av/rtmp/amf.go

/*
NAME
  amf.go

DESCRIPTION
  See Readme.md

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

LICENSE
  amf.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

/*
#cgo CFLAGS: -I/usr/local/include/librtmp
#cgo LDFLAGS: -lrtmp -Wl,-rpath=/usr/local/lib

#include <stdlib.h>
#include <string.h>
#include <rtmp.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/tcp.h>

typedef enum {
  RTMPT_OPEN=0, RTMPT_SEND, RTMPT_IDLE, RTMPT_CLOSE
} RTMPTCmd;

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

import (
	"log"
	"unsafe"
)

var (
	AMFObj_Invalid  C_AMFObject
	AMFProp_Invalid = C_AMFObjectProperty{p_type: AMF_INVALID}
)

// char* AMFPropEncode(AMFOBjectProperty* prop, char* pBufer, char* pBufEnd);
// amf.c +366
func C_AMF_PropEncode(p *C_AMFObjectProperty, pBuffer *byte, pBufEnd *byte) *byte {
	if p.p_type == AMF_INVALID {
		return nil
	}

	if p.p_type != AMF_NULL && int(uintptr(unsafe.Pointer(pBuffer)))+
		int(p.p_name.av_len)+2+1 >= int(
		uintptr(unsafe.Pointer(pBufEnd))) {
		return nil
	}

	if p.p_type != AMF_NULL && p.p_name.av_len != 0 {
		*indxBytePtr(unsafe.Pointer(pBuffer), 0) = byte(p.p_name.av_len >> 8)
		pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))
		*indxBytePtr(unsafe.Pointer(pBuffer), 0) = byte(p.p_name.av_len & 0xff)
		pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))
		memmove(unsafe.Pointer(pBuffer), unsafe.Pointer(p.p_name.av_val),
			uintptr(p.p_name.av_len))
		pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), int(p.p_name.av_len)))
	}

	switch p.p_type {
	case AMF_NUMBER:
		pBuffer = C_AMF_EncodeNumber(pBuffer, pBufEnd, float64(p.p_vu.p_number))
	case AMF_BOOLEAN:
		val := 0
		if p.p_vu.p_number != 0 {
			val = 1
		}
		pBuffer = C_AMF_EncodeBoolean(pBuffer, pBufEnd, val)
	case AMF_STRING:
		pBuffer = C_AMF_EncodeString(pBuffer, pBufEnd, &p.p_vu.p_aval)
	case AMF_NULL:
		if uintptr(incBytePtr(unsafe.Pointer(pBuffer), 1)) >= uintptr(unsafe.Pointer(
			pBufEnd)) {
			return nil
		}
		*(*byte)(unsafe.Pointer(pBuffer)) = AMF_NULL
		pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))
	case AMF_OBJECT:
		pBuffer = C_AMF_Encode(&p.p_vu.p_object, pBuffer, pBufEnd)
		//pBuffer = (*byte)(unsafe.Pointer(C.AMF_Encode(&p.p_vu.p_object, (*byte)(
		//unsafe.Pointer(pBuffer)), (*byte)(unsafe.Pointer(pBufEnd)))))
	case AMF_ECMA_ARRAY:
		pBuffer = C_AMF_EncodeEcmaArray(&p.p_vu.p_object, pBuffer, pBufEnd)
		//pBuffer = (*byte)(unsafe.Pointer(C.AMF_EncodeEcmaArray(&p.p_vu.p_object, (*byte)(unsafe.Pointer(pBuffer)), (*byte)(unsafe.Pointer(pBufEnd)))))
	case AMF_STRICT_ARRAY:
		//pBuffer = (*byte)(unsafe.Pointer(C.AMF_EncodeArray(&p.p_vu.p_object, (*byte)(unsafe.Pointer(pBuffer)), (*byte)(unsafe.Pointer(pBufEnd)))))
		pBuffer = C_AMF_EncodeArray(&p.p_vu.p_object, pBuffer, pBufEnd)
	default:
		log.Println("C_AMF_PropEncode: invalid type!")
		pBuffer = nil
	}
	return pBuffer
}

// char* AMF_Encode(AMFObject* obj, char* pBuffer, char* pBufEnd);
// amf.c +891
func C_AMF_Encode(obj *C_AMFObject, pBuffer *byte, pBufEnd *byte) *byte {
	if uintptr(unsafe.Pointer(pBuffer))+uintptr(4) >= uintptr(unsafe.Pointer(pBufEnd)) {
		return nil
	}

