, &hbuf[1], 2) != 2 {
			log.Println("C_RTMP_ReadPacket: failed to read RTMP packet 3rd byte")
			return false
		}

		tmp = int32((hbuf[2] << 8) + hbuf[1])
		packet.m_nChannel = tmp + 64
		header = (*byte)(incBytePtr(unsafe.Pointer(header), 2))
	}

	nSize = int32(packetSize[packet.m_headerType])

	if packet.m_nChannel >= r.m_channelsAllocatedIn {
		n := packet.m_nChannel + 10
		timestamp := append(r.m_channelTimestamp, make([]int32, 10)...)

		var packets []*C_RTMPPacket
		if r.m_vecChannelsIn == nil {
			packets = make([]*C_RTMPPacket, n)
		} else {
			packets = append(r.m_vecChannelsIn[:packet.m_nChannel:packet.m_nChannel], make([]*C_RTMPPacket, 10)...)
		}

		r.m_channelTimestamp = timestamp
		r.m_vecChannelsIn = packets

		for i := int(r.m_channelsAllocatedIn); i < len(r.m_channelTimestamp); i++ {
			r.m_channelTimestamp[i] = 0
		}
		for i := int(r.m_channelsAllocatedIn); i < int(n); i++ {
			r.m_vecChannelsIn[i] = nil
		}
		r.m_channelsAllocatedIn = n
	}

	switch {
	case nSize == RTMP_LARGE_HEADER_SIZE:
		packet.m_hasAbsTimestamp = true
	case nSize < RTMP_LARGE_HEADER_SIZE:
		if r.m_vecChannelsIn[packet.m_nChannel] != nil {
			*packet = *(r.m_vecChannelsIn[packet.m_nChannel])
		}
	}

	nSize--

	if nSize > 0 && C_ReadN(r, header, int(nSize)) != int(nSize) {
		log.Println("C_RTMP_ReadPacket: failed to read rtmp packet header.")
		return false
	}

	hSize = int32(uintptr(incBytePtr(decBytePtr(unsafe.Pointer(header), int(uintptr(
		unsafe.Pointer(&hbuf[0])))), int(nSize))))

	if nSize >= 3 {
		packet.m_nTimeStamp = C_AMF_DecodeInt24((*[_Gi]byte)(unsafe.Pointer(header))[:3])

		if nSize >= 6 {
			packet.m_nBodySize = C_AMF_DecodeInt24((*[_Gi]byte)(unsafe.Pointer(header))[3:6])
			packet.m_nBytesRead = 0

			if nSize > 6 {
				packet.m_packetType = (*[_Gi]byte)(unsafe.Pointer(header))[6]

				if nSize == 11 {
					packet.m_nInfoField2 = C_DecodeInt32LE((*[_Gi]byte)(unsafe.Pointer(header))[7:11])
				}
			}
		}
	}
	extendedTimestamp = 0
	if packet.m_nTimeStamp == 0xffffff {
		extendedTimestamp = 1
	}

	if extendedTimestamp != 0 {
		if C_ReadN(r, (*byte)(incBytePtr(unsafe.Pointer(header), int(nSize))), 4) != 4 {
			log.Println("RTMPRead_Packet: Failed to read extended timestamp")
			return false
		}
		// TODO: port this
		packet.m_nTimeStamp = C_AMF_DecodeInt32((*[_Gi]byte)(unsafe.Pointer(header))[nSize : nSize+4])
		hSize += 4
	}

	if packet.m_nBodySize > 0 && packet.m_body == nil {
		// TODO: port this
		if !C_RTMPPacket_Alloc(packet, packet.m_nBodySize) {
			log.Println("RTMPRead_Packet: failed to allocate packet")
			return false
		}
		packet.m_headerType = (hbuf[0] & 0xc0) >> 6
	}

	nToRead = int32(packet.m_nBodySize - packet.m_nBytesRead)
	nChunk = r.m_inChunkSize

	if nToRead < nChunk {
		nChunk = nToRead
	}

	if packet.m_chunk != nil {
		packet.m_chunk.c_headerSize = hSize
		copy(packet.m_chunk.c_header[:], hbuf[:hSize])
		packet.m_chunk.c_chunk = (*[_Gi]byte)(unsafe.Pointer(packet.m_body))[packet.m_nBytesRead : packet.m_nBytesRead+uint32(nChunk)]
	}

	if C_ReadN(r, (*byte)(incBytePtr(unsafe.Pointer(packet.m_body), int(packet.m_nBytesRead))),
		int(nChunk)) != int(nChunk) {
		log.Println("C_RTMP_ReadPacket: failed to read RTMP packet body")
		return false
	}

	packet.m_nBytesRead += uint32(nChunk)

