iphone 上的相机应用程序的 AVFoundation AVCaptureDevice 设置是什么？

Question

我想知道 iPhone 上相机应用的 AVCaptureDevice 设置是什么。特别是 AVCaptureExposureMode、AVCaptureFocusMode 和 AVCaptureWhiteBalanceMode。我正在尝试制作自定义相机，但由于某种原因，我无法让照片的光线在对焦时正确改变。我为我的相机设置了 ExposurePointOfInterest 和 FocusPointOfInterest，但由于某种原因，似乎相机对焦正确，但照明没有聚焦在我点击的地方。当我点击黑暗区域时，它不会像相机应用程序中那样变亮。是否有一些我忘记设置的设置？这是我的相机对焦代码。

CGPoint touchPoint = [gesture locationInView:collectView];
float focus_x = touchPoint.x / collectView.frame.size.width;
float focus_y = touchPoint.y / collectView.frame.size.height;
NSError *tError = nil;
NSLog(@"previous: %.2f, %.2f", backCamera.focusPointOfInterest.x, backCamera.focusPointOfInterest.y);
if (isFrontCamera) {
    focus_x = collectView.frame.size.width - focus_x; //the view is mirrored for the front camera
    if ([frontCamera lockForConfiguration:&tError]) {
        if ([frontCamera isExposurePointOfInterestSupported]) {
            [frontCamera setExposurePointOfInterest:CGPointMake(focus_x, focus_y)];
            if ([frontCamera isExposureModeSupported:AVCaptureExposureModeAutoExpose]) {
                [frontCamera setExposureMode:AVCaptureExposureModeAutoExpose];
            }
        }
        if ([frontCamera isFocusPointOfInterestSupported]) {
            [frontCamera setFocusPointOfInterest:CGPointMake(focus_x, focus_y)];
            if ([frontCamera isExposureModeSupported:AVCaptureExposureModeAutoExpose]) {
                [frontCamera setExposureMode:AVCaptureExposureModeAutoExpose];
            }
        }
        if ([frontCamera isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance]) {
            [frontCamera setWhiteBalanceMode:AVCaptureWhiteBalanceModeAutoWhiteBalance];
        }
        [frontCamera unlockForConfiguration];
    }
    else {
        NSLog(@"Couldn't change focus point:%@",tError);
    }
}
else {
    if ([backCamera lockForConfiguration:&tError]) {
        if ([backCamera isExposurePointOfInterestSupported]) {
            [backCamera setExposurePointOfInterest:CGPointMake(focus_x, focus_y)];
            if ([backCamera isExposureModeSupported:AVCaptureExposureModeAutoExpose]) {
                [backCamera setExposureMode:AVCaptureExposureModeAutoExpose];
            }
        }
        if ([backCamera isFocusPointOfInterestSupported]) {
            [backCamera setFocusPointOfInterest:CGPointMake(focus_x, focus_y)];
            if ([backCamera isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
                [backCamera setFocusMode:AVCaptureFocusModeAutoFocus];
            }
        }
        if ([backCamera isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance]) {
            [backCamera setWhiteBalanceMode:AVCaptureWhiteBalanceModeAutoWhiteBalance];
        }
        [backCamera unlockForConfiguration];
    }
    else {
        NSLog(@"Couldn't change focus point:%@",tError);
    }
}

Answer 1

This document 里面有很多东西，会部分回答你的问题。

希望这会有所帮助，因为我们无法确定相机应用程序的每个属性的值。