Video Functions

Function	Description
`DBR_StartFrameDecoding`	Decode barcodes from inner frame queue.
`DBR_StartFrameDecodingEx`	Decode barcodes from inner frame queue.
`DBR_AppendFrame`	Append a frame image buffer to the inner frame queue.
`DBR_StopFrameDecoding`	Stop thread used for frame decoding.
`DBR_InitFrameDecodingParameters`	Initialize frame decoding parameter.
`DBR_SetErrorCallback`	Set callback function to process errors which is triggered when the library finishes decoding a frame.
`DBR_SetTextResultCallback`	Set callback function to process text results which is triggered when the library finishes decoding a frame.
`DBR_SetUniqueBarcodeCallback`	Set callback function to process text results which is triggered when the library finishes decoding a frame and finds unique barcodes.
`DBR_SetIntermediateResultCallback`	Set callback function to process intermediate results which is triggered when the library finishes decoding a frame.
`DBR_GetLengthOfFrameQueue`	Get length of current inner frame queue.

DBR_StartFrameDecoding

Start a new thread to decode barcodes from the inner frame queue with specific frame decoding setting passed in.

DBR_API int DBR_StartFrameDecoding (void* barcodeReader, const int maxQueueLength, const int maxResultQueueLength, const int width, const int height, const int stride, const ImagePixelFormat format, const char* pTemplateName)	

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] maxQueueLength The max number of frames waiting for decoding.
[in] maxResultQueueLength The max number of frames whose results (text result/localization result) will be kept.
[in] width The width of the frame image in pixels.
[in] height The height of the frame image in pixels.
[in] stride The stride (or scan width) of the frame image.
[in] format The image pixel format used in the image byte array.
[in] pTemplateName The template name.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_FRAME_DECODING_THREAD_EXISTS; DBRERR_PARAMETER_VALUE_INVALID; DBRERR_NULL_POINTER.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    int errorCode = DBR_StartFrameDecoding(barcodeReader, 2, 10, 1024, 720, 720, IPF_BINARY, "");
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_StartFrameDecodingEx

Start a new thread to decode barcodes from the inner frame queue with specific frame decoding setting defined in FrameDecodingParameters struct.

DBR_API int DBR_StartFrameDecodingEx (void* barcodeReader, FrameDecodingParameters parameters, const char* pTemplateName)	

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] parameters The frame decoding parameters.
[in] pTemplateName The template name.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    FrameDecodingParameters parameters;
    int errorCode = DBR_InitFrameDecodingParameters(barcodeReader, &parameters);
    if(errorCode == DBR_OK)
    {
        parameters.maxQueueLength = 3;
        parameters.maxResultQueueLength = 10;
        parameters.width = 20;
        parameters.height = 30;
        parameters.stride = 10;
        parameters.imagePixelFormat = IPF_GRAYSCALED;
        parameters.region.regionMeasuredByPercentage = 1;
        parameters.region.regionTop = 0;
        parameters.region.regionBottom = 100;
        parameters.region.regionLeft = 0;
        parameters.region.regionRight = 100;
        parameters.threshold = 0.1;
        parameters.fps = 0;
        int errorCode = DBR_StartFrameDecodingEx(barcodeReader, parameters, "");
        //... more process here
        DBR_RecycleInstance(barcodeReader);
    }
}

DBR_AppendFrame

Appends a frame image buffer to the inner frame queue.

DBR_API int DBR_AppendFrame (void* barcodeReader, unsigned char* pBufferBytes)

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] pBufferBytes The array of bytes which contain the image data.

Return Value
Returns the ID of the appended frame.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    int frameId = DBR_AppendFrame(barcodeReader, pBufferBytes);
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_StopFrameDecoding

Stops the frame decoding thread created by DBR_StartFrameDecoding or DBR_StartFrameDecodingEx.

DBR_API int DBR_StopFrameDecoding (void* barcodeReader)

Parameters
[in] barcodeReader Handle of the barcode reader instance.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_STOP_DECODING_THREAD_FAILED.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    // call DBR_StartFrameDecodingEx and add more process here
    int errorCode = DBR_StopFrameDecoding(barcodeReader);
    DBR_RecycleInstance(barcodeReader);
}

DBR_InitFrameDecodingParameters

Initialize frame decoding parameters with default values.

