RTMP协议详解

一、RTMP协议详解

RTMP（Real Time Messaging Protocol）是一种用于网络流媒体传输的协议，由Adobe公司开发。RTMP常用于视频直播、在线游戏和VoIP（Voice over IP，即语音通信）中。RTMP是TCP协议通过HTTP协议进行封装和路由的协议，具有良好的实时性和低延迟性。

RTMP包括三个组成部分：消息格式、消息传输和命令传输。其中，消息格式决定了消息包的格式，消息传输决定了消息包的传输机制，命令传输负责启动传输、维护连接等控制任务。

二、RTMP协议推流

在使用RTMP协议进行视频直播时，推流是非常重要的一步。推流指的是将本地数据流发送到服务器上，使得其他用户可以获取该数据流。以下是使用RTMP协议进行推流的代码示例：

var video = document.getElementById('video');
var mediaRecorder = new MediaRecorder(video.srcObject);

let chunks = [];
mediaRecorder.ondataavailable = function(e) {
  chunks.push(e.data);
}

mediaRecorder.onstop = function(e) {
  let blob = new Blob(chunks, { 'type' : 'video/mp4;' });
  chunks = [];
  let videoURL = URL.createObjectURL(blob);
  let rtmpUrl = 'rtmp://your-server-url';
  let rtmpStreamName = 'your-stream-name';
  let swfUrl = 'flash.swf';
  let playPath = rtmpStreamName;

  let url = rtmpUrl + '/' + playPath;
  let videoElement = document.createElement('video');
  let flashvars = {
    url: url,
    play: true,
    player: 'vod'
  };
  let params = {
    wmode: 'opaque',
    allowfullscreen: 'true',
    allowscriptaccess: 'always'
  };
  let attrs = {
    name: 'player',
    id: 'player'
  };

  let handler = new RTMPPlayer(videoElement, swfUrl, flashvars, params, attrs);
  handler.init();
}
mediaRecorder.start();

三、RTMP协议代码

下面是使用RTMP协议进行视频直播时需要用到的部分代码：

var rtmpUrl = 'rtmp://your-server-url';
var rtmpStreamName = 'your-stream-name';
var swfUrl = 'flash.swf';
var playPath = rtmpStreamName;

var url = rtmpUrl + '/' + playPath;
var videoElement = document.createElement('video');
var flashvars = {
  url: url,
  play: true,
  player: 'vod'
};
var params = {
  wmode: 'opaque',
  allowfullscreen: 'true',
  allowscriptaccess: 'always'
};
var attrs = {
  name: 'player',
  id: 'player'
};

var handler = new RTMPPlayer(videoElement, swfUrl, flashvars, params, attrs);
handler.init();

四、RTMP协议分流

在使用RTMP协议进行视频直播时，经常会遇到需要对不同的流（stream）进行不同的操作，比如推流、录播、转码等。RTMP协议提供了多种流的管理方案，如流的创建、删除、查询等操作。以下是使用RTMP协议进行流管理的代码示例：

// 建立RTMP连接
var connection = createConnection();
connection.connect("rtmp://your-server-url");

// 创建一个流
var stream = new createStream(connection);

var rtmpStreamName = 'your-stream-name';
function onPublishCallback(success) {
  if (success) {
    console.log("Publish started successfully!");
  }
  else {
    console.log("Failed to start publish!");
    // 失败的处理
  }
}
stream.publish(rtmpStreamName, "live", "push");

// 删除流
stream.deleteStream();

// 查询流
stream.queryStream(rtmpStreamName, onQueryStreamCallback);

五、RTMP协议直播

RTMP协议广泛应用于视频直播领域，可以支持多种媒体格式的直播。以下是使用RTMP协议进行直播的代码示例：

<script type="text/javascript" src="/clappr.js"></script>

  

<script type="text/javascript">
  var playerElement = document.getElementById("player-wrapper");
  var player = new Clappr.Player({
    source: "rtmp://your-server-url/your-stream-name",
    parentId: "#player-wrapper",
    autoPlay: true,
    width: 640,
    height: 360
  });
</script>

六、RTMP协议摄像头

RTMP协议可以与摄像头结合使用，使得用户可以使用自己的摄像头进行视频直播。以下是使用RTMP协议进行摄像头直播的代码示例：

var mediaConstraints = {
  audio: true,
  video: true
};

navigator.mediaDevices.getUserMedia(mediaConstraints)
  .then(function success(videoStream) {
    var videoElement = document.getElementById('videoElement');
    videoElement.srcObject = videoStream;
    var mediaRecorder = new MediaStreamRecorder(videoStream, {
      mimeType: 'video/mp4'
    });

    var rtmpUrl = 'rtmp://your-server-url';
    var rtmpStreamName = 'your-stream-name';
    var flvPlayer = flvjs.createPlayer({
      type: 'flv',
      isLive: true,
      url: rtmpUrl + '/' + rtmpStreamName + '.flv'
    });

    mediaRecorder.ondataavailable = function(blob) {
      var reader = new FileReader();
      reader.readAsArrayBuffer(blob);
      reader.addEventListener('load', function() {
        // 发送视频数据到RTMP服务器
        flvPlayer.options.mediaDataSource.segments.push({
          payload: new Uint8Array(reader.result),
          contentStart: 0,
          contentEnd: blob.size - 1
        })
      });
    };

