我刚刚开始使用Objective-C,我正在尝试创建一个简单的应用程序,它会显示带有模糊效果的摄像机视图.我让Camera输出与AVFoundation框架一起工作.现在,我正在尝试连接核心图像框架,但不知道如何,Apple文档让我感到困惑,在线搜索指南和教程导致没有结果.在此先感谢您的帮助.
#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
@interface ViewController ()
@property (strong,nonatomic) CIContext *context;
@end
@implementation ViewController
AVCaptureSession *session;
AVCaptureStillImageOutput *stillImageOutput;
-(CIContext *)context
{
if(!_context)
{
_context = [CIContext contextWithOptions:nil];
}
return _context;
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view,typically from a nib.
}
-(void)viewWillAppear:(BOOL)animated{
session = [[AVCaptureSession alloc] init];
[session setSessionPreset:AVCaptureSessionPresetPhoto];
AVCaptureDevice *inputDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
NSError *error;
AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:inputDevice error:&error];
if ([session canAddInput:deviceInput]) {
[session addInput:deviceInput];
}
AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
CALayer *rootLayer = [[self view] layer];
[rootLayer setMasksToBounds:YES];
CGRect frame = self.imageView.frame;
[previewLayer setFrame:frame];
[previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
[rootLayer insertSublayer:previewLayer atIndex:0];
stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[stillImageOutput setOutputSettings:outputSettings];
[session addOutput:stillImageOutput];
[session startRunning];
}
@end
解决方法
这是让你入门的东西.这是以下链接的代码的更新版本.
https://gist.github.com/eladb/9662102
https://gist.github.com/eladb/9662102
诀窍是使用AVCaptureVideoDataOutputSampleBufferDelegate.
使用此委托,您可以使用imageWithCVPixelBuffer从相机缓冲区构建CIImage.
现在虽然我想弄清楚如何减少滞后.我会尽快更新.
更新：延迟现在很小,并且在某些影响上无法察觉.不幸的是,模糊似乎是最慢的之一.您可能想要查看vImage.
#import "ViewController.h"
#import <CoreImage/CoreImage.h>
#import <AVFoundation/AVFoundation.h>
@interface ViewController () {
}
@property (strong,nonatomic) CIContext *coreImageContext;
@property (strong,nonatomic) AVCaptureSession *cameraSession;
@property (strong,nonatomic) AVCaptureVideoDataOutput *videoOutput;
@property (strong,nonatomic) UIView *blurCameraView;
@property (strong,nonatomic) CIFilter *filter;
@property BOOL cameraOpen;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.blurCameraView = [[UIView alloc]initWithFrame:[[UIScreen mainScreen] bounds]];
[self.view addSubview:self.blurCameraView];
//setup filter
self.filter = [CIFilter filterWithName:@"CIGaussianBlur"];
[self.filter setDefaults];
[self.filter setValue:@(3.0f) forKey:@"inputRadius"];
[self setupCamera];
[self openCamera];
// Do any additional setup after loading the view,typically from a nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)setupCamera
{
self.coreImageContext = [CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer : @(YES)}];
// session
self.cameraSession = [[AVCaptureSession alloc] init];
[self.cameraSession setSessionPreset:AVCaptureSessionPresetLow];
[self.cameraSession commitConfiguration];
// input
AVCaptureDevice *shootingCamera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *shootingDevice = [AVCaptureDeviceInput deviceInputWithDevice:shootingCamera error:NULL];
if ([self.cameraSession canAddInput:shootingDevice]) {
[self.cameraSession addInput:shootingDevice];
}
// video output
self.videoOutput = [[AVCaptureVideoDataOutput alloc] init];
self.videoOutput.alwaysDiscardsLateVideoFrames = YES;
[self.videoOutput setSampleBufferDelegate:self queue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH,0)];
if ([self.cameraSession canAddOutput:self.videoOutput]) {
[self.cameraSession addOutput:self.videoOutput];
}
if (self.videoOutput.connections.count > 0) {
AVCaptureConnection *connection = self.videoOutput.connections[0];
connection.videoOrientation = AVCaptureVideoOrientationPortrait;
}
self.cameraOpen = NO;
}
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {
// Get a CMSampleBuffer's Core Video image buffer for the media data
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
// turn buffer into an image we can manipulate
CIImage *result = [CIImage imageWithCVPixelBuffer:imageBuffer];
// filter
[self.filter setValue:result forKey:@"inputImage"];
// render image
CGImageRef blurredImage = [self.coreImageContext createCGImage:self.filter.outputImage fromRect:result.extent];
dispatch_async(dispatch_get_main_queue(),^{
self.blurCameraView.layer.contents = (__bridge id)blurredImage;
CGImageRelease(blurredImage);
});
}
- (void)openCamera {
if (self.cameraOpen) {
return;
}
self.blurCameraView.alpha = 0.0f;
[self.cameraSession startRunning];
[self.view layoutIfNeeded];
[UIView animateWithDuration:3.0f animations:^{
self.blurCameraView.alpha = 1.0f;
}];
self.cameraOpen = YES;
}
