Add auto-white balance locking to the Camera API.
Adds a new camera parameter for locking auto-white balance to its
current value. Also adds a function for checking if auto-white balance
lock is supported by the current platform. Lock semantics match that
of the auto-exposure lock.
Hidden for now.
Change-Id: Id59339a4be84d55c1b0b8473d765b6aa765999b2
diff --git a/include/camera/CameraParameters.h b/include/camera/CameraParameters.h
index 513239f..dc5fc84 100644
--- a/include/camera/CameraParameters.h
+++ b/include/camera/CameraParameters.h
@@ -309,25 +309,54 @@
// 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.
+ // 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 values. If auto-exposure is already locked,
+ // setting this to true again has no effect (the driver will not
+ // recalculate exposure values). 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 call to
+ // startPreview may result in severely 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 state of the auto-white balance lock. "true" means that
+ // auto-white balance is locked to its current value and will not
+ // change. "false" means the auto-white balance routine is free to
+ // change white balance values. If auto-white balance is already
+ // locked, setting this to true again has no effect (the driver
+ // will not recalculate white balance values). 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 white balance values from the previous lock. In conjunction
+ // with exposure compensation, this allows for capturing
+ // multi-exposure brackets with fixed white balance. Locking
+ // auto-white balance after open but before the first call to
+ // startPreview may result in severely incorrect color. The
+ // driver may independently enable the AWB 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 AWB without restarting
+ // preview.
+ static const char KEY_AUTO_WHITEBALANCE_LOCK[];
+ // Whether locking the auto-white balance is supported. "true"
+ // means it is, and "false" or this key not existing means it is
+ // not supported.
+ static const char KEY_AUTO_WHITEBALANCE_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.