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⏰发布时间⏰： 2025-07-07

本文未经允许，不得转发！！！

前面系列文章回顾：
【音视频 | RTSP】RTSP协议详解及抓包例子解析（详细而不赘述）
【音视频 | RTSP】SDP(会话描述协议)详解及抓包例子分析
【音视频 | RTP】RTP协议详解(H.264的RTP封包格式、AAC的RTP封包格式)
【RTSP从零实践】1、根据RTSP协议实现一个RTSP服务
【RTSP从零实践】2、使用RTP协议封装并传输H264
【RTSP从零实践】3、实现最简单的传输H264的RTSP服务器
【RTSP从零实践】4、使用RTP协议封装并传输AAC
【RTSP从零实践】5、实现最简单的传输AAC的RTSP服务器
【RTSP从零实践】6、实现最简单的同时传输H264、AAC的RTSP服务器

在这里插入图片描述

🎄一、概述

上篇文章介绍了使用多播来传输RTP包，这篇继续介绍使用一个多播的方式来传输H264码流的RTSP服务器，读者阅读的时候可以将这篇文章的代码与之前的文章【RTSP从零实践】3、实现最简单的传输H264的RTSP服务器进行对比，主要改了两点：

1、将UDP单播发送的方式改为UDP多播发送；
2、处理RTSP命令时，返回多播的相关信息。

下面章节先是介绍多播的一些简单概念，然后介绍多播的方式处理RTSP命令时的注意点。

在这里插入图片描述

🎄二、多播的概念

关于多播的概念可以参考这篇文章：多播的概念、多播地址、UDP实现多播的C语言例子。下面只简单介绍一下多播。

IP 多播(也称多址广播或组播)技术，是允许一台主机向多台主机发送消息的一种通信方式。单播只向单个IP接口发送数据，广播是向子网内所有IP接口发送数据，多播则介于两者之间，向一组IP接口发送数据。

多播地址：用来标识多播组，IPv4使用D类地址的某一个来表示一个多播组地址。IPv4的D类地址（从224.0.0.0到239.255.255.255）是IPv4多播地址，见下图：

多播发送端：用于发送多播数据报的程序，下面是一个简单的多播发送端例子的代码。基本上就是在发送数据包时，将目的地址设置为 多播地址。

// multicastCli.c
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>int main()
{// 1、创建UDP套接字socketint sockfd = socket(AF_INET, SOCK_DGRAM, 0);if(sockfd<0)perror("socket error" );// 2、准备多播组地址和端口struct sockaddr_in servaddr;bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons (10086);if (inet_pton(AF_INET, "239.0.1.1", &servaddr.sin_addr) <= 0)perror("inet_pton error");// 4、使用 sendto 发送多播组数据报if(sendto(sockfd, "Hello,I am udp client", strlen("Hello,I am udp client"), 0, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)perror("sendto error" );// 5、处理应答char recvline[256];int n = 0;struct sockaddr_in tmpAddr;bzero(&tmpAddr, sizeof(tmpAddr));socklen_t addrLen=sizeof(tmpAddr);while ( (n = recvfrom (sockfd, recvline, sizeof(recvline), 0, (struct sockaddr*)&tmpAddr, &addrLen)) > 0){recvline[n] = 0 ;/*null terminate */printf("recvfrom ip=[%s], [%s]\n",inet_ntoa(tmpAddr.sin_addr), recvline);bzero(&tmpAddr, sizeof(tmpAddr));}if (n < 0)perror("read error" );// 6、关闭close(sockfd);return 0;
}

多播接收端：接收端是使用UDP服务端代码修改，需要在交互数据之前，将套接字加入多播组239.0.1.1，让链路层接口接收该多播组的数据报，使用完需要离开多播组。下面是一个多播接收端代码：

