前言

本文主要介绍自研的RtmpStreamSender.dll，rtmp库提供接口接收裸流数据，支持将裸流数据封装为flv格式并通过rtmp协议发流。

关于rtmp协议基础介绍可查看：https://blog.csdn.net/www_dong/article/details/131026072

关于rtmp收流介绍可查看：https://blog.csdn.net/www_dong/article/details/135073488

设计

主要流程：

1. rtmp服务端启动tcp（端口:1935）监听，创建rtmp server对象；
2. rtmp客户端发起tcp连接，连接成功后等到收流；
3. rtmp服务端以动态库的形式呈现，提供SendData接口，有上层应用调用时塞入数据；
4. rtmp服务端接收数据，将数据封装为flv格式；
5. rtmp服务端将flv格式的流发送给rtmp客户端；
6. rtmp客户端将数据解复用、解码和播放；

流程

• 创建tcp、启动端口监听；

int RtmpServerThread(void* param)
{assert(param);CRtmpStreamSender* receiver = (CRtmpStreamSender*)param;receiver->RtmpServerWorker();return 0;
}int CRtmpStreamSender::InitRtmpSession_()
{if (0 != ParseUrl_()){printf("parse url failed\n");return -1;}do{m_tcpServer = std::make_shared<ZDTcpServer>(nullptr, this);if (!m_tcpServer.get()|| 0 != m_tcpServer->TcpCreate()|| 0 != m_tcpServer->TcpBind(m_rtmpPort)|| 0 != m_tcpServer->TcpListen(5)){break;}m_command = std::make_shared<CRtmpServerCommand>(m_tcpServer);if (!m_command.get()|| 0 != m_command->Create()){break;}m_thread = std::thread(RtmpServerThread, this);return 0;} while (0);Stop();return 0;
}// 在线程中等待连接
void CRtmpStreamSender::RtmpServerWorker()
{bool bAccept = false;while (m_running){if (!bAccept){if (0 == m_tcpServer->TcpAccept()){bAccept = true;}continue;}std::this_thread::sleep_for(std::chrono::seconds(5));}
}

• 创建rtmp server

// CRtmpServerCommand:librtmp封装类
m_command = std::make_shared<CRtmpServerCommand>(m_tcpServer);
if (!m_command.get()|| 0 != m_command->Create())
{break;
}// 创建rtmp server
int CRtmpServerCommand::Create()
{// 创建flv复用对象m_flvMuxer = flv_muxer_create(SendRtmpDataMutexFLV, this);if (!m_flvMuxer)return -1;struct rtmp_server_handler_t handler;memset(&handler, 0, sizeof(handler));handler.send = SendCallback;// 创建rtmp serverm_rtmp = rtmp_server_create(this, &handler);if (!m_rtmp)return -1;return 0;
}

• 数据封装

// 上层通过SendData塞数据
int CRtmpStreamSender::SendData(void* data, int len, char* codec)
{if (!m_command.get())return -1;return m_command->InputData(data, len, codec);
}// 数据做flv封装
int CRtmpServerCommand::InputData(void* data, int len, const std::string& codec)
{if (!m_flvMuxer || !data || len <= 0 || codec.empty())return -1;int ret = -1;if (0 == codec.compare("H264")){ret = flv_muxer_avc(m_flvMuxer, data, len, 0, 0);}else if (0 == codec.compare("H265")){ret = flv_muxer_hevc(m_flvMuxer, data, len, 0, 0);}else if (0 == codec.compare("AAC")){ret = flv_muxer_aac(m_flvMuxer, data, len, 0, 0);}return 0;
}

• 发送数据

int CRtmpServerCommand::Package(int type, const void* data, size_t bytes, uint32_t timestamp)
{if (!m_rtmp || !data || bytes <= 0)return -1;int ret = -1;if (FLV_TYPE_AUDIO == type){ret = rtmp_server_send_audio(m_rtmp, data, bytes, timestamp);}else if (FLV_TYPE_VIDEO == type){ret = rtmp_server_send_video(m_rtmp, data, bytes, timestamp);}else if (FLV_TYPE_SCRIPT == type){ret = rtmp_server_send_script(m_rtmp, data, bytes, timestamp);}if (0 != ret)return ret;return 0;
}

• 资源销毁

void CRtmpServerCommand::Destroy()
{if (m_rtmp){rtmp_server_destroy(m_rtmp);m_rtmp = nullptr;}if (m_flvMuxer){flv_muxer_destroy(m_flvMuxer);m_flvMuxer = nullptr;}
}