	*pBuffer = AMF_OBJECT
	pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))

	for i := 0; i < int(obj.o_num); i++ {
		res := C_AMF_PropEncode((*C_AMFObjectProperty)(incPtr(unsafe.Pointer(
			obj.o_props), i, int(unsafe.Sizeof(*obj.o_props)))), pBuffer, pBufEnd)
		if res == nil {
			log.Println("C_AMF_Encode: failed to encode property in index")
			break
		} else {
			pBuffer = res
		}
	}

	if uintptr(incBytePtr(unsafe.Pointer(pBuffer), 3)) >= uintptr(unsafe.Pointer(pBufEnd)) {
		return nil
	}

	pBuffer = C_AMF_EncodeInt24(pBuffer, pBufEnd, int32(AMF_OBJECT_END))

	return pBuffer
}

// char* AMF_EncodeEcmaArray(AMFObject* obj, char* pBuffer, char* pBufEnd);
// amf.c +924
func C_AMF_EncodeEcmaArray(obj *C_AMFObject, pBuffer *byte, pBufEnd *byte) *byte {
	if int(uintptr(unsafe.Pointer(pBuffer)))+4 >= int(uintptr(unsafe.Pointer(pBufEnd))) {
		return nil
	}

	*pBuffer = AMF_ECMA_ARRAY
	pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))

	pBuffer = C_AMF_EncodeInt32(pBuffer, pBufEnd, int32(obj.o_num))

	for i := 0; i < int(obj.o_num); i++ {
		res := C_AMF_PropEncode((*C_AMFObjectProperty)(incPtr(unsafe.Pointer(
			obj.o_props), i, int(unsafe.Sizeof(*obj.o_props)))), pBuffer, pBufEnd)
		if res == nil {
			log.Println("C_AMF_EncodeEcmaArray: failed to encode property!")
			break
		} else {
			pBuffer = res
		}
	}

	if int(uintptr(unsafe.Pointer(pBuffer)))+3 >= int(uintptr(unsafe.Pointer(pBufEnd))) {
		return nil
	}

	pBuffer = C_AMF_EncodeInt24(pBuffer, pBufEnd, AMF_OBJECT_END)

	return pBuffer
}

// char* AMF_EncodeArray(AMFObject* obj, char* pBuffer, char* pBufEnd);
// amf.c +959
func C_AMF_EncodeArray(obj *C_AMFObject, pBuffer *byte, pBufEnd *byte) *byte {
	if int(uintptr(unsafe.Pointer(pBuffer)))+4 >= int(uintptr(unsafe.Pointer(pBufEnd))) {
		return nil
	}

	*pBuffer = AMF_STRICT_ARRAY
	pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))

	pBuffer = C_AMF_EncodeInt32(pBuffer, pBufEnd, int32(obj.o_num))

	for i := 0; i < int(obj.o_num); i++ {
		res := C_AMF_PropEncode((*C_AMFObjectProperty)(incPtr(unsafe.Pointer(
			obj.o_props), i, int(unsafe.Sizeof(*obj.o_props)))), pBuffer, pBufEnd)
		if res == nil {
			log.Println("C_AMF_EncodeEcmaArray: failed to encode property!")
			break
		} else {
			pBuffer = res
		}
	}

	return pBuffer
}

// int AMF_DecodeArray(AMFObject *obj, const char *pBuffer, int nSize, int nArrayLen, int bDecodeName);
func C_AMF_DecodeArray(obj *C_AMFObject, pBuffer *byte, nSize, nArrayLen, bDecodeName int32) int32 {
	nOriginalSize := nSize
	var bError int32 = 0

	obj.o_num = 0
	obj.o_props = nil
	for nArrayLen > 0 {
		var prop C_AMFObjectProperty
		var nRes int32
		nArrayLen--

		if nSize <= 0 {
			bError = 1
			break
		}
		nRes = C_AMFProp_Decode(&prop, pBuffer, nSize, bDecodeName)
		if nRes == -1 {
			bError = 1
			break
		} else {
			nSize -= nRes
			pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), int(nRes)))
			C_AMF_AddProp(obj, &prop)
		}
	}
	if bError != 0 {
		return -1
	}

	return nOriginalSize - nSize
}

// void AMF_Reset(AMFObject* obj);
// amf.c +1282
func C_AMF_Reset(obj *C_AMFObject) {
	var n int32
	for n = 0; n < int32(obj.o_num); n++ {
		C_AMFProp_Reset(&(*(*C_AMFObjectProperty)(incPtr(unsafe.Pointer(obj.o_props),
			int(n), int(unsafe.Sizeof(*obj.o_props))))))
	}
	//C.free(unsafe.Pointer(obj.o_props))
	obj.o_props = nil
	obj.o_num = 0
}

