Question

我正在使用带AVFoundation的前置摄像头开发镜像应用程序。我已完成将相机屏幕显示到UIView。但是我如何调整亮度？代码是这样的：

-(void)AVCaptureInit {   
    mCameraAVSession = [[AVCaptureSession alloc] init];
    [mCameraAVSession setSessionPreset:AVCaptureSessionPresetPhoto];

    mCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for (AVCaptureDevice *device in devices) {
        if ([device position] == AVCaptureDevicePositionFront) {
            mCaptureDevice = device;
            break;
        }
    }

    //if ([mCaptureDevice hasTorch] && [mCaptureDevice hasFlash])
    {
        [mCaptureDevice lockForConfiguration:nil];
        // [mCaptureDevice setTorchMode:AVCaptureTorchModeOn];
        //[mCaptureDevice setExposurePointOfInterest:0.5];

        [mCaptureDevice setExposureMode:AVCaptureExposureModeManual];

        [mCaptureDevice unlockForConfiguration];
    }



    // [inputDevice setTorchModeOnWithLevel:0.5 error:NULL];

    NSError *error;
    AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:mCaptureDevice error:&error];

    if ([mCameraAVSession canAddInput:deviceInput]) {
        [mCameraAVSession addInput:deviceInput];
    }

    AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:mCameraAVSession];
    [previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    CALayer *rootLayer = [mCameraView layer];
    [rootLayer setMasksToBounds:YES];
    CGRect frame = mCaptureView.frame;
    [previewLayer setFrame:frame];
    [rootLayer insertSublayer:previewLayer atIndex:0];

    mCameraImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [mCameraImageOutput setOutputSettings:outputSettings];


    [mCameraAVSession addOutput:mCameraImageOutput];

    [mCameraAVSession startRunning];

    [self setVisible:mCaptureImage IsVisible:NO];
}

任何人都说可以通过曝光调节亮度，但我不知道如何使用它。特别是，我想在捏时调整相机亮度。

Answer 1

WWDC2014 Session 508和Manual AVCam Sample Code中描述了手动（自定义）相机曝光。

通过运行AVCamManual，点击Exposure＆gt;尝试自己。自定义并拖动“曝光”滑块。

在代码中，归结为将AVCaptureDevice exposureMode设置为AVCaptureExposureModeCustom并调用

if ([mCaptureDevice lockForConfiguration:&error]) {
    [mCaptureDevice setExposureModeCustomWithDuration:exposureDuration ISO:AVCaptureISOCurrent completionHandler:nil];
    [mCaptureDevice unlockForConfiguration];
}

P.S。我不知道你从哪里获得AVCaptureExposureModeManual。它似乎不存在。

AVCaptureSession亮度

1 个答案: