AVCaptureDevice的低光增强属性无法启用。我正在使用iOS 6的iPhone 5上测试这个。这是代码:
// finds a device that supports the video media type
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSArray *allDevices = [AVCaptureDevice devices];
for (AVCaptureDevice *currentDevice in allDevices) {
if (currentDevice.position == AVCaptureDevicePositionBack) {
device = currentDevice;
}
}
NSError *deviceError = nil;
if (device.isFlashAvailable){
[device lockForConfiguration:&deviceError];
device.flashMode = AVCaptureFlashModeAuto;
[device unlockForConfiguration];
}
if ([device respondsToSelector:@selector(isLowLightBoostSupported)]) {
if ([device lockForConfiguration:nil]) {
if (device.isLowLightBoostSupported)
device.automaticallyEnablesLowLightBoostWhenAvailable = YES;
[device unlockForConfiguration];
}
}
if ([device isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure]) {
[device lockForConfiguration:&deviceError];
device.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
// CODE FOR device.exposurePointOfInterest determined from wherever the face is based off of the faceScan method
[device unlockForConfiguration];
}
AVCaptureDeviceInput *newVideoInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&deviceError];
AVCaptureStillImageOutput *newStillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
AVVideoCodecJPEG, AVVideoCodecKey,
nil];
[newStillImageOutput setOutputSettings:outputSettings];
self.sess = [[AVCaptureSession alloc] init];
if ([self.sess canAddInput:newVideoInput]) {
[self.sess addInput:newVideoInput];
}
if ([self.sess canAddOutput:newStillImageOutput]) {
[self.sess addOutput:newStillImageOutput];
}
self.stillImageOutput = newStillImageOutput;
if (device.lowLightBoostEnabled) {
NSLog(@"ENABLED");
}
// register as an observer of changes to lowLightBoostEnabled
[device addObserver:self forKeyPath:@"automaticallyEnablesLowLightBoostWhenAvailable" options:(NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld) context:NULL];
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqual:@"lowLightBoostEnabled"]) {
NSLog(@"lowLightBoostEnabled changed");
NSNumber *boostIsActiveValue = [change objectForKey:NSKeyValueChangeNewKey];
BOOL boostIsActive = boostIsActiveValue.boolValue;
NSLog(@"is low light boost currently active: %d", boostIsActive);
}
}
任何人都可以给我任何帮助吗?我看过网上但没有找到非常确定的结果。我很感激能得到的所有帮助。
答案 0 :(得分:0)
根据文档(以及头文件),你需要lockForConfiguration:
if ([[self backFacingCamera] respondsToSelector:@selector(isLowLightBoostSupported)]) {
if ([[self backFacingCamera] lockForConfiguration:nil]) {
if ([self backFacingCamera].isLowLightBoostSupported)
[self backFacingCamera].automaticallyEnablesLowLightBoostWhenAvailable = YES;
[[self backFacingCamera] unlockForConfiguration];
}
}
此外,isLowLightBoostEnabled会告诉您实际上是否正在提升低光,而不是它是否可以提升。这是isLowLightBoostSupported选择器,如上所述(仅iOS 6设备响应)。