// void AMFProp_Reset(AMFObjectProperty* prop);
// amf.c +875
func C_AMFProp_Reset(prop *C_AMFObjectProperty) {
	if prop.p_type == AMF_OBJECT || prop.p_type == AMF_ECMA_ARRAY ||
		prop.p_type == AMF_STRICT_ARRAY {
		C_AMF_Reset(&prop.p_vu.p_object)
	} else {
		prop.p_vu.p_aval.av_len = 0
		prop.p_vu.p_aval.av_val = nil
	}
	prop.p_type = AMF_INVALID
}

// void AMFProp_GetString(AMFObjectProperty* prop, AVal* str);
// amf.c
func C_AMFProp_GetString(prop *C_AMFObjectProperty, str *C_AVal) {
	if prop.p_type == AMF_STRING {
		*str = prop.p_vu.p_aval
	} else {
		*str = AV_empty
	}
}

// void AMFProp_GetObject(AMFObjectProperty *prop, AMFObject *obj);
// amf.c +351
func C_AMFProp_GetObject(prop *C_AMFObjectProperty, obj *C_AMFObject) {
	if prop.p_type == AMF_OBJECT {
		*obj = prop.p_vu.p_object
	} else {
		*obj = AMFObj_Invalid
	}
}

// AMFObjectProperty* AMF_GetProp(AMFObject *obj, const AVal* name, int nIndex);
// amf.c + 1249
func C_AMF_GetProp(obj *C_AMFObject, name *C_AVal, nIndex int32) *C_AMFObjectProperty {
	if nIndex >= 0 {
		if nIndex < int32(obj.o_num) {
			return &(*(*C_AMFObjectProperty)(incPtr(unsafe.Pointer(obj.o_props),
				int(nIndex), int(unsafe.Sizeof(*obj.o_props)))))
			//return &obj.o_props[nIndex]
		}
	} else {
		var n int32
		for n = 0; n < int32(obj.o_num); n++ {
			if C_AVMATCH(&(*(*C_AMFObjectProperty)(incPtr(unsafe.Pointer(obj.o_props),
				int(n), int(unsafe.Sizeof(*obj.o_props))))).p_name, name) != 0 {
				return &(*(*C_AMFObjectProperty)(incPtr(unsafe.Pointer(obj.o_props),
					int(n), int(unsafe.Sizeof(*obj.o_props)))))
			}
		}
	}
	return (*C_AMFObjectProperty)(&AMFProp_Invalid)
}

// double AMFProp_GetNumber(AMFObjectProperty* prop);
// amf.c +330
func C_AMFProp_GetNumber(prop *C_AMFObjectProperty) float64 {
	return float64(prop.p_vu.p_number)
}

// int AMF_Decode(AMFObject *obj, const char* pBuffer, int nSize, int bDecodeName);
// amf.c +1180
func C_AMF_Decode(obj *C_AMFObject, pBuffer *byte, nSize int32, bDecodeName int32) int32 {
	var nOriginalSize int32 = nSize
	var bError int32 = 0

	obj.o_num = 0
	obj.o_props = nil

	for nSize > 0 {
		var prop C_AMFObjectProperty
		var nRes int32

		if nSize >= 3 && C_AMF_DecodeInt24(pBuffer) == AMF_OBJECT_END {
			nSize -= 3
			bError = 0
			break
		}

		if bError != 0 {
			// TODO use new logger here
			log.Println("AMF_Decode: decoding error, ignoring bytes until next known pattern!")
			nSize--
			pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))
			continue
		}
		// TODO port AMFProp_Decode
		nRes = int32(C_AMFProp_Decode(&prop, (*byte)(unsafe.Pointer(pBuffer)),
			int32(nSize), int32(bDecodeName)))
		// nRes = int32(C.AMFProp_Decode(&prop, (*byte)(unsafe.Pointer(pBuffer)),
		// int32(nSize), int32(bDecodeName)))
		if nRes == -1 {
			bError = 1
			break
		} else {
			nSize -= nRes
			if nSize < 0 {
				bError = 1
				break
			}
			pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), int(nRes)))
			C_AMF_AddProp(obj, &prop)
		}
	}

	if bError != 0 {
		return -1
	}

	return nOriginalSize - nSize
}

// int AMFProp_Decode(C_AMFObjectProperty* prop, const char* pBuffer, int nSize, int bDecodeName);
// amf.c +619
func C_AMFProp_Decode(prop *C_AMFObjectProperty, pBuffer *byte, nSize, bDecodeName int32) int32 {

