我正在尝试使用以下功能在Android中开发应用程序：无缝录制视频和音频，即使用户在前台有另一个应用程序。常见的情况是：用户打开应用程序，开始录制，然后打开导航应用程序或接听电话。 我希望我的应用继续录制。
我已经汇总了一些代码，主要受到这个tutorial的启发，将在下面引用。然而，我遇到了两个问题：
1。当我按下＆＃34; home＆＃34;键，视频录制冻结，但声音很好
2。当我导航回应用程序时，预览为黑色
我的问题是：
我的代码：
public class GlobalState extends Application {
private boolean recording = false;
private boolean loggingEnabled = true;
private Camera serviceCamera = null;
private CameraPreview cameraPreview = null;
@Override
public void onCreate() {
try {
serviceCamera = Camera.open();
} catch (Exception e) {
}
super.onCreate();
}
public boolean isRecording() {
return recording;
}
public boolean isLoggingEnabled() {
return loggingEnabled;
}
public void setRecording(boolean recording) {
this.recording = recording;
}
public void setCamera(Camera serviceCamera) {
this.serviceCamera = serviceCamera;
}
public Camera getCamera() {
return serviceCamera;
}
public void setCameraPreview(CameraPreview cameraPreview) {
this.cameraPreview = cameraPreview;
}
public CameraPreview getCameraPreview() {
return this.cameraPreview;
}
}
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
private static final String TAG = "CameraPreview";
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (mHolder.getSurface() == null) {
return;
}
try {
mCamera.stopPreview();
} catch (Exception e) {
}
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
public class MainActivity extends Activity {
public String TAG = "DE-MainActivity";
ImageView mRecordView;
ImageView mMenuButtonView;
LinearLayout mMenuView;
TextView mVideosTextView;
TextView mSettingsTextView;
private Camera mCamera;
private CameraPreview mPreview;
GlobalState mAppState = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAppState = (GlobalState) getApplicationContext();
if (mAppState.isLoggingEnabled()) {
Log.v(TAG, "Activity: onCreate");
}
mCamera = mAppState.getCamera();
if (mAppState.getCameraPreview() == null) {
mPreview = new CameraPreview(this, mCamera);
mAppState.setCameraPreview(mPreview);
}
FrameLayout preview = (FrameLayout) findViewById(R.id.fl_camera);
preview.addView(mPreview);
mMenuView = (LinearLayout) findViewById(R.id.ll_menu_list);
mVideosTextView = (TextView) findViewById(R.id.tv_menu_item_videos);
mSettingsTextView = (TextView) findViewById(R.id.tv_menu_item_settings);
mRecordView = (ImageView) findViewById(R.id.iv_record);
mRecordView.setImageResource(R.drawable.btn_not_recording);
mRecordView.setAlpha((float) 0.5);
mRecordView.bringToFront();
mRecordView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!mAppState.isRecording()) {
mRecordView.setImageResource(R.drawable.btn_recording);
mRecordView.setAlpha((float) 0.3);
startService(new Intent(MainActivity.this,
RecorderService.class));
} else {
mRecordView.setImageResource(R.drawable.btn_not_recording);
mRecordView.setAlpha((float) 0.5);
stopService(new Intent(MainActivity.this,
RecorderService.class));
}
}
});
mMenuButtonView = (ImageView) findViewById(R.id.iv_menu);
mMenuButtonView.setImageResource(R.drawable.btn_menu);
mMenuButtonView.setAlpha((float) 0.5);
mMenuButtonView.bringToFront();
mMenuButtonView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mMenuView.getVisibility() == View.VISIBLE) {
mMenuView.setVisibility(View.INVISIBLE);
} else {
mMenuView.setVisibility(View.VISIBLE);
}
}
});
mSettingsTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mAppState.isLoggingEnabled())
Log.v(TAG, "settings clicked!");
}
});
mVideosTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mAppState.isLoggingEnabled())
Log.v(TAG, "videos clicked!");
}
});
}
@Override
protected void onDestroy() {
if (mAppState.isLoggingEnabled())
Log.v(TAG, "APPLICATION EXIT!");
if (mCamera != null) {
mCamera.release(); // release the camera for other applications
mCamera = null;
}
super.onDestroy();
}
public boolean onCreateOptionsMenu(Menu menu) {
if (mMenuView.getVisibility() == View.VISIBLE) {
mMenuView.setVisibility(View.INVISIBLE);
} else {
mMenuView.setVisibility(View.VISIBLE);
}
return false;
}
}
public class RecorderService extends Service {
private static final String TAG = "RecorderService";
private static Camera mServiceCamera;
private MediaRecorder mMediaRecorder;
private GlobalState mAppState;
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
@Override
public void onCreate() {
mAppState = (GlobalState) getApplicationContext();
mServiceCamera = mAppState.getCamera();
if (mAppState.isLoggingEnabled())
Log.v(TAG, "onCreate");
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
if (!mAppState.isRecording()) {
if (prepareVideoRecorder()) {
mMediaRecorder.start();
mAppState.setRecording(true);
} else {
releaseMediaRecorder();
}
}
return 5;
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onDestroy() {
if (mAppState.isLoggingEnabled())
Log.v(TAG, "onDestroy");
// stop recording and release camera
mMediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