	// keep the packet as ref for other packets on this channel
	if r.m_vecChannelsIn[packet.m_nChannel] == nil {
		r.m_vecChannelsIn[packet.m_nChannel] = &C_RTMPPacket{}
	}
	*(r.m_vecChannelsIn[packet.m_nChannel]) = *packet

	if extendedTimestamp != 0 {
		r.m_vecChannelsIn[packet.m_nChannel].m_nTimeStamp = 0xffffff
	}

	// TODO: port this
	if C_RTMPPacket_IsReady(packet) {
		if !packet.m_hasAbsTimestamp {
			// timestamps seem to always be relative
			packet.m_nTimeStamp += uint32(r.m_channelTimestamp[packet.m_nChannel])
		}
		r.m_channelTimestamp[packet.m_nChannel] = int32(packet.m_nTimeStamp)

		r.m_vecChannelsIn[packet.m_nChannel].m_body = nil
		r.m_vecChannelsIn[packet.m_nChannel].m_nBytesRead = 0
		r.m_vecChannelsIn[packet.m_nChannel].m_hasAbsTimestamp = false
	} else {
		packet.m_body = nil /* so it won't be erased on free */
	}
	return true
}

// int HandShake(RTMP* r, int FP9HandShake);
// rtmp.c +3744
func C_HandShake(r *C_RTMP, FP9HandShake int32) (ok bool) {
	var uptime, suptime uint32
	var typ byte
	//clientbuf := make([]byte, RTMP_SIG_SIZE+1)
	var clientbuf [RTMP_SIG_SIZE + 1]byte
	clientsig := (*byte)(incBytePtr(unsafe.Pointer(&clientbuf[0]), 1))
	//serversig := make([]byte, RTMP_SIG_SIZE)
	var serversig [RTMP_SIG_SIZE]byte

	clientbuf[0] = 0x03 // not encrypted

	// TODO: port rtmp_getTime
	uptime = inet.Htonl(uint32(C_RTMP_GetTime()))
	memmove(unsafe.Pointer(clientsig), unsafe.Pointer(&uptime), 4)

	memset((*byte)(sliceToPtr((*[_Gi]byte)(unsafe.Pointer(clientsig))[4:])), 0, 4)

	for i := 8; i < RTMP_SIG_SIZE; i++ {
		(*[_Gi]byte)(unsafe.Pointer(clientsig))[i] = byte(rand.Intn(256))
	}

	if !C_WriteN(r, unsafe.Pointer(&clientbuf[0]), RTMP_SIG_SIZE+1) {
		return false
	}

	if C_ReadN(r, (*byte)(unsafe.Pointer(&typ)), 1) != 1 {
		return false
	}

	if debugMode {
		log.Printf("C_HandShake: Type answer: %v\n", typ)
	}
	if typ != clientbuf[0] {
		log.Printf("C_HandShake: type mismatch: client sent %v, server sent: %v\n",
			clientbuf[0], typ)
	}
	if C_ReadN(r, (*byte)(unsafe.Pointer(&serversig[0])), RTMP_SIG_SIZE) != RTMP_SIG_SIZE {
		return false
	}

	// decode server response
	memmove(unsafe.Pointer(&suptime), unsafe.Pointer(&serversig[0]), 4)
	suptime = inet.Ntohl(suptime)

	// 2nd part of handshake
	if !C_WriteN(r, unsafe.Pointer(&serversig[0]), RTMP_SIG_SIZE) {
		return false
	}

	if C_ReadN(r, (*byte)(unsafe.Pointer(&serversig[0])), RTMP_SIG_SIZE) != RTMP_SIG_SIZE {
		return false
	}

	if !bytes.Equal(serversig[:RTMP_SIG_SIZE], clientbuf[1:RTMP_SIG_SIZE+1]) {
		log.Printf("Client signature does not match: %q != %q",
			serversig[:RTMP_SIG_SIZE], clientbuf[1:RTMP_SIG_SIZE+1])
	}
	return true
}