    // 通过Flv.js进行媒体播放
    flvPlayer.attachMediaElement(videoElement);
    flvPlayer.load();
    flvPlayer.play();

    // 启动媒体录制
    mediaRecorder.start(1000);
  });

七、RTMP协议加密吗

RTMP协议本身不提供加密功能，但是可以通过在RTMP基础上使用TLS（Transport Layer Security）来实现数据传输的加密保护。以下是使用RTMP协议进行数据传输加密的代码示例：

var socket = new WebSocket("wss://your-server-url:443");

socket.onopen = function() {
  var rtmpUrl = 'rtmp://your-server-url';
  var rtmpStreamName = 'your-stream-name';
  var swfUrl = 'flash.swf';
  var playPath = rtmpStreamName;

  // TLS加密
  socket.send('rtmp://' + rtmpUrl + '/' + playPath);
};

socket.onmessage = function(evt) {
  console.log(evt.data);
};

socket.onclose = function() {
  console.log("Connection closed.");
};

八、RTMP协议端口

RTMP协议使用TCP协议进行数据传输，因此可以通过TCP协议的端口来进行RTMP协议数据传输。默认情况下，RTMP使用1935端口进行数据传输。以下是使用RTMP协议连接指定端口的代码示例：

var rtmpUrl = 'rtmp://your-server-url';
var rtmpPort = 1935;
var rtmpStreamName = 'your-stream-name';
var swfUrl = 'flash.swf';
var playPath = rtmpStreamName;

var url = rtmpUrl + ':' + rtmpPort + '/' + playPath;
var videoElement = document.createElement('video');
var flashvars = {
  url: url,
  play: true,
  player: 'vod'
};
var params = {
  wmode: 'opaque',
  allowfullscreen: 'true',
  allowscriptaccess: 'always'
};
var attrs = {
  name: 'player',
  id: 'player'
};

var handler = new RTMPPlayer(videoElement, swfUrl, flashvars, params, attrs);
handler.init();

九、RTMP协议UDP

RTMP协议本身不使用UDP协议进行数据传输，而是基于TCP协议进行数据传输。但是RTMP协议可以通过UDP协议进行数据传输的转换，比如使用RTMFP（Real Time Media Flow Protocol）协议来实现P2P数据传输。以下是RTMFP协议的代码示例：

var rtmfpUrl = 'rtmfp://your-server-url';
var rtmfpPort = '1935';
var rtmpUrl = 'rtmp://your-server-url';
var rtmpPort = '1935';
var rtmpStreamName = 'your-stream-name';
var swfUrl = 'flash.swf';
var playPath = rtmpStreamName;

var url = rtmpUrl + ':' + rtmpPort + '/' + playPath;
var mediaConnection = new RTMFPConnection(rtmfpUrl + ':' + rtmfpPort + '/');

mediaConnection.connect();

var stream = new createStream(mediaConnection);

function onPublishCallback(success) {
  if (success) {
    console.log("Publish started successfully!");
  }
  else {
    console.log("Failed to start publish!");
    // 失败的处理
  }
}

stream.publish(rtmpStreamName, "live", "push");

var videoElement = document.createElement('video');
var flashvars = {
  url: url,
  play: true,
  player: 'vod'
};
var params = {
  wmode: 'opaque',
  allowfullscreen: 'true',
  allowscriptaccess: 'always'
};
var attrs = {
  name: 'player',
  id: 'player'
};

var handler = new RTMPPlayer(videoElement, swfUrl, flashvars, params, attrs);
handler.init();

十、RTMP协议代理选取

在使用RTMP协议进行数据传输时，可能需要选择一个代理服务器进行数据传输。以下是使用RTMP协议进行代理选取的代码示例：

var rtmpUrl = 'rtmp://your-server-url';
var rtmpProxy = 'your-proxy-url';
var rtmpStreamName = 'your-stream-name';
var swfUrl = 'flash.swf';
var playPath = rtmpStreamName;

var url = rtmpUrl + '/' + playPath + ' proxy:' + rtmpProxy;
var videoElement = document.createElement('video');
var flashvars = {
  url: url,
  play: true,
  player: 'vod'
};
var params = {
  wmode: 'opaque',
  allowfullscreen: 'true',
  allowscriptaccess: 'always'
};
var attrs = {
  name: 'player',
  id: 'player'
};

var handler = new RTMPPlayer(videoElement, swfUrl, flashvars, params, attrs);
handler.init();