Video Decoding Methods

Note:

• You have to include DynamsoftCameraEnhancer when using Video Decoding Methods.
• DynamsoftCameraEnhancer provide APIs that help you quickly deploy a camera module and capture video streaming for barcode decoding.
• Through Video Decoding Methods you can control whether to start video streaming barcode decoding and get the barcode results.
• Be sure that your DynamsoftBarcodeReader version is 8.9.0+ and DynamsoftCameraEnhancer is 2.1.0+ when using the methods on this page.

setCameraEnhancer

Bind a DynamsoftCameraEnhancer instance to the Barcode Reader.

- (void)setCameraEnhancer:(DynamsoftCameraEnhancer* _Nonnull)cameraInstance;

Parameters

cameraInstance: An instance of Dynamsoft Camera Enhancer.

Code Snippet

This code snippet displays a complete code on how to add DynamsoftCameraEnhancer to your project and start to use Video Decoding Methods to decode and get barcode results from the video streaming.

• Objective-C
• Swift

1. /* Be sure that you have import the following headers when using video decoding methods */
   #import <DynamsoftBarcodeReader/DynamsoftBarcodeReader.h>
   #import <DynamsoftCameraEnhancer/DynamsoftCameraEnhancer.h>
   /* You have to add DBRTextResultListener to your interface. */
   @interface ViewController ()<DBRTextResultListener>
   @property(nonatomic, strong) DynamsoftBarcodeReader *barcodeReader;
   @property(nonatomic, strong) DynamsoftCameraEnhancer *dce;
   @property(nonatomic, strong) DCECameraView *dceView;
   @end
   @implementation ViewController
   - (void)viewDidLoad{
      [super viewDidLoad];
      [self configurationDBR];
   }
   - (void)configurationDBR{
      _barcodeReader =  [[DynamsoftBarcodeReader alloc] init];
      _dceView = [DCECameraView cameraWithFrame:self.view.bounds];
      [self.view addSubview:_dceView];
      _dce = [[DynamsoftCameraEnhancer alloc] initWithView:_dceView];
      [_dce open];
      [_barcodeReader setCameraEnhancer:_dce];
      [_barcodeReader startScanning];
      [_barcodeReader setDBRTextResultListener:self];
   }
   - (void)textResultCallback:(NSInteger)frameId imageData:(iImageData *)imageData results:(NSArray<iTextResult *> *)results{
      // Add your code to do when barcode result is returned.
   }
   

2. // Be sure that you have import the following headers when using video decoding methods
   import DynamsoftBarcodeReader
   import DynamsoftCameraEnhancer
   // You have to add setDBRTextResultListener to your class.
   class ViewController: UIViewController, DBRTextResultListener{
      var SafeAreaBottomHeight:CGFloat = UIApplication.shared.statusBarFrame.size.height > 20 ? 34 : 0
      var mainHeight = UIScreen.main.bounds.height
      var mainWidth = UIScreen.main.bounds.width
      var dce:DynamsoftCameraEnhancer! = nil
      var dceView:DCECameraView! = nil
      var barcodeReader:DynamsoftBarcodeReader! = nil
      override func viewDidLoad(){
         super.viewDidLoad()
         configurationDBR()
      }
      override func viewWillAppear(_ animated: Bool) {
       barcodeReader.startScanning()
      }
      override func viewWillDisappear(_ animated: Bool) {
       barcodeReader.stopScanning()
      }
      func configurationDBR(){
         barcodeReader = DynamsoftBarcodeReader.init()
         var barHeight = self.navigationController?.navigationBar.frame.height
         if UIApplication.shared.statusBarFrame.size.height <= 20 {
            barHeight = 20
         }
         dceView = DCECameraView.init(frame: CGRect(x: 0, y: barHeight!, width: mainWidth, height: mainHeight - SafeAreaBottomHeight - barHeight!))
         self.view.addSubview(dceView)
         dce = DynamsoftCameraEnhancer.init(view: dceView)
         dce.open()
         barcodeReader.setCameraEnhancer(dce)
         barcodeReader.setDBRTextResultListener(self)
      }
      func textResultCallback(_ frameId: Int, imageData: iImageData, results: [iTextResult]?){
         // Add your code
      }
   }
   

startScanning

Start the video streaming barcode decoding thread. Please be sure that you have bound a DynamsoftCameraEnhacner or ImageSource to the barcode reader before you trigger startScanning.

