State	Transition Cause	New State	Notes
INACTIVE		INACTIVE	Camera device auto exposure algorithm is disabled

State	Transition Cause	New State	Notes
INACTIVE	Camera device initiates AE scan	SEARCHING	Values changing
INACTIVE	CaptureRequest.ControlAeLock is ON	LOCKED	Values locked
SEARCHING	Camera device finishes AE scan	CONVERGED	Good values, not changing
SEARCHING	Camera device finishes AE scan	FLASH_REQUIRED	Converged but too dark w/o flash
SEARCHING	CaptureRequest.ControlAeLock is ON	LOCKED	Values locked
CONVERGED	Camera device initiates AE scan	SEARCHING	Values changing
CONVERGED	CaptureRequest.ControlAeLock is ON	LOCKED	Values locked
FLASH_REQUIRED	Camera device initiates AE scan	SEARCHING	Values changing
FLASH_REQUIRED	CaptureRequest.ControlAeLock is ON	LOCKED	Values locked
LOCKED	CaptureRequest.ControlAeLock is OFF	SEARCHING	Values not good after unlock
LOCKED	CaptureRequest.ControlAeLock is OFF	CONVERGED	Values good after unlock
LOCKED	CaptureRequest.ControlAeLock is OFF	FLASH_REQUIRED	Exposure good, but too dark
PRECAPTURE	Sequence done. CaptureRequest.ControlAeLock is OFF	CONVERGED	Ready for high-quality capture
PRECAPTURE	Sequence done. CaptureRequest.ControlAeLock is ON	LOCKED	Ready for high-quality capture
Any state	CaptureRequest.ControlAePrecaptureTrigger is START	PRECAPTURE	Start AE precapture metering sequence

State	Transition Cause	New State	Notes
INACTIVE	Camera device finished AE scan	CONVERGED	Values are already good, transient states are skipped by camera device.
Any state	CaptureRequest.ControlAePrecaptureTrigger is START, sequence done	FLASH_REQUIRED	Converged but too dark w/o flash after a precapture sequence, transient states are skipped by camera device.
Any state	CaptureRequest.ControlAePrecaptureTrigger is START, sequence done	CONVERGED	Converged after a precapture sequence, transient states are skipped by camera device.
CONVERGED	Camera device finished AE scan	FLASH_REQUIRED	Converged but too dark w/o flash after a new scan, transient states are skipped by camera device.
FLASH_REQUIRED	Camera device finished AE scan	CONVERGED	Converged after a new scan, transient states are skipped by camera device.

Current state of the auto-exposure (AE) algorithm.

Switching between or enabling AE modes (CaptureRequest.ControlAeMode) always resets the AE state to INACTIVE. Similarly, switching between CaptureRequest.ControlMode, or CaptureRequest.ControlSceneMode if CaptureRequest.ControlMode == USE_SCENE_MODE resets all the algorithm states to INACTIVE.

The camera device can do several state transitions between two results, if it is allowed by the state transition table. For example: INACTIVE may never actually be seen in a result.

The state in the result is the state for this image (in sync with this image): if AE state becomes CONVERGED, then the image data associated with this result should be good to use.

Below are state transition tables for different AE modes.

When CaptureRequest.ControlAeMode is AE_MODE_ON_*:

For the above table, the camera device may skip reporting any state changes that happen without application intervention (i.e. mode switch, trigger, locking). Any state that can be skipped in that manner is called a transient state.

For example, for above AE modes (AE_MODE_ON_*), in addition to the state transitions listed in above table, it is also legal for the camera device to skip one or more transient states between two results. See below table for examples:

Possible values:

• CameraMetadata.CONTROL_AE_STATE_INACTIVE
• CameraMetadata.CONTROL_AE_STATE_SEARCHING
• CameraMetadata.CONTROL_AE_STATE_CONVERGED
• CameraMetadata.CONTROL_AE_STATE_LOCKED
• CameraMetadata.CONTROL_AE_STATE_FLASH_REQUIRED
• CameraMetadata.CONTROL_AE_STATE_PRECAPTURE

Optional - This value may be null on some devices.

Limited capability - Present on all camera devices that report being at least CameraMetadata.INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED devices in the CameraCharacteristics.InfoSupportedHardwareLevel key

[Android Documentation]