camera

Make new project – CameraFun – Give permission to use camera write_external _storage Make two buttons – id takePictureButton – id showLastPicButton Add SurfaceView to layout – Surface view is something we can draw on Graphics on a SurfaceView is discussed in the video GraphicWithCanvas – This will show the picture preview – Set layout height = fill_parent (or try 10dip) – Set layout width = fill_parent – Set layout weight = 1 – Id SurfaceView changes when the phone’s orientation changes.

SurfaceView To handle the surface and changes in the surface, we need our activity to implement SurfaceHolder.Callback. – public class CameraFunActivity extends Activity implements SurfaceHolder.Callback { – See Graphics with Canvas notes for how to make surfaceView a class, not the activity Our CameraFunActivity class needs some objects – Camera mCamera; // to hold the camera object – //!! When importing package camera, make sure to get android.hardware.camera – private SurfaceView mSurfaceView; // to hold the surface view – private SurfaceHolder mSurfaceHolder; // to hold the interface for the surfaceview – boolean previewRunning = false; – We’ll add some more later In onCreate, add – mSurfaceView = (SurfaceView) findViewById(R.id.surface_camera); // get surface object – mSurfaceHolder = mSurfaceView.getHolder();// get surface holder – mSurfaceHolder.addCallback(this);// this activity is the callback – // note, instead this, we could make a new class that implements SurfaceHolder.Callback – mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); Implementing SurfaceHolder.CallBack requires three functions to be implemented – surfaceCreated – surfaceChanged Called when orientation is changed and after surfaceCreated – surfaceDestroyed

surfaceCreated and surfaceDestroyed public void surfaceCreated(SurfaceHolder holder) { – Log.e("CameraFun", "surfaceCreated"); – mCamera = Camera.open(); // this will not compile if the wrong camera package was imported (see previous slide) – } public void surfaceDestroyed(SurfaceHolder holder) { Log.e("CamerFun", "surfaceDestroyed"); mCamera.stopPreview(); mCamera.release(); previewRunning = false; }

surfaceChanged public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { – // called when surface created and when orientation is changed – Log.d("CameraFun", "surfaceChanged"); – if (previewRunning) mCamera.stopPreview(); – Log.e("CameraFun","view width"+width+" height"+height); – Camera.Parameters p = mCamera.getParameters(); // set the preview size – p.setPreviewSize(width, height); – mCamera.setParameters(p); – try { mCamera.setPreviewDisplay(holder); – } catch (IOException e) { e.printStackTrace(); – } – mCamera.startPreview(); – mPreviewRunning = true; }

run It crashes on most devices Check log Note that error when setting preview size Note that preview size is odd. Check web for more info on Camera.Parameters and Camera.Parameters.setPreviewSize – see getSupportedPreviewSizes

Improved surfaceChanged In surfaceChanged, before setParameters, add – Log.e("MyCameraFun","width"+width+" h"+height); – List sizes = mCamera.getParameters().getSupportedPreviewSizes(); – Camera.Size sizeToSet = null; – for (Camera.Size t: sizes) – { – String str = "view"; – str += t.width; – str += "by" + t.height; – Log.e("CameraFun", str); – if (t.width<= width && t.height<= height && sizeToSet == null) – sizeToSet = t; – } – Log.e("CameraFun","w="+sizeToSet.width+" h="+sizeToSet.height); change – p.setPreviewSize(width, height); – to – p.setPreviewSize(sizeToSet.width, sizeToSet.height); – // note that this sizetoSet might be null. In which case none of the supported sizes works. This condition should be handled run

Rotation/orientation Note that the orientation is messed up – Perhaps the image is correct in only one orientation. Two fixes – Fix the orientation to be in portrait or landscape and set display orientation accordingly In onCreate, add – setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); In surfaceChanged, add – In version 2.2 and above: » mCamera.setDisplayOrientation(180); // or 90 or whatever value works – In 2.1 » Camera.Parameters parameters = mCamera.getParameters(); parameters.set("orientation", "portrait"); mCamera.setParameters(parameters); – Get the rotation and then set camera orientation accordingly In surfaceChanged, add – Display display = getWindowManager().getDefaultDisplay(); – switch (display.getRotation()) { » case Surface.ROTATION_0: Log.e("DEBUG INFO","rotation = 0"); mCamera.setDisplayOrientation(180); // whatever value works break; » case Surface.ROTATION_90: Etc. etc.

Take picture In onCreate add button click listener – When clicked call mCamera.takePicture(null, null, pictureCallback); – The first null could be set to play a sound. But we will just use the default – pictureCallback is a Camera.PictureCallback object that we must make

PictureCallback Camera.PictureCallback pictureCallback = new Camera.PictureCallback() { public void onPictureTaken(byte[] imageData, Camera c) { – if (imageData == null) { Log.e("DEBUG INFO","image is null"); – } else { File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES); File fileToSave = new File(path,"myPic.jpeg"); Log.e("CameraFun","saving pic to: "+fileToSave); Bitmap bitmap = BitmapFactory.decodeByteArray(imageData,0,imageData.length); FileOutputStream fos = new FileOutputStream(fileToSave); bitmap.compress(CompressFormat.JPEG, 50, fos); // quality is 50, but could be between 0 and 100 fos.close(); } – } – mCamera.startPreview(); }; Notes: there are many bitmap functions. Check documentation Need to something to handle throw Run Get pic from storage and view on your laptop

Show picture Make new activity (see previous tutorial on making another activity) In layout add – Add ImageView In onCreate, add – // get file with picture – File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES); – File fileToView = new File(path,"myPic.jpeg"); – Log.e("Still image source filename:", fileToView.getPath()); – // load file as bitmap – Bitmap bm = BitmapFactory.decodeFile(fileToView.getPath()); – // show bitmap – android.widget.ImageView imageView = (android.widget.ImageView)findViewById(R.id.imageView); – imageView.setImageBitmap(bm);

Record video Add android.permission.RECORD_AUDIO Add member variable: MediaRecorder mediaRecorder; Add button for stopping the record – We’ll use the button for taking a picture to start recording In the start recording button, replace – mCamera.takePicture(null, null, pictureCallback); With – File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES); – File fileToSave = new File(path,"myMov.mpeg"); – mCamera.unlock(); – mediaRecorder = new MediaRecorder(); – mediaRecorder.setCamera(mCamera); – mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); – mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); – mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT); – mediaRecorder.setMaxDuration(-1); – mediaRecorder.setOutputFile(fileToSave.getPath()); // your file – mediaRecorder.setVideoFrameRate(10);//videoFramesPerSecond); – mediaRecorder.setVideoSize(320, 240); // or some other size – mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT); – mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT); – mediaRecorder.setPreviewDisplay(mSurfaceHolder.getSurface()); – mediaRecorder.setMaxFileSize( ); // size in bytes – mediaRecorder.prepare(); – mediaRecorder.start();

In stop video button mediaRecorder.stop(); mCamera.lock();

Playing Video in picviewer.xml (layout), – delete image view – Add VideoView in ImageView – Comment out everything with showing the picture – Add File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES); File fileToLoad = new File(path,"myMov.mpeg"); VideoView mVideoView = (VideoView) findViewById(R.id.videoView); mVideoView.setVideoPath(fileToLoad.getPath()); mVideoView.setMediaController(new MediaController(this)); mVideoView.requestFocus(); mVideoView.start(); //mVideoView.stop() //mVideoView.suspend();