// multicastSer.c
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>int main()
{// 1、创建UDP套接字socketint sockfd = socket(AF_INET, SOCK_DGRAM, 0);if(sockfd<0)perror("socket error" );// 2、准备本地ip接口和多播组端口struct sockaddr_in servaddr;bzero(&servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons (10086);servaddr.sin_addr.s_addr = INADDR_ANY; // 指定ip地址为 INADDR_ANY，这样要是服务器主机有多个网络接口，服务器进程就可以在任一网络接口上接受客户端的连接// 3、绑定多播组端口 bindif (bind(sockfd,(struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)perror("bind error" );// 4、加入多播组 239.0.1.1struct ip_mreq mreq;mreq.imr_multiaddr.s_addr = inet_addr("239.0.1.1");	// 多播组的IP地址mreq.imr_interface.s_addr = htonl(INADDR_ANY);		// 加入的客服端主机IP地址if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) == -1)    {perror("setsockopt");return -1;}// 5、使用 sendto、recvfrom 交互数据printf("UdpSer sockfd=%d, start \n",sockfd);char recvline[256];while(1){struct sockaddr_in cliaddr;bzero(&cliaddr, sizeof(cliaddr));socklen_t addrLen=sizeof(cliaddr);int n = recvfrom(sockfd, recvline, sizeof(recvline), 0, (struct sockaddr*)&cliaddr, &addrLen);if(n>0){recvline[n] = 0 ;/*null terminate */printf("recv sockfd=%d %d byte, [%s] addrLen=%d, cliIp=%s, cliPort=%d\n",sockfd, n, recvline, addrLen, inet_ntoa(cliaddr.sin_addr),cliaddr.sin_port);sendto(sockfd, "Hello,I am udp server", strlen("Hello,I am udp server"), 0, (struct sockaddr*)&cliaddr, addrLen);}}// 6、离开多播组setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP,&mreq, sizeof(mreq)); // 7、关闭close(sockfd);return 0;
}

在这里插入图片描述

🎄三、实现步骤、实现细节

多播传输H264格式的RTSP服务器的实现步骤如下：
1、实现 H264文件读取器。
2、实现 H264 的 RTP 数据包封装。
3、实现多播发送RTP包。
4、处理RTSP命令并发送码流。

前两点在文章使用RTP协议封装并传输H264 介绍得很详细，需要看的童鞋，留言一下，我给你复制过来。😑

实现多播发送RTP包，我们只需要在UDP单播发送的代码里将UDP的目的地址改为我们要使用的多播组地址即可，我们这里要使用的是"239.0.0.1"。

下面内容是多播方式处理RTSP命令的过程：

OPTION
处理OPTION消息时，直接返回本服务器支持的方法即可，没什么特别的：
DESCRIBE
SETUP
PLAY
TEARDOWN

在这里插入图片描述

🎄四、多播传输H264格式的RTP包的实现源码

1、H264Reader.h

#ifndef __H264_READER_H__
#define __H264_READER_H__#include <stdio.h>#define MAX_STARTCODE_LEN (4)typedef enum
{FALSE,TRUE,
} BOOL;typedef enum
{H264_NALU_TYPE_SLICE = 1,H264_NALU_TYPE_DPA = 2,H264_NALU_TYPE_DPB = 3,H264_NALU_TYPE_DPC = 4,H264_NALU_TYPE_IDR = 5,H264_NALU_TYPE_SEI = 6,H264_NALU_TYPE_SPS = 7,H264_NALU_TYPE_PPS = 8,H264_NALU_TYPE_AUD = 9,H264_NALU_TYPE_EOSEQ = 10,H264_NALU_TYPE_EOSTREAM = 11,H264_NALU_TYPE_FILL = 12,
} H264NaluType;typedef enum
{H264_NALU_PRIORITY_DISPOSABLE = 0,H264_NALU_PRIRITY_LOW = 1,H264_NALU_PRIORITY_HIGH = 2,H264_NALU_PRIORITY_HIGHEST = 3
} H264NaluPriority;typedef struct
{int startcode_len;		  //! 4 for parameter sets and first slice in picture, 3 for everything else (suggested)int forbidden_bit;		  //! should be always FALSEint nal_reference_idc;	  //! H264_NALU_PRIORITY_xxxxint nal_unit_type;		  //! H264_NALU_TYPE_xxxxBOOL isLastFrame;		  //!int frame_len;			  //!unsigned char *pFrameBuf; //!
} H264Frame_t;typedef struct H264ReaderInfo_s
{FILE *pFileFd;int frameNum;
} H264ReaderInfo_t;int H264_FileOpen(char *fileName, H264ReaderInfo_t *pH264Info);
int H264_FileClose(H264ReaderInfo_t *pH264Info);
int H264_GetFrame(H264Frame_t *pH264Frame, H264ReaderInfo_t *pH264Info);
BOOL H264_IsEndOfFile(const H264ReaderInfo_t *pH264Info);
void H264_SeekFile(H264ReaderInfo_t *pH264Info);#endif // __H264_READER_H__

