Android 在安卓平板电脑上，前置摄像头录制的视频显示模糊

我正在用媒体录像机在安卓系统中录制视频。在手机中，前后摄像头的视频都录制得很好，但对于平板电脑，后摄像头的视频录制得很好，但前摄像头的视频显示模糊。这是我录制的视频的外观：

我的录像代码是

private Camera getCameraInstance() {
    // TODO Auto-generated method stub
    Camera c = null;
    try {

        if (Camera.getNumberOfCameras() >= 2) {

            //if you want to open front facing camera use this line   
            c = Camera.open(CameraInfo.CAMERA_FACING_FRONT);}

    //  c.setDisplayOrientation(90);
        //c = Camera.open(1); // attempt to get a Camera instance
    } catch (Exception e) {
        // Camera is not available (in use or does not exist)
    }
    return c; // returns null if camera is unavailable
}

private boolean prepareMediaRecorder() {
    myCamera = getCameraInstance();
    mediaRecorder = new MediaRecorder();

    myCamera.unlock();
    mediaRecorder.setCamera(myCamera);

    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

    mediaRecorder.setProfile(CamcorderProfile
            .get(CamcorderProfile.QUALITY_HIGH));

    mediaRecorder.setOutputFile("/sdcard/myvideo.mp4");
    //mediaRecorder.setMaxDuration(60000); // Set max duration 60 sec.
    //mediaRecorder.setMaxFileSize(5000000); // Set max file size 5M

    mediaRecorder.setPreviewDisplay(myCameraSurfaceView.getHolder()
            .getSurface());

    try {
        mediaRecorder.prepare();
    } catch (IllegalStateException e) {
        releaseMediaRecorder();
        return false;
    } catch (IOException e) {
        releaseMediaRecorder();
        return false;
    }
    return true;

}