MediaRecorder.start()抛出IllegalStateException

时间:2014-12-17 11:51:00

标签: java android android-asynctask mediarecorder android-mediarecorder

我读过类似的帖子,但没有找到可以解决我问题的答案。

我正在使用2种不同的MediaRecorder编写应用程序。一个用于噪声检测,另一个用于记录。我想要做的是 - 当第一个MediaRecorder检测到高于4.0的噪音水平时(我正在使用Google的SoundMeter类进行检测),它将启动另一个MediaRecorder并开始录制。如果声级保持在4.0以下10秒,则停止录音并继续听。所有这一切都在一个AsynTask中完成,在一个无尽的while(true)循环中,只有在单击相应的按钮时才会被破坏。

检测工作正常,但在录制MediaRecorder上调用start()时抛出IllegalStateException。

这是AsyncTask:

private class NoiseDetection extends AsyncTask {
    double currentSoundInputLevel;

    @Override
    protected Object doInBackground(Object[] params) {
        int i = 0;
        soundMeter = new SoundMeter();
        try {
            soundMeter.start();
        } catch (IOException e) {
            Log.e("error", e.getMessage());
        }
        while(true){
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                Log.e("error", e.getMessage());
            }
            if(isCancelled()){
                soundMeter.stop();
                if(currentlyRecording) {
                    soundRecorder.stop();
                }
                break;
            }
            currentSoundInputLevel = soundMeter.getAmplitudeEMA();
            if(!currentlyRecording && currentSoundInputLevel > 4.0){
                soundRecorder = new SoundRecorder();
                try {
                    soundRecorder.start(getFileNameString());
                    currentlyRecording = true;
                } catch (IOException e) {
                    Log.e("error", e.getMessage());
                }
            } else if(currentlyRecording && currentSoundInputLevel < 4.0) {
                i++;
                if(i > 10) {
                    soundRecorder.stop();
                }
            }
        }
        return null;
    }
}

这是SoundRecorder:

public class SoundRecorder {
    private MediaRecorder mRecorder = null;

    public void start(String fileName) throws IOException {
        if (mRecorder == null) {
            mRecorder = new MediaRecorder();
            mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
            mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
            mRecorder.setOutputFile(Environment.getExternalStorageDirectory().getPath() + "/" + fileName);
            mRecorder.prepare();
            mRecorder.start();
        }
    }

    public void stop() {
        if (mRecorder != null) {
            mRecorder.stop();
            mRecorder.release();
            mRecorder = null;
        }
    }
}

mRecorder.start();上会抛出异常。

我认为问题在于在这个循环中做所有事情的想法,但我还没有想出实现上述目标的更好的想法。 此外,我尝试了不同的OutputFormats和AudioEncoders但没有成功。 (参考https://stackoverflow.com/a/23065021/1826152

另一个可能有用的注释是文件实际上是在sdcard目录中创建的。

我用于开发的手机是Nexus 5. android清单中的权限如下:

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

更新

现在我试图通过创建RecordingHandler从while循环中删除SoundRecorder操作。 doInBackground()的新代码如下:

    protected Object doInBackground(Object[] params) {
        int i = 0;
        soundMeter = new SoundMeter();
        RecordingHandler recordingHandler = null;
        try {
            soundMeter.start();
        } catch (IOException e) {
            Log.e("error", e.getMessage());
        }
        while(true){
            if(isCancelled()){
                soundMeter.stop();
                if(currentlyRecording && recordingHandler != null){
                    recordingHandler.kill();
                }
                break;
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                Log.e("error", e.getMessage());
            }
            if(!currentlyRecording && soundMeter.getAmplitudeEMA() > 4.0){
                recordingHandler =  new RecordingHandler(deviceId);
                currentlyRecording = true;
                recordingHandler.run();
            }
        }
        return null;
    }

