Instance Method

setWhiteBalanceModeLocked(with:completionHandler:)

Sets white balance to locked mode with the specified deviceWhiteBalanceGains values.

Declaration

func setWhiteBalanceModeLocked(with whiteBalanceGains: AVCaptureDevice.WhiteBalanceGains, completionHandler handler: ((CMTime) -> Void)? = nil)

Parameters

whiteBalanceGains

The white balance gains to set.

A value of currentWhiteBalanceGains can be used to indicate that the caller does not wish to specify a value for deviceWhiteBalanceGains.

handler

A block to be called when white balance gains have been set to the values specified and whiteBalanceMode property is AVCaptureDevice.WhiteBalanceMode.locked. The block receives a timestamp matching that of the first buffer to which all settings have been applied. The timestamp is synchronized to the device clock, and thus must be converted to the master clock before comparison with the timestamps of buffers delivered via an AVCaptureVideoDataOutput instance.

This parameter may be nil if synchronization is not required.

Discussion

For each channel in the whiteBalanceGains structure, only values between 1.0 and maxWhiteBalanceGain are supported. Gain values are normalized to the minimum channel value to avoid brightness changes (for example, R:2 G:2 B:4 is normalized to R:1 G:1 B:2).

This method throws an invalidArgumentException if any of the whiteBalanceGains fields are set to an unsupported level. This method throws a genericException if called without first obtaining exclusive access to the receiver using lockForConfiguration().

See Also

Managing the White Balance

func isWhiteBalanceModeSupported(AVCaptureDevice.WhiteBalanceMode) -> Bool

Returns a Boolean value that indicates whether the given white balance mode is supported.

var isAdjustingWhiteBalance: Bool

Indicates whether the devise is currently adjusting the white balance.

func chromaticityValues(for: AVCaptureDevice.WhiteBalanceGains) -> AVCaptureDevice.WhiteBalanceChromaticityValues

Converts device-specific white balance RGB gain values to device-independent chromaticity values.

var deviceWhiteBalanceGains: AVCaptureDevice.WhiteBalanceGains

The current device-specific RGB white balance gain values.

var maxWhiteBalanceGain: Float

The maximum supported value to which a channel in the AVCaptureWhiteBalanceGains may be set.

func deviceWhiteBalanceGains(for: AVCaptureDevice.WhiteBalanceChromaticityValues) -> AVCaptureDevice.WhiteBalanceGains

Converts device-independent chromaticity values to device-specific white balance RGB gain values.

func deviceWhiteBalanceGains(for: AVCaptureDevice.WhiteBalanceTemperatureAndTintValues) -> AVCaptureDevice.WhiteBalanceGains

Converts device-independent temperature and tint values to device-specific white balance RGB gain values.

var grayWorldDeviceWhiteBalanceGains: AVCaptureDevice.WhiteBalanceGains

The current device-specific white balance values required for a neutral gray white point.

func temperatureAndTintValues(for: AVCaptureDevice.WhiteBalanceGains) -> AVCaptureDevice.WhiteBalanceTemperatureAndTintValues

Converts device-specific white balance RGB gain values to device-independent temperature and tint values.

var isLockingWhiteBalanceWithCustomDeviceGainsSupported: Bool

A Boolean value indicating whether the device supports locking white balance to specific gain values.

class let currentWhiteBalanceGains: AVCaptureDevice.WhiteBalanceGains

A special constant representing the current white balance setting.

struct AVCaptureDevice.WhiteBalanceGains

Structure containing RGB white balance gain values.

struct AVCaptureDevice.WhiteBalanceChromaticityValues

Structure containing CIE 1931 xy chromaticity values.

struct AVCaptureDevice.WhiteBalanceTemperatureAndTintValues

Structure containing temperature and tint values correlated to a white-balance color.

enum AVCaptureDevice.WhiteBalanceMode

Constants to specify the white balance mode of a capture device.