// int RTMP_SendPacket(RTMP* r, RTMPPacket* packet, int queue);
// rtmp.c +3896
func C_RTMP_SendPacket(r *C_RTMP, packet *C_RTMPPacket, queue int) (ok bool) {
	var prevPacket *C_RTMPPacket
	last := 0
	var header, hptr, hend, buffer, tbuf, toff unsafe.Pointer
	var goHbuf [RTMP_MAX_HEADER_SIZE]byte
	var hbuf = unsafe.Pointer(&goHbuf[0])
	var c byte
	var t uint32

	if packet.m_nChannel >= r.m_channelsAllocatedOut {
		n := int(packet.m_nChannel + 10)

		var packets []*C_RTMPPacket
		if r.m_vecChannelsOut == nil {
			packets = make([]*C_RTMPPacket, n)
		} else {
			packets = append(r.m_vecChannelsOut[:packet.m_nChannel:packet.m_nChannel], make([]*C_RTMPPacket, 10)...)
		}
		r.m_vecChannelsOut = packets

		for i := int(r.m_channelsAllocatedOut); i < n; i++ {
			r.m_vecChannelsOut[i] = nil
		}

		r.m_channelsAllocatedOut = int32(n)
	}
	prevPacket = r.m_vecChannelsOut[packet.m_nChannel]

	if prevPacket != nil && packet.m_headerType != RTMP_PACKET_SIZE_LARGE {
		// compress a bit by using the prev packet's attributes
		if prevPacket.m_nBodySize == packet.m_nBodySize &&
			prevPacket.m_packetType == packet.m_packetType &&
			packet.m_headerType == RTMP_PACKET_SIZE_MEDIUM {

			packet.m_headerType = RTMP_PACKET_SIZE_SMALL
		}

		if prevPacket.m_nTimeStamp == packet.m_nTimeStamp &&
			packet.m_headerType == RTMP_PACKET_SIZE_SMALL {
			packet.m_headerType = RTMP_PACKET_SIZE_MINIMUM
		}

		last = int(prevPacket.m_nTimeStamp)
	}

	if packet.m_headerType > 3 {
		log.Printf("Sanity failed! trying to send header of type: 0x%02x.",
			packet.m_headerType)
		return false
	}

	nSize := packetSize[int(packet.m_headerType)]
	hSize := nSize
	cSize := 0
	t = uint32(int(packet.m_nTimeStamp) - last)

	if packet.m_body != nil {
		header = decBytePtr(unsafe.Pointer(packet.m_body), nSize)
		hend = unsafe.Pointer(packet.m_body)
	} else {
		header = incBytePtr(hbuf, 6)
		// TODO: be cautious about this sizeof - make sure it works how you think it
		// does. C code used sizeof(hbuf) where hbuf is a *char
		hend = incBytePtr(hbuf, RTMP_MAX_HEADER_SIZE)
	}

	switch {
	case packet.m_nChannel > 319:
		cSize = 2
	case packet.m_nChannel > 63:
		cSize = 1
	}

	if cSize != 0 {
		header = decBytePtr(header, cSize)
		hSize += cSize
	}

	if t >= 0xffffff {
		header = decBytePtr(header, 4)
		hSize += 4
		log.Printf("Larger timestamp than 24-bit: 0x%v", t)
	}

	hptr = header
	c = packet.m_headerType << 6

	switch cSize {
	case 0:
		c |= byte(packet.m_nChannel)
	case 1:
	case 2:
		c |= byte(1)
	}
	*(*byte)(hptr) = c
	hptr = incBytePtr(hptr, 1)

	if cSize != 0 {
		tmp := packet.m_nChannel - 64
		*(*byte)(hptr) = byte(tmp & 0xff)
		hptr = incBytePtr(hptr, 1)

		if cSize == 2 {
			*(*byte)(hptr) = byte(tmp >> 8)
			hptr = incBytePtr(hptr, 1)
		}
	}

	if nSize > 1 {
		res := t
		if t > 0xffffff {
			res = 0xffffff
		}
		hptr = unsafe.Pointer(C_AMF_EncodeInt24((*byte)(hptr), (*byte)(hend), int32(res)))
	}

