我正在实现一个相机应用程序，当我查看预览时（尤其是前置摄像头），图像非常胖。看起来图像被水平拉伸。我按照优化相机尺寸的 sdk 示例进行操作，但没有帮助。如何调整我的相机设置，以便它可以像其他相机应用程序一样预览？
谢谢。
我的代码如下。
public class CameraActivity extends Activity implements SurfaceHolder.Callback, Camera.ShutterCallback, Camera.PictureCallback {
Camera m_camera;
SurfaceView m_surfaceView;
int m_numOfCamera;
int m_defaultCameraId;
int m_currentCamera;
int m_surfaceWidth;
int m_surfaceHeight;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
getActionBar().setDisplayHomeAsUpEnabled(true);
m_surfaceView = (SurfaceView)findViewById(R.id.cameraPreview);
m_surfaceView.getHolder().addCallback(this);
m_camera = Camera.open();
m_numOfCamera = Camera.getNumberOfCameras();
CameraInfo cameraInfo = new CameraInfo();
for (int i = 0; i < m_numOfCamera; ++i) {
Camera.getCameraInfo(i, cameraInfo);
if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
m_defaultCameraId = i;
m_currentCamera = m_defaultCameraId;
}
}
if (m_numOfCamera < 1) {
MenuItem switchCam = (MenuItem)findViewById(R.id.menu_switch_camera);
switchCam.setVisible(false);
}
}
@Override
public void onPause() {
super.onPause();
m_camera.stopPreview();
}
@Override
public void onDestroy() {
super.onDestroy();
m_camera.release();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_camera, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(final MenuItem item)
{
if (item.getItemId() == android.R.id.home)
{
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
return true;
}
else if (item.getItemId() == R.id.menu_switch_camera)
{
if (m_camera != null) {
m_camera.stopPreview();
m_camera.release();
m_camera = null;
}
m_camera = Camera.open((m_currentCamera + 1) % m_numOfCamera);
m_currentCamera = (m_currentCamera + 1) % m_numOfCamera;
Camera.Parameters params = m_camera.getParameters();
List<Camera.Size> sizes = params.getSupportedPreviewSizes();
Camera.Size size = getOptimalPreviewSize(sizes, m_surfaceWidth, m_surfaceHeight);
params.setPreviewSize(size.width, size.height);
m_camera.setParameters(params);
setCameraDisplayOrientation(this, m_currentCamera, m_camera);
m_camera.startPreview();
try {
m_camera.setPreviewDisplay(m_surfaceView.getHolder());
} catch (Exception e) {
e.printStackTrace();
}
return true;
}
return true;
}
public void onPictureTaken(byte[] arg0, Camera arg1) {
// TODO Auto-generated method stub
}
public void onShutter() {
// TODO Auto-generated method stub
}
public void surfaceChanged(SurfaceHolder arg0, int format, int w, int h) {
m_surfaceWidth = w;
m_surfaceHeight = h;
Camera.Parameters params = m_camera.getParameters();
List<Camera.Size> sizes = params.getSupportedPreviewSizes();
Camera.Size selected = getOptimalPreviewSize(sizes, w, h);
params.setPreviewSize(selected.width, selected.height);
m_camera.setParameters(params);
setCameraDisplayOrientation(this, m_currentCamera, m_camera);
m_camera.startPreview();
}
private static void setCameraDisplayOrientation(Activity activity,
int cameraId, android.hardware.Camera camera) {
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay()
.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0: degrees = 0; break;
case Surface.ROTATION_90: degrees = 90; break;
case Surface.ROTATION_180: degrees = 180; break;
case Surface.ROTATION_270: degrees = 270; break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
public void surfaceCreated(SurfaceHolder arg0) {
try {
m_camera.setPreviewDisplay(m_surfaceView.getHolder());
} catch (Exception e) {
e.printStackTrace();
}
}
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null)
return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
}