	var nOriginalSize int32 = nSize
	var nRes int32

	prop.p_name.av_len = 0
	prop.p_name.av_val = nil

	if nSize == 0 || pBuffer == nil {
		// TODO use new logger here
		// RTMP_Log(RTMP_LOGDEBUG, "%s: Empty buffer/no buffer pointer!", __FUNCTION__);
		return -1
	}

	if bDecodeName != 0 && nSize < 4 {
		// at least name (length + at least 1 byte) and 1 byte of data
		// TODO use new logger here
		// RTMP_Log(RTMP_LOGDEBUG, "%s: Not enough data for decoding with name, less than 4 bytes!",__FUNCTION__);
		return -1
	}

	if bDecodeName != 0 {
		nNameSize := C_AMF_DecodeInt16(pBuffer)
		if int32(nNameSize) > nSize-2 {
			// TODO use new logger here
			//RTMP_Log(RTMP_LOGDEBUG, "%s: Name size out of range: namesize (%d) > len (%d) - 2",__FUNCTION__, nNameSize, nSize);
			return -1
		}

		C_AMF_DecodeString(pBuffer, &prop.p_name)
		nSize -= int32(2 + nNameSize)
		pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), int(2+nNameSize)))
	}

	if nSize == 0 {
		return -1
	}

	nSize--

	prop.p_type = (C_AMFDataType)(int32(*pBuffer))
	pBuffer = (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 1))

	switch prop.p_type {
	case AMF_NUMBER:
		log.Println("1")
		if nSize < 8 {
			return -1
		}
		prop.p_vu.p_number = float64(C_AMF_DecodeNumber(pBuffer))
		nSize -= 8

		/*
			case AMF_BOOLEAN:
				log.Println("2")
				if nSize < 1 {
					return -1
				}
				prop.p_vu.p_number = float64(C_AMF_DecodeBoolean((*byte)(unsafe.Pointer(pBuffer))))
				nSize--
		*/
	case AMF_STRING:
		{
			log.Println("3")
			var nStringSize = C_AMF_DecodeInt16(pBuffer)

			if int64(nSize) < int64(nStringSize)+2 {
				return -1
			}
			C_AMF_DecodeString(pBuffer, &prop.p_vu.p_aval)
			nSize -= int32(2 + nStringSize)
		}

	case AMF_OBJECT:
		{
			log.Println("4")
			var nRes int32 = int32(C_AMF_Decode(&prop.p_vu.p_object, pBuffer, nSize, 1))
			if nRes == -1 {
				return -1
			}
			nSize -= nRes

		}

	case AMF_MOVIECLIP:
		{
			log.Println("5")
			// TODO use new logger here
			log.Println("AMFProp_Decode: MAF_MOVIECLIP reserved!")
			//RTMP_Log(RTMP_LOGERROR, "AMF_MOVIECLIP reserved!");
			return -1

		}
	case AMF_NULL:
		log.Println("6")
	case AMF_UNDEFINED:
		log.Println("7")
	case AMF_UNSUPPORTED:
		log.Println("8")
		prop.p_type = AMF_NULL

	case AMF_REFERENCE:
		{
			log.Println("9")
			// TODO use new logger here
			log.Println("AMFProp_Decode: AMF_REFERENCE not supported!")
			//RTMP_Log(RTMP_LOGERROR, "AMF_REFERENCE not supported!");
			return -1
		}

	case AMF_ECMA_ARRAY:
		{
			log.Println("10")
			nSize -= 4

			// next comes the rest, mixed array has a final 0x000009 mark and names, so its an object
			nRes = C_AMF_Decode(&prop.p_vu.p_object, (*byte)(incBytePtr(
				unsafe.Pointer(pBuffer), 4)), nSize, 1)
			if nRes == -1 {
				return -1
			}
			nSize -= nRes
		}

	case AMF_OBJECT_END:
		{
			log.Println("11")
			return -1
		}
	/*
		case AMF_STRICT_ARRAY:
			{
				log.Println("12")
				nArrayLen := int32(C_AMF_DecodeInt32(pBuffer))
				nSize -= 4

				nRes = C_AMF_DecodeArray(&prop.p_vu.p_object, (*byte)(incBytePtr(unsafe.Pointer(pBuffer), 4)), nSize, int32(nArrayLen), FALSE)
				if nRes == -1 {
					return -1
				}
				nSize -= nRes
			}
	*/
	/*
		case AMF_DATE:
			{
				log.Println("13")
				// TODO use new logger here
				//RTMP_Log(RTMP_LOGDEBUG, "AMF_DATE");

