使用 android mediaplayer 播放 .mp4 时出现 IOException

Question

我正在尝试在 MediaPlayer 中播放 .mp4 文件，但它总是在 mediaplayer.prepare() 处引发 IOException：

09-21 12:59:33.570 14926-14937/com.alex.videoplayertest E/MediaPlayer: 错误 (-2147483648, 0) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err: java.io.IOException: Prepare failed.: status=0x80000000 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err: 在 android.media.MediaPlayer.prepare(Native Method) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 com.alex.videoplayertest.MainActivity.onResume(MainActivity.java:53) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1185) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.Activity.performResume(Activity.java:5182) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread.performResumeActivity(ActivityThread.java:2732) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2771) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2235) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread.access$600(ActivityThread.java:141) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.os.Handler.dispatchMessage(Handler.java:99) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.os.Looper.loop(Looper.java:137) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 android.app.ActivityThread.main(ActivityThread.java:5041) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 java.lang.reflect.Method.invokeNative(Native Method) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 java.lang.reflect.Method.invoke(Method.java:511) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err：在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 09-21 12:59:33.570 14926-14926/com.alex.videoplayertest W/System.err: at dalvik.system.NativeStart.main(Native Method)

这是我的代码：

public class MainActivity extends Activity
{
private MediaPlayer mediaPlayer;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

}

@Override
protected void onResume()
{
    super.onResume();
    String file = "/storage/emulated/0/Download/media/Light_Bulb.mp4";

    File f = new File(file);
    if (f.exists())
    {
        mediaPlayer = new MediaPlayer();
        mediaPlayer.setScreenOnWhilePlaying(true);
        mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
        mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener()
        {
            @Override
            public void onPrepared(MediaPlayer mp)
            {
                if (mediaPlayer != null)
                    mediaPlayer.start();
            }
        });

        mediaPlayer.reset();
        try
        {
            FileInputStream fileInputStream = new FileInputStream(file);
            mediaPlayer.setDataSource(getApplicationContext(), Uri.parse(file));
            fileInputStream.close();
            mediaPlayer.prepare();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

}

有人可以帮帮我吗？

Answer 1

尝试使用

String file= Environment.getExternalStorageDirectory().toString()+"/Download/media/_29187_v.1_Light_Bulb_16HD_25fps.mp4";

File f = new File(file);

而且还要加

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

到您的清单文件

Answer 2

我现在有一个解决我的问题的方法。
我真的不知道为什么使用 MediaPlayer 无法在我的测试应用程序中播放此视频，但使用 VideoView 可以。

这是我的 Videoview 代码：

public class VideoViewActivity extends Activity
{
VideoView videoView;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_video_view);

    videoView = (VideoView) findViewById(R.id.videoView);
}

@Override
protected void onResume()
{
    super.onResume();

    String file = Environment.getExternalStorageDirectory().toString() + "/Download/media/Light_Bulb.mp4";

    File f = new File(file);
    if (f.exists())
    {
        videoView.setMediaController(null);
        videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener()
        {
            @Override
            public void onPrepared(MediaPlayer mp)
            {
                videoView.start();
            }
        });
        videoView.setVideoURI(Uri.parse(file));
    }

    findViewById(R.id.closeVideoView).setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            System.exit(0);
        }
    });
}

@Override
protected void onPause()
{
    super.onPause();
    if (videoView != null)
        videoView.stopPlayback();
}