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RTP打包发送H.264

2022-08-09 13:05:00 zhouyongku

RTP打包发送H.264  

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <string.h>
#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                "192.168.0.25"
#define DEST_PORT				1234

#define H264                    96

/******************************************************************
RTP_FIXED_HEADER
0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V=2|P|X|  CC   |M|     PT      |       sequence number         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                           timestamp                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           synchronization source (SSRC) identifier            |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
|            contributing source (CSRC) identifiers             |
|                             ....                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

******************************************************************/
typedef struct 
{
    /* byte 0 */
    unsigned char csrc_len:4; /* CC expect 0 */
    unsigned char extension:1;/* X  expect 1, see RTP_OP below */
    unsigned char padding:1;  /* P  expect 0 */
    unsigned char version:2;  /* V  expect 2 */
    /* byte 1 */
    unsigned char payload:7; /* PT  RTP_PAYLOAD_RTSP */
    unsigned char marker:1;  /* M   expect 1 */
    /* byte 2,3 */
    unsigned short seq_no;   /*sequence number*/
    /* byte 4-7 */
    unsigned  long timestamp;
    /* byte 8-11 */
    unsigned long ssrc; /* stream number is used here. */
} RTP_FIXED_HEADER;/*12 bytes*/

/******************************************************************
NALU_HEADER
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|F|NRI|  Type   |
+---------------+
******************************************************************/
typedef struct {
    //byte 0
	unsigned char TYPE:5;
    unsigned char NRI:2;
	unsigned char F:1;
} NALU_HEADER; /* 1 byte */


/******************************************************************
FU_INDICATOR
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|F|NRI|  Type   |
+---------------+
******************************************************************/
typedef struct {
    //byte 0
    unsigned char TYPE:5;
	unsigned char NRI:2; 
	unsigned char F:1;         
} FU_INDICATOR; /*1 byte */


/******************************************************************
FU_HEADER
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|S|E|R|  Type   |
+---------------+
******************************************************************/
typedef struct {
    //byte 0
    unsigned char TYPE:5;
	unsigned char R:1;
	unsigned char E:1;
	unsigned char S:1;    
} FU_HEADER; /* 1 byte */


H264.h头文件内容:



 

RTPSend.cpp文件内容:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include "h264.h"

#define  UDP_MAX_SIZE 1400

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;

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 int info2=0, info3=0;
RTP_FIXED_HEADER *rtp_hdr;

NALU_HEADER		*nalu_hdr;
FU_INDICATOR	*fu_ind;
FU_HEADER		*fu_hdr;

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);
	}
}

void OpenBitstreamFile (char *fn)
{
	if (NULL == (bits=fopen(fn, "rb")))
	{
		printf("open file error\n");
		exit(0);
	}
}

//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
}

static int FindStartCode2 (unsigned char *Buf)
{
	if(Buf[0]!=0 || Buf[1]!=0 || Buf[2] !=1) return 0; //判断是否为0x000001,如果是返回1
	else return 1;
}

static int FindStartCode3 (unsigned char *Buf)
{
	if(Buf[0]!=0 || Buf[1]!=0 || Buf[2] !=0 || Buf[3] !=1) return 0;//判断是否为0x00000001,如果是返回1
	else return 1;
}

int rtpnum = 0;

//输出NALU长度和TYPE
void dump(NALU_t *n)
{
	if (!n)return;
	printf("%3d, len: %6d  ",rtpnum++, n->len);
	printf("nal_unit_type: %x\n", n->nal_unit_type);
}

int main(int argc, char* argv[])
{
	OpenBitstreamFile("E:\\测试数据\\tv480x320.264");
	NALU_t *n;
	char* nalu_payload;  
	char sendbuf[1500];

	unsigned short seq_num =0;
	int	bytes=0;
	InitWinsock(); //初始化套接字库
	SOCKET    socket1;
	struct sockaddr_in server;
	int len =sizeof(server);
	float framerate=15;
	unsigned int timestamp_increse=0,ts_current=0;
	timestamp_increse=(unsigned int)(90000.0 / framerate); //+0.5);

	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 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->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->payload = H264;//负载类型号,
		rtp_hdr->ssrc    = htonl(10);//随机指定为10,并且在本RTP会话中全局唯一

		//当一个NALU小于1400字节的时候,采用一个单RTP包发送
		if(n->len<=UDP_MAX_SIZE){
			//设置rtp M 位;
			rtp_hdr->marker=1;
			rtp_hdr->seq_no = htons(seq_num ++); //序列号,每发送一个RTP包增1

			//设置NALU HEADER,并将这个HEADER填入sendbuf[12]
			nalu_hdr =(NALU_HEADER*)&sendbuf[12]; //将sendbuf[12]的地址赋给nalu_hdr,之后对nalu_hdr的写入就将写入sendbuf中;
			nalu_hdr->F=n->forbidden_bit;
			nalu_hdr->NRI=n->nal_reference_idc>>5;//有效数据在n->nal_reference_idc的第6,7位,需要右移5位才能将其值赋给nalu_hdr->NRI。
			nalu_hdr->TYPE=n->nal_unit_type;

			nalu_payload=&sendbuf[13];//同理将sendbuf[13]赋给nalu_payload
			memcpy(nalu_payload,n->buf+1,n->len-1);//去掉nalu头的nalu剩余内容写入sendbuf[13]开始的字符串。

			ts_current=ts_current+timestamp_increse;
			rtp_hdr->timestamp=htonl(ts_current);
			bytes=n->len + 12 ;	//获得sendbuf的长度,为nalu的长度(包含NALU头但除去起始前缀)加上rtp_header的固定长度12字节
			send(socket1,sendbuf,bytes,0);//发送RTP包
			//Sleep(100);
		}else{
			int packetNum = n->len/UDP_MAX_SIZE;
			if (n->len%UDP_MAX_SIZE != 0)
				packetNum ++;

			int lastPackSize = n->len - (packetNum-1)*UDP_MAX_SIZE;
			int packetIndex = 1 ;
	
			ts_current=ts_current+timestamp_increse;

			rtp_hdr->timestamp=htonl(ts_current);