				if nSize < 10 {
					return -1
				}

				prop.p_vu.p_number = float64(C_AMF_DecodeNumber(pBuffer))
				prop.p_UTCoffset = C.int16_t(C_AMF_DecodeInt16((*byte)(incBytePtr(unsafe.Pointer(pBuffer), 8))))

				nSize -= 10

			}
	*/
	case AMF_LONG_STRING:
		log.Println("14")
	/*
		case AMF_XML_DOC:
			{
				log.Println("15")
				var nStringSize uint32 = C_AMF_DecodeInt32(pBuffer)
				if int64(nSize) < int64(nStringSize)+4 {
					return -1
				}
				C_AMF_DecodeLongString(pBuffer, &prop.p_vu.p_aval)
				nSize -= int32(4 + nStringSize)
				if prop.p_type == AMF_LONG_STRING {
					prop.p_type = AMF_STRING
				}
			}
	*/
	case AMF_RECORDSET:
		{
			log.Println("16")
			// TODO use new logger here
			log.Println("AMFProp_Decode: AMF_RECORDSET reserved!")
			//RTMP_Log(RTMP_LOGERROR, "AMF_RECORDSET reserved!");
			return -1

		}
	case AMF_TYPED_OBJECT:
		{
			log.Println("17")
			// TODO use new logger here
			// RTMP_Log(RTMP_LOGERROR, "AMF_TYPED_OBJECT not supported!")
			return -1
		}

	/*
		case AMF_AVMPLUS:
			{
				log.Println("18")
				nRes := int32(C.AMF3_Decode(&prop.p_vu.p_object, (*byte)(unsafe.Pointer(pBuffer)), int32(nSize), 1))
				if nRes == -1 {
					return -1
				}
				nSize -= nRes
				prop.p_type = AMF_OBJECT
			}
	*/
	default:
		log.Println("19")
		// TODO use new logger here
		//RTMP_Log(RTMP_LOGDEBUG, "%s - unknown datatype 0x%02x, @%p", __FUNCTION__,
		//prop.p_type, pBuffer - 1);
		return -1
	}

	return nOriginalSize - nSize
}

// void AMF_AddProp(AMFObject* obj, const AMFObjectProperty* prop);
// amf.c + 1234
func C_AMF_AddProp(obj *C_AMFObject, prop *C_AMFObjectProperty) {
	if (obj.o_num & 0x0f) == 0 {
		//obj.o_props = (*C_AMFObjectProperty)(realloc(unsafe.Pointer(obj.o_props),
		//uint32(int(obj.o_num+16)*int(unsafe.Sizeof(*obj.o_props)))))
		obj.o_props = (*C_AMFObjectProperty)(C.realloc(unsafe.Pointer(obj.o_props),
			C.size_t(int(obj.o_num+16)*int(unsafe.Sizeof(*obj.o_props)))))
	}
	memmove(unsafe.Pointer(&(*(*C_AMFObjectProperty)(incPtr(
		unsafe.Pointer(obj.o_props), int(obj.o_num), int(unsafe.Sizeof(*obj.o_props)))))),
		unsafe.Pointer(prop), unsafe.Sizeof(*obj.o_props))
	obj.o_num++
}

// unsigned int AMF_DeocdeInt32(const char* data);
// amf.c +59
func C_AMF_DecodeInt32(data *byte) uint32 {
	c := (*uint8)(data)
	val := uint32(
		int32(*c)<<24 |
			int32(*(*uint8)(incBytePtr(unsafe.Pointer(c), 1)))<<16 |
			int32(*(*uint8)(incBytePtr(unsafe.Pointer(c), 2)))<<8 |
			int32(*(*uint8)(incBytePtr(unsafe.Pointer(c), 3))))
	return uint32(val)
}

// char* AMF_EncodeNamedNumber(char* output, char* outend, const C_AVal* strName, double dVal);
// amf.c +286
func C_AMF_EncodeNamedNumber(output *byte, outend *byte, strName *C_AVal, dVal float64) *byte {
	if int(uintptr(unsafe.Pointer(output)))+2+int(strName.av_len) > int(uintptr(unsafe.Pointer(outend))) {
		return nil
	}
	output = C_AMF_EncodeInt16(output, outend, int16(strName.av_len))
	memmove(unsafe.Pointer(output), unsafe.Pointer(strName.av_val), uintptr(strName.av_len))
	output = (*byte)(incBytePtr(unsafe.Pointer(output), int(strName.av_len)))
	return C_AMF_EncodeNumber(output, outend, dVal)
}