2、H264Reader.c

/*** @file H264Reader.c* @author https://blog.csdn.net/wkd_007* @brief* @version 0.1* @date 2025-06-30** @copyright Copyright (c) 2025**/
#include "H264Reader.h"
#include <stdlib.h>#define MAX_FRAME_LEN (1920 * 1080 * 1.5) // 一帧数据最大字节数static BOOL findStartCode_001(unsigned char *Buf)
{// printf("[%d %d %d]\n", Buf[0], Buf[1], Buf[2]);return (Buf[0] == 0 && Buf[1] == 0 && Buf[2] == 1); // 0x000001 ?
}static BOOL findStartCode_0001(unsigned char *Buf)
{// printf("[%d %d %d %d]\n", Buf[0], Buf[1], Buf[2], Buf[3]);return (Buf[0] == 0 && Buf[1] == 0 && Buf[2] == 0 && Buf[3] == 1); // 0x00000001 ?
}int H264_FileOpen(char *fileName, H264ReaderInfo_t *pH264Info)
{pH264Info->pFileFd = fopen(fileName, "rb+");if (pH264Info->pFileFd == NULL){printf("[%s %d]Open file error\n", __FILE__, __LINE__);return -1;}pH264Info->frameNum = 0;return 0;
}int H264_FileClose(H264ReaderInfo_t *pH264Info)
{if (pH264Info->pFileFd != NULL){fclose(pH264Info->pFileFd);pH264Info->pFileFd = NULL;}return 0;
}BOOL H264_IsEndOfFile(const H264ReaderInfo_t *pH264Info)
{return feof(pH264Info->pFileFd);
}void H264_SeekFile(H264ReaderInfo_t *pH264Info)
{fseek(pH264Info->pFileFd, 0, SEEK_SET);pH264Info->frameNum = 0;
}/*** @brief 获取一阵h264视频帧** @param pH264Frame ：输出参数，使用后 pH264Frame->pFrameBuf 需要free* @param pH264Info ：输入参数* @return int*/
int H264_GetFrame(H264Frame_t *pH264Frame, H264ReaderInfo_t *pH264Info)
{int rewind = 0;if (pH264Info->pFileFd == NULL){printf("[%s %d]pFileFd error\n", __FILE__, __LINE__);return -1;}// 1.读取帧数据// unsigned char *pFrame = (unsigned char *)malloc(MAX_FRAME_LEN);unsigned char *pFrame = pH264Frame->pFrameBuf;int readLen = fread(pFrame, 1, MAX_FRAME_LEN, pH264Info->pFileFd);if (readLen <= 0){printf("[%s %d]fread error\n", __FILE__, __LINE__);// free(pFrame);return -1;}// 2.查找当前帧开始码int i = 0;for (; i < readLen - MAX_STARTCODE_LEN; i++){if (!findStartCode_0001(&pFrame[i])){if (!findStartCode_001(&pFrame[i])){continue;}else{pH264Frame->startcode_len = 3;break;}}else{pH264Frame->startcode_len = 4;break;}}if (i != 0) // 不是帧开头，偏移到帧开头重新读{printf("[%s %d]startcode error, i=%d\n", __FILE__, __LINE__, i);// free(pFrame);rewind = (-(readLen - i));fseek(pH264Info->pFileFd, rewind, SEEK_CUR);return -1;}// 3.查找下一帧开始码i += MAX_STARTCODE_LEN;for (; i < readLen - MAX_STARTCODE_LEN; i++){if (!findStartCode_0001(&pFrame[i])){if (!findStartCode_001(&pFrame[i])){continue;}else{break;}}else{break;}}if (i == (readLen - MAX_STARTCODE_LEN)){if (!feof(pH264Info->pFileFd)){printf("[%s %d]MAX_FRAME_LEN too small\n", __FILE__, __LINE__);// free(pFrame);return -1;}else{pH264Frame->isLastFrame = TRUE;}}// 4.填数据pH264Frame->forbidden_bit = pFrame[pH264Frame->startcode_len] & 0x80;     // 1 bitpH264Frame->nal_reference_idc = pFrame[pH264Frame->startcode_len] & 0x60; // 2 bitpH264Frame->nal_unit_type = pFrame[pH264Frame->startcode_len] & 0x1f;     // 5 bit, naluType 是开始码后一个字节的最后 5 位// pH264Frame->pFrameBuf = pFrame;pH264Frame->frame_len = i;// 5.文件读取指针偏移到下一帧位置rewind = (-(readLen - i));fseek(pH264Info->pFileFd, rewind, SEEK_CUR);pH264Info->frameNum++;return pH264Frame->frame_len;
}