	if nSize > 4 {
		hptr = unsafe.Pointer(C_AMF_EncodeInt24((*byte)(hptr), (*byte)(hend), (int32(packet.m_nBodySize))))
		*(*byte)(hptr) = packet.m_packetType
		hptr = incBytePtr(hptr, 1)
	}

	if nSize > 8 {
		// TODO: port this
		hptr = incBytePtr(hptr, int(C_EncodeInt32LE((*byte)(hptr), packet.m_nInfoField2)))
	}

	if t >= 0xffffff {
		hptr = unsafe.Pointer(C_AMF_EncodeInt32((*byte)(hptr), (*byte)(hend), (int32)(t)))
	}

	nSize = int(packet.m_nBodySize)
	buffer = unsafe.Pointer(packet.m_body)
	nChunkSize := int(r.m_outChunkSize)

	if debugMode {
		log.Printf("C_RTMP_SendPacket: fd=%v, size=%v", r.m_sb.sb_socket, nSize)
	}

	for (nSize + hSize) != 0 {
		if nSize < nChunkSize {
			nChunkSize = nSize
		}

		if tbuf != nil {
			copy((*[_Gi]byte)(toff)[:nChunkSize+hSize], (*[_Gi]byte)(header)[:nChunkSize+hSize])
			toff = incBytePtr(toff, nChunkSize+hSize)
		} else {
			// TODO: port this
			if !C_WriteN(r, header, nChunkSize+hSize) {
				return false
			}
		}

		nSize -= nChunkSize
		buffer = incBytePtr(buffer, nChunkSize)
		hSize = 0

		if nSize > 0 {
			header = decBytePtr(buffer, 1)
			hSize = 1

			if cSize != 0 {
				header = decBytePtr(header, cSize)
				hSize += cSize
			}

			if t >= 0xffffff {
				header = decBytePtr(header, 4)
				hSize += 4
			}

			*(*byte)(header) = 0xc0 | c

			if cSize != 0 {
				tmp := int(packet.m_nChannel) - 64
				(*[_Gi]byte)(header)[1] = byte(tmp)

				if cSize == 2 {
					(*[_Gi]byte)(header)[2] = byte(tmp >> 8)
				}
			}
			if t >= 0xffffff {
				extendedTimestamp := incBytePtr(header, 1+cSize)
				C_AMF_EncodeInt32((*byte)(extendedTimestamp),
					(*byte)(incBytePtr(extendedTimestamp, 4)), (int32)(t))
			}
		}
	}

	if tbuf != nil {
		ok := C_WriteN(r, tbuf, int(uintptr(decBytePtr(toff, int(uintptr(tbuf))))))
		////C.free(tbuf)
		tbuf = nil

		if !ok {
			return false
		}
	}

	// We invoked a remote method
	// TODO: port the const
	if packet.m_packetType == RTMP_PACKET_TYPE_INVOKE {
		// TODO: port C_AVal
		var ptr unsafe.Pointer
		ptr = incBytePtr(unsafe.Pointer(packet.m_body), 1)
		method := C_AMF_DecodeString((*[_Gi]byte)(unsafe.Pointer(ptr))[:2])

		if debugMode {
			log.Printf("invoking %v", method)
		}
		// keep it in call queue till result arrives
		if queue != 0 {
			ptr = incBytePtr(ptr, 3+len(method))
			txn := int32(C_AMF_DecodeNumber((*[_Gi]byte)(unsafe.Pointer(ptr))[:8]))
			r.m_methodCalls = append(r.m_methodCalls, C_RTMP_METHOD{name: method, num: txn})
		}
	}

	if r.m_vecChannelsOut[packet.m_nChannel] == nil {
		r.m_vecChannelsOut[packet.m_nChannel] = &C_RTMPPacket{}
	}
	*(r.m_vecChannelsOut[packet.m_nChannel]) = *packet

	return true
}

// void RTMP_Close(RTMP *r);
// rtmp.c +4168
func C_RTMP_Close(r *C_RTMP) {
	C_CloseInternal(r, 0)
}