// char* AMF_EncodeNamedBoolean(char* output, char* outend, const C_AVal* strname, int bVal);
// amf.c +299
func C_AMF_EncodeNamedBoolean(output *byte, outend *byte, strName *C_AVal, bVal int) *byte {
	if int(uintptr(unsafe.Pointer(output)))+2+int(strName.av_len) > int(uintptr(unsafe.Pointer(outend))) {
		return nil
	}
	output = C_AMF_EncodeInt16(output, outend, int16(strName.av_len))
	memmove(unsafe.Pointer(output), unsafe.Pointer(strName.av_val), uintptr(strName.av_len))
	output = (*byte)(incBytePtr(unsafe.Pointer(output), int(strName.av_len)))
	return C_AMF_EncodeBoolean(output, outend, bVal)
}

// void AMFProp_SetName(AMFObjectProperty *prop, AVal *name);
// amf.c +318
func C_AMFProp_SetName(prop *C_AMFObjectProperty, name *C_AVal) {
	prop.p_name = *name
}

const (
	AMF3_INTEGER_MAX = 268435455
	AMF3_INTEGER_MIN = -268435456
)

// int AMF3ReadInteger(const char *data, int32_t *valp);
// amf.c +426
// TODO test
func C_AMF3ReadInteger(data *byte, valp *int32) int32 {
	var i int
	var val int32

	for i <= 2 {
		/* handle first 3 bytes */
		if *indxBytePtr(unsafe.Pointer(data), i)&0x80 != 0 {
			/* byte used */
			val <<= 7                                                  /* shift up */
			val |= int32(*indxBytePtr(unsafe.Pointer(data), i) & 0x7f) /* add bits */
			i++
		} else {
			break
		}
	}

	if i > 2 {
		/* use 4th byte, all 8bits */
		val <<= 8
		val |= int32(*indxBytePtr(unsafe.Pointer(data), 3))

		/* range check */
		if val > AMF3_INTEGER_MAX {
			val -= (1 << 29)
		}
	} else {
		/* use 7bits of last unparsed byte (0xxxxxxx) */
		val <<= 7
		val |= int32(*indxBytePtr(unsafe.Pointer(data), i))
	}

	*valp = val

	if i > 2 {
		return 4
	}
	return int32(i + 1)
}

// int AMF3ReadString(const char *data, AVal *str);
// amf.c +466
func C_AMF3ReadString(data *byte, str *C_AVal) int32 {
	var ref int32
	// assert elided - we will get a panic if it's nil.

	len := C_AMF3ReadInteger(data, &ref)
	data = indxBytePtr(unsafe.Pointer(data), int(len))

	if ref&0x1 == 0 {
		/* reference: 0xxx */
		// TODO(kortschak) Logging.
		// refIndex := (ref >> 1)
		// RTMP_Log(RTMP_LOGDEBUG,
		// "%s, string reference, index: %d, not supported, ignoring!",
		// __FUNCTION__, refIndex);
		str.av_val = nil
		str.av_len = 0
		return len
	} else {
		nSize := (ref >> 1)
		str.av_val = (*byte)(unsafe.Pointer(data))
		str.av_len = int32(nSize)
		return len + nSize
	}
	return len
}

// char* AMF_EncodeBoolean(char* output, char* outend, int bVal);
// amf.c +260
func C_AMF_EncodeBoolean(output *byte, outend *byte, bVal int) *byte {
	if int(uintptr(unsafe.Pointer(output)))+2 > int(uintptr(unsafe.Pointer(outend))) {
		return nil
	}
	*(*byte)(unsafe.Pointer(output)) = AMF_BOOLEAN
	output = (*byte)(incBytePtr(unsafe.Pointer(output), 1))
	val := byte(0x01)
	if bVal == 0 {
		val = byte(0x00)
	}
	*(*byte)(unsafe.Pointer(output)) = val
	output = (*byte)(incBytePtr(unsafe.Pointer(output), 1))
	return output
}