-(void)startScanning;

Code Snippet

You can view detailed code snippet in setCameraEnhancer

stopScanning

Stop the video streaming barcode decoding thread.

-(void)stopScanning;

Code Snippet

• Objective-C
• Swift

1. [_barcodeReader stopScanning];
   

2. barcodeReader.stopScanning()
   

setDBRTextResultListener

Set callback function to process text results generated during frame decoding.

-(void)setDBRTextResultListener:(id _Nullable)textResultListener;

Parameters

[in] textResultListener: Callback function.

Code Snippet

You can view detailed code snippet in setCameraEnhancer

setDBRIntermediateResultListener

Set callback function to process intermediate results generated during frame decoding.

-(void)setDBRIntermediateResultListener:(id _Nullable)intermediateResultListener;

Parameters

[in] intermediateResultListener: Callback function.

Code Snippet

The usage of intermediateResultListener is similar to the textResultListener. You can view detailed code snippet in setCameraEnhancer and replace the textResultListener code with the intermediateResultListener code.

• Objective-C
• Swift

1. // You have to add DBRIntermediateResultListener to your interface.
   @interface ViewController ()<DBRIntermediateResultListener>
   - (void)configurationDBR{
      _barcodeReader =  [[DynamsoftBarcodeReader alloc] init];
      [_barcodeReader setDBRIntermediateResultListener:self];
   }
   - (void)intermediateResultCallback:(NSInteger)frameId imageData:(iImageData *)imageData results:(NSArray<iTextResult *> *)results{
      // Add your code to execute when intermediate result is returned.
   }
   

2. // You have to add DBRIntermediateResultListener to your class.
   class ViewController: UIViewController, DBRIntermediateResultListener{
      func configurationDBR(){
         barcodeReader = DynamsoftBarcodeReader.init()
         barcodeReader.setDBRIntermediateResultListener(self)
      }
      func intermediateResultCallback(_ frameId: Int, imageData: iImageData, results: [iTextResult]?){
         // Add your code to execute when intermediate result is returned.
      }
   }
   

enableResultVerification

Enable Result Verification on the barcode results of video streaming barcode decoding. This feature is not enabled by default.

There are 2 way for you to get barcode results:

• From the return value of decode methods when processing a single image.
• From the textResultCallback when processing the video streaming.

Result verification feature only effects on the OneD barcode results you get from textResultCallback.

@property (nonatomic, assign) BOOL enableResultVerification;

Parameters

boolean value which stands for the target status of result verification mode.

Code Snippet

• Objective-C
• Swift

1. [barcodeReader enableResultVerification:true];
   // To check the status of this mode
   [barcodeReader getEnableResultVerification]
   

2. barcodeReader.enableResultVerification = true
   // To check the status of this mode
   let x = barcodeReader.enableResultVerification
   

enableDuplicateFilter

Filter out the duplicate results in the period of 3000ms for video barcode decoding. Barcode results with the same text and format will be returned only once during the period.

There are 2 way for you to get barcode results:

• From the return value of decode methods when processing a single image.
• From the textResultCallback when processing the video streaming.

Duplicate filter only effects on the duplicate results that output by textResultCallback.

@property (nonatomic, assign) BOOL enableDuplicateFilter;

Parameters

boolean value which stands for the target status of result duplicate filter mode.

Code Snippet

• Objective-C
• Swift

1. [barcodeReader enableDuplicateFilter:true];
   // To check the status of this mode
   [barcodeReader getEnableDuplicateFilter]
   

2. barcodeReader.enableDuplicateFilter = true
   // To check the status of this mode
   let x = barcodeReader.enableDuplicateFilter