目标：实现一个最简单的视频流
AVCaptureSession 会话管理者
_session = [[AVCaptureSession alloc] init];
视频输入设备
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *input = [[AVCaptureDeviceInput alloc] initWithDevice:device error:nil];
if ([_session canAddInput:input]) {
[_session addInput:input];
}
视频输出设备
AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
if ([_session canAddOutput:output]) {
[_session addOutput:output];
}
识别类型，代理
output.metadataObjectTypes = output.availableMetadataObjectTypes;
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
PreviewLayer
_preview = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_session];
_preview.frame = self.view.bounds;
[self.view.layer insertSublayer:_preview atIndex:0];
回调方法
- (void)captureOutput:(AVCaptureOutput *)output didOutputMetadataObjects:(NSArray<__kindof AVMetadataObject *> *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
}
