重要提示：如果我使用：session.sessionPreset = AVCaptureSessionPresetHigh;我的预览图像没有拉伸!!如果我将照片保存到设备UI
ImageWriteToSavedPhotosAlbum(image,nil,nil);图像是正常的,仅在预览中被拉伸.
我正在使用AVFoundation捕捉照片.
session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetHigh;
CALayer *viewLayer = vImagePreview.layer;
NSLog(@"viewLayer = %@",viewLayer);
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = vImagePreview.bounds;
[vImagePreview.layer addSublayer:captureVideoPreviewLayer];
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
// Handle the error appropriately.
NSLog(@"ERROR: trying to open camera: %@",error);
}
[session addInput:input];
stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG,AVVideoCodecKey,nil];
[stillImageOutput setOutputSettings:outputSettings];
[session addOutput:stillImageOutput];
我将sessionPreset设置为AVCaptureSessionPresetPhoto：
session.sessionPreset = AVCaptureSessionPresetPhoto;
我的捕获方法：
-(void)captureNow {
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in stillImageOutput.connections)
{
for (AVCaptureInputPort *port in [connection inputPorts])
{
if ([[port mediaType] isEqual:AVMediaTypeVideo] )
{
videoConnection = connection;
break;
}
}
if (videoConnection)
{
break;
}
}
NSLog(@"about to request a capture from: %@",stillImageOutput);
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer,NSError *error)
{
CFDictionaryRef exifAttachments = CMGetAttachment( imageSampleBuffer,kCGImagePropertyExifDictionary,NULL);
if (exifAttachments)
{
// Do something with the attachments.
NSLog(@"attachements: %@",exifAttachments);
} else {
NSLog(@"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
NSLog(@"%@",NSStringFromCGSize(image.size));
[self animateUpTheImageWithImage:image];
}];
}
我在哪里添加拍摄的照片预览：
- (void) animateUpTheImageWithImage:(UIImage*)theImage{
UIView* preview = [[UIView alloc] initWithFrame:CGRectMake(0,self.frame.size.width,self.frame.size.height/*426*/)];
CALayer *previewLayer = preview.layer;
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.frame = previewLayer.frame;
[previewLayer addSublayer:captureVideoPreviewLayer];
captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspect;
[self addSubview:preview];
}
结果是我拍摄的图像被拉伸了！
解决方法
所以我解决了我的问题.这是我现在使用的代码,它工作正常：
session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetHigh;
captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
captureVideoPreviewLayer.frame = vImagePreview.bounds;
[vImagePreview.layer addSublayer:captureVideoPreviewLayer];
device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
…
stillImageOutput = [[AVCaptureStillImageOutput alloc] init]; NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG,nil]; [stillImageOutput setOutputSettings:outputSettings]; [session addOutput:stillImageOutput]; capturedImageView = [[UIView alloc]initWithFrame:CGRectMake(0,self.screenWidth,self.screenHeight)]; [self addSubview:capturedImageView];
重要的输出imagaView：
vImage = [[UIImageView alloc]initWithFrame:CGRectMake(0,self.screenHeight)];
[capturedImageView addSubview:vImage];
vImage.autoresizingMask = (UIViewAutoresizingFlexibleBottomMargin|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleRightMargin|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleWidth);
vImage.contentMode = UIViewContentModeScaleAspectFill;
vImage.image = theImage;
一些额外的信息：
相机图层必须是全屏(您可以修改其y坐标,但宽度和高度必须是完整尺寸),并且outputImageView也必须是.
我希望这些对某些人来说也是有用的信息.
