Android多媒体应用

用MediaPlayer播放音频

1.创建并装载音频

MediaPlayer player = MediaPlayer.create(this,R.raw.<id>);
MediaPlayer player = MediaPlayer.create(this,Uri.parse(“http://”));
如果要访问网络中的资源，要有网络访问权限
<uses-permission android:name="android.permission.INTERNET"/>
 
或者用无参构造函数
MediaPlayer player = new MediaPlayer();
player.setDataSource(“”);                 //磁盘路径
player.prepare();

 2.MediaPlayer操作

player.start();
player.stop();
player.pause();

用SoundPool播放音频

1.创建对象

SoundPool(int maxStream, int streamType,int srcQuality)

maxStream指可容纳多少个音频，

streamType指声音类型，可取为STREAM_VOICE_CALL（通话）、STREAM_SYSTEM（系统声音）、STREAM_RING（铃声）、STREAM_MUSIC（音乐）、STREAM_ALARM（闹铃声）；

srcQuality指音质，通常为1

SoundPool soundpool = new SoundPool(10,AudioManager.STREAM_SYSTEM, 0);

2.加载音频

public int load(Context context, int resid,int priority);

public int load(String path, int priority);

int soundId = soundpool.load(this, R.raw.ding, 1);

3.播放音频

play(int soundID, float leftVolume, floatrightVolume, int priority, int loop, float rate);

leftVolume，rightVolume通常取1；priority指优先级，通常为1；loop指定循环次数，0为不循环，-1循环；rate指播放速率，正常为1

soundpool.play(soundID, 1, 1, 0, 0, 1);

通常为了管理，使用HashMap

HashMap<Integer, Integer> soundmap =new HashMap<Integer, Integer>();
SoundPool soundpool = new SoundPool(5,AudioManager.STREAM_SYSTEM, 0);
soundmap.put(1, soundpool.load(this,R.raw.login1, 1));
soundmap.put(2, soundpool.load(this,R.raw.login2, 1));
soundmap.put(3, soundpool.load(this,R.raw.login3, 1));
soundmap.put(4, soundpool.load(this,R.raw.login4, 1));
soundmap.put(5, soundpool.load(this,R.raw.login5, 1));

使用VideoView播放音频

现在layout文件中创建该组件，然后

       VideoView video = (VideoView)findViewById(R.id.videoView1);
       video.setVideoPath(String path);
       video.setVideoURI(Uri uri);
       video.start();
       video.pause();
       video.stopPlayback();

使用MediaPlayer和SurfaceView播放视频

1定义SurfaceView

   <!--keepScreenOn是否打开屏幕-->
   <SurfaceView
       android:id="@+id/surfaceView1"
       android:keepScreenOn="true"
       android:layout_gravity="center"
       android:layout_width="300sp"
       android:layout_height="400sp" />

2创建MediaPlayer

3将视频输出到SurfaceView

mediaplayer.setDisplay(surfaceview.getHolder());

4利用MediaPlayer控制视频的播放

 

控制相机拍照

requestWindowFeature(Window.FEATURE_NO_TITLE);

//设置全屏显示，放在setContentView之前

       final PictureCallback jpeg = new PictureCallback(){
                            @Override
                            publicvoid onPictureTaken(byte[] arg0, Camera arg1) {
                                     //TODO Auto-generated method stub
                                     //用来接收数据并且写入文件
                            }
       };
       //拍摄的图片一般放在SD卡内
       if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                Toast.makeText(this,"请安装SD卡！", Toast.LENGTH_SHORT).show();
       }
            
       Camera camera = Camera.open();
       
       Camera.Parameters params = camera.getParameters();
       params.setPictureSize(100, 100);
       
       camera.setParameters(params);
       camera.startPreview();//开始预览
       camera.takePicture(null, null, jpeg);
       camera.stopPreview();
       camera.release();

Camera.takePicture(ShutterCallback shutter,PictureCallback raw, PictureCallback jpeg)

该函数的详细解释在这里 http://www.cnblogs.com/mengdd/archive/2013/04/06/3002975.html