【RTSP从零实践】3、实现最简单的传输H264的RTSP服务器_RTSP协议通信与TCP套接字编程

😁博客主页😁：🚀https://blog.csdn.net/wkd_007🚀
🤑博客内容🤑：🍭嵌入式开发、Linux、C语言、C++、数据结构、音视频🍭
🤣本文内容🤣：🍭介绍怎么实现最简单的传输H264的RTSP服务器🍭
😎金句分享😎：🍭你不能选择最好的，但最好的会来选择你——泰戈尔🍭
⏰发布时间⏰： 2025-06-30

本文未经允许，不得转发！！！

目录

• 🎄一、概述
• 🎄二、实现步骤、实现细节
• • ✨2.1、使用RTSP服务的TCP套接字并监听
  • ✨2.2、接收客户端请求并处理RTSP命令
  • ✨2.3、读取H264并发送
• 🎄三、传输H264的RTSP服务器的实现源码
• 🎄四、总结

RTSP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】01、根据RTSP协议实现一个RTSP服务
【RTSP从零实践】02、使用RTP协议封装并传输H264
【RTSP从零实践】03、实现最简单的传输H264的RTSP服务器
【RTSP从零实践】04、使用RTP协议封装并传输AAC
【RTSP从零实践】05、实现最简单的传输AAC的RTSP服务器
【RTSP从零实践】06、实现最简单的同时传输H264、AAC的RTSP服务器
【RTSP从零实践】07、多播传输H264格式的RTP包(附带源码)
【RTSP从零实践】08、多播传输H264码流的RTSP服务器——最简单的实现例子(附带源码)
【RTSP从零实践】09、多播传输AAC格式的RTP包(附带源码)
【RTSP从零实践】10、多播传输AAC码流的RTSP服务器——最简单的实现例子(附带源码)
【RTSP从零实践】11、多播同时传输H264、AAC码流的RTSP服务器——最简单的实现例子(附带源码)
【RTSP从零实践】12、TCP传输H264格式RTP包(RTP_over_TCP)的RTSP服务器(附带源码)
【RTSP从零实践】13、TCP传输AAC格式RTP包(RTP_over_TCP)的RTSP服务器(附带源码)
【RTSP从零实践】14、TCP传输H264格式、AAC格式RTP包(RTP_over_TCP)的RTSP服务器(附带源码)

🎄一、概述

这篇文章主要就是介绍怎么通过RTSP协议通信，将H264视频数据封装成RTP包并发送的，目的是写一个最简单的RTSP服务器，熟悉RTSP协议处理、RTP协议封包。

包含了下面知识点：
1、RTSP协议的内容；
2、实现TCP协议实现RTSP；
3、RTP协议；
4、怎么实现RTP协议；

这些知识点都可以从上面 【RTSP从零实践】系列文章学习到，这篇文章不再赘述，只介绍步骤和代码。

🎄二、实现步骤、实现细节

这个小写介绍怎么实现的步骤、细节，下个小节会提供源码，可以结合着源码看帮助理解消化。

✨2.1、使用RTSP服务的TCP套接字并监听

RTSP协议是基于TCP作为传输层协议去实现的。

// 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;}

✨2.2、接收客户端请求并处理RTSP命令

RTSP通信不直接传输音视频码流，会先进行一些命令通信，所以第二个步骤就是处理这些命令：

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, rtpPort);}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);}

✨2.3、读取H264并发送

处理完RTSP命令后，就需要读取并发送RTP包了。

// 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 HZ usleep(1000 * 1000 / FPS); } } else { printf(\"warning need SeekFile 1\\n\"); }}

🎄三、传输H264的RTSP服务器的实现源码

总共有5个源代码文件，具体如下：

1、H264Reader.h

/** * @file H264Reader.h * @author https://blog.csdn.net/wkd_007 * @brief * @version 0.1 * @date 2025-06-24 * * @copyright Copyright (c) 2025 * */#ifndef __H264_READER_H__#define __H264_READER_H__#include #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 FALSE int nal_reference_idc; //! H264_NALU_PRIORITY_xxxx int nal_unit_type; //! H264_NALU_TYPE_xxxx BOOL 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 #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 bit pH264Frame->nal_reference_idc = pFrame[pH264Frame->startcode_len] & 0x60; // 2 bit pH264Frame->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  #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 #include #include #include #include #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、rtsp_h264_main.c

/** * @file rtsp_h264_main.c * @author https://blog.csdn.net/wkd_007 * @brief * @version 0.1 * @date 2025-06-30 * * @copyright Copyright (c) 2025 * */#include #include #include #include #include #include #include #include #include #include #include #include \"rtp.h\"#include \"H264Reader.h\"#define H264_FILE_NAME \"test.h264\"#define FPS 25#define RTSP_PORT 8554#define RTP_PORT 55666#define MAX_CLIENTS 5#define SESSION_ID 10086001#define SESSION_TIMEOUT 60typedef 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;  // start else if (remainPktSize == 0 && i == pktNum - 1) // 最后一包数据 rtpPacket->payload[1] |= 0x40;  // end memcpy(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; // end memcpy(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); // h264 H264ReaderInfo_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 HZ usleep(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const char *generate_sdp(){ return \"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\"  \"m=video 0 RTP/AVP 96\\r\\n\"  \"a=rtpmap:96 H264/90000\\r\\n\"  \"a=control:streamid=0\\r\\n\";}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, int rtpPort){ sprintf(response, \"RTSP/1.0 200 OK\\r\\n\" \"CSeq: %d\\r\\n\" \"Session: %u; timeout=%d\\r\\n\" \"Transport: RTP/AVP;unicast;client_port=%d-%d;server_port=%d-%d\\r\\n\\r\\n\", cseq, SESSION_ID, SESSION_TIMEOUT, rtpPort, rtpPort + 1, RTP_PORT, RTP_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 [%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, rtpPort); } 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 [%s]\\n\\n\", response); if (bSendFlag == RTP_PLAY) // PLAY { rtpSend.rtpSendFd = rtp_send_fd; rtpSend.rtpPort = rtpPort; rtpSend.cliIp = cli_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 int rtp_send_fd = createUdpSocket(); if (rtp_send_fd < 0) { printf(\"failed to create socket\\n\"); return -1; } address.sin_port = htons(RTP_PORT); if (bind(rtp_send_fd, (struct sockaddr *)&address, sizeof(address)) < 0) { perror(\"rtp_send_fd bind failed\"); 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;}

将上面代码保存在同一个目录后，并且在同目录里放一个.h264文件，然后运行 gcc *.c -lpthread 编译，再执行./a.out运行程序，下面是我运行的过程：

🎄四、总结

本文介绍了实现介绍怎么通过RTSP协议通信，将H264视频数据封装成RTP包并发送的，也提供了实现源码和运行结果，可以帮助读者快速了解怎样实现一个最简单的RTSP服务器。

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参考：
https://blog.csdn.net/huabiaochen/article/details/104557971