// char* AMF_EncodeNumber(char* output, char* outend, double dVal);
// amf.c +199
func C_AMF_EncodeNumber(output *byte, outend *byte, dVal float64) *byte {
	if int(uintptr(unsafe.Pointer(output)))+1+8 > int(uintptr(unsafe.Pointer(outend))) {
		return nil
	}
	// TODO: port this
	*(*byte)(unsafe.Pointer(output)) = AMF_NUMBER
	output = (*byte)(incBytePtr(unsafe.Pointer(output), 1))
	// NOTE: here we are assuming little endian for both byte order and float
	// word order
	var ci, co *uint8
	ci = (*uint8)(unsafe.Pointer(&dVal))
	co = (*uint8)(unsafe.Pointer(output))
	for i := 0; i < 8; i++ {
		*indxBytePtr(unsafe.Pointer(co), i) = *indxBytePtr(unsafe.Pointer(ci), 7-i)
	}
	return (*byte)(incBytePtr(unsafe.Pointer(output), 8))
}

// void AMF_DecodeLongString(const char *data, AVal *bv);
// amf.c +75
func C_AMF_DecodeLongString(data *byte, bv *C_AVal) {
	bv.av_len = int32(C_AMF_DecodeInt32(data))
	if bv.av_len > 0 {
		bv.av_val = (*byte)(incBytePtr(unsafe.Pointer(data), 4))
	} else {
		bv.av_val = nil
	}
}

// double AMF_DecodeNumber(const char* data);
// amf.c +82
func C_AMF_DecodeNumber(data *byte) float64 {
	var dVal float64
	var ci, co *uint8
	ci = (*uint8)(unsafe.Pointer(data))
	co = (*uint8)(unsafe.Pointer(&dVal))
	for i := 0; i < 8; i++ {
		*indxBytePtr(unsafe.Pointer(co), i) = *indxBytePtr(unsafe.Pointer(ci), 7-i)
	}
	return dVal
}

// int AMF_DecodeBoolean(const char *data);
// amf.c +132
func C_AMF_DecodeBoolean(data *byte) int32 {
	if *data != 0 {
		return 1
	}
	return 0
}

// char* AMF_EncodeNamedString(char* output, char* outend, const C_AVal* strName, const C_AVal* strValue);
// amf.c +273
func C_AMF_EncodeNamedString(output *byte, outend *byte, strName *C_AVal, strValue *C_AVal) *byte {
	if int(uintptr(unsafe.Pointer(output)))+2+int(strName.av_len) > int(uintptr(unsafe.Pointer(outend))) {
		return nil
	}
	output = C_AMF_EncodeInt16(output, outend, int16(strName.av_len))
	memmove(unsafe.Pointer(output), unsafe.Pointer(strName.av_val), uintptr(strName.av_len))
	output = (*byte)(incBytePtr(unsafe.Pointer(output), int(strName.av_len)))
	return C_AMF_EncodeString(output, outend, strValue)
}

// void AMF_DecodeString(const char* data, C_AVal* bv);
// amf.c +68
func C_AMF_DecodeString(data *byte, bv *C_AVal) {
	dataPtr := unsafe.Pointer(data)
	//bv.av_len = int32(C.AMF_DecodeInt16((*byte)(dataPtr)))
	bv.av_len = int32(C_AMF_DecodeInt16((*byte)(dataPtr)))
	if bv.av_len > 0 {
		bv.av_val = (*byte)(incBytePtr(dataPtr, 2))
	} else {
		bv.av_val = nil
	}
}

// unsigned short AMF_DecodeInt16(const char* data);
// amf.c +41
func C_AMF_DecodeInt16(data *byte) uint16 {
	c := unsafe.Pointer(data)
	return uint16(*(*uint8)(c)<<8 | *(*byte)(incBytePtr(c, 1)))
}

// char* AMF_EncodeInt24(char* output, char* outend, int nVal);
// amf.c +149
func C_AMF_EncodeInt24(output *byte, outend *byte, nVal int32) *byte {
	outputPtr := unsafe.Pointer(output)
	outendPtr := unsafe.Pointer(outend)
	if uintptr(outputPtr)+3 > uintptr(outendPtr) {
		// length < 3
		return nil
	}
	// Assign output[2]
	third := (*byte)(incBytePtr(outputPtr, 2))
	*third = (byte)(nVal & 0xff)
	// Assign output[1]
	second := (*byte)(incBytePtr(outputPtr, 1))
	*second = (byte)(nVal >> 8)
	// Assign output[0]
	*output = (byte)(nVal >> 16)
	return (*byte)(incBytePtr(outputPtr, 3))
}

// unsigned int AMF_DecodeInt24(const char* data);
// amf.c +50
func C_AMF_DecodeInt24(data *byte) uint32 {
	// TODO Understand logic and simplify
	c := (*uint8)(unsafe.Pointer(data))
	dst := uint32(int32(*c) << 16)
	dst |= uint32(int32(*((*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(c)) +
		(uintptr)(int32(1))*unsafe.Sizeof(*c))))) << 8)
	dst |= uint32(int32(*((*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(c)) +
		(uintptr)(int32(2))*unsafe.Sizeof(*c))))))
	return dst
}

