ios - AVFoundation、AVCaptureMetadataOutput 截屏

Question

我正在使用 AVCaptureMetadataOutput 以使用 iOS QRCode、条形码扫描功能。这很好用，我得到了通过 AVCaptureMetadataOutput 委托(delegate)方法扫描的结果

-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{

但我不知道如何用我在这个委托(delegate)中的数据捕获扫描的二维码、条形码的图像。

Answer 1

我有 captured image同时scanning QRCode像这样:

1) 首先添加AVCaptureStillImageOutput's的属性

@property (strong, nonatomic) AVCaptureStillImageOutput *stillImageOutput;

2) 在AVCaptureSession中添加 session 预设初始化之后

[self.session setSessionPreset:AVCaptureSessionPreset640x480];

3)现在添加AVCaptureStillImageOutput's作为 AVCaptureSession 中的输出

// Prepare an output for snapshotting
self.stillImageOutput = [AVCaptureStillImageOutput new];
[self.session addOutput:self.stillImageOutput];
self.stillImageOutput.outputSettings = @{AVVideoCodecKey: AVVideoCodecJPEG};

4) 添加以下代码以在委托(delegate)方法中捕获扫描图像captureOutput:didOutputMetadataObjects:fromConnection:connection

 __block UIImage *scannedImg = nil;
// Take an image of the face and pass to CoreImage for detection
AVCaptureConnection *stillConnection = [self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo];
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:stillConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
    if(error) {
        NSLog(@"There was a problem");
        return;
    }

    NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];

    scannedImg = [UIImage imageWithData:jpegData];
    NSLog(@"scannedImg : %@",scannedImg);
}];

引用使用CodeScanViewController

就是这样@Enjoy