// static void CloseInternal(RTMP *r, int reconnect);
// rtmp.c +4175
func C_CloseInternal(r *C_RTMP, reconnect int32) {
	var i int32

	if C_RTMP_IsConnected(r) != 0 {
		if r.m_stream_id > 0 {
			i = r.m_stream_id
			if r.Link.protocol&RTMP_FEATURE_WRITE != 0 {
				C_SendFCUnpublish(r)
			}
			C_SendDeleteStream(r, float64(i))
		}
		C_RTMPSockBuf_Close(&r.m_sb)
	}

	r.m_stream_id = -1
	r.m_sb.sb_socket = -1
	r.m_nBWCheckCounter = 0
	r.m_nBytesIn = 0
	r.m_nBytesInSent = 0

	r.m_write.m_nBytesRead = 0
	C_RTMPPacket_Free(&r.m_write)

	// NOTE: C frees - not using in our case
	for i := 0; i < int(r.m_channelsAllocatedIn); i++ {
		if r.m_vecChannelsIn[i] != nil {
			r.m_vecChannelsIn[i] = nil
		}
	}

	//C.free(unsafe.Pointer(r.m_vecChannelsOut))
	r.m_vecChannelsOut = nil
	r.m_channelsAllocatedOut = 0
	r.m_methodCalls = nil //C_AV_clear(r.m_methodCalls, r.m_numCalls)

	r.m_methodCalls = r.m_methodCalls[:0]
	r.m_numInvokes = 0

	r.m_bPlaying = false
	r.m_sb.sb_size = 0

	r.m_msgCounter = 0
	r.m_resplen = 0
	r.m_unackd = 0

	if ((r.Link.lFlags & RTMP_LF_FTCU) != 0) && (reconnect == 0) {
		r.Link.app = ""
		r.Link.lFlags ^= RTMP_LF_FAPU
	}

	if reconnect == 0 {
		r.Link.playpath0 = ""
	}
}

// int RTMPSockBuf_Fill(RTMPSockBuf* sb);
// rtmp.c +4253
func C_RTMPSockBuf_Fill(sb *C_RTMPSockBuf) int {
	var nBytes int

	if sb.sb_size == 0 {
		sb.sb_start = &sb.sb_buf[0]
	}

	for {
		nBytes = int(unsafe.Sizeof(sb.sb_buf)) - 1 - int(sb.sb_size) -
			int(uintptr(unsafe.Pointer(sb.sb_start))-uintptr(unsafe.Pointer(
				&sb.sb_buf[0])))

		// TODO: figure out what to do with recv
		nBytes = int(C.recv(C.int(sb.sb_socket), unsafe.Pointer(uintptr(unsafe.Pointer(
			sb.sb_start))+uintptr(int(sb.sb_size))), C.size_t(nBytes), 0))

		if nBytes != -1 {
			sb.sb_size += int32(nBytes)
		} else {
			log.Println("C_RTMPSockBuf_Fill: recv error!")
		}
		break
	}
	return nBytes
}

// int RTMPSockBuf_Send(RTMPSockBuf* sb, const char* buf, int len);
// rtmp.c +4297
// TODO replace send with golang net connection send
func C_RTMPSockBuf_Send(sb *C_RTMPSockBuf, buf *byte, l int32) int32 {
	return int32(C.send(C.int(sb.sb_socket), unsafe.Pointer(buf), C.size_t(l), 0))
}

// int
// RTMPSockBuf_Close(RTMPSockBuf *sb)
// rtmp.c +4369
func C_RTMPSockBuf_Close(sb *C_RTMPSockBuf) int32 {
	if sb.sb_socket != -1 {
		return int32(C.close(C.int(sb.sb_socket)))
	}
	return 0
}

// int RTMP_Write(RTMP* r, const char* buf, int size);
// rtmp.c +5136
func C_RTMP_Write(r *C_RTMP, buf []byte) int {
	// TODO: port RTMPPacket
	var pkt = &r.m_write
	var pend, enc []byte
	size := len(buf)
	var num int

	pkt.m_nChannel = 0x04
	pkt.m_nInfoField2 = r.m_stream_id
	for len(buf) != 0 {
		if pkt.m_nBytesRead == 0 {
			if size < minDataSize {
				log.Printf("size: %d\n", size)
				log.Printf("too small \n")
				return 0
			}