3、rtp.h

#ifndef _RTP_H_
#define _RTP_H_
#include <stdint.h>#define RTP_VESION              2#define RTP_PAYLOAD_TYPE_H264   96
#define RTP_PAYLOAD_TYPE_AAC    97#define RTP_HEADER_SIZE         12
#define RTP_MAX_PKT_SIZE        1400/***    0                   1                   2                   3*    7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0*   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*   |V=2|P|X|  CC   |M|     PT      |       sequence number         |*   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*   |                           timestamp                           |*   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*   |           synchronization source (SSRC) identifier            |*   +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+*   |            contributing source (CSRC) identifiers             |*   :                             ....                              :*   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+**/
struct RtpHeader
{/* byte 0 */uint8_t csrcLen:4;uint8_t extension:1;uint8_t padding:1;uint8_t version:2;/* byte 1 */uint8_t payloadType:7;uint8_t marker:1;/* bytes 2,3 */uint16_t seq;/* bytes 4-7 */uint32_t timestamp;/* bytes 8-11 */uint32_t ssrc;
};struct RtpPacket
{struct RtpHeader rtpHeader;uint8_t payload[0];
};void rtpHeaderInit(struct RtpPacket* rtpPacket, uint8_t csrcLen, uint8_t extension,uint8_t padding, uint8_t version, uint8_t payloadType, uint8_t marker,uint16_t seq, uint32_t timestamp, uint32_t ssrc);
int rtpSendPacket(int socket, char* ip, int16_t port, struct RtpPacket* rtpPacket, uint32_t dataSize);#endif //_RTP_H_

4、rtp.c

#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <arpa/inet.h>#include "rtp.h"void rtpHeaderInit(struct RtpPacket *rtpPacket, uint8_t csrcLen, uint8_t extension,uint8_t padding, uint8_t version, uint8_t payloadType, uint8_t marker,uint16_t seq, uint32_t timestamp, uint32_t ssrc)
{rtpPacket->rtpHeader.csrcLen = csrcLen;rtpPacket->rtpHeader.extension = extension;rtpPacket->rtpHeader.padding = padding;rtpPacket->rtpHeader.version = version;rtpPacket->rtpHeader.payloadType = payloadType;rtpPacket->rtpHeader.marker = marker;rtpPacket->rtpHeader.seq = seq;rtpPacket->rtpHeader.timestamp = timestamp;rtpPacket->rtpHeader.ssrc = ssrc;
}int rtpSendPacket(int socket, char *ip, int16_t port, struct RtpPacket *rtpPacket, uint32_t dataSize)
{struct sockaddr_in addr;int ret;addr.sin_family = AF_INET;addr.sin_port = htons(port);addr.sin_addr.s_addr = inet_addr(ip);rtpPacket->rtpHeader.seq = htons(rtpPacket->rtpHeader.seq);rtpPacket->rtpHeader.timestamp = htonl(rtpPacket->rtpHeader.timestamp);rtpPacket->rtpHeader.ssrc = htonl(rtpPacket->rtpHeader.ssrc);ret = sendto(socket, (void *)rtpPacket, dataSize + RTP_HEADER_SIZE, 0,(struct sockaddr *)&addr, sizeof(addr));rtpPacket->rtpHeader.seq = ntohs(rtpPacket->rtpHeader.seq);rtpPacket->rtpHeader.timestamp = ntohl(rtpPacket->rtpHeader.timestamp);rtpPacket->rtpHeader.ssrc = ntohl(rtpPacket->rtpHeader.ssrc);return ret;
}

