Android播放视频

package cn.c;  

import java.io.File;  

import java.io.IOException;  

import android.app.Activity;  

import android.media.MediaPlayer;  

import android.media.MediaPlayer.OnCompletionListener;  

import android.media.MediaPlayer.OnErrorListener;  

import android.media.MediaPlayer.OnInfoListener;  

import android.media.MediaPlayer.OnPreparedListener;  

import android.media.MediaPlayer.OnSeekCompleteListener;  

import android.media.MediaPlayer.OnVideoSizeChangedListener;  

import android.os.Bundle;  

import android.os.Environment;  

import android.view.Display;  

import android.view.SurfaceHolder;  

import android.view.SurfaceView;  

import android.widget.LinearLayout;  

 

  

 

  

public class MainActivity extends Activity implements   

OnCompletionListener,OnErrorListener,OnInfoListener,OnPreparedListener,  

OnSeekCompleteListener,OnVideoSizeChangedListener,SurfaceHolder.Callback{  

    private SurfaceView mSurfaceView;  

    private SurfaceHolder mSurfaceHolder;  

    private Display mDisplay;  

    private MediaPlayer mMediaPlayer;  

    int videoWidth=0;  

    int videoHeight=0;  

      

    @Override  

    public void onCreate(Bundle savedInstanceState) {  

        super.onCreate(savedInstanceState);  

        setContentView(R.layout.main);  

        mDisplay=getWindowManager().getDefaultDisplay();  

        mSurfaceView=(SurfaceView) findViewById(R.id.surfaceView);  

        mSurfaceHolder=mSurfaceView.getHolder();  

        //SurfaceHolder是用于管理SurfaceView对象  

        //那它是怎么做到管理的呢?即用mSurfaceHolder  

        //添加回调即addCallback.  

        //该类实现了SurfaceHolder.Callback接口,所以addCallback(this)  

        //在SurfaceHolder.Callback接口中一共有三个方法来实现对于  

        //SurfaceView对象的管理,即:  

        //surfaceCreated()  

        //surfaceChanged()  

        //surfaceDestroyed()  

        //概况:SurfaceHolder主要作用是监控底层的情况  

        mSurfaceHolder.addCallback(this);  

        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);  

          

        mMediaPlayer=new MediaPlayer();  

        mMediaPlayer.setOnCompletionListener(this);  

        mMediaPlayer.setOnErrorListener(this);  

        mMediaPlayer.setOnInfoListener(this);  

        mMediaPlayer.setOnPreparedListener(this);  

        mMediaPlayer.setOnSeekCompleteListener(this);  

        mMediaPlayer.setOnVideoSizeChangedListener(this);  

        String path=Environment.getExternalStorageDirectory().getPath()  

        +File.separator+"Test_Movie.m4v";  

        try {  

            //设置MediaPlayer将要播放的视频  

            mMediaPlayer.setDataSource(path);  

        } catch (IllegalArgumentException e) {  

            e.printStackTrace();  

            finish();  

        } catch (IllegalStateException e) {  

            e.printStackTrace();  

            finish();  

        } catch (IOException e) {  

            e.printStackTrace();  

            finish();  

        }  

    }  

    //来自于SurfaceHolder.Callback接口  

    //创建SurfaceView完成时,会调用该方法  

    public void surfaceCreated(SurfaceHolder holder) {  

        //设置MediaPlayer的视频输出界面  

        //只显示音频而不显示视频时可不调用这个方法  

        mMediaPlayer.setDisplay(mSurfaceHolder);  

        try {  

            //准备播放,调用mMediaPlayer.prepareAsync();  

            //方法后会执行覆写后的  

            //public void onPrepared(MediaPlayer mp)  

            //注意:  

            //也可调用prepare()解码,但为一个同步的操作  

            mMediaPlayer.prepareAsync();  

        } catch (Exception e) {  

            e.printStackTrace();  

            finish();  

        }  

    }  

    //来自于SurfaceHolder.Callback接口  

    //当SurfaceView的宽度,高度或其他参数发生变化时,会调用该方法  

    public void surfaceChanged(SurfaceHolder holder,   

            int format, int width,int height) {  

          

    }  

    //来自于SurfaceHolder.Callback接口  

    //当SurfaceView摧毁时,会调用该方法  

    public void surfaceDestroyed(SurfaceHolder holder) {  

          

    }  

    //来自于MediaPlayer.OnVideoSizeChangedListener接口  

    //当视频的宽度或高度发生变化时调用该方法  

    public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {  

          

    }  

    //来自于MediaPlayer.OnSeekCompleteListener接口  

    public void onSeekComplete(MediaPlayer mp) {  

          

    }  

    //来自于MediaPlayer.OnPreparedListener接口  

    //一旦调用该方法,MediaPlayer就进入了"准备就绪"  

    //状态,准备开始播放.  

    //此处可用于动态设置SurfaceView的宽和高!!!  

    public void onPrepared(MediaPlayer mediaPlayer) {  

        videoWidth=mediaPlayer.getVideoWidth();  

        videoHeight=mediaPlayer.getVideoHeight();  

        if (videoWidth > mDisplay.getWidth()|| videoHeight > mDisplay.getHeight()) {  

            float heightRatio = (float) videoHeight/ (float) mDisplay.getHeight();  

            float widthRatio = (float) videoWidth/ (float) mDisplay.getWidth();  

            if (heightRatio > 1 || widthRatio > 1) {  

                if (heightRatio > widthRatio) {  

                    videoHeight = (int) Math.ceil((float) videoHeight/ (float) heightRatio);  

                    videoWidth = (int) Math.ceil((float) videoWidth/ (float) heightRatio);  

                } else {  

                    videoHeight = (int) Math.ceil((float) videoHeight/ (float) widthRatio);  

                    videoWidth = (int) Math.ceil((float) videoWidth/ (float) widthRatio);  

                }  

            }  

        }  

        //设置SurfaceView的宽和高  

        mSurfaceView.setLayoutParams  

        (new LinearLayout.LayoutParams(videoWidth,videoHeight));  

        //MediaPlayer开始播放  

        mediaPlayer.start();  

    }  

    //来自于MediaPlayer.OnInfoListener接口  

    //当出现关于播放媒体的特定信息或者需要发出警告的时候  

    //将调用该方法  

    //比如开始缓冲、缓冲结束、下载速度变化(该行待验证)  

    //小结:这些Info都是以MediaPlayer.MEDIA_INFO_开头的  

    public boolean onInfo(MediaPlayer mp, int what, int extra) {  

        if (what==MediaPlayer.MEDIA_INFO_BAD_INTERLEAVING) {  

            //音频和视频数据不正确地交错时将出现该提示信息.在一个  

            //正确交错的媒体文件中,音频和视频样本将依序排列,从而  

            //使得播放可以有效和平稳地进行  

        }  

        if (what==MediaPlayer.MEDIA_INFO_NOT_SEEKABLE) {  

            //当媒体不能正确定位时将出现该提示信息.  

            //此时意味着它可能是一个在线流  

        }  

        if (what==MediaPlayer.MEDIA_INFO_VIDEO_TRACK_LAGGING) {  

            //当设备无法播放视频时将出现该提示信息  

            //比如视频太复杂或者码率过高  

        }  

        if (what==MediaPlayer.MEDIA_INFO_METADATA_UPDATE) {  

            //当新的元数据可用时将出现该提示信息  

        }  

        if (what==MediaPlayer.MEDIA_INFO_UNKNOWN) {  

            //其余不可知提示信息  

        }  

        return false;  

    }  

    //来自于MediaPlayer.OnErrorListener接口  

    //MediaPlayer发生错误时会调用该方法  

    //只有如下这三种错误.  

    //小结:这些错误都是以MediaPlayer.MEDIA_ERROR.开头的  

    public boolean onError(MediaPlayer mp, int what, int extra) {  

        if (what==MediaPlayer.MEDIA_ERROR_NOT_VALID_FOR_PROGRESSIVE_PLAYBACK) {  

            System.out.println("第一种错误");  

        }  

        if (what==MediaPlayer.MEDIA_ERROR_SERVER_DIED) {  

            System.out.println("第二种错误");  

        }  

        if (what==MediaPlayer.MEDIA_ERROR_UNKNOWN) {  

            System.out.println("第三种错误");  

        }  

        return false;  

    }  

    //来自于MediaPlayer.OnCompletionListener接口  

    //当MediaPlayer播放完文件时,会调用该方法.  

    //此时可以进行一些其他的操作比如:播放下一个视频  

    public void onCompletion(MediaPlayer mp) {  

           finish();          

    }  

}