iphone - AVFoundation对焦模式iPad2

我正在尝试在iPad2中测试的应用程序中使自动对焦工作。我的问题是，当我调用诸如isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus之类的检查方法时，它总是返回NO。但是，我可以点击以聚焦设备中的其他相机应用程序

devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
for (AVCaptureDevice *tempDevice in devices) {
    [tempDevice lockForConfiguration:nil];
    if ([tempDevice isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
        NSLog(@"Here");
    }

    if ([tempDevice isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus]) {
        NSLog(@"Here");
    }

    if ([tempDevice isFocusModeSupported:AVCaptureFocusModeLocked]) {
        NSLog(@"Here");
    }

    if ([tempDevice isFocusPointOfInterestSupported]) {
        NSLog(@"Here");
    }
    [tempDevice unlockForConfiguration];
}

最佳答案

我只是今晚在调查。从我收集到的信息来看，iPad 2不会对焦-会进行曝光调整-因此在默认的“相机”应用中，点击屏幕会在出现点击的地方显示一个矩形，指示要进行白点调整的区域。

也许我错了，但这就是我所发现的，并且似乎已通过您的API（isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus返回NO）测试得到了证实。

iPad 2中的相机非常薄弱-尤其是前置相机。令苹果感到惊讶的是我。

更新：这是来自更新的Apple的AVCamDemo示例的代码，该示例处理焦点+曝光+白点。我不认为这是在AVCam示例中。 AVCamDemo可能只能从开发人员中心下载WWDC代码.dmg软件包，而不能从Web上一次下载。
 在我的iPad 2上，从未调用过曝光代码。
//-来自AVCamDemo：

- (BOOL) hasExposure
 {
AVCaptureDevice *device = [[self videoInput] device];

return  [device isExposureModeSupported:AVCaptureExposureModeLocked] ||
        [device isExposureModeSupported:AVCaptureExposureModeAutoExpose] ||
        [device isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure];
}

- (AVCaptureExposureMode) exposureMode
{
return [[[self videoInput] device] exposureMode];
}

- (void) setExposureMode:(AVCaptureExposureMode)exposureMode
{
if (exposureMode == 1) {
    exposureMode = 2;
}
AVCaptureDevice *device = [[self videoInput] device];
if ([device isExposureModeSupported:exposureMode] && [device exposureMode] != exposureMode) {
    NSError *error;
    if ([device lockForConfiguration:&error]) {
        [device setExposureMode:exposureMode];
        [device unlockForConfiguration];
    } else {
        id delegate = [self delegate];
        if ([delegate respondsToSelector:@selector(acquiringDeviceLockFailedWithError:)]) {
            [delegate acquiringDeviceLockFailedWithError:error];
        }
    }
}
}

- (BOOL) hasWhiteBalance
{
AVCaptureDevice *device = [[self videoInput] device];

return  [device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeLocked] ||
        [device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance];
}

- (AVCaptureWhiteBalanceMode) whiteBalanceMode
{
return [[[self videoInput] device] whiteBalanceMode];
}

- (void) setWhiteBalanceMode:(AVCaptureWhiteBalanceMode)whiteBalanceMode
{
if (whiteBalanceMode == 1) {
    whiteBalanceMode = 2;
}
AVCaptureDevice *device = [[self videoInput] device];
if ([device isWhiteBalanceModeSupported:whiteBalanceMode] && [device whiteBalanceMode] != whiteBalanceMode) {
    NSError *error;
    if ([device lockForConfiguration:&error]) {
        [device setWhiteBalanceMode:whiteBalanceMode];
        [device unlockForConfiguration];
    } else {
        id delegate = [self delegate];
        if ([delegate respondsToSelector:@selector(acquiringDeviceLockFailedWithError:)]) {
            [delegate acquiringDeviceLockFailedWithError:error];
        }
    }
}
}

- (BOOL) hasFocus
{
AVCaptureDevice *device = [[self videoInput] device];

return  [device isFocusModeSupported:AVCaptureFocusModeLocked] ||
        [device isFocusModeSupported:AVCaptureFocusModeAutoFocus] ||
        [device isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus];
}

- (AVCaptureFocusMode) focusMode
{
return [[[self videoInput] device] focusMode];
}

- (void) setFocusMode:(AVCaptureFocusMode)focusMode
{


AVCaptureDevice *device = [[self videoInput] device];
if ([device isFocusModeSupported:focusMode] && [device focusMode] != focusMode) {
    NSError *error;

      printf(" setFocusMode    \n");
    if ([device lockForConfiguration:&error]) {
        [device setFocusMode:focusMode];
        [device unlockForConfiguration];
    } else {
        id delegate = [self delegate];
        if ([delegate respondsToSelector:@selector(acquiringDeviceLockFailedWithError:)]) {
            [delegate acquiringDeviceLockFailedWithError:error];
        }
    }
}
}

关于iphone - AVFoundation对焦模式iPad2，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/9107773/