Merge "Add an auto-exposure lock feature to the Camera API." (3723396c) · Commits · e / os / android_frameworks_base

core/java/android/hardware/Camera.java

+77 −0

Original line number	Diff line number	Diff line
		@@ -1179,6 +1179,8 @@ public class Camera {
		private static final String KEY_MAX_EXPOSURE_COMPENSATION = "max-exposure-compensation";
		private static final String KEY_MIN_EXPOSURE_COMPENSATION = "min-exposure-compensation";
		private static final String KEY_EXPOSURE_COMPENSATION_STEP = "exposure-compensation-step";
		private static final String KEY_AUTO_EXPOSURE_LOCK = "auto-exposure-lock";
		private static final String KEY_AUTO_EXPOSURE_LOCK_SUPPORTED = "auto-exposure-lock-supported";
		private static final String KEY_METERING_AREAS = "metering-areas";
		private static final String KEY_MAX_NUM_METERING_AREAS = "max-num-metering-areas";
		private static final String KEY_ZOOM = "zoom";
		@@ -1195,6 +1197,7 @@ public class Camera {
		private static final String SUPPORTED_VALUES_SUFFIX = "-values";

		private static final String TRUE = "true";
		private static final String FALSE = "false";

		// Values for white balance settings.
		public static final String WHITE_BALANCE_AUTO = "auto";
		@@ -2462,6 +2465,80 @@ public class Camera {
		return getFloat(KEY_EXPOSURE_COMPENSATION_STEP, 0);
		}

		/**
		* Sets the auto-exposure lock state. Applications should check
		* {@link #isAutoExposureLockSupported} before using this method.
		*
		* If set to true, the camera auto-exposure routine will pause until the
		* lock is set to false. Exposure compensation settings changes will
		* still take effect while auto-exposure is locked. Stopping preview
		* with {@link #stopPreview()}, or triggering still image capture with
		* {@link #takePicture(Camera.ShutterCallback, Camera.PictureCallback,
		* Camera.PictureCallback)}, will automatically set the lock to
		* false. However, the lock can be re-enabled before preview is
		* re-started to keep the same AE parameters. Exposure compensation, in
		* conjunction with re-enabling the AE lock after each still capture,
		* can be used to capture an exposure-bracketed burst of images, for
		* example. Auto-exposure state, including the lock state, will not be
		* maintained after camera {@link #release()} is called. Locking
		* auto-exposure after {@link #open()} but before the first call to
		* {@link #startPreview()} will not allow the auto-exposure routine to
		* run at all, and may result in severely over- or under-exposed images.
		*
		* The driver may also independently lock auto-exposure after auto-focus
		* completes. If this is undesirable, be sure to always set the
		* auto-exposure lock to false after the
		* {@link AutoFocusCallback#onAutoFocus(boolean, Camera)} callback is
		* received. The {@link #getAutoExposureLock()} method can be used after
		* the callback to determine if the camera has locked auto-exposure
		* independently.
		*
		* @param toggle new state of the auto-exposure lock. True means that
		* auto-exposure is locked, false means that the auto-exposure
		* routine is free to run normally.
		*
		* @hide
		*/
		public void setAutoExposureLock(boolean toggle) {
		set(KEY_AUTO_EXPOSURE_LOCK, toggle ? TRUE : FALSE);
		}

		/**
		* Gets the state of the auto-exposure lock. Applications should check
		* {@link #isAutoExposureLockSupported} before using this method. See
		* {@link #setAutoExposureLock} for details about the lock.
		*
		* @return State of the auto-exposure lock. Returns true if
		* auto-exposure is currently locked, and false otherwise. The
		* auto-exposure lock may be independently enabled by the camera
		* subsystem when auto-focus has completed. This method can be
		* used after the {@link AutoFocusCallback#onAutoFocus(boolean,
		* Camera)} callback to determine if the camera has locked AE.
		*
		* @see #setAutoExposureLock(boolean)
		*
		* @hide
		*/
		public boolean getAutoExposureLock() {
		String str = get(KEY_AUTO_EXPOSURE_LOCK);
		return TRUE.equals(str);
		}

