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 = @+id/surface_camera

• 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<Camera.Size> 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(100000000); // 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();