5、multicast_rtp_h264_main

/*** @file multicast_rtsp_h264_main.c* @author : https://blog.csdn.net/wkd_007* @brief* @version 0.1* @date 2025-07-07** @copyright Copyright (c) 2025**/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <fcntl.h>#include "rtp.h"
#include "H264Reader.h"#define H264_FILE_NAME  "test.h264"
#define FPS             25
#define RTSP_PORT       8554
#define MAX_CLIENTS     5
#define SESSION_ID      10086001
#define SESSION_TIMEOUT 60#define MULTICAST_IP    "239.0.0.1"
#define MULTICAST_PORT  55666typedef struct
{int   rtpSendFd;int   rtpPort;int   bPlayFlag; // 播放标志char *cliIp;
} RTP_Send_t;typedef enum
{RTP_NULL,RTP_PLAY,RTP_PLAYING,RTP_STOP,
} RTP_PLAY_STATE;static int createUdpSocket()
{int fd = socket(AF_INET, SOCK_DGRAM, 0);if (fd < 0)return -1;int on = 1;setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));return fd;
}static int rtpSendH264Frame(int socket, char *ip, int16_t port,struct RtpPacket *rtpPacket, uint8_t *frame, uint32_t frameSize)
{uint8_t naluType; // nalu第一个字节int     sendBytes = 0;int     ret;naluType = frame[0];if (frameSize <= RTP_MAX_PKT_SIZE) // nalu长度小于最大包场：单一NALU单元模式{/**   0 1 2 3 4 5 6 7 8 9*  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*  |F|NRI|  Type   | a single NAL unit ... |*  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*/memcpy(rtpPacket->payload, frame, frameSize);ret = rtpSendPacket(socket, ip, port, rtpPacket, frameSize);if (ret < 0)return -1;rtpPacket->rtpHeader.seq++;sendBytes += ret;if ((naluType & 0x1F) == 7 || (naluType & 0x1F) == 8) // 如果是SPS、PPS就不需要加时间戳goto out;}else // nalu长度大于最大包场：分片模式{/**  0                   1                   2*  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+* | FU indicator  |   FU header   |   FU payload   ...  |* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*//**     FU Indicator*    0 1 2 3 4 5 6 7*   +-+-+-+-+-+-+-+-+*   |F|NRI|  Type   |*   +---------------+*//**      FU Header*    0 1 2 3 4 5 6 7*   +-+-+-+-+-+-+-+-+*   |S|E|R|  Type   |*   +---------------+*/int pktNum        = frameSize / RTP_MAX_PKT_SIZE; // 有几个完整的包int remainPktSize = frameSize % RTP_MAX_PKT_SIZE; // 剩余不完整包的大小int i, pos = 1;/* 发送完整的包 */for (i = 0; i < pktNum; i++){rtpPacket->payload[0] = (naluType & 0x60) | 28;rtpPacket->payload[1] = naluType & 0x1F;if (i == 0)                                     // 第一包数据rtpPacket->payload[1] |= 0x80;              // startelse if (remainPktSize == 0 && i == pktNum - 1) // 最后一包数据rtpPacket->payload[1] |= 0x40;              // endmemcpy(rtpPacket->payload + 2, frame + pos, RTP_MAX_PKT_SIZE);ret = rtpSendPacket(socket, ip, port, rtpPacket, RTP_MAX_PKT_SIZE + 2);if (ret < 0)return -1;rtpPacket->rtpHeader.seq++;sendBytes += ret;pos += RTP_MAX_PKT_SIZE;}/* 发送剩余的数据 */if (remainPktSize > 0){rtpPacket->payload[0] = (naluType & 0x60) | 28;rtpPacket->payload[1] = naluType & 0x1F;rtpPacket->payload[1] |= 0x40; // endmemcpy(rtpPacket->payload + 2, frame + pos, remainPktSize + 2);ret = rtpSendPacket(socket, ip, port, rtpPacket, remainPktSize + 2);if (ret < 0)return -1;rtpPacket->rtpHeader.seq++;sendBytes += ret;}}out:return sendBytes;
}void *sendRtp(void *arg)
