Android with front camera to take a picture

Question

This is my first time using a camera. I read a lot of examples, as well as documentation, so I tried to make my own class for shooting with the front camera.

Here is what I came up with:

public class CameraController { private Context context; private boolean hasCamera; private Camera camera; private int cameraId; public CameraController(Context c){ context = c.getApplicationContext(); if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){ cameraId = getFrontCameraId(); if(cameraId != -1){ hasCamera = true; }else{ hasCamera = false; } }else{ hasCamera = false; } } public boolean hasCamera(){ return hasCamera; } public void getCameraInstance(){ camera = null; if(hasCamera){ try{ camera = Camera.open(cameraId); } catch(Exception e){ } } } public void takePicture(){ if(hasCamera){ camera.takePicture(null,null,mPicture); } } public void releaseCamera(){ if(camera != null){ camera.release(); camera = null; } } private int getFrontCameraId(){ int camId = -1; int numberOfCameras = Camera.getNumberOfCameras(); CameraInfo ci = new CameraInfo(); for(int i = 0;i < numberOfCameras;i++){ Camera.getCameraInfo(i,ci); if(ci.facing == CameraInfo.CAMERA_FACING_FRONT){ camId = i; } } return camId; } private PictureCallback mPicture = new PictureCallback(){ @Override public void onPictureTaken(byte[] data, Camera camera){ File pictureFile = getOutputMediaFile(); if(pictureFile == null){ Log.d("TEST", "Error creating media file, check storage permissions"); return; } try{ FileOutputStream fos = new FileOutputStream(pictureFile); fos.write(data); fos.close(); }catch(FileNotFoundException e){ Log.d("TEST","File not found: "+e.getMessage()); } catch (IOException e){ Log.d("TEST","Error accessing file: "+e.getMessage()); } } }; private File getOutputMediaFile(){ // To be safe, you should check that the SDCard is mounted // using Environment.getExternalStorageState() before doing this. File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),"MyCameraApp"); // This location works best if you want the created images to be shared // between applications and persist after your app has been uninstalled. // Create the storage directory if it does not exist if(!mediaStorageDir.exists()){ if(!mediaStorageDir.mkdirs()){ return null; } } // Create a media file name String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); File mediaFile; mediaFile = new File(mediaStorageDir.getPath()+File.separator+"IMG_"+timeStamp+".jpg"); return mediaFile; } } 

So the class seems wonderful, but I can't get any picture from it. In LogCat, I get the following:

 03-11 19:23:58.556: D/TEST(18655): SNAPSHOT GO! 03-11 19:23:58.556: I/caladbolg(272): 2752686164 cald_client.c (464) 24404 I [INF] + Cald_Client_ICamera_GetBufInfo index[0x2] 03-11 19:23:58.556: I/caladbolg(272): 2752687080 cald_client.c (487) 24404 I [INF] - Cald_Client_ICamera_GetBufInfo (0) 03-11 19:23:58.556: I/caladbolg(272): 2752687355 cald_client.c (464) 24404 I [INF] + Cald_Client_ICamera_GetBufInfo index[0x3] 03-11 19:23:58.566: I/caladbolg(272): 2752688057 cald_client.c (487) 24404 I [INF] - Cald_Client_ICamera_GetBufInfo (0) 03-11 19:23:58.566: I/caladbolg(272): 2752691108 cald_client.c (755) 24404 I [INF] + Cald_Client_ICamera_EnableThumbnail 03-11 19:23:58.566: I/caladbolg(272): 2752691749 cald_client.c (772) 24404 I [INF] pBufNum[1] 03-11 19:23:58.566: I/caladbolg(272): 2752692024 cald_client.c (778) 24404 I [INF] pBuf[0]:0x4311b000 03-11 19:23:58.566: I/caladbolg(272): 2752692817 cald_client.c (792) 24404 I [INF] - Cald_Client_ICamera_EnableThumbnail (0) 03-11 19:23:58.566: I/caladbolg(272): 2752693519 cald_client.c (832) 24404 I [INF] + Cald_Client_ICamera_TakeSnapshot 03-11 19:23:58.566: I/caladbolg(272): 2752693763 cald_client.c (849) 24404 I [INF] pBufNum[1] 03-11 19:23:58.566: I/caladbolg(272): 2752694007 cald_client.c (855) 24404 I [INF] pBuf[0]:0x4ad01000 03-11 19:23:58.566: I/caladbolg(272): 2752694831 cald_camctrl.c (6197) 20324 P [PFM] 2752694831 Cald_CamCtrl_ICamera_TakeSnapshot 03-11 19:23:58.566: E/caladbolg(272): 2752695137 cald_camctrl.c (19650) 20324 E [CAM] Error: The event is not ready in the current state. 03-11 19:23:58.566: E/libcamera(272): receivePictureDone: unnecessary callback was received. 03-11 19:23:58.566: I/caladbolg(272): 2752696205 cald_client.c (869) 24404 I [INF] - Cald_Client_ICamera_TakeSnapshot (0) 