		/**
		* Returns true if auto-exposure locking is supported. Applications
		* should call this before trying to lock auto-exposure. See
		* {@link #setAutoExposureLock} for details about the lock.
		*
		* @return true if auto-exposure lock is supported.
		* @see #setAutoExposureLock(boolean)
		*
		* @hide
		*/
		public boolean isAutoExposureLockSupported() {
		String str = get(KEY_AUTO_EXPOSURE_LOCK_SUPPORTED);
		return TRUE.equals(str);
		}

		/**
		* Gets current zoom value. This also works when smooth zoom is in
		* progress. Applications should check {@link #isZoomSupported} before

include/camera/CameraParameters.h

+20 −0

Original line number	Diff line number	Diff line
		@@ -309,6 +309,25 @@ public:
		// 0.3333, EV is -2.
		// Example value: "0.333333333" or "0.5". Read only.
		static const char KEY_EXPOSURE_COMPENSATION_STEP[];
		// The state of the auto-exposure lock. "true" means that auto-exposure is
		// locked to its current value and will not change. "false" means the
		// auto-exposure routine is free to change exposure settings. Changing
		// exposure compensation settings will still affect the exposure settings
		// while auto-exposure is locked. Stopping preview or taking a still image
		// will release the lock. However, the lock can be re-enabled prior to
		// preview being re-started, to keep the exposure values from the previous
		// lock. In conjunction with exposure compensation, this allows for
		// capturing multi-exposure brackets with known relative exposure
		// values. Locking auto-exposure after open but before the first cal to
		// startPreview may result in severly over- or under-exposed images. The
		// driver may independently enable the AE lock after auto-focus
		// completes. If it does so, this key must have its value updated to reflect
		// the lock's existence. Applications are free to release such a lock, to
		// re-enable AE without restarting preview.
		static const char KEY_AUTO_EXPOSURE_LOCK[];
		// Whether locking the auto-exposure is supported. "true" means it is, and
		// "false" or this key not existing means it is not supported.
		static const char KEY_AUTO_EXPOSURE_LOCK_SUPPORTED[];
		// The maximum number of metering areas supported. This is the maximum
		// length of KEY_METERING_AREAS.
		// Example value: "0" or "2". Read only.
		@@ -428,6 +447,7 @@ public:

		// Value for KEY_ZOOM_SUPPORTED or KEY_SMOOTH_ZOOM_SUPPORTED.
		static const char TRUE[];
		static const char FALSE[];

		// Value for KEY_FOCUS_DISTANCES.
		static const char FOCUS_DISTANCE_INFINITY[];

libs/camera/CameraParameters.cpp

+3 −0

Original line number	Diff line number	Diff line
		@@ -68,6 +68,8 @@ const char CameraParameters::KEY_EXPOSURE_COMPENSATION[] = "exposure-compensatio
		const char CameraParameters::KEY_MAX_EXPOSURE_COMPENSATION[] = "max-exposure-compensation";
		const char CameraParameters::KEY_MIN_EXPOSURE_COMPENSATION[] = "min-exposure-compensation";
		const char CameraParameters::KEY_EXPOSURE_COMPENSATION_STEP[] = "exposure-compensation-step";
		const char CameraParameters::KEY_AUTO_EXPOSURE_LOCK[] = "auto-exposure-lock";
		const char CameraParameters::KEY_AUTO_EXPOSURE_LOCK_SUPPORTED[] = "auto-exposure-lock-supported";
		const char CameraParameters::KEY_MAX_NUM_METERING_AREAS[] = "max-num-metering-areas";
		const char CameraParameters::KEY_METERING_AREAS[] = "metering-areas";
		const char CameraParameters::KEY_ZOOM[] = "zoom";
		@@ -82,6 +84,7 @@ const char CameraParameters::KEY_SUPPORTED_VIDEO_SIZES[] = "video-size-values";
		const char CameraParameters::KEY_PREFERRED_PREVIEW_SIZE_FOR_VIDEO[] = "preferred-preview-size-for-video";

		const char CameraParameters::TRUE[] = "true";
		const char CameraParameters::FALSE[] = "false";
		const char CameraParameters::FOCUS_DISTANCE_INFINITY[] = "Infinity";

		// Values for white balance settings.