(转)VLC播放RTP打包发送的.264文件

VLC播放RTP打包发送的.264文件

1,要有一个发送RTP包的264文件的服务器;

具体代码如下:

rtp.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                "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 */

rtp.cpp

#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        = 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<=1400)
{
//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_increase;
rtp_hdr->timestamp=htonl(ts_current);
bytes=n->len + 13 ;                      //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(1);
//fwrite(sendbuf,bytes, 1, stream);
}

else if(n->len>1400)
{
//得到该nalu需要用多少长度为1400字节的RTP包来发送
int k=0,l=0;
k=n->len/1400;//需要k个1400字节的RTP包
l=n->len%1400;//最后一个RTP包的需要装载的字节数
int t=0;//用于指示当前发送的是第几个分片RTP包
ts_current=ts_current+timestamp_increase;
rtp_hdr->timestamp=htonl(ts_current);
while(t<=k)
{
rtp_hdr->seq_no = htons(seq_num ++); //序列号，每发送一个RTP包增1
if(!t)//发送一个需要分片的NALU的第一个分片，置FU HEADER的S位
{
//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->E=0;
fu_hdr->R=0;
fu_hdr->S=1;
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+1,1400);//去掉NALU头

bytes=1400+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
//fwrite(sendbuf,bytes, 1, stream);
//sleep(1);
t++;

}
//发送一个需要分片的NALU的非第一个分片，清零FU HEADER的S位，如果该分片是该NALU的最后一个分片，置FU HEADER的E位
else if(k==t)//发送的是最后一个分片，注意最后一个分片的长度可能超过1400字节（当l>1386时）。
{

//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->R=0;
fu_hdr->S=0;
fu_hdr->TYPE=n->nal_unit_type;
fu_hdr->E=1;

nalu_payload=&sendbuf[14];//同理将sendbuf[14]的地址赋给nalu_payload
memcpy(nalu_payload,n->buf+t*1400+1,l-1);//将nalu最后剩余的l-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=l-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
//fwrite(sendbuf,bytes, 1, stream);
t++;
//sleep(1);
}
else if(t<k&&0!=t)
{
//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->E=0;
fu_hdr->R=0;
fu_hdr->S=0;
fu_hdr->E=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+t*1400+1,1400);//去掉起始前缀的nalu剩余内容写入sendbuf[14]开始的字符串。
bytes=1400+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
//fwrite(sendbuf,bytes, 1, stream);
//sleep(1);
t++;
}
}
}
//usleep(40000);
}
FreeNALU(n);

return 0;
}

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;
}

2,下载vlc;

3,进行如下设置:
1>设置w.sdp
a,打开vlc->Media->Open network stream
b,-->network->rtp://@192.168.1.101:1234
c,-->file->add...w.sdp->play
这里要讲一下sdp文件，sdp文件时vlc播放是需要的文件，这里是必须的，否则是无法播放的，w.sdp文件其实只是几句话，这里我贴出来：

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

上面的1234和192.168.1.101就是RTP的端口和IP

2〉点击vlc播放按钮
3〉再运行264文件的RTP包发送的服务器
4〉一会儿就看看vlc播放视频了

参考:

1,VLC播放RTP打包发送的.264文件
http://blog.csdn.net/liuzongming1988/article/details/8292455