#include <WinSock2.h>#pragma comment(lib,"ws2_32.lib")  #define PACKET_BUFFER_END            (unsigned int)0x00000000  #define MAX_RTP_PKT_LENGTH     1400  #define DEST_IP                "172.18.191.194"  #define DEST_PORT            554#define H264                    96  typedef struct   {  	/**//* byte 0 */  	unsigned char csrc_len:4;        /**//* expect 0 */  	unsigned char extension:1;        /**//* expect 1, see RTP_OP below */  	unsigned char padding:1;        /**//* expect 0 */  	unsigned char version:2;        /**//* expect 2 */  	/**//* byte 1 */  	unsigned char payload:7;        /**//* RTP_PAYLOAD_RTSP */  	unsigned char marker:1;        /**//* expect 1 */  	/**//* bytes 2, 3 */  	unsigned short seq_no;              	/**//* bytes 4-7 */  	unsigned  long timestamp;          	/**//* bytes 8-11 */  	unsigned long ssrc;            /**//* stream number is used here. */  } RTP_FIXED_HEADER;  typedef struct {  	//byte 0  	unsigned char TYPE:5;  	unsigned char NRI:2;  	unsigned char F:1;      } NALU_HEADER; /**//* 1 BYTES */  typedef struct {  	//byte 0  	unsigned char TYPE:5;  	unsigned char NRI:2;   	unsigned char F:1;      } FU_INDICATOR; /**//* 1 BYTES */  typedef struct {  	//byte 0  	unsigned char TYPE:5;  	unsigned char R:1;  	unsigned char E:1;  	unsigned char S:1;      } FU_HEADER; /**//* 1 BYTES */  

#include "rtp.h"  #include <stdio.h>FILE * bits = NULL;                //!< the bit stream file  static int FindStartCode2 (unsigned char *Buf);//查找开始字符0x000001  static int FindStartCode3 (unsigned char *Buf);//查找开始字符0x00000001  //static bool flag = true;  static int info2=0, info3=0;  RTP_FIXED_HEADER        *rtp_hdr;  NALU_HEADER     *nalu_hdr;  FU_INDICATOR    *fu_ind;  FU_HEADER       *fu_hdr; typedef struct  {  	int startcodeprefix_len;      //! 4 for parameter sets and first slice in picture, 3 for everything else (suggested)  	unsigned len;                 //! Length of the NAL unit (Excluding the start code, which does not belong to the NALU)  	unsigned max_size;            //! Nal Unit Buffer size  	int forbidden_bit;            //! should be always FALSE  	int nal_reference_idc;        //! NALU_PRIORITY_xxxx  	int nal_unit_type;            //! NALU_TYPE_xxxx      	char *buf;                    //! contains the first byte followed by the EBSP  	unsigned short lost_packets;  //! true, if packet loss is detected  } NALU_t;  BOOL InitWinsock() { 	int Error; 	WORD VersionRequested; 	WSADATA WsaData; 	VersionRequested=MAKEWORD(2,2); 	Error=WSAStartup(VersionRequested,&WsaData); //启动WinSock2 	if(Error!=0) 	{ 		return FALSE; 	} 	else 	{ 		if(LOBYTE(WsaData.wVersion)!=2||HIBYTE(WsaData.wHighVersion)!=2) 		{ 			WSACleanup(); 			return FALSE; 		} 	} 	return TRUE; }//为NALU_t结构体分配内存空间  NALU_t *AllocNALU(int buffersize)  {  	NALU_t *n;  	if ((n = (NALU_t*)calloc (1, sizeof (NALU_t))) == NULL)  	{  		printf("AllocNALU: n");  		exit(0);  	}  	n->max_size=buffersize;  	if ((n->buf = (char*)calloc (buffersize, sizeof (char))) == NULL)  	{  		free (n);  		printf ("AllocNALU: n->buf");  		exit(0);  	}  	return n;  }  //释放  void FreeNALU(NALU_t *n)  {  	if (n)  	{  		if (n->buf)  		{  			free(n->buf);  			n->buf=NULL;  		}  		free (n);  	}  }  //这个函数输入为一个NAL结构体，主要功能为得到一个完整的NALU并保存在NALU_t的buf中，获取他的长度，填充F,IDC,TYPE位。  //并且返回两个开始字符之间间隔的字节数，即包含有前缀的NALU的长度  int GetAnnexbNALU (NALU_t *nalu)  {  	int pos = 0;  	int StartCodeFound, rewind;  	unsigned char *Buf;  	if ((Buf = (unsigned char*)calloc (nalu->max_size , sizeof(char))) == NULL)   		printf ("GetAnnexbNALU: Could not allocate Buf memory\n");  	nalu->startcodeprefix_len=3;//初始化码流序列的开始字符为3个字节  	if (3 != fread (Buf, 1, 3, bits))//从码流中读3个字节  	{  		free(Buf);  		return 0;  	}  	info2 = FindStartCode2 (Buf);//判断是否为0x000001   	if(info2 != 1)   	{  		//如果不是，再读一个字节  		if(1 != fread(Buf+3, 1, 1, bits))//读一个字节  		{  			free(Buf);  			return 0;  		}  		info3 = FindStartCode3 (Buf);//判断是否为0x00000001  		if (info3 != 1)//如果不是，返回-1  		{   			free(Buf);  			return -1;  		}  		else   		{  			//如果是0x00000001,得到开始前缀为4个字节  			pos = 4;  			nalu->startcodeprefix_len = 4;  		}  	}  	else  	{  		//如果是0x000001,得到开始前缀为3个字节  		nalu->startcodeprefix_len = 3;  		pos = 3;  	}  	//查找下一个开始字符的标志位  	StartCodeFound = 0;  	info2 = 0;  	info3 = 0;  	while (!StartCodeFound)  	{  		if (feof (bits))//判断是否到了文件尾  		{  			nalu->len = (pos-1)-nalu->startcodeprefix_len;  			memcpy (nalu->buf, &Buf[nalu->startcodeprefix_len], nalu->len);       			nalu->forbidden_bit = nalu->buf[0] & 0x80; //1 bit  			nalu->nal_reference_idc = nalu->buf[0] & 0x60; // 2 bit  			nalu->nal_unit_type = (nalu->buf[0]) & 0x1f;// 5 bit  			free(Buf);  			return pos-1;  		}  		Buf[pos++] = fgetc (bits);//读一个字节到BUF中  		info3 = FindStartCode3(&Buf[pos-4]);//判断是否为0x00000001  		if(info3 != 1)  			info2 = FindStartCode2(&Buf[pos-3]);//判断是否为0x000001  		StartCodeFound = (info2 == 1 || info3 == 1);  	}  	// Here, we have found another start code (and read length of startcode bytes more than we should  	// have.  Hence, go back in the file  	rewind = (info3 == 1)? -4 : -3;  	if (0 != fseek (bits, rewind, SEEK_CUR))//把文件指针指向前一个NALU的末尾  	{  		free(Buf);  		printf("GetAnnexbNALU: Cannot fseek in the bit stream file");  	}  	// Here the Start code, the complete NALU, and the next start code is in the Buf.    	// The size of Buf is pos, pos+rewind are the number of bytes excluding the next  	// start code, and (pos+rewind)-startcodeprefix_len is the size of the NALU excluding the start code  	nalu->len = (pos+rewind)-nalu->startcodeprefix_len;  	memcpy (nalu->buf, &Buf[nalu->startcodeprefix_len], nalu->len);//拷贝一个完整NALU，不拷贝起始前缀0x000001或0x00000001  	nalu->forbidden_bit = nalu->buf[0] & 0x80; //1 bit  	nalu->nal_reference_idc = nalu->buf[0] & 0x60; // 2 bit  	nalu->nal_unit_type = (nalu->buf[0]) & 0x1f;// 5 bit  	free(Buf);  	return (pos+rewind);//返回两个开始字符之间间隔的字节数，即包含有前缀的NALU的长度  }  //输出NALU长度和TYPE  void dump(NALU_t *n)  {  	if (!n)return;  	//printf("a new nal:");  	printf(" len: %d  ", n->len);  	printf("nal_unit_type: %x\n", n->nal_unit_type);  }  int main(int argc, char* argv[])  {   	NALU_t * n;  	char* nalu_payload;    	char sendbuf[1500]; 	unsigned short seq_num =0;  	int bytes=0;  	SOCKET    socket1;	struct sockaddr_in server;  	int len =sizeof(server);  	float framerate=25;  	unsigned int timestamp_increase=0,ts_current=0;  	timestamp_increase=(unsigned int)(90000.0 / framerate); //+0.5);  	bits=fopen("my.h264","rb");	InitWinsock(); //初始化套接字库  		server.sin_family=AF_INET;  	server.sin_port=htons(DEST_PORT);            	server.sin_addr.s_addr=inet_addr(DEST_IP);   	socket1=socket(AF_INET,SOCK_DGRAM,0);  	connect(socket1, (const struct sockaddr *)&server, len) ;//申请UDP套接字  	n = AllocNALU(8000000);//为结构体nalu_t及其成员buf分配空间。返回值为指向nalu_t存储空间的指针  	while(!feof(bits))   	{  		GetAnnexbNALU(n);//每执行一次，文件的指针指向本次找到的NALU的末尾，下一个位置即为下个NALU的起始码0x000001  		dump(n);//输出NALU长度和TYPE  		memset(sendbuf,0,1500);//清空sendbuf；此时会将上次的时间戳清空，因此需要ts_current来保存上次的时间戳值  		//rtp固定包头，为12字节,该句将sendbuf[0]的地址赋给rtp_hdr，以后对rtp_hdr的写入操作将直接写入sendbuf。  		rtp_hdr =(RTP_FIXED_HEADER*)&sendbuf[0];   		//设置RTP HEADER，  		rtp_hdr->payload     = H264;  //负载类型号，  		rtp_hdr->version     = 2;  //版本号，此版本固定为2  		rtp_hdr->marker    = 0;   //标志位，由具体协议规定其值。  		rtp_hdr->ssrc        = http://www.mamicode.com/htonl(10);    //随机指定为10，并且在本RTP会话中全局唯一  >

m=video 1234 RTP/AVP 96 //96表示的是动态净荷类型号 意思就是负载类型不确定，要通过其他方式来确定 a=rtpmap:96 H264 a=framerate:15 c=IN IP4 192.168.0.30