Answer 1

I solved the problem. After reading some other posts and tutorials, it seems like the camera needs a “dummy” surface for preview, even if we don't want to show the preview.

Here is my last code if someone needs it. Please note that with "hasCamera" I mean the front camera:

  public class CameraController { private Context context; private boolean hasCamera; private Camera camera; private int cameraId; public CameraController(Context c){ context = c.getApplicationContext(); if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){ cameraId = getFrontCameraId(); if(cameraId != -1){ hasCamera = true; }else{ hasCamera = false; } }else{ hasCamera = false; } } public boolean hasCamera(){ return hasCamera; } public void getCameraInstance(){ camera = null; if(hasCamera){ try{ camera = Camera.open(cameraId); prepareCamera(); } catch(Exception e){ hasCamera = false; } } } public void takePicture(){ if(hasCamera){ camera.takePicture(null,null,mPicture); } } public void releaseCamera(){ if(camera != null){ camera.stopPreview(); camera.release(); camera = null; } } private int getFrontCameraId(){ int camId = -1; int numberOfCameras = Camera.getNumberOfCameras(); CameraInfo ci = new CameraInfo(); for(int i = 0;i < numberOfCameras;i++){ Camera.getCameraInfo(i,ci); if(ci.facing == CameraInfo.CAMERA_FACING_FRONT){ camId = i; } } return camId; } private void prepareCamera(){ SurfaceView view = new SurfaceView(context); try{ camera.setPreviewDisplay(view.getHolder()); }catch(IOException e){ throw new RuntimeException(e); } camera.startPreview(); Camera.Parameters params = camera.getParameters(); params.setJpegQuality(100); camera.setParameters(params); } private PictureCallback mPicture = new PictureCallback(){ @Override public void onPictureTaken(byte[] data, Camera camera){ File pictureFile = getOutputMediaFile(); if(pictureFile == null){ Log.d("TEST", "Error creating media file, check storage permissions"); return; } try{ Log.d("TEST","File created"); FileOutputStream fos = new FileOutputStream(pictureFile); fos.write(data); fos.close(); }catch(FileNotFoundException e){ Log.d("TEST","File not found: "+e.getMessage()); } catch (IOException e){ Log.d("TEST","Error accessing file: "+e.getMessage()); } } }; private File getOutputMediaFile(){ // To be safe, you should check that the SDCard is mounted // using Environment.getExternalStorageState() before doing this. File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),"MyCameraApp"); // This location works best if you want the created images to be shared // between applications and persist after your app has been uninstalled. // Create the storage directory if it does not exist if(!mediaStorageDir.exists()){ if(!mediaStorageDir.mkdirs()){ return null; } } // Create a media file name String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); File mediaFile; mediaFile = new File(mediaStorageDir.getPath()+File.separator+"IMG_"+timeStamp+".jpg"); return mediaFile; } } 

Answer 2

Take a look at this question for information and code on how to do this: Shooting with a camera using Android software

The code you used here is not wrong, but this one works.

If you want to take a snapshot without having the user preview, look at this code: https://github.com/aporter/coursera-android/blob/master/Examples/AudioVideoCamera/src/course/examples/AudioVideo/Camera/AudioVideoCameraActivity. java p>

You need to get rid of SurfaceView, which shows the user a preview.