{RTP_Send_t *pRtpSend    = (RTP_Send_t *)arg;int         rtp_send_fd = pRtpSend->rtpSendFd;int         rtpPort     = pRtpSend->rtpPort;char       *cli_ip      = pRtpSend->cliIp;struct RtpPacket *rtpPacket = (struct RtpPacket *)malloc(sizeof(struct RtpPacket) + (1920 * 1080 * 4));rtpHeaderInit(rtpPacket, 0, 0, 0, RTP_VESION, RTP_PAYLOAD_TYPE_H264, 0,0, 0, 0x88923423);// h264H264ReaderInfo_t h264Info;if (H264_FileOpen(H264_FILE_NAME, &h264Info) < 0){printf("failed to open %s\n", H264_FILE_NAME);return NULL;}H264Frame_t h264Frame;h264Frame.pFrameBuf = (unsigned char *)malloc(1920 * 1080 * 4);while (pRtpSend->bPlayFlag){if (!H264_IsEndOfFile(&h264Info)){h264Frame.isLastFrame = 0;H264_GetFrame(&h264Frame, &h264Info);if (h264Frame.pFrameBuf != NULL){if (h264Frame.isLastFrame) // 最后一帧，移到开头重新读{printf("warning SeekFile 1\n");H264_SeekFile(&h264Info);}// printf("rtpSendH264Frame, frameNum=%d, time=%u\n", h264Info.frameNum, rtpPacket->rtpHeader.timestamp);rtpSendH264Frame(rtp_send_fd, cli_ip, rtpPort, rtpPacket,h264Frame.pFrameBuf + h264Frame.startcode_len,h264Frame.frame_len - h264Frame.startcode_len);rtpPacket->rtpHeader.timestamp += 90000 / FPS; // RTP 传输视频每秒 90k HZusleep(1000 * 1000 / FPS);}}else{printf("warning need SeekFile 1\n");}}free(h264Frame.pFrameBuf);free(rtpPacket);H264_FileClose(&h264Info);
}// 解析RTSP请求
static void rtsp_request_parse(char *buffer, char *method, char *url, int *cseq, int *pRtpPort)
{char *line = strtok(buffer, "\r\n");sscanf(line, "%s %s RTSP/1.0", method, url);while ((line = strtok(NULL, "\r\n")) != NULL){if (strncmp(line, "CSeq:", 5) == 0){sscanf(line, "CSeq: %d", cseq);}char *pCliPort = strstr(line, "client_port=");if (pCliPort != NULL){int rtcpPort = 0;sscanf(pCliPort, "client_port=%d-%d", pRtpPort, &rtcpPort);// printf("rtpPort: %d-%d\n",*pRtpPort, rtcpPort);}}
}// 生成SDP描述
char        g_sdp[512] = {0};
const char *generate_sdp()
{memset(g_sdp, 0, sizeof(g_sdp));sprintf(g_sdp,"v=0\r\n""o=- 0 0 IN IP4 0.0.0.0\r\n""s=Example Stream\r\n""t=0 0\r\n""a=type:broadcast\r\n""a=rtcp-unicast: reflection\r\n""m=video %d RTP/AVP 96\r\n""c=IN IP4 %s/255\r\n""a=rtpmap:96 H264/90000\r\n""a=control:streamid=0\r\n",MULTICAST_PORT, MULTICAST_IP);return g_sdp;
}void rtsp_handle_OPTION(char *response, int cseq)
{sprintf(response,"RTSP/1.0 200 OK\r\n""CSeq: %d\r\n""Public: OPTIONS, DESCRIBE, SETUP, PLAY, TEARDOWN\r\n\r\n",cseq);
}static void rtsp_handle_DESCRIBE(char *response, int cseq)
{sprintf(response,"RTSP/1.0 200 OK\r\n""CSeq: %d\r\n""Content-Type: application/sdp\r\n""Content-Length: %zu\r\n\r\n%s",cseq, strlen(generate_sdp()), generate_sdp());
}static void rtsp_handle_SETUP(char *response, int cseq, char *url)
{char localIp[32];sscanf(url, "rtsp://%[^:]:", localIp);sprintf(response,"RTSP/1.0 200 OK\r\n""CSeq: %d\r\n""Session: %u; timeout=%d\r\n""Transport: RTP/AVP;multicast;destination=%s;source=%s;port=%d-%d;ttl=255\r\n\r\n",cseq, SESSION_ID, SESSION_TIMEOUT, MULTICAST_IP, localIp, MULTICAST_PORT, MULTICAST_PORT + 1);
}static void rtsp_handle_PLAY(char *response, int cseq)
{sprintf(response,"RTSP/1.0 200 OK\r\n""CSeq: %d\r\n""Session: %u; timeout=%d\r\n""Range: npt=0.000-\r\n\r\n",cseq, SESSION_ID, SESSION_TIMEOUT);
