Android应用程序开发之七——移动多媒体.ppt

Android应用程序开发,移动多媒体,音频播放,1.播放音频资源:android.media.MediaPlayerp=MediaPlayer.create(Context,R.raw.XXX);p.prepare();p.start();/播放2.播放外部音频文件MediaPlayerp=newMediaPlayer();p.setDataSource(url)url可以是/sdcard/XXX也可以是网络中的URLp.prepare();p.start(),MediaPlayer的生命周期,创建-setDatasourse-prepare-start-pause-start-stop-release调用stop进入停止状态,再播放要先调用prepare再调用start,tryMediaPlayerplayer=newMediaPlayer();player.setDataSource(/sdcard/nx.mp3);player.prepare();player.start();Thread.sleep(15000);player.stop();Thread.sleep(5000);player.prepare();player.start();Thread.sleep(20000);player.stop();player.release();catch(Exceptione)e.printStackTrace();,音频采集录音,创建MediaRecorder对象rec(来自android.media包)开始录音:创建File对象,扩展名为amr,rec.setOutputFile(f.getAbsoulutePath()rec.setAudioSource(MediaRecorder.AudioSource.MIC)/设置声源rec.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT)/输出格式rec.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT)/音频格式rec.prepare()rec.start()结束录音:rec.stop()rec.release()rec=null权限:android.permission.RECORD_AUDIO,start.setOnClickListener(newView.OnClickListener()publicvoidonClick(Viewv)if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)trymyFile=File.createTempFile(huxz,.amr,Environment.getExternalStorageDirectory();rec=newMediaRecorder();rec.setAudioSource(MediaRecorder.AudioSource.MIC);rec.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);rec.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);rec.setOutputFile(myFile.getAbsolutePath();rec.prepare();rec.start();catch(Exceptione);,stop.setOnClickListener(newView.OnClickListener()publicvoidonClick(Viewv)if(myFile!=null)rec.stop();rec.release();rec=null;);,视频采集,与音频采集类似,也使用MediaRecorder权限:android.permission.RECORD_AUDIOandroid.permission.CAMERA,WindowManagerwm=(WindowManager)getSystemService(Context.WINDOW_SERVICE);/获取窗口服务Displaydisplay=wm.getDefaultDisplay();/获取屏幕信息recorder=newMediaRecorder();recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);/从照相机采集视频recorder.setAudioSource(MediaRecorder.AudioSource.MIC);recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);recorder.setVideoSize(display.getWidth(),display.getHeight();/大小为屏幕的宽和高recorder.setVideoFrameRate(3);/每秒3帧recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);/设置视频编码方式recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);recorder.setOutputFile(/sdcard/huxz.3gp);recorder.previewDisplay(holder.getSurface();/设置预览组件recorder.prepare();/预期准备recorder.start();/开始刻录,图像采集,android.hardware.Camera类open()得到Camera对象getParameters()setParameters()获取/设置参数setPreviewDisplay()设置预览视图参数为SurfaceHolder对象startPreview()stopPreview()开始/停止预览takePicture()拍照,takePicture()参数,Camera.ShutterCallback快门空实现Camera.PictureCallbackraw图像空实现Camera.PictureCallbackpic实现onPictureTaken(bytedata,Camerac)data数组中储存了采集的图像数据,SurfaceView,一个视图,系统会用一个独立的线程来绘制用于相机应用或录像机应用中的预览视图后台由SurfaceHolder对象控制,调用getHolder得到SurfaceHolder可以添加事件监听SurfaceHolder.Callback定义当Surface创建,改变和销毁时的处理holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);/依靠屏幕的渲染引擎推送内容,publicclassCameraActivityextendsActivityimplementsSurfaceHolder.Callback,OnClickListenerSurfaceViewmySurfaceView;/SurfaceView的引用SurfaceHoldermySurfaceHolder;/SurfaceHolder的引用Buttonbutton1;/打开按钮Buttonbutton2;/关闭按钮Buttonbutton3;/拍照按钮CameramyCamera;/Camera的引用booleanisView=false;/是否在浏览中,相机应用示例,publicvoidonCreate(BundlesavedInstanceState)super.onCreate(savedInstanceState);/全屏requestWindowFeature(Window.FEATURE_NO_TITLE);getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);setContentView(R.layout.main);mySurfaceView=(SurfaceView)findViewById(R.id.mySurfaceView);/得到SurfaceView的引用button1=(Button)findViewById(R.id.button1);/得到按钮的引用button2=(Button)findViewById(R.id.button2);/得到按钮的引用button3=(Button)findViewById(R.id.button3);/得到按钮的引用button1.setOnClickListener(this);/为按钮添加监听button2.setOnClickListener(this);/为按钮添加监听button3.setOnClickListener(this);/为按钮添加监听mySurfaceHolder=mySurfaceView.getHolder();/获得SurfaceHoldermySurfaceHolder.addCallback(this);/添加接口的实现mySurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);,publicvoidonClick(Viewv)if(v=button1)/打开按钮initCamera();/初始化相机elseif(v=button2)if(myCamera!