并且RecordingHandler本身如下:

public class RecordingHandler implements Runnable {

    SoundRecorder soundRecorder;
    SoundMeter soundMeter;
    String deviceID;
    boolean isKilled = false;

    public RecordingHandler(String deviceID){
        this.soundRecorder = new SoundRecorder();
        this.soundMeter = new SoundMeter();
        this.deviceID = deviceID;
    }

    @Override
    public void run() {
        int i = 0;
        try {
            soundMeter.start();
            soundRecorder.start(getFileNameString());
        } catch (IOException e) {
            Log.e("error", e.getMessage());
        }
        while(true){
            if(isKilled){
                break;
            }
            if(soundMeter.getAmplitudeEMA() < 4.0){
                i++;
                if(i > 10){
                    break;
                }
            } else {
                i = 0;
            }
        }
        soundMeter.stop();
        soundRecorder.stop();
        EavesDrop.currentlyRecording = false;
    }

    public void kill(){
        this.isKilled = true;
    }

    private String getFileNameString() {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
        return deviceID + "_" + sdf.format(new Date());
    }
}

现在从Recordinghandler抛出IllegalStateException - 在soundMeter.start();行。 考虑到这个soundMeter对象基本上不再在循环中处理,应该消除虽然while循环是罪魁祸首。有什么东西我错过了吗? 问题在于多个MediaRecorder同时工作吗?正如您所看到的,现在它是SoundMeter,而不是抛出异常的SoundRecorder。实际上 - 无论我在RecordingHandler中首先调用start()调用,都会抛出相同的IllegalStateException。

问题可能与Android: Two instances of Media recorder at same time有关,但很遗憾没有答案。

非常感谢任何进一步的帮助!

1 个答案:

答案 0 :(得分:0)

好吧,我似乎解决了这个问题。问题似乎是让多个MediaRecorder实例同时工作。我所做的是,我现在不使用单独的类进行检测和录音,因此录音机现在可以自己进行检测。

首先,我启动了初始SoundMeter,它可以监听直到它在4.0级上输入。然后我停止初始的SoundMeter并制作一个新的SoundMeter(具有不同的输出目录),它开始记录和记录,直到水平低于4.0为apprixamtely 10秒。然后停止第二个SoundMeter,后台任务可以再次启动初始SoundMeter。

以下是解决我问题的代码, 的AsyncTask:

    protected Object doInBackground(Object[] params) {
        int i = 0;
        soundMeter = new SoundMeter();
        RecordingHandler recordingHandler = null;
        try {
            soundMeter.start("/dev/null");
        } catch (IOException e) {
            Log.e("error", e.getMessage());
        }
        while(true){
            if(isCancelled()){
                soundMeter.stop();
                if(currentlyRecording && recordingHandler != null){
                    recordingHandler.kill();
                }
                break;
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                Log.e("error", e.getMessage());
            }
            if(!currentlyRecording && soundMeter.getAmplitudeEMA() > 4.0){
                soundMeter.stop();
                recordingHandler =  new RecordingHandler(deviceId);
                currentlyRecording = true;
                recordingHandler.run();
            } else if(!currentlyRecording && !soundMeter.isRunning()){
                try {
                    soundMeter.start("/dev/null");
                } catch (IOException e) {
                    Log.e("error", e.getMessage());
                }
            }
        }
        return null;
    }
}

和RecordingHandler.run():

@Override
public void run() {
    int i = 0;
    try {
        soundMeter.start(getFileNameString());
    } catch (IOException e) {
        Log.e("error", e.getMessage());
    }
    while(true){
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            Log.e("error", e.getMessage());
        }
        if(isKilled){
            break;
        }
        if(soundMeter.getAmplitudeEMA() < 4.0){
            i++;
            if(i > 10){
                break;
            }
        } else {
            i = 0;
        }
    }
    soundMeter.stop();
    EavesDrop.currentlyRecording = false;
}

http://developer.android.com/reference/android/media/MediaRecorder.html上的文档,在release()方法文档下,它讨论了某些设备上没有支持的多个实例。所以它可能是一个特定的设备相关问题。