DBR_API int DBR_InitFrameDecodingParameters (void* barcodeReader, FrameDecodingParameters* pParameters)	

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in,out] pParameters The frame decoding parameters.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_NULL_POINTER.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    FrameDecodingParameters parameters;
    int errorCode = DBR_InitFrameDecodingParameters(barcodeReader, &parameters);
    if(errorCode == DBR_OK)
    {
        parameters.maxQueueLength = 3;
        parameters.maxResultQueueLength = 10;
        parameters.width = 20;
        parameters.height = 30;
        parameters.stride = 10;
        parameters.imagePixelFormat = IPF_GRAYSCALED;
        parameters.region.regionMeasuredByPercentage = 1;
        parameters.region.regionTop = 0;
        parameters.region.regionBottom = 100;
        parameters.region.regionLeft = 0;
        parameters.region.regionRight = 100;
        parameters.threshold = 0.1;
        parameters.fps = 0;
    }
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_SetErrorCallback

Set callback function to process errors which is triggered when the library finishes decoding a frame.

DBR_API int DBR_SetErrorCallback (void* barcodeReader, CB_Error cbFunction, void* pUser)

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] cbFunction Callback function.
[in] pUser Customized arguments passed to your function.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_FRAME_DECODING_THREAD_EXISTS.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

void ErrorFunction(int frameId, int errorCode, void * pUser)
{
    //TODO add your code for using error code
}
char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    DBR_SetErrorCallback(barcodeReader, ErrorFunction, NULL);
    DBR_StartFrameDecoding(barcodeReader, 2, 10, 1024, 720, 720, IPF_BINARY, "");
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_SetTextResultCallback

Set callback function to process text results which is triggered when the library finishes decoding a frame.

DBR_API int DBR_SetTextResultCallback (void* barcodeReader, CB_TextResult cbFunction, void* pUser)

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] cbFunction Callback function.
[in] pUserCustomized arguments passed to your function.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_FRAME_DECODING_THREAD_EXISTS.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

void TextResultFunction(int frameId, TextResultArray *pResults, void * pUser)
{
    //TODO add your code for using test results
}
char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    DBR_SetTextResultCallback(barcodeReader, TextResultFunction, NULL);
    DBR_StartFrameDecoding(barcodeReader, 2, 10, 1024, 720, 720, IPF_BINARY, "");
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_SetUniqueBarcodeCallback

Set callback function to process text results which is triggered when the library finishes decoding a frame and finds unique barcodes.

DBR_API int DBR_SetUniqueBarcodeCallback(void* barcodeReader, CB_TextResult cbFunction, void* pUser)

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] cbFunction Callback function.
[in] pUserCustomized arguments passed to your function.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_FRAME_DECODING_THREAD_EXISTS.
You can call DBR_GetErrorString to get detailed error message.

Code Snippet

void TextResultFunction(int frameId, TextResultArray *pResults, void * pUser)
{
    //TODO add your code for processing barcode results
}
char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    DBR_SetUniqueBarcodeCallback(barcodeReader, TextResultFunction, NULL);
    DBR_StartFrameDecoding(barcodeReader, 2, 10, 1024, 720, 720, IPF_BINARY, "");
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_SetIntermediateResultCallback

Set callback function to process intermediate results which is triggered when the library finishes decoding a frame.

DBR_API int DBR_SetIntermediateResultCallback (void* barcodeReader, CB_IntermediateResult cbFunction, void* pUser)	

Parameters
[in] barcodeReader Handle of the barcode reader instance.
[in] cbFunction Callback function.
[in] pUser Customized arguments passed to your function.

Return Value
Returns error code. Possible return(s): DBR_OK; DBRERR_FRAME_DECODING_THREAD_EXISTS. You can call DBR_GetErrorString to get detailed error message.

Code Snippet

void IntermediateResultFunction(int frameId, IntermediateResultArray *pResults, void * pUser)
{
    //TODO add your code for using intermediate results
}
char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    PublicRuntimeSettings settings;
    int errorCode = DBR_GetRuntimeSettings(barcodeReader, &settings);
    settings.intermediateResultTypes = IRT_ORIGINAL_IMAGE | IRT_COLOUR_CLUSTERED_IMAGE | IRT_COLOUR_CONVERTED_GRAYSCALE_IMAGE;
    char errorMessage[256];
    DBR_UpdateRuntimeSettings(barcodeReader, &settings, errorMessage, 256);
    DBR_SetIntermediateResultCallback(barcodeReader, IntermediateResultFunction, NULL);
    DBR_StartFrameDecoding(barcodeReader, 2, 10, 1024, 720, 720, IPF_BINARY, "");
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}

DBR_GetLengthOfFrameQueue

Get length of current inner frame queue.

DBR_API int DBR_GetLengthOfFrameQueue (void* barcodeReader)

Parameters
[in] barcodeReader Handle of the barcode reader instance.

Return Value
Returns the length of the inner frame queue.

Code Snippet

char errorBuf[512];
DBR_InitLicense("YOUR-LICENSE-KEY", errorBuf, 512);
void* barcodeReader = DBR_GetInstance();
if(barcodeReader != NULL)
{
    int frameLength = DBR_GetLengthOfFrameQueue(barcodeReader);
    //... more process here
    DBR_RecycleInstance(barcodeReader);
}