一、WebRTC实现简单的屏幕共享
屏幕共享原理：其实就还是利用系统提供的录屏服务，把录制好的屏幕内容通通过P2P发送给对等端，让对等端能够看到分享者的屏幕。其实对于分享者来说是推流，对于观看分享的端来说就是拉取视频流
二、代码演示
1.初始化截屏服务
//屏幕截取服务 private MediaProjectionManager mediaProjectionManager = null; private DeviceManager(Context context) { this.context = context; audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE); bluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (Build.VERSION.SDK_INT >= 21) { mediaProjectionManager = (MediaProjectionManager) context.getSystemService(Context.MEDIA_PROJECTION_SERVICE); } else { Toast.makeText(context, "您的设备不支持屏幕共享", Toast.LENGTH_SHORT).show(); } }
2.启动Android系统的屏幕共享
/** * 开启屏幕截屏，调用此方法后会弹框提示用户开始截屏 * @param activity */ public void startScreenCapture(Activity activity) { if(mediaProjectionManager == null){ Toast.makeText(context, "截屏服务不可用", Toast.LENGTH_SHORT).show(); return; } Intent intent = null; if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) { intent = mediaProjectionManager.createScreenCaptureIntent(); activity.startActivityForResult(intent, SCREEN_CAPTURE_REQUEST_CODE); } }
3.启动系统的屏幕共享后会再当前Activity的onActivityResult中收到回调
@Override public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) { super.onActivityResult(requestCode, resultCode, data); if (requestCode == DeviceManager.SCREEN_CAPTURE_REQUEST_CODE) { rtcClient.startShareScreen(data); } }
rtcClient.startShareScreen(data)
/** * 开始分享屏幕 * * @param intent 分享屏幕创建的intent，用于创建ScreenCaptureAndroid */ public void startShareScreen(Intent intent) { Log.e(TAG, "startShareScreen----->start"); //创建屏幕捕获 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { if (shareScreenCapture == null) { shareScreenCapture = new ScreenCapturerAndroid(intent, new MediaProjection.Callback() { @Override public void onStop() { super.onStop(); } }); } } if (videoSource == null) { Log.e(TAG, "startShareScreen----->createVideoSource"); videoSource = createVideoSource(shareScreenCapture); } Log.e(TAG, "startShareScreen----->startCapture"); shareScreenCapture.initialize(surfaceTextureHelper, context, videoSource.getCapturerObserver()); shareScreenCapture.startCapture(480, 640, 30); if (videoTrack == null) { Log.e(TAG, "startShareScreen----->createVideoTrack"); videoTrack = createVideoTrack(videoSource); } //将视频加入媒体流 Log.e(TAG, "startShareScreen----->createMediaStream"); mediaStream = createMediaStream(); mediaStream.addTrack(videoTrack); Log.e(TAG, "startShareScreen----->end"); }
其实除了前几步和P2P通信不一样外，后几步都是一样的：都是先创建一个VideoCapture，然后调用其startCapture方法--->创建VideoTrack--->创建mediaStrea--->然后将videoTrack加入mediaStream。