我需要创建一个具有视频处理功能的应用程序。
我的要求是必须使用相机预览层创建3个视图。第一个视图应显示原始捕获视频，第二个视图应显示原始捕获视频的翻转，最后一个视图应显示原始捕获视频的反色。
我开始开发此要求。
首先，我创建了3个视图和Camera Capture所需的属性
@IBOutlet weak var captureView: UIView!
@IBOutlet weak var flipView: UIView!
@IBOutlet weak var InvertView: UIView!
//Camera Capture requiered properties
var videoDataOutput: AVCaptureVideoDataOutput!
var videoDataOutputQueue: DispatchQueue!
var previewLayer:AVCaptureVideoPreviewLayer!
var captureDevice : AVCaptureDevice!
let session = AVCaptureSession()
var replicationLayer: CAReplicatorLayer!
现在，我调用AVCaptureVideoDataOutputSampleBufferDelegate来启动摄像机会话。
extension ViewController: AVCaptureVideoDataOutputSampleBufferDelegate{
func setupAVCapture(){
session.sessionPreset = AVCaptureSessionPreset640x480
guard let device = AVCaptureDevice
.defaultDevice(withDeviceType: .builtInWideAngleCamera,
mediaType: AVMediaTypeVideo,
position: .back) else{
return
}
captureDevice = device
beginSession()
}
func beginSession(){
var err : NSError? = nil
var deviceInput:AVCaptureDeviceInput?
do {
deviceInput = try AVCaptureDeviceInput(device: captureDevice)
} catch let error as NSError {
err = error
deviceInput = nil
}
if err != nil {
print("error: \(err?.localizedDescription)");
}
if self.session.canAddInput(deviceInput){
self.session.addInput(deviceInput);
}
videoDataOutput = AVCaptureVideoDataOutput()
videoDataOutput.alwaysDiscardsLateVideoFrames=true
videoDataOutputQueue = DispatchQueue(label: "VideoDataOutputQueue")
videoDataOutput.setSampleBufferDelegate(self, queue:self.videoDataOutputQueue)
if session.canAddOutput(self.videoDataOutput){
session.addOutput(self.videoDataOutput)
}
videoDataOutput.connection(withMediaType: AVMediaTypeVideo).isEnabled = true
self.previewLayer = AVCaptureVideoPreviewLayer(session: self.session)
self.previewLayer.frame = self.captureView.bounds
self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspect
self.replicationLayer = CAReplicatorLayer()
self.replicationLayer.frame = self.captureView.bounds
self.replicationLayer.instanceCount = 1 //
self.replicationLayer.instanceTransform = CATransform3DMakeTranslation(0.0, self.captureView.bounds.size.height / 1, 0.0)
self.replicationLayer.addSublayer(self.previewLayer)
self.captureView.layer.addSublayer(self.replicationLayer)
self.flipView.layer.addSublayer(self.replicationLayer)
self.InvertView.layer.addSublayer(self.replicationLayer)
session.startRunning()
}
func captureOutput(_ captureOutput: AVCaptureOutput!,
didOutputSampleBuffer sampleBuffer: CMSampleBuffer!,
from connection: AVCaptureConnection!) {
// do stuff here
}
// clean up AVCapture
func stopCamera(){
session.stopRunning()
}
}
如果我将self.replicationLayer.instanceCount指定为3，则得到这样的输出。
因此，指导我如何以3种不同的视图显示捕获的视频。并提出一些将原始捕获视频转换为翻转和反转颜色的想法。提前致谢。
最佳答案
最后，我在JohnnySlagle/Multiple-Camera-Feeds代码的帮助下找到了答案。
我创建了三个视图，例如
@property (weak, nonatomic) IBOutlet UIView *video1;
@property (weak, nonatomic) IBOutlet UIView *video2;
@property (weak, nonatomic) IBOutlet UIView *video3;
然后稍微改变setUpFeedViews
- (void)setupFeedViews {
NSUInteger numberOfFeedViews = 3;
for (NSUInteger i = 0; i < numberOfFeedViews; i++) {
VideoFeedView *feedView = [self setupFeedViewWithFrame:CGRectMake(0, 0, self.video1.frame.size.width, self.video1.frame.size.height)];
feedView.tag = i+1;
switch (i) {
case 0:
[self.video1 addSubview:feedView];
break;
case 1:
[self.video2 addSubview:feedView];
break;
case 2:
[self.video3 addSubview:feedView];
break;
default:
break;
}
[self.feedViews addObject:feedView];
}
}
然后在AVCaptureVideoDataOutputSampleBufferDelegate中应用过滤器
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
CMFormatDescriptionRef formatDesc = CMSampleBufferGetFormatDescription(sampleBuffer);
// update the video dimensions information
_currentVideoDimensions = CMVideoFormatDescriptionGetDimensions(formatDesc);
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CIImage *sourceImage = [CIImage imageWithCVPixelBuffer:(CVPixelBufferRef)imageBuffer options:nil];
CGRect sourceExtent = sourceImage.extent;
CGFloat sourceAspect = sourceExtent.size.width / sourceExtent.size.height;
for (VideoFeedView *feedView in self.feedViews) {
CGFloat previewAspect = feedView.viewBounds.size.width / feedView.viewBounds.size.height;
// we want to maintain the aspect radio of the screen size, so we clip the video image
CGRect drawRect = sourceExtent;
if (sourceAspect > previewAspect) {
// use full height of the video image, and center crop the width
drawRect.origin.x += (drawRect.size.width - drawRect.size.height * previewAspect) / 2.0;
drawRect.size.width = drawRect.size.height * previewAspect;
} else {
// use full width of the video image, and center crop the height
drawRect.origin.y += (drawRect.size.height - drawRect.size.width / previewAspect) / 2.0;
drawRect.size.height = drawRect.size.width / previewAspect;
}
[feedView bindDrawable];
if (_eaglContext != [EAGLContext currentContext]) {
[EAGLContext setCurrentContext:_eaglContext];
}
// clear eagl view to grey
glClearColor(0.5, 0.5, 0.5, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
// set the blend mode to "source over" so that CI will use that
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// This is necessary for non-power-of-two textures
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
if (feedView.tag == 1) {
if (sourceImage) {
[_ciContext drawImage:sourceImage inRect:feedView.viewBounds fromRect:drawRect];
}
} else if (feedView.tag == 2) {
sourceImage = [sourceImage imageByApplyingTransform:CGAffineTransformMakeScale(1, -1)];
sourceImage = [sourceImage imageByApplyingTransform:CGAffineTransformMakeTranslation(0, sourceExtent.size.height)];
if (sourceImage) {
[_ciContext drawImage:sourceImage inRect:feedView.viewBounds fromRect:drawRect];
}
} else {
CIFilter *effectFilter = [CIFilter filterWithName:@"CIColorInvert"];
[effectFilter setValue:sourceImage forKey:kCIInputImageKey];
CIImage *invertImage = [effectFilter outputImage];
if (invertImage) {
[_ciContext drawImage:invertImage inRect:feedView.viewBounds fromRect:drawRect];
}
}
[feedView display];
}
}
而已。成功地满足了我的要求。