=null,publicvoidinitCamera()if(!isView)myCamera=Camera.open();if(myCamera!=null,ShutterCallbackmyShutterCallback=newShutterCallback()publicvoidonShutter();PictureCallbackmyRawCallback=newPictureCallback()publicvoidonPictureTaken(bytedata,Cameracamera);PictureCallbackmyjpegCallback=newPictureCallback()publicvoidonPictureTaken(bytedata,Cameracamera)Bitmapbm=BitmapFactory.decodeByteArray(data,0,data.length);ImageViewmyImageView=(ImageView)findViewById(R.id.myImageView);myImageView.setImageBitmap(bm);/将图片显示到ImageView中isView=false;myCamera.stopPreview();myCamera.release();myCamera=null;initCamera();/初始化相机;,/实现SurfaceHolder.Callback接口中的方法OverridepublicvoidsurfaceChanged(SurfaceHolderholder,intformat,intwidth,intheight)OverridepublicvoidsurfaceCreated(SurfaceHolderholder)OverridepublicvoidsurfaceDestroyed(SurfaceHolderholder),视频播放,使用android.widget.VideoViewMediaControllermc=newMediaController(Context)videoView.setMediaController(mc);videoView.setVideoPath(“/sdcard/XXX.mp4”);videoView.start();videoView.pause();,publicvoidonCreate(BundlesavedInstanceState)requestWindowFeature(Window.FEATURE_NO_TITLE);this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);super.onCreate(savedInstanceState);setContentView(R.layout.main);VideoViewvv=(VideoView)this.findViewById(R.id.video);vv.setMediaController(newMediaController(this);vv.setVideoPath(/sdcard/hujc.mp4);vv.start();,Google地图,获取GoogleKey,获取GoogleKey,Eclipsewindow-preferences-android-build得到keystore的位置在命令行下keytoollistaliasandroiddebugkeykeystorekeystore位置storepassandroidkeypassandroid得到MD5认证指纹,获取GoogleKey,得到本机APIKey为0YI48AYoAgrp0EoF_DYWKybum0btyr55r8_kWgQ,创建运行环境,安装GoogleAPI创建模拟器target为GoogleAPI创建AndroidProject,选择target为GoogleAPI,配置文件,AndroidManifest.xmlapplication标签中:manifest标签中加入INTERNET权限main.xml布局文件定义com.google.android.maps.MapView,除了常规属性外还要定义android:apiKey,取值为从google获得的密钥.android:clickable是否支持触屏操作,MapView,定义一个类继承MapActivity得到MapView对象,调用getController获得MapController对象controller创建GeoPoint对象,参数为纬度*1E6和经度*1E6,调用controller.animateTo(geoPoint),设置地图的经纬度,controller.setZoom(16)设置缩放尺度覆盖isRouteDisplayed()是否显示导航路线MapView的方法setSatellite:是否显示卫星视图setBuiltInZoomControls是否显示缩放按钮,监听GPS数据,使用的类来自android.location包为应用添加权限:android.permission.ACCESS_FINE_LOCATION程序中:getSystemService(Context.LOCATION_SERVICE)获得LocationManager对象manager.requestLocationUpdates(LocationManager.GPS_PROVIDER,时间间隔,位置间隔,LocationListener)需要自己实现LocationListener,实现onLocationChanged方法,publicclassGoogleMapActivityextendsMapActivityMapViewmv;MapControllercontroller;LocationManagermanager;Buttonbtn;EditTextet1;EditTextet2;doublejingdu=116.46;doubleweidu=39.92;,GPS应用示例,publicvoidonCreate(BundlesavedInstanceState)super.onCreate(savedInstanceState);setContentView(R.layout.main);btn=(Button)this.findViewById(R.id.btn);et1=(EditText)this.findViewById(R.id.e1);et2=(EditText)this.findViewById(R.id.e2);mv=(MapView)this.findViewById(R.id.mapview);controller=mv.getController();setGeoPoint();mv.setSatellite(false);mv.setBuiltInZoomControls(true);,LocationListenerlistener=newLocationListener()publicvoidonLocationCh