			//发送第一个的FU,S=1,E=0,R=0

			rtp_hdr->seq_no = htons(seq_num ++); //序列号,每发送一个RTP包增1
			//设置rtp M 位;
			rtp_hdr->marker=0;
			//设置FU INDICATOR,并将这个HEADER填入sendbuf[12]
			fu_ind =(FU_INDICATOR*)&sendbuf[12]; //将sendbuf[12]的地址赋给fu_ind,之后对fu_ind的写入就将写入sendbuf中;
			fu_ind->F=n->forbidden_bit;
			fu_ind->NRI=n->nal_reference_idc>>5;
			fu_ind->TYPE=28;

			//设置FU HEADER,并将这个HEADER填入sendbuf[13]
			fu_hdr =(FU_HEADER*)&sendbuf[13];
			fu_hdr->S=1;
			fu_hdr->E=0;
			fu_hdr->R=0;
			fu_hdr->TYPE=n->nal_unit_type;

			nalu_payload=&sendbuf[14];//同理将sendbuf[14]赋给nalu_payload
			memcpy(nalu_payload,n->buf+1,UDP_MAX_SIZE);//去掉NALU头
			bytes=UDP_MAX_SIZE+14;//获得sendbuf的长度,为nalu的长度(除去起始前缀和NALU头)加上rtp_header,fu_ind,fu_hdr的固定长度14字节
			send( socket1, sendbuf, bytes, 0 );//发送RTP包

			//发送中间的FU,S=0,E=0,R=0
			for(packetIndex=2;packetIndex<packetNum;packetIndex++)
			{
				rtp_hdr->seq_no = htons(seq_num ++); //序列号,每发送一个RTP包增1
		 
				//设置rtp M 位;
				rtp_hdr->marker=0;
				//设置FU INDICATOR,并将这个HEADER填入sendbuf[12]
				fu_ind =(FU_INDICATOR*)&sendbuf[12]; //将sendbuf[12]的地址赋给fu_ind,之后对fu_ind的写入就将写入sendbuf中;
				fu_ind->F=n->forbidden_bit;
				fu_ind->NRI=n->nal_reference_idc>>5;
				fu_ind->TYPE=28;

				//设置FU HEADER,并将这个HEADER填入sendbuf[13]
				fu_hdr =(FU_HEADER*)&sendbuf[13];
				fu_hdr->S=0;
				fu_hdr->E=0;
				fu_hdr->R=0;
				fu_hdr->TYPE=n->nal_unit_type;

				nalu_payload=&sendbuf[14];//同理将sendbuf[14]的地址赋给nalu_payload
				memcpy(nalu_payload,n->buf+(packetIndex-1)*UDP_MAX_SIZE+1,UDP_MAX_SIZE);//去掉起始前缀的nalu剩余内容写入sendbuf[14]开始的字符串。
				bytes=UDP_MAX_SIZE+14;//获得sendbuf的长度,为nalu的长度(除去原NALU头)加上rtp_header,fu_ind,fu_hdr的固定长度14字节
				send( socket1, sendbuf, bytes, 0 );//发送rtp包				
			}

			//发送最后一个的FU,S=0,E=1,R=0
		
			rtp_hdr->seq_no = htons(seq_num ++);
			//设置rtp M 位;当前传输的是最后一个分片时该位置1		
			rtp_hdr->marker=1;
			//设置FU INDICATOR,并将这个HEADER填入sendbuf[12]
			fu_ind =(FU_INDICATOR*)&sendbuf[12]; //将sendbuf[12]的地址赋给fu_ind,之后对fu_ind的写入就将写入sendbuf中;
			fu_ind->F=n->forbidden_bit;
			fu_ind->NRI=n->nal_reference_idc>>5;
			fu_ind->TYPE=28;

			//设置FU HEADER,并将这个HEADER填入sendbuf[13]
			fu_hdr =(FU_HEADER*)&sendbuf[13];
			fu_hdr->S=0;
			fu_hdr->E=1;
			fu_hdr->R=0;
			fu_hdr->TYPE=n->nal_unit_type;

			nalu_payload=&sendbuf[14];//同理将sendbuf[14]的地址赋给nalu_payload
			memcpy(nalu_payload,n->buf+(packetIndex-1)*UDP_MAX_SIZE+1,lastPackSize-1);//将nalu最后剩余的-1(去掉了一个字节的NALU头)字节内容写入sendbuf[14]开始的字符串。
			bytes=lastPackSize-1+14;//获得sendbuf的长度,为剩余nalu的长度l-1加上rtp_header,FU_INDICATOR,FU_HEADER三个包头共14字节
			send( socket1, sendbuf, bytes, 0 );//发送rtp包		
		}

		//Sleep(33);
	}

	FreeNALU(n);
	return 0;
}



将以下文本保存为rtpPara.sdp文件

m=video 1234 RTP/AVP 96
a=rtpmap:96 H264
a=framerate:30
c=IN IP4 192.168.0.25

用VLC打开该文件,然后运行编译好的发送程序。

注意头文件和sdp文件的IP都要与实验机器的IP吻合。

该代码在NALDecoder程序基础上修改了一个内存bug而已。感谢前人的开源。

                                     转载自:RTP打包发送H.264_JMAVI的博客-CSDN博客

原网站

版权声明
本文为[zhouyongku]所创,转载请带上原文链接,感谢
https://blog.csdn.net/zhouyongku/article/details/46301341