我有两个 fragment (左和右)并在左侧 fragment 中获取 radio 流列表。通过单击这些流之一，正确的 fragment 应该更改流的名称并开始使用给定的 uri 播放流。

2个问题:

1. 一些 radio 流不是最新的，所以其中很多都不再工作了。问题是，这会导致我的应用强制关闭!我做了错误处理，但在调用这样的流后我得到:

03-20 14:23:28.192: A/libc(1021): Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1)

03-20 14:23:28.192: W/AudioSystem(1021): AudioFlinger server died!

03-20 14:23:28.192: W/IMediaDeathNotifier(1021): media server died

03-20 14:23:28.192: E/MediaPlayer(1021): error (100, 0)

03-20 14:23:28.192: I/ServiceManager(1021): Waiting for service media.audio_flinger...

03-20 14:23:28.752: I/dalvikvm(1021): threadid=3: reacting to signal 3

03-20 14:23:28.782: I/dalvikvm(1021): Wrote stack traces to '/data/anr/traces.txt'

03-20 14:23:29.192: I/ServiceManager(1021): Waiting for service media.audio_flinger...

我不知道为什么。还有其他方法可以进行错误处理吗？或者有没有办法在调用 mediaPlayer.setDataSource(uri) 之前检查所有流以避免准备 defekt uris？ (最后看我的代码)

1. 我正在使用 Remote 控制左侧的 ListFragment。当我尝试从一个 channel 快速切换到另一个 channel 时，一切都非常滞后。似乎 Mediaplayer 的 reinstanciation 需要很长时间。当我不重新实例化时，再次调用 mediaPlayer.setDataSource(..) 时会出现运行时错误。有没有办法在一个 MediaPlayer 对象上调用 .setDataSource 两次？

这是我的代码: 我的 MediaPlayer 包装类:

package net.smart4life.tvplay.model;

import java.io.IOException;
import java.lang.reflect.Method;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnCompletionListener;
import android.media.MediaPlayer.OnErrorListener;
import android.media.MediaPlayer.OnInfoListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.util.Log;

/**
 * A wrapper class for {@link android.media.MediaPlayer}.
 * <p>
 * Encapsulates an instance of MediaPlayer, and makes a record of its internal
 * state accessible via a {@link MediaPlayerWrapper#getState()} accessor.
 */
public class MediaPlayerStateWrapper {

    private static String tag = "MediaPlayerWrapper";
    private MediaPlayer mPlayer;
    private State currentState;
    private MediaPlayerStateWrapper mWrapper;

    public MediaPlayerStateWrapper() {
        mWrapper = this;
        mPlayer = new MediaPlayer();
        currentState = State.IDLE;
        mPlayer.setOnPreparedListener(mOnPreparedListener);
        mPlayer.setOnCompletionListener(mOnCompletionListener);
        mPlayer.setOnBufferingUpdateListener(mOnBufferingUpdateListener);
        mPlayer.setOnErrorListener(mOnErrorListener);
        mPlayer.setOnInfoListener(mOnInfoListener);
    }

    /* METHOD WRAPPING FOR STATE CHANGES */
    public static enum State {
        IDLE, ERROR, INITIALIZED, PREPARING, PREPARED, STARTED, STOPPED, PLAYBACK_COMPLETE, PAUSED;
    }

    public void setDataSource(String path) {
        if (currentState == State.IDLE) {
            try {
                mPlayer.setDataSource(path);
                currentState = State.INITIALIZED;
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            } catch (IllegalStateException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else
            throw new RuntimeException();
    }

    public void prepareAsync() {
        Log.d(tag, "prepareAsync()");
        if (EnumSet.of(State.INITIALIZED, State.STOPPED).contains(currentState)) {
            mPlayer.prepareAsync();
            currentState = State.PREPARING;
        } else
            throw new RuntimeException();
    }

    public boolean isPlaying() {
        Log.d(tag, "isPlaying()");
        if (currentState != State.ERROR) {
            return mPlayer.isPlaying();
        } else
            throw new RuntimeException();
    }

    public void seekTo(int msec) {
        Log.d(tag, "seekTo()");
        if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
                State.PLAYBACK_COMPLETE).contains(currentState)) {
            mPlayer.seekTo(msec);
        } else
            throw new RuntimeException();
    }

    public void pause() {
        Log.d(tag, "pause()");
        if (EnumSet.of(State.STARTED, State.PAUSED).contains(currentState)) {
            mPlayer.pause();
            currentState = State.PAUSED;
        } else
            throw new RuntimeException();
    }

    public void start() {
        Log.d(tag, "start()");
        if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
                State.PLAYBACK_COMPLETE).contains(currentState)) {
            mPlayer.start();
            currentState = State.STARTED;
        } else
            throw new RuntimeException();
    }

    public void stop() {
        Log.d(tag, "stop()");
        if (EnumSet.of(State.PREPARED, State.STARTED, State.STOPPED,
                State.PAUSED, State.PLAYBACK_COMPLETE).contains(currentState)) {
            mPlayer.stop();
            currentState = State.STOPPED;
        } else
            throw new RuntimeException();
    }

    public void reset() {
        Log.d(tag, "reset()");
        mPlayer.reset();
        currentState = State.IDLE;
    }

    /**
     * @return The current state of the mediaplayer state machine.
     */
    public State getState() {
        Log.d(tag, "getState()");
        return currentState;
    }

    public void release() {
        Log.d(tag, "release()");
        mPlayer.release();
    }

    /* INTERNAL LISTENERS */
    private OnPreparedListener mOnPreparedListener = new OnPreparedListener() {

