我在Samsung S5上使用新的Camera2 API.该设备报告的支持硬件级别是LEGACY,这很好.
但是,我似乎无法自动关注此设备.触发自动对焦的请求如下所示：
previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,CaptureRequest.CONTROL_AF_MODE_AUTO);
previewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,CaptureRequest.CONTROL_AF_TRIGGER_START);
state = STATE_PREVIEW;
try {
captureSession.setRepeatingRequest(previewRequestBuilder.build(),captureCallback,backgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
发送请求后,请求的结果始终为CONTROL_AF_STATE_ACTIVE_SCAN,偶尔为CONTROL_AF_STATE_NOT_FOCUSED_LOCKED.
奇怪的是,当状态为CONTROL_AF_STATE_NOT_FOCUSED_LOCKED时,自动对焦会返回CONTROL_AF_STATE_ACTIVE_SCAN状态一段时间,然后返回CONTROL_AF_STATE_NOT_FOCUSED_LOCKED,从而产生无限焦点循环.根据文档,当状态为CONTROL_AF_STATE_NOT_FOCUSED_LOCKED时……
The lens will remain stationary until the AF mode (android.control.afMode) is changed or a new AF trigger is sent to the camera device (android.control.afTrigger).
我想知道这种差异是否是因为硬件级别是LEGACY并且我应该回到使用已弃用的Camera API这一事实,但这对于诸如自动对焦这样的流行功能来说似乎很疯狂.
是否有任何建议如何处理报告LEGACY的设备？
解决方法
我分支表格
google’s Camera2Basic example并将其更改为使用CaptureRequest.CONTROL_AF_MODE_AUTO而不是CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE
您可以从git中获取该项目并对其进行测试 – https://github.com/pinhassi/android-Camera2Basic
或者只是将其添加到Camera2BasicFragment：
private static final long LOCK_FOCUS_DELAY_ON_FOCUSED = 5000;
private static final long LOCK_FOCUS_DELAY_ON_UNFOCUSED = 1000;
private Integer mLastAfState = null;
private Handler mUiHandler = new Handler(); // UI handler
private Runnable mLockAutoFocusRunnable = new Runnable() {
@Override
public void run() {
lockAutoFocus();
}
};
public void lockAutoFocus() {
try {
// This is how to tell the camera to lock focus.
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,CameraMetadata.CONTROL_AF_TRIGGER_START);
CaptureRequest captureRequest = mPreviewRequestBuilder.build();
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,null); // prevent CONTROL_AF_TRIGGER_START from calling over and over again
mCaptureSession.capture(captureRequest,mCaptureCallback,mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
/**
*
* @return
*/
private float getMinimumFocusDistance() {
if (mCameraId == null)
return 0;
Float minimumLens = null;
try {
CameraManager manager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics c = manager.getCameraCharacteristics(mCameraId);
minimumLens = c.get(CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE);
} catch (Exception e) {
Log.e(TAG,"isHardwareLevelSupported Error",e);
}
if (minimumLens != null)
return minimumLens;
return 0;
}
/**
*
* @return
*/
private boolean isAutoFocusSupported() {
return isHardwareLevelSupported(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) || getMinimumFocusDistance() > 0;
}
// Returns true if the device supports the required hardware level,or better.
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private boolean isHardwareLevelSupported(int requiredLevel) {
boolean res = false;
if (mCameraId == null)
return res;
try {
CameraManager manager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics cameraCharacteristics = manager.getCameraCharacteristics(mCameraId);
int deviceLevel = cameraCharacteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
switch (deviceLevel) {
case CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_3:
Log.d(TAG,"Camera support level: INFO_SUPPORTED_HARDWARE_LEVEL_3");
break;
case CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_FULL:
Log.d(TAG,"Camera support level: INFO_SUPPORTED_HARDWARE_LEVEL_FULL");
break;
case CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY:
Log.d(TAG,"Camera support level: INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY");
break;
case CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED:
Log.d(TAG,"Camera support level: INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED");
break;
default:
Log.d(TAG,"Unknown INFO_SUPPORTED_HARDWARE_LEVEL: " + deviceLevel);
break;
}
if (deviceLevel == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) {
res = requiredLevel == deviceLevel;
} else {
// deviceLevel is not LEGACY,can use numerical sort
res = requiredLevel <= deviceLevel;
}
} catch (Exception e) {
Log.e(TAG,e);
}
return res;
}
然后,添加到STATE_PREVIEW块：
case STATE_PREVIEW: {
// We have nothing to do when the camera preview is working normally.
// TODO: handle auto focus
Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
if (afState != null && !afState.equals(mLastAfState)) {
switch (afState) {
case CaptureResult.CONTROL_AF_STATE_INACTIVE:
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_INACTIVE");
lockAutoFocus();
break;
case CaptureResult.CONTROL_AF_STATE_ACTIVE_SCAN:
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_ACTIVE_SCAN");
break;
case CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED:
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED");
mUiHandler.removeCallbacks(mLockAutoFocusRunnable);
mUiHandler.postDelayed(mLockAutoFocusRunnable,LOCK_FOCUS_DELAY_ON_FOCUSED);
break;
case CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED:
mUiHandler.removeCallbacks(mLockAutoFocusRunnable);
mUiHandler.postDelayed(mLockAutoFocusRunnable,LOCK_FOCUS_DELAY_ON_UNFOCUSED);
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED");
break;
case CaptureResult.CONTROL_AF_STATE_PASSIVE_UNFOCUSED:
mUiHandler.removeCallbacks(mLockAutoFocusRunnable);
//mUiHandler.postDelayed(mLockAutoFocusRunnable,"CaptureResult.CONTROL_AF_STATE_PASSIVE_UNFOCUSED");
break;
case CaptureResult.CONTROL_AF_STATE_PASSIVE_SCAN:
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_PASSIVE_SCAN");
break;
case CaptureResult.CONTROL_AF_STATE_PASSIVE_FOCUSED:
mUiHandler.removeCallbacks(mLockAutoFocusRunnable);
//mUiHandler.postDelayed(mLockAutoFocusRunnable,LOCK_FOCUS_DELAY_ON_FOCUSED);
Log.d(TAG,"CaptureResult.CONTROL_AF_STATE_PASSIVE_FOCUSED");
break;
}
}
mLastAfState = afState;
break;
}
并替换所有出现的：
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
附：
if (isAutoFocusSupported())
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,CaptureRequest.CONTROL_AF_MODE_AUTO);
else
mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
