我使用以下代码录制了一段视频，录制效果很好，但播放视频时会倒置播放。
我在 mrec.prepare(); 之前尝试设置 mrec.setOrientationHint(180)，但是这没有用。有什么提示吗？
import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.app.Activity;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
/**
* @author SANA HASSAN
*/
public class CameraSurfaceView extends Activity {
private Preview mPreview;
private MediaRecorder mrec = new MediaRecorder();
private int cameraId = 0;
private Camera mCamera;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
mPreview = new Preview(this);
setContentView(mPreview);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
menu.add(0, 0, 0, "Start");
menu.add(0, 1, 0, "Stop");
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 0:
try {
startRecording();
}
catch (Exception e) {
e.printStackTrace();
mrec.release();
}
break;
case 1:
mrec.stop();
mrec.release();
mrec = null;
break;
default:
break;
}
return super.onOptionsItemSelected(item);
}
protected void startRecording() throws IOException {
mrec = new MediaRecorder();
mrec.setCamera(mCamera);
mCamera.unlock();
File directory = new File(Environment.getExternalStorageDirectory()+"/NICUVideos");
directory.mkdirs();
mrec.setAudioSource( MediaRecorder.AudioSource.MIC);
mrec.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mrec.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mrec.setOutputFile(Environment.getExternalStorageDirectory()+"/NICUVideos/"+System.currentTimeMillis()+".mp4");
mrec.setPreviewDisplay(mPreview.getHolder().getSurface());
mrec.setVideoSize(640, 480);
Method[] methods = mrec.getClass().getMethods();
for (Method method: methods){
try{
if(method.getName().equals("setAudioEncodingBitRate")){
method.invoke(mrec, 12200);
}
else if(method.getName().equals("setVideoEncodingBitRate")){
method.invoke(mrec, 800000);
}
else if(method.getName().equals("setAudioSamplingRate")){
method.invoke(mrec, 8000);
}
else if(method.getName().equals("setVideoFrameRate")){
method.invoke(mrec, 20);
}
}
catch (IllegalArgumentException e) {
e.printStackTrace();
}
catch (IllegalAccessException e) {
e.printStackTrace();
}
catch (InvocationTargetException e) {
e.printStackTrace();
}
}
mrec.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mrec.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
mrec.setMaxDuration(60000); // 60 seconds
mrec.setMaxFileSize(10000000); // Approximately 10 megabytes
mrec.prepare();
mrec.start();
}
protected void stopRecording() {
mrec.stop();
mrec.release();
mCamera.release();
}
class Preview extends SurfaceView implements SurfaceHolder.Callback {
SurfaceHolder mHolder;
Activity activity;
Preview(Activity activity) {
super(activity);
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
Camera.CameraInfo info=new Camera.CameraInfo();
for (int i=0; i < Camera.getNumberOfCameras(); i++) {
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
mCamera=Camera.open(i);
cameraId = i;
}
}
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException exception) {
mCamera.release();
mCamera = null;
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
setCameraDisplayOrientation(mCamera);
mCamera.startPreview();
}
public void setCameraDisplayOrientation(Camera camera) {
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(cameraId, info);
int rotation = CameraSurfaceView.this.getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0: degrees = 0; break;
case Surface.ROTATION_90: degrees = 90; break;
case Surface.ROTATION_180: degrees = 180; break;
case Surface.ROTATION_270: degrees = 270; break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
Log.d(Vars.TAG, "Result = "+result);
camera.setDisplayOrientation(result);
}
}
}