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Category: Android Development
Tips for increasing camera performance

Hello All,
I followed a camera tutorial and it "works".
however I am not satisfied with the performance of it.
when you take a picture you have to wait 1 whole second before taking the next one.
Any tips for decreasing the delay would be welcome.
here is my code


public class MainActivity extends AppCompatActivity {
private TextureView textureView;
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
private String cameraId;
private File file;
static {
ORIENTATIONS.append(Surface.ROTATION_0, 90);
ORIENTATIONS.append(Surface.ROTATION_90, 0);
ORIENTATIONS.append(Surface.ROTATION_180, 270);
ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
protected CameraDevice cameraDevice;
protected CameraCaptureSession cameraCaptureSession;
protected CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
private ImageReader imageReader;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textureView = findViewById(R.id.portal);
assert textureView != null;
textureView.setSurfaceTextureListener(textureListener);
}
TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {
openCamera();
}

@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {

}

@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
return false;
}

@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {

}
};
private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(@NonNull CameraDevice camera) {
Log.d("86","onOpened");
cameraDevice = camera;
createCameraPreview();
}

@Override
public void onDisconnected(@NonNull CameraDevice camera) {
cameraDevice.close();
}

@Override
public void onError(@NonNull CameraDevice camera, int i) {
cameraDevice.close();
cameraDevice = null;
}
};
final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Toast.makeText(MainActivity.this,"Saved:"+file,Toast.LENGTH_SHORT).show();
createCameraPreview();
}
};
protected void startBackgroundThread() {
mBackgroundThread = new HandlerThread("CameraBackground");
mBackgroundThread.start();
mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
protected void stopBackgroundThread() {
try {
mBackgroundThread.join();
mBackgroundThread = null;
mBackgroundHandler = null;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void takePicture(View view){
if(cameraDevice == null){
Log.e("128","cameraDevice is Null!");
return;
}
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try{
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraDevice.getId());
Size[] jpegSizes = null;
if(characteristics != null){
jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP).getOutputSizes(ImageForma t.JPEG);
}
int width = 640;
int height = 480;
if(jpegSizes != null && jpegSizes.length > 0){
width = jpegSizes[0].getWidth();
height = jpegSizes[0].getHeight();
}
ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
List<Surface> outputSurfaces = new ArrayList<>(2);
outputSurfaces.add(reader.getSurface());
outputSurfaces.add(new Surface(textureView.getSurfaceTexture()));
final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
captureBuilder.addTarget(reader.getSurface());
captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
int rotation = getWindowManager().getDefaultDisplay().getRotation();
captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
final File file = new File(Environment.getExternalStorageDirectory()+"/DCIM/"+SystemClock.uptimeMillis()+".jpg");
ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Image image = null;
try {
image = reader.acquireLatestImage();
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
byte[] bytes = new byte[buffer.capacity()];
buffer.get(bytes);
save(bytes);
}catch (FileNotFoundException e){
e.printStackTrace();
}catch (IOException e){
e.printStackTrace();
}finally {
if(image != null){
image.close();
}
}
}
private void save(byte[] bytes) throws IOException {
OutputStream output = null;
try {
output = new FileOutputStream(file);
output.write(bytes);
}finally {
if(output != null){
output.close();
}
}
}
};
reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
super.onCaptureCompleted(session, request, result);
Toast.makeText(MainActivity.this,"Saved:"+file,Toast.LENGTH_SHORT).show();
createCameraPreview();
}
};
cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession session) {
try {
session.capture(captureBuilder.build(),captureListener,mBackgroundHandler);
}catch (CameraAccessException e){
e.printStackTrace();
}
}

@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {

}
}, mBackgroundHandler);
}catch (Exception e){
e.printStackTrace();
}
}
protected void createCameraPreview() {
try {
SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
Surface surface = new Surface(texture);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(surface);
cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cCaptureSession) {
if (cameraDevice == null) {
return;
}
cameraCaptureSession = cCaptureSession;
updatePreview();
}

@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(MainActivity.this, "Configuration Change", Toast.LENGTH_SHORT).show();
}
}, null);
}catch (CameraAccessException e){
e.printStackTrace();
}
}
private void openCamera(){
CameraManager manager = (CameraManager)getSystemService(Context.CAMERA_SERVICE);
Log.d("260","camera is open");
try{
cameraId = manager.getCameraIdList()[0];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
if(ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(MainActivity.this,new String[]{
Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE
}, REQUEST_CAMERA_PERMISSION);
return;
}
manager.openCamera(cameraId,stateCallback, null);
}catch (CameraAccessException e){
e.printStackTrace();
}
Log.d("282","OpenCamera X");
}
protected void updatePreview(){
if(cameraDevice == null){
Log.e("286","updatePreview error");
}
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE,CameraMetadata.CONTROL_MODE_AUTO);
try{
cameraCaptureSession.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
}catch (CameraAccessException e){
e.printStackTrace();
}
}
private void closeCamera(){
if(cameraDevice != null){
cameraDevice.close();
cameraDevice = null;
}
if (imageReader != null){
imageReader.close();
imageReader = null;
}
}
@Override
public void onRequestPermissionsResult(int requestCode,@NonNull String[] permissions,int[] grantResults){
if(requestCode == REQUEST_CAMERA_PERMISSION){
if (grantResults[0] == PackageManager.PERMISSION_DENIED){
Toast.makeText(MainActivity.this,"This app is pouting because you didn't give it permission.",Toast.LENGTH_LONG).show();
finish();
}
}
}
@Override
protected void onResume(){
super.onResume();
Log.d("317","onResume");
startBackgroundThread();
if (textureView.isAvailable()){
openCamera();
} else {
textureView.setSurfaceTextureListener(textureListener);
}
}
protected void onPause(){
Log.d("326","onPause");
stopBackgroundThread();
super.onPause();
}
}










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