}static void rtsp_handle_TEARDOWN(char *response, int cseq)
{sprintf(response,"RTSP/1.0 200 OK\r\n""CSeq: %d\r\n""Session: %d; timeout=%d\r\n\r\n",cseq, SESSION_ID, SESSION_TIMEOUT);
}// 处理客户端连接
int handle_client(int cli_fd, int rtp_send_fd, char *cli_ip)
{int           client_sock  = cli_fd;char          buffer[1024] = {0};int           cseq         = 0;int           rtpPort      = 0;unsigned char bSendFlag    = RTP_NULL;RTP_Send_t    rtpSend;pthread_t     thread_id;while (1){memset(buffer, 0, sizeof(buffer));int len = read(client_sock, buffer, sizeof(buffer) - 1);if (len <= 0)break;printf("C->S [\n%s]\n\n", buffer);char method[16] = {0};char url[128]   = {0};rtsp_request_parse(buffer, method, url, &cseq, &rtpPort);char response[1024] = {0}; // 构造响应if (strcmp(method, "OPTIONS") == 0){rtsp_handle_OPTION(response, cseq);}else if (strcmp(method, "DESCRIBE") == 0){rtsp_handle_DESCRIBE(response, cseq);}else if (strcmp(method, "SETUP") == 0){rtsp_handle_SETUP(response, cseq, url);}else if (strcmp(method, "PLAY") == 0){rtsp_handle_PLAY(response, cseq);bSendFlag = RTP_PLAY;}else if (strcmp(method, "TEARDOWN") == 0){rtsp_handle_TEARDOWN(response, cseq);bSendFlag = RTP_STOP;}else{snprintf(response, sizeof(response),"RTSP/1.0 501 Not Implemented\r\nCSeq: %d\r\n\r\n", cseq);}write(client_sock, response, strlen(response));printf("S->C [\n%s]\n\n", response);if (bSendFlag == RTP_PLAY) // PLAY{rtpSend.rtpSendFd = rtp_send_fd;rtpSend.rtpPort   = MULTICAST_PORT;rtpSend.cliIp     = MULTICAST_IP;rtpSend.bPlayFlag = 1;// 这里不使用线程的话，会一直无法处理 client_sock 发过来的 OPTION 消息，导致播放出问题if (pthread_create(&thread_id, NULL, (void *)sendRtp, (void *)&rtpSend) < 0){perror("pthread_create");}bSendFlag = RTP_PLAYING;}if (bSendFlag == RTP_STOP) // TEARDOWN{rtpSend.bPlayFlag = 0;pthread_join(thread_id); // 等待线程结束bSendFlag = RTP_NULL;break;}}printf("close ip=[%s] fd=[%d]\n", cli_ip, client_sock);close(client_sock);return 0;
}int main()
{int                server_fd, client_fd;struct sockaddr_in address;int                opt     = 1;socklen_t          addrlen = sizeof(address);// 创建套接字if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0){perror("socket failed");return -1;}// 设置套接字选项if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))){perror("setsockopt");return -1;}address.sin_family      = AF_INET;address.sin_addr.s_addr = INADDR_ANY;address.sin_port        = htons(RTSP_PORT);// 绑定端口if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0){perror("bind failed");return -1;}// 开始监听if (listen(server_fd, MAX_CLIENTS) < 0){perror("listen");return -1;}// 用于发送 rtp 包的udp套接字，不需要绑定端口int rtp_send_fd = createUdpSocket();if (rtp_send_fd < 0){printf("failed to create socket\n");return -1;}printf("RTSP Server listening on port %d\n", RTSP_PORT);// 主循环接受连接，目前处理一个客户端while (1){char cli_ip[40] = {0};if ((client_fd = accept(server_fd, (struct sockaddr *)&address, &addrlen)) < 0){perror("accept");return -1;}strncpy(cli_ip, inet_ntoa(address.sin_addr), sizeof(cli_ip));printf("handle cliend [%s]\n", cli_ip);handle_client(client_fd, rtp_send_fd, cli_ip);}return 0;
}