[英]iOS Camera Video Live Preview Is Offset To Picture Taken
我正在使用相机。
摄像机向用户呈现实时供稿,并且当他们单击图像时,图像就会创建并传递给用户。
问题在于图像被设计为移至最高位置,该位置高于实时预览显示的位置。
您知道如何调整摄像机的帧,以使实时视频源的顶部与他们要拍摄的图片的顶部相匹配吗?
我以为可以这样做,但事实并非如此。 这是我当前的相机框架代码:
//Add the device to the session, get the video feed it produces and add it to the video feed layer
func initSessionFeed()
{
_session = AVCaptureSession()
_session.sessionPreset = AVCaptureSessionPresetPhoto
updateVideoFeed()
_videoPreviewLayer = AVCaptureVideoPreviewLayer(session: _session)
_videoPreviewLayer.frame = CGRectMake(0,0, self.frame.width, self.frame.width) //the live footage IN the video feed view
_videoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
self.layer.addSublayer(_videoPreviewLayer)//add the footage from the device to the video feed layer
}
func initOutputCapture()
{
//set up output settings
_stillImageOutput = AVCaptureStillImageOutput()
var outputSettings:Dictionary = [AVVideoCodecJPEG:AVVideoCodecKey]
_stillImageOutput.outputSettings = outputSettings
_session.addOutput(_stillImageOutput)
_session.startRunning()
}
func configureDevice()
{
if _currentDevice != nil
{
_currentDevice.lockForConfiguration(nil)
_currentDevice.focusMode = .Locked
_currentDevice.unlockForConfiguration()
}
}
func captureImage(callback:(iImage)->Void)
{
if(_captureInProcess == true)
{
return
}
_captureInProcess = true
var videoConnection:AVCaptureConnection!
for connection in _stillImageOutput.connections
{
for port in (connection as AVCaptureConnection).inputPorts
{
if (port as AVCaptureInputPort).mediaType == AVMediaTypeVideo
{
videoConnection = connection as AVCaptureConnection
break;
}
if videoConnection != nil
{
break;
}
}
}
if videoConnection != nil
{
_stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection)
{
(imageSampleBuffer : CMSampleBuffer!, _) in
let imageDataJpeg = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageSampleBuffer)
var pickedImage = UIImage(data: imageDataJpeg, scale: 1)
UIGraphicsBeginImageContextWithOptions(pickedImage.size, false, pickedImage.scale)
pickedImage.drawInRect(CGRectMake(0, 0, pickedImage.size.width, pickedImage.size.height))
pickedImage = UIGraphicsGetImageFromCurrentImageContext() //this returns a normalized image
if(self._currentDevice == self._frontCamera)
{
var context:CGContextRef = UIGraphicsGetCurrentContext()
pickedImage = UIImage(CGImage: pickedImage.CGImage, scale: 1.0, orientation: .UpMirrored)
pickedImage.drawInRect(CGRectMake(0, 0, pickedImage.size.width, pickedImage.size.height))
pickedImage = UIGraphicsGetImageFromCurrentImageContext()
}
UIGraphicsEndImageContext()
var image:iImage = iImage(uiimage: pickedImage)
self._captureInProcess = false
callback(image)
}
}
}
如果我说通过提高y值来调整AVCaptureVideoPreviewLayer的名气,我只会得到显示偏移量的黑条。 我非常好奇为什么视频帧的顶部与我的输出图像不匹配。
我“修剪”了照相机,使其成为一个完美的正方形,但是为什么实时摄影机供稿的顶部不是实际的顶部(因为图像默认显示在照相机供稿的更高位置)
更新:
这是我在说的前后屏幕截图
之前: 之前的图像这是实时供稿显示的内容
之后: 图像之后这是用户单击拍照后生成的图像
代替
_videoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
你可以尝试
_videoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspect
通常,预览和捕获的图像的宽度和高度必须匹配。 您可能需要对预览或最终图像(或两者)进行更多的“裁剪”。
我遇到了同样的问题,此代码对我有用:
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
var bounds = UIScreen.mainScreen().bounds
previewLayer?.bounds = bounds
previewLayer?.videoGravity = AVLayerVideoGravityResize
previewLayer?.position = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds))
self.cameraPreview.layer.addSublayer(previewLayer)
captureSession.startRunning()
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.