        @Override
        public void onPrepared(MediaPlayer mp) {
            Log.d(tag, "on prepared");
            currentState = State.PREPARED;
            mWrapper.onPrepared(mp);
            mPlayer.start();
            currentState = State.STARTED;
        }
    };
    private OnCompletionListener mOnCompletionListener = new OnCompletionListener() {

        @Override
        public void onCompletion(MediaPlayer mp) {
            Log.d(tag, "on completion");
            currentState = State.PLAYBACK_COMPLETE;
            mWrapper.onCompletion(mp);
        }
    };
    private OnBufferingUpdateListener mOnBufferingUpdateListener = new OnBufferingUpdateListener() {

        @Override
        public void onBufferingUpdate(MediaPlayer mp, int percent) {
            Log.d(tag, "on buffering update");
            mWrapper.onBufferingUpdate(mp, percent);
        }
    };
    private OnErrorListener mOnErrorListener = new OnErrorListener() {

        @Override
        public boolean onError(MediaPlayer mp, int what, int extra) {
            Log.d(tag, "on error");
            currentState = State.ERROR;
            mWrapper.onError(mp, what, extra);
            return false;
        }
    };
    private OnInfoListener mOnInfoListener = new OnInfoListener() {

        @Override
        public boolean onInfo(MediaPlayer mp, int what, int extra) {
            Log.d(tag, "on info");
            mWrapper.onInfo(mp, what, extra);
            return false;
        }
    };

    /* EXTERNAL STUBS TO OVERRIDE */
    public void onPrepared(MediaPlayer mp) {
    }

    public void onCompletion(MediaPlayer mp) {
    }

    public void onBufferingUpdate(MediaPlayer mp, int percent) {
    }

    boolean onError(MediaPlayer mp, int what, int extra) {
        // Error Handling of type: "MEdiaPlayer error(100,0)
        mp.stop();
        mp.release();
        return false;
    }

    public boolean onInfo(MediaPlayer mp, int what, int extra) {
        return false;
    }

    /* OTHER STUFF */
    public int getCurrentPosition() {
        if (currentState != State.ERROR) {
            return mPlayer.getCurrentPosition();
        } else {
            return 0;
        }
    }

    public int getDuration() {
        // Prepared, Started, Paused, Stopped, PlaybackCompleted
        if (EnumSet.of(State.PREPARED, State.STARTED, State.PAUSED,
                State.STOPPED, State.PLAYBACK_COMPLETE).contains(currentState)) {
            return mPlayer.getDuration();
        } else {
            return 100;
        }
    }
}

这是我的 TestFragment(右侧 fragment )。注意:每次单击列表项时，左侧 fragment 都会从 TestFragment 调用方法“newChannel(radioChannel)”。

package net.smart4life.tvplay.fragment;

import java.io.IOException;

import net.smart4life.tvplay.R;
import net.smart4life.tvplay.model.MediaPlayerStateWrapper;
import net.smart4life.tvplay.model.RadioChannel;
import android.app.Fragment;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnErrorListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class TestFragment extends Fragment {

    private RadioChannel radioCh;
    private TextView tv_RadioCh;
    private MediaPlayerStateWrapper mediaWrapper;
    private View view;


    // firstcall
    public TestFragment(RadioChannel radioChannel) {
        this.radioCh = radioChannel;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onActivityCreated(savedInstanceState);

        setRetainInstance(true);

        tv_RadioCh = (TextView) view.findViewById(R.id.radioText);

        mediaWrapper = new MediaPlayerStateWrapper();

        newChannel(radioCh);
    }

    public void newChannel (RadioChannel radioChannel) {
        this.radioCh = radioChannel;
        Log.e("RadioChannel", radioCh.getName());
        tv_RadioCh.setText(radioCh.getName());

        if(mediaWrapper.isPlaying()) {
            mediaWrapper.stop();
            mediaWrapper.reset(); 
        } else if(mediaWrapper.getState() == MediaPlayerStateWrapper.State.PREPARING) {
            mediaWrapper.release();
            mediaWrapper = new MediaPlayerStateWrapper();
        }
        mediaWrapper.setDataSource(radioCh.getUrl().toString());    
        mediaWrapper.prepareAsync();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        view = inflater.inflate(R.layout.fragment_radio_player, container,
                false);

        return view;
    }

    @Override
    public void onDetach() {
        super.onDetach();

        mediaWrapper.release();
    }

}

专业人士，您能帮我解决一个或两个问题吗？

最佳答案

如果无法加载流，您经常会卡在准备状态，您可以在此处尝试此操作，当 mediaWrapper.getState() == MediaPlayerStateWrapper.State.ERROR 时:

mediaWrapper.reset();
mediaWrapper.release();
System.gc();
mediaWrapper = new MediaPlayerStateWrapper();
mediaWrapper.setDataSource(radioCh.getUrl().toString());
mediaWrapper.prepareAsync();

最好放在AsyncTask中，避免Not responding error。或者，当您遇到错误时，您必须创建一个新的 MediaPlayer，因为 Media Server 已死:

if(mediaWrapper.getState() == MediaPlayerStateWrapper.State.ERROR){
    mediaWrapper = new MediaPlayerStateWrapper();
    mediaWrapper.setDataSource(radioCh.getUrl().toString());
    mediaWrapper.prepareAsync();
}

如果 MediaPlayer 正在播放流，您必须先停止并重置它:

mediaWrapper.stop();
mediaWrapper.reset();
mediaWrapper.setDataSource(radioCh.getUrl().toString());
mediaWrapper.prepareAsync();

它对我有用，但我认为这不是最好的方法。当您陷入准备状态时，希望有人能找到更好的解决方案。

关于Android MediaPlayer AudioStream AudioFlinger 服务器死了!，致命信号 11，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15526023/