			if buf[0] == 'F' && buf[1] == 'L' && buf[2] == 'V' {
				buf = buf[13:]
			}

			pkt.m_packetType = buf[0]
			buf = buf[1:]
			pkt.m_nBodySize = C_AMF_DecodeInt24(buf[:3])
			buf = buf[3:]
			pkt.m_nTimeStamp = C_AMF_DecodeInt24(buf[:3])
			buf = buf[3:]
			pkt.m_nTimeStamp |= uint32(buf[0]) << 24
			buf = buf[4:]

			if ((pkt.m_packetType == RTMP_PACKET_TYPE_AUDIO ||
				pkt.m_packetType == RTMP_PACKET_TYPE_VIDEO) &&
				pkt.m_nTimeStamp == 0) || pkt.m_packetType == RTMP_PACKET_TYPE_INFO {

				pkt.m_headerType = RTMP_PACKET_SIZE_LARGE

				if pkt.m_packetType == RTMP_PACKET_TYPE_INFO {
					pkt.m_nBodySize += 16
				}
			} else {
				pkt.m_headerType = RTMP_PACKET_SIZE_MEDIUM
			}
			// TODO: Port this
			if !C_RTMPPacket_Alloc(pkt, pkt.m_nBodySize) {
				log.Println("Failed to allocate packet")
				return 0
			}

			enc = (*[_Gi]byte)(unsafe.Pointer(pkt.m_body))[:pkt.m_nBodySize]
			pend = enc[pkt.m_nBodySize:]

			if pkt.m_packetType == RTMP_PACKET_TYPE_INFO {
				enc = (*[_Gi]byte)(unsafe.Pointer(C_AMF_EncodeString((*byte)(unsafe.Pointer(&enc[0])),
					(*byte)(unsafe.Pointer(&pend[0])), setDataFrame)))[:pkt.m_nBodySize]

				// TODO: work out what to do with this
				pkt.m_nBytesRead = uint32(float64(uintptr(unsafe.Pointer(&enc[0])) -
					uintptr(unsafe.Pointer(pkt.m_body))))
			}

		} else {
			enc = ((*[_Gi]byte)(unsafe.Pointer(pkt.m_body))[:pkt.m_nBodySize])[pkt.m_nBytesRead:]
		}
		num = int(pkt.m_nBodySize - pkt.m_nBytesRead)
		if num > len(buf) {
			num = len(buf)
		}

		copy(enc[:num], buf[:num])
		pkt.m_nBytesRead += uint32(num)
		buf = buf[num:]
		if pkt.m_nBytesRead == pkt.m_nBodySize {
			// TODO: Port this
			ok := C_RTMP_SendPacket(r, pkt, 0)
			// TODO: Port this
			C_RTMPPacket_Free(pkt)
			pkt.m_nBytesRead = 0
			if !ok {
				return -1
			}
			if len(buf) < 4 {
				return size + (len(buf) - 4)
			}
			buf = buf[4:]
		}
	}
	return size
}

func memmove(to, from unsafe.Pointer, n uintptr) {
	if to != nil && from != nil && n != 0 {
		copy((*[_Gi]byte)(to)[:n], (*[_Gi]byte)(from)[:n])
	}
}

// TODO: write test for this func
func memcmp(a, b unsafe.Pointer, size int) int {
	for i := 0; i < size; i++ {
		aValue := (*[_Gi]byte)(a)[i]
		bValue := (*[_Gi]byte)(b)[i]
		if aValue != bValue {
			if aValue < bValue {
				return -1
			} else {
				return 1
			}
		}
	}
	return 0
}

func memset(ptr *byte, val byte, num int) {
	for i := 0; i < num; i++ {
		(*[_Gi]byte)(unsafe.Pointer(ptr))[i] = val
	}
}

func strLen(str string) int {
	return len(str)
}

// wrapper for converting byte pointer to unsafe.Pointer
func bToUP(b *byte) unsafe.Pointer {
	return unsafe.Pointer(b)
}

// Creates a new C style string from a go string
func goStrToCStr(str string) *byte {
	l := len(str)
	slice := make([]byte, l+1)
	ptr := unsafe.Pointer(&[]byte(str)[0])
	for i := 0; i < l; i++ {
		slice[i] = (*[_Gi]byte)(ptr)[i]
	}
	slice[l] = '\x00'
	return &slice[0]
}