mServiceCamera.lock(); // take camera access back from MediaRecorder
mAppState.setRecording(false);
super.onDestroy();
}
private void releaseMediaRecorder() {
if (mMediaRecorder != null) {
mMediaRecorder.reset(); // clear recorder configuration
mMediaRecorder.release(); // release the recorder object
mMediaRecorder = null;
}
}
/** Create a file Uri for saving an image or video */
private static Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type) {
File mediaStorageDir = new File(
Environment.getExternalStorageDirectory(), "DashEyeApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
} else if (type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "VID_" + timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
private boolean prepareVideoRecorder() {
mMediaRecorder = new MediaRecorder();
mServiceCamera.unlock();
mMediaRecorder.setCamera(mServiceCamera);
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mMediaRecorder.setProfile(CamcorderProfile
.get(CamcorderProfile.QUALITY_HIGH));
mMediaRecorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO)
.toString());
// Step 5: Set the preview output
// mMediaRecorder.setPreviewDisplay(mAppState.getCameraPreview().getHolder().getSurface());
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
Log.d(TAG,
"IllegalStateException preparing MediaRecorder: "
+ e.getMessage());
releaseMediaRecorder();
return false;
} catch (IOException e) {
Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
}
return true;
}
}
答案 0 :(得分：1)
我的解决方案很好，试一试：
服务android：
import java.util.Calendar;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.view.Gravity;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;
import android.view.WindowManager.LayoutParams;
public class BackgroundVideoRecorder extends Service implements
SurfaceHolder.Callback {
private WindowManager windowManager;
private SurfaceView surfaceView;
private Camera camera = null;
private MediaRecorder mediaRecorder = null;
int contTime = 0, duracaoGravacao = 30; //interval in seconds to record video
private class thread implements Runnable {
public void run() {
contTime++;
if (contTime >= duracaoGravacao) {
StopService();
}
tick_Handler.postDelayed(tick_thread, 1000);
}
}
Handler tick_Handler;
thread tick_thread;
Preferences pref;
@Override
public void onCreate() {
windowManager = (WindowManager) this
.getSystemService(Context.WINDOW_SERVICE);
surfaceView = new SurfaceView(this);
LayoutParams layoutParams = new WindowManager.LayoutParams(1, 1,
WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
PixelFormat.TRANSLUCENT);
layoutParams.gravity = Gravity.LEFT | Gravity.TOP;
windowManager.addView(surfaceView, layoutParams);
surfaceView.getHolder().addCallback(this);
tick_Handler = new Handler();
tick_thread = new thread();
VIDEO_RECORDER_FOLDER = new _Path().getPathVideo();
}
@Override
public void onStart(Intent intent, int startId) {
tick_Handler.post(tick_thread);
}
// Method called right after Surface created (initializing and starting
// MediaRecorder)
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
boolean found = false;
int i = 0;
try {
for (i = 0; i < Camera.getNumberOfCameras(); i++) {
Camera.CameraInfo newInfo = new Camera.CameraInfo();
Camera.getCameraInfo(i, newInfo);
if (newInfo.facing == CameraInfo.CAMERA_FACING_FRONT) {
found = true;
break;
}
}
} catch (Exception e) {
e.printStackTrace();
}
if (found) {
camera = Camera.open(i);
} else {
camera = Camera.open();
}
Calendar lCDateTime = Calendar.getInstance();
String t = String.valueOf(lCDateTime.getTimeInMillis());
nomeArquivo = "hire_me_now_" + t + ".mp4";
nomeArquivo = nomeArquivo.replace(" ", "_").replace(":", "_")
.replace("-", "_");
String caminhoArquivo = VIDEO_RECORDER_FOLDER + "/" + nomeArquivo;
mediaRecorder = new MediaRecorder();
camera.unlock();
mediaRecorder.setPreviewDisplay(surfaceHolder.getSurface());
mediaRecorder.setCamera(camera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setProfile(CamcorderProfile
.get(CamcorderProfile.QUALITY_QVGA));
mediaRecorder.setVideoFrameRate(15);
mediaRecorder.setOutputFile(caminhoArquivo);
try {
mediaRecorder.prepare();
} catch (Exception e) {
e.printStackTrace();
}
mediaRecorder.start();
}
// Stop recording and remove SurfaceView
@Override
public void onDestroy() {
mediaRecorder.stop();
mediaRecorder.reset();
mediaRecorder.release();
camera.lock();
camera.release();
windowManager.removeView(surfaceView);
}
protected void StopService() {
try {
this.stopSelf();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format,
int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
答案 1 :(得分：0)
事实证明，Android不喜欢预览被破坏（例如，当用户点击“主页”按钮时），因此它会切断视频录制。
解决方法是使用WindowManager设置叠加层，当用户点击“主页”按钮时，将其调整为1x1。我找到了解决方案here。非常感谢 cman ！
答案 2 :(得分：-1)
可以这样做但是从API级别23开始你需要询问相机权限，你可以参考这个答案https://stackoverflow.com/a/49919386/4604234