// char* AMF_EncodeString(char* output, char* outend, const C_AVal* bv);
// amf.c +174
func C_AMF_EncodeString(output *byte, outend *byte, bv *C_AVal) *byte {
	outputPtr := unsafe.Pointer(output)
	outendPtr := unsafe.Pointer(outend)
	if (bv.av_len < 65536 && uintptr(incBytePtr(outputPtr, 1+2+int(bv.av_len))) >
		uintptr(outendPtr)) || uintptr(incBytePtr(outputPtr, 1+4+int(bv.av_len))) >
		uintptr(outendPtr) {
		return nil
	}
	if bv.av_len < 65536 {
		*(*byte)(outputPtr) = AMF_STRING
		outputPtr = incBytePtr(outputPtr, 1)
		// TODO: port AMF_EncodeInt16
		outputPtr = unsafe.Pointer(C_AMF_EncodeInt16((*byte)(outputPtr), (*byte)(
			outendPtr), int16(bv.av_len)))
		//outputPtr = unsafe.Pointer(C_AMF_EncodeInt16((*byte)(outputPtr),
		//(*byte)(outendPtr), (int16)(bv.av_len)))
	} else {
		*(*byte)(outputPtr) = AMF_LONG_STRING
		outputPtr = incBytePtr(outputPtr, 1)
		outputPtr = unsafe.Pointer(C_AMF_EncodeInt32((*byte)(outputPtr), (*byte)(
			outendPtr), int32(bv.av_len)))
		//outputPtr = unsafe.Pointer(C_AMF_EncodeInt32((*byte)(outputPtr),
		//(*byte)(outendPtr), (int32)(bv.av_len)))
	}
	memmove(unsafe.Pointer(outputPtr), unsafe.Pointer(bv.av_val), uintptr(bv.av_len))
	//C.memcpy(unsafe.Pointer(outputPtr), unsafe.Pointer(bv.av_val), (C.size_t)(bv.av_len))
	outputPtr = incBytePtr(outputPtr, int(bv.av_len))
	return (*byte)(outputPtr)
}

// char* AMF_EncodeInt16(char* output, char* outend, short nVal);
// amf.c +138
func C_AMF_EncodeInt16(output *byte, outend *byte, nVal int16) *byte {
	outputPtr := unsafe.Pointer(output)
	outendPtr := unsafe.Pointer(outend)
	if uintptr(outputPtr)+2 > uintptr(outendPtr) {
		// length < 2
		return nil
	}
	// Assign output[1]
	second := (*byte)(incBytePtr(outputPtr, 1))
	*second = (byte)(nVal & 0xff)
	// Assign output[0]
	*output = (byte)(nVal >> 8)
	return (*byte)(incBytePtr(outputPtr, 2))
}

// char* AMF_EncodeInt32(char* output, char* outend, int nVal);
// amf.c +161
func C_AMF_EncodeInt32(output *byte, outend *byte, nVal int32) *byte {
	outputPtr := unsafe.Pointer(output)
	outendPtr := unsafe.Pointer(outend)
	if uintptr(outputPtr)+4 > uintptr(outendPtr) {
		// length < 4
		return nil
	}
	// Assign output[3]
	forth := (*byte)(incBytePtr(outputPtr, 3))
	*forth = (byte)(nVal & 0xff)
	// Assign output[2]
	third := (*byte)(incBytePtr(outputPtr, 2))
	*third = (byte)(nVal >> 8)
	// Assign output[1]
	second := (*byte)(incBytePtr(outputPtr, 1))
	*second = (byte)(nVal >> 16)
	// Assign output[0]
	*output = (byte)(nVal >> 24)
	return (*byte)(incBytePtr(outputPtr, 4))
}

/*
// void AMF3CD_AddProp(AMF3ClassDef *cd, AVal *prop);
// amf.c +1298
func AMF3CD_AddProp(cd *C.AMF3ClassDef, prop *C_AVal) {
	if cd.cd_num&0x0f == 0 {
		cd.cd_props = (*C_AVal)(realloc(unsafe.Pointer(cd.cd_props), int(uintptr(cd.cd_num+16)*unsafe.Sizeof(C_AVal{}))))
	}
	*(*C_AVal)(incPtr(unsafe.Pointer(cd.cd_props), int(cd.cd_num), int(unsafe.Sizeof(C_AVal{})))) = *prop
	cd.cd_num++
}
*/