// TODO: need a test in rtmp_test.go
func cStrToGoStr(cStr *byte) string {
	return string((*[_Gi]byte)(unsafe.Pointer(cStr))[:strlen(cStr)])
}

// Duplicates a string given as a byte pointer
func strdup(str *byte) *byte {
	length := strlen(str)
	newMem := make([]byte, length+1)
	oldMem := (*[_Gi]byte)(unsafe.Pointer(str))[:length+1]
	copy(newMem, oldMem)
	return &newMem[0]
}

// Gets the length of the string found at str - length is number of chars
// between start and terminating null char. Returns -1 if a null char is not
// found before a count of 1000
func strlen(str *byte) int32 {
	for i := 0; i < 1000; i++ {
		if (*[_Gi]byte)(unsafe.Pointer(str))[i] == '\000' {
			return int32(i)
		}
	}
	return int32(-1)
}

// Returns the pointer where the first occurance of val is located in a string
// which is terminated by a null char. Returns nil if null char is not found
// before a count of 10000
func strchr(str *byte, val byte) *byte {
	for i := 0; i < 1000; i++ {
		if (*[_Gi]byte)(unsafe.Pointer(str))[i] == val {
			return &(*[_Gi]byte)(unsafe.Pointer(str))[i]
		}
		if (*[_Gi]byte)(unsafe.Pointer(str))[i] == '\000' {
			break
		}
	}
	return nil
}

// TODO: need a test in rtmp_test.go
// Porting: http://www.ai.mit.edu/projects/im/cam8/cam8/working/CAMlib/tcl/compat/strstr.c
func strstr(str *byte, substring *byte) *byte {
	var a, b *byte
	/* First scan quickly through the two strings looking for a
	 * single-character match.  When it's found, then compare the
	 * rest of the substring.
	 */

	b = substring
	if *b == 0 {
		return str
	}

	for *str != 0 {
		str = (*byte)(incBytePtr(unsafe.Pointer(str), 1))
		if *str != *b {
			continue
		}
		a = str
		for {
			if *b == 0 {
				return str
			}
			tmp1 := a
			a = (*byte)(incBytePtr(unsafe.Pointer(a), 1))
			tmp2 := b
			b = (*byte)(incBytePtr(unsafe.Pointer(b), 1))
			if *tmp1 != *tmp2 {
				break
			}
		}
		b = substring
	}
	return nil
}

// Creates mem of the size noOfBytes. returns as unsafe pointer
func malloc(nOfBytes uintptr) unsafe.Pointer {
	mem := make([]byte, int(nOfBytes))
	return unsafe.Pointer(&mem[0])
}

// incBytePtr returns an unsafe.Pointer to a byte that is inc positive positions
// from the passed ptr
func incBytePtr(ptr unsafe.Pointer, inc int) unsafe.Pointer {
	return incPtr(ptr, inc, 1)
}

// incPtr attempts to replicate C like pointer arithmatic functionality
func incPtr(ptr unsafe.Pointer, inc, typeSize int) unsafe.Pointer {
	return unsafe.Pointer(uintptr(ptr) + uintptr(inc*typeSize))
}

// incPtr attempts to replicate C like pointer arithmatic functionality
func decPtr(ptr unsafe.Pointer, dec, typeSize int) unsafe.Pointer {
	return unsafe.Pointer(uintptr(ptr) - uintptr(dec*typeSize))
}

// decBytePtr returns an unsafe.Pointer to a byte that is dec negative positions
// from ptr
func decBytePtr(ptr unsafe.Pointer, dec int) unsafe.Pointer {
	return decPtr(ptr, dec, 1)
}

// sliceToPtr get's the address of the first data element and returns as unsafe
// pointer
func sliceToPtr(data []byte) unsafe.Pointer {
	if len(data) == 0 {
		return nil
	}
	return unsafe.Pointer(&data[0])
}

var rtmpErrs = [...]string{
	1: "rtmp: not connected",
	2: "rtmp: write error",
	3: "rtmp: not started",
}

type Err uint

func (e Err) Error() string {
	if 0 <= int(e) && int(e) < len(rtmpErrs) {
		s := rtmpErrs[e]
		if s != "" {
			return s
		}
	}
	return "rtmp: " + strconv.Itoa(int(e))
}