在服务中使用 mediaReorder。音频正常 - 视频崩溃

Question

if (audio == true & video == true) 
{
Camera camera = Camera.open();
camera.unlock();
recorder.setCamera(camera);
recorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
recorder.setVideoSize(640,480);
recorder.setVideoFrameRate(15);
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
recorder.setAudioEncoder((MediaRecorder.AudioEncoder.DEFAULT));
recorder.setPreviewDisplay(null);
filesuffix = ".mp4";
filename = formatteddate.concat(filesuffix);
recorder.setOutputFile(path.concat(filename));
recorder.setAudioEncodingBitRate(96000);
recorder.setAudioSamplingRate(96000);
try {recorder.prepare();} 
catch (IllegalStateException e) {e.printStackTrace();} 
catch (IOException e) {e.printStackTrace();}
recorder.start();
};

它创建文件，然后服务崩溃。

logcat 报告失败：

Caused by: java.lang.IllegalStateException
    at android.media.MediaRecorder.start(Native Method)
    at [         ].PPS.onCreate(PPS.java:144)
    at android.app.ActivityThread.handleCreateService(ActivityThread.java:3033)

仅录制音频时，效果非常好。任何建议表示赞赏。