java.lang.RuntimeException: start failed at android.media.MediaRecorder.start(Native Method)

问题

I am working on records a phone calls. When i start a record a phone call then it's unfortunately stop. & it's gives error MediaRecorder start fail -2147483648. I Please tell me what is the problem in my code? Here is my Code.

public class incomingcall extends BroadcastReceiver {
Context c;
MediaRecorder recorder;
public incomingcall() {
}
@Override
public void onReceive(Context context, Intent intent) {
    c = context;
    try {
        PhoneStateChangeListener pscl = new PhoneStateChangeListener();
        TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        tm.listen(pscl, PhoneStateListener.LISTEN_CALL_STATE);
    } catch (Exception e) {
        Log.e("", "", e);
    }
}

private class PhoneStateChangeListener extends PhoneStateListener {
    @Override
    public void onCallStateChanged(int state, String incomingNumber) {
        switch (state) {
            case TelephonyManager.CALL_STATE_RINGING:
                Toast.makeText(c, "ring", Toast.LENGTH_SHORT).show();
                break;
            case TelephonyManager.CALL_STATE_OFFHOOK:
                startRecording();
                Toast.makeText(c, "offhook", Toast.LENGTH_SHORT).show();
                break;
            case TelephonyManager.CALL_STATE_IDLE:
                stopRecording();
                Toast.makeText(c, "idle", Toast.LENGTH_SHORT).show();
                break;
        }
    }
}
private void startRecording() {
    try {
        recorder = new MediaRecorder();
        recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        String file=c.getFilesDir().getAbsolutePath();
        file+="/sound.3gp";
        recorder.setOutputFile(file);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.prepare();
        recorder.start();
    } catch (IOException e) {
        Log.e("", "prepare() failed", e);
    }
}
private void stopRecording() {
    try {
        recorder.stop();
        recorder.release();
        recorder = null;
    } catch (Exception e) {
        Log.e("", "", e);
    }
 }
}

Log

    07-20 15:33:47.867 18525-18525/in.pounkumar.callblocker E/MediaRecorder: start failed: -2147483648
07-20 15:33:47.868 18525-18525/in.pounkumar.callblocker E/AndroidRuntime: FATAL EXCEPTION: main
                                                                          Process: in.pounkumar.callblocker, PID: 18525
                                                                          java.lang.RuntimeException: start failed.
                                                                              at android.media.MediaRecorder.start(Native Method)
                                                                              at in.pounkumar.callblocker.incomingcall.startRecording(incomingcall.java:73)
                                                                              at in.pounkumar.callblocker.incomingcall.access$100(incomingcall.java:20)
                                                                              at in.pounkumar.callblocker.incomingcall$PhoneStateChangeListener.onCallStateChanged(incomingcall.java:53)
                                                                              at android.telephony.PhoneStateListener$2.handleMessage(PhoneStateListener.java:295)
                                                                              at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                              at android.os.Looper.loop(Looper.java:148)
                                                                              at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                              at java.lang.reflect.Method.invoke(Native Method)
                                                                              at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                              at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

回答1:

I have the same problem and i solved it by using different initializations for Samsung and LG devices.

        String manufacturer = Build.MANUFACTURER;
    if (manufacturer.toLowerCase().contains("samsung")) {
        recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION);
    } else {
        recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);
    }

Hope it helps you.

回答2:

MediaRecorder.AudioSource.VOICE_CALL source requires the CAPTURE_AUDIO_OUTPUT permission. See Android Docs

Have you added this permission in your manifest

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

回答3:

The MediaRecorder.start method fails in your case, due to this :

recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);

The reason why MediaRecorder.AudioSource.VOICE_CALL source doesn't work depends on your device manufacturer/country etc.

So, this is throwing an exception as MediaRecorder.AudioSource.VOICE_CALL is NOT supported on your device.

Try changing it to MediaRecorder.AudioSource.MIC and it will work :

recorder.setAudioSource(MediaRecorder.AudioSource.MIC);

Read this for more details.

来源：https://stackoverflow.com/questions/38479041/java-lang-runtimeexception-start